Bio

Bio


Allen was born and raised in Irvine, California. He completed his undergraduate training at University of California, San Diego as part of the combined-degree Medical Scholars Program with a major in Economics. He then left California to attend Harvard Medical School where he earned his MD in 2014. His research interests include expanding indications for deep brain stimulation and neuromodulation, technology-driven minimally-invasive approaches to cranial and spinal neurosurgery, and quality improvement initiatives within clinical neurosurgery. In the Halpern Lab, Allen is utilizing advanced functional imaging (fMRI, DTI) to study the effects of functional neurosurgery and exploring the role of neuromodulation in addiction, OCD, and obesity in both animal models and humans. He has also completed an enfolded fellowship in complex spine surgery and has a clinical interest in spinal deformity surgery via both minimally invasive and open approaches.

Clinical Focus


  • Residency
  • Neurosurgery

Honors & Awards


  • National Merit Scholar, National Merit Scholarship Program (2005-2009)
  • UCSD Medical Scholar, University of California, San Diego School of Medicine (2005-2009)
  • Amylin Chancellor?s Research Award, University of California, San Diego (2008)
  • Donald A. Strauss Public Service Scholarship, Donald A. Strauss Foundation (2008)
  • Richard L. and Fern W. Erion and Laidlaw-Erion Scholarship, University of California, San Diego (2008)
  • J. William Fulbright Fellowship, US Dept of State, Bureau of Educational and Cultural Affairs (2009)
  • Harvard Medical School National Scholarship, Harvard Medical School (2009-2013)
  • American Cancer Society (ACS) Betty Lea Stone Research Fellowship, American Cancer Society (2010)
  • American Foundation for Aging Research (AFAR) Research Grant, American Foundation for Aging Research (2010)
  • North American Taiwanese Medical Association (NATMA) Scholarship, North American Taiwanese Medical Association (2010)
  • American Medical Association (AMA) Foundation Research Seed Grant, American Medical Association (2011)
  • American Heart Association?s (AHA) Scholarship in Cerebrovascular Disease and Stroke, American Heart Association (2012)
  • Howard Hughes Medical Institute (HHMI) Medical Research Fellowship, Howard Hughes Medical Institute (2013)
  • Hanbery Award for Best Clinical Paper, San Francisco Neurological Society (2015)
  • Stanford Society of Physician Scholars Research Grant, Stanford Society of Physician Scholars (2015)
  • Donald A. Quest Clinical Science Award for Best Oral Presentation, American Association of Neurological Surgeons (2016)
  • NIH funded Spectrum-Stanford Health Care Innovation Challenge Grant, Stanford Center for Clinical and Translational Research and Education (2016)
  • Stanford Society of Physician Scholars Research Grant, Stanford Society for Physician Scholars (2016)
  • North American Neuromodulation Junior Scientist Award, North American Neuromodulation Society (2017)
  • Charles Kuntz IV Scholar, AANS/CNS Section on Disorders of the Spine and Peripheral Nerve (2018)
  • Stanford Society of Physician Scholars Research Grant, Stanford Society for Physician Scholars (2018)
  • Top Abstract Oral Presentation Award, Spine Summit (2018)

Boards, Advisory Committees, Professional Organizations


  • Member, American Association of Neurological Surgeons (2009 - Present)
  • Member, Congress of Neurological Surgeons (2009 - Present)
  • Resident Lead, Advanced Practice Practioners Hiring Committee (2015 - 2017)
  • Resident Lead, Clinical Advice Service (CAS) (2015 - 2017)
  • Resident Lead, Spine Enhanced Recovery After Surgery (ERAS) Committee (2015 - Present)
  • Member, North American Neuromodulation Society (2016 - Present)
  • Member, American Society Stereotactic and Functional Neurosurgery (2016 - Present)
  • Member, North American Spine Society (2016 - Present)
  • Member, American Association of Neurological Surgeons Young Neurosurgeons Committee (2016 - Present)
  • MD Champion, Stanford Hospital/LPCH Voalte Program (2017 - Present)
  • Neurosurgery Resident Safety Champion, Stanford Medicine Safety Council (2017 - Present)
  • Resident Lead, Stanford Global Health Neurosurgery (2017 - Present)
  • Resident Lead, Neurosurgery Quality Council (2017 - Present)
  • YNC Liaison, NeurosurgeryPAC (2017 - Present)
  • Member, Neurosurgery Non-Intensive CarE (NICE) Post-Operative Implementation Committee (2018 - Present)
  • Member, American Epilepsy Society (2018 - Present)
  • Resident Representative, 500P New Stanford Hospital MD Advisory Council (2018 - Present)
  • YNC Liaison, AANS/CNS Section on Stereotactic and Functional Surgery (2018 - Present)

Professional Education


  • Internship, Stanford University Hospital and Clinics, Combined General Surgery/Clinical Neuroscience (2015)
  • M.D., Harvard Medical School, Medicine (2014)
  • B.A., University of California, San Diego (UCSD), Economics (2008)

Publications

All Publications


  • Frameless Robot-Assisted Deep Brain Stimulation Surgery: An Initial Experience. Operative neurosurgery (Hagerstown, Md.) Ho, A. L., Pendharkar, A. V., Brewster, R., Martinez, D. L., Jaffe, R. A., Xu, L. W., Miller, K. J., Halpern, C. H. 2019

    Abstract

    BACKGROUND: Modern robotic-assist surgical systems have revolutionized stereotaxy for a variety of procedures by increasing operative efficiency while preserving and even improving accuracy and safety. However, experience with robotic systems in deep brain stimulation (DBS) surgery is scarce.OBJECTIVE: To present an initial series of DBS surgery performed utilizing a frameless robotic solution for image-guided stereotaxy, and report on operative efficiency, stereotactic accuracy, and complications.METHODS: This study included the initial 20 consecutive patients undergoing bilateral robot-assisted DBS. The prior 20 nonrobotic, frameless cohort of DBS cases was sampled as a baseline historic control. For both cohorts, patient demographic and clinical data were collected including postoperative complications. Intraoperative duration and number of Microelectrode recording (MER) and final lead passes were recorded. For the robot-assisted cohort, 2D radial errors were calculated.RESULTS: Mean case times (total operating room, anesthesia, and operative times) were all significantly decreased in the robot-assisted cohort (all P-values<.02) compared to frameless DBS. When looking at trends in case times, operative efficiency improved over time in the robot-assisted cohort across all time assessment points. Mean radial error in the robot-assisted cohort was 1.40▒0.11mm, and mean depth error was 1.05▒0.18mm. There was a significant decrease in the average number of MER passes in the robot-assisted cohort (1.05) compared to the nonrobotic cohort (1.45, P<.001).CONCLUSION: This is the first report of application of frameless robotic-assistance with the Mazor Renaissance platform (Mazor Robotics Ltd, Caesarea, Israel) for DBS surgery, and our findings reveal that an initial experience is safe and can have a positive impact on operative efficiency, accuracy, and safety.

    View details for PubMedID 30629245

  • The nucleus accumbens and alcoholism: a target for deep brain stimulation NEUROSURGICAL FOCUS Ho, A. L., Salib, A. N., Pendharkar, A., Sussman, E. S., Giardino, W. J., Halpern, C. H. 2018; 45 (2): E12

    Abstract

    Alcohol use disorder (AUD) is a difficult to treat condition with a significant global public health and cost burden. The nucleus accumbens (NAc) has been implicated in AUD and identified as an ideal target for deep brain stimulation (DBS). There are promising preclinical animal studies of DBS for alcohol consumption as well as some initial human clinical studies that have shown some promise at reducing alcohol-related cravings and, in some instances, achieving long-term abstinence. In this review, the authors discuss the evidence and concepts supporting the role of the NAc in AUD, summarize the findings from published NAc DBS studies in animal models and humans, and consider the challenges and propose future directions for neuromodulation of the NAc for the treatment of AUD.

    View details for PubMedID 30064314

  • Improved operative efficiency using a real-time MRI-guided stereotactic platform for laser amygdalohippocampotomy JOURNAL OF NEUROSURGERY Ho, A. L., Sussman, E. S., Pendharkar, A. V., Le, S., Mantovani, A., Keebaugh, A. C., Drover, D. R., Grant, G. A., Wintermark, M., Halpern, C. H. 2018; 128 (4): 1165?72

    Abstract

    OBJECTIVE MR-guided laser interstitial thermal therapy (MRgLITT) is a minimally invasive method for thermal destruction of benign or malignant tissue that has been used for selective amygdalohippocampal ablation for the treatment of temporal lobe epilepsy. The authors report their initial experience adopting a real-time MRI-guided stereotactic platform that allows for completion of the entire procedure in the MRI suite. METHODS Between October 2014 and May 2016, 17 patients with mesial temporal sclerosis were selected by a multidisciplinary epilepsy board to undergo a selective amygdalohippocampal ablation for temporal lobe epilepsy using MRgLITT. The first 9 patients underwent standard laser ablation in 2 phases (operating room [OR] and MRI suite), whereas the next 8 patients underwent laser ablation entirely in the MRI suite with the ClearPoint platform. A checklist specific to the real-time MRI-guided laser amydalohippocampal ablation was developed and used for each case. For both cohorts, clinical and operative information, including average case times and accuracy data, was collected and analyzed. RESULTS There was a learning curve associated with using this real-time MRI-guided system. However, operative times decreased in a linear fashion, as did total anesthesia time. In fact, the total mean patient procedure time was less in the MRI cohort (362.8 ▒ 86.6 minutes) than in the OR cohort (456.9 ▒ 80.7 minutes). The mean anesthesia time was significantly shorter in the MRI cohort (327.2 ▒ 79.9 minutes) than in the OR cohort (435.8 ▒ 78.4 minutes, p = 0.02). CONCLUSIONS The real-time MRI platform for MRgLITT can be adopted in an expedient manner. Completion of MRgLITT entirely in the MRI suite may lead to significant advantages in procedural times.

    View details for PubMedID 28665249

  • Awake versus asleep deep brain stimulation for Parkinson's disease: a critical comparison and meta-analysis. Journal of neurology, neurosurgery, and psychiatry Ho, A. L., Ali, R., Connolly, I. D., Henderson, J. M., Dhall, R., Stein, S. C., Halpern, C. H. 2017

    Abstract

    No definitive comparative studies of the efficacy of 'awake' deep brain stimulation (DBS) for Parkinson's disease (PD) under local or general anaesthesia exist, and there remains significant debate within the field regarding differences in outcomes between these two techniques.We conducted a literature review and meta-analysis of all published DBS for PD studies (n=2563) on PubMed from January 2004 to November 2015. Inclusion criteria included patient number >15, report of precision and/or clinical outcomes data, and at least 6 months of follow-up. There were 145 studies, 16 of which were under general anaesthesia. Data were pooled using an inverse-variance weighted, random effects meta-analytic model for observational data.There was no significant difference in mean target error between local and general anaesthesia, but there was a significantly less mean number of DBS lead passes with general anaesthesia (p=0.006). There were also significant decreases in DBS complications, with fewer intracerebral haemorrhages and infections with general anaesthesia (p<0.001). There were no significant differences in Unified Parkinson's Disease Rating Scale (UPDRS) Section II scores off medication, UPDRS III scores off and on medication or levodopa equivalent doses between the two techniques. Awake DBS cohorts had a significantly greater decrease in treatment-related side effects as measured by the UPDRS IV off medication score (78.4% awake vs 59.7% asleep, p=0.022).Our meta-analysis demonstrates that while DBS under general anaesthesia may lead to lower complication rates overall, awake DBS may lead to less treatment-induced side effects. Nevertheless, there were no significant differences in clinical motor outcomes between the two techniques. Thus, DBS under general anaesthesia can be considered at experienced centres in patients who are not candidates for traditional awake DBS or prefer the asleep alternative.

    View details for DOI 10.1136/jnnp-2016-314500

    View details for PubMedID 28250028

  • Qki deficiency maintains sternness of glioma stem cells in suboptimal environment by downregulating endolysosomal degradation NATURE GENETICS Shingu, T., Ho, A. L., Yuan, L., Zhou, X., Dai, C., Zheng, S., Wang, Q., Zhong, Y., Chang, Q., Horner, J. W., Liebelt, B. D., Yao, Y., Hu, B., Chen, Y., Fuller, G. N., Verhaak, R. G., Heimberger, A. B., Hu, J. 2017; 49 (1): 75-86

    Abstract

    Stem cells, including cancer stem cells (CSCs), require niches to maintain stemness, yet it is unclear how CSCs maintain stemness in the suboptimal environment outside their niches during invasion. Postnatal co-deletion of Pten and Trp53 in mouse neural stem cells (NSCs) leads to the expansion of these cells in their subventricular zone (SVZ) niches but fails to maintain stemness outside the SVZ. We discovered that Qki is a major regulator of NSC stemness. Qk deletion on a Pten(-/-); Trp53(-/-) background helps NSCs maintain their stemness outside the SVZ in Nes-CreER(T2); Qk(L/L); Pten(L/L); Trp53(L/L) mice, which develop glioblastoma with a penetrance of 92% and a median survival time of 105 d. Mechanistically, Qk deletion decreases endolysosome-mediated degradation and enriches receptors essential for maintaining self-renewal on the cytoplasmic membrane to cope with low ligand levels outside niches. Thus, downregulation of endolysosome levels by Qki loss helps glioma stem cells (GSCs) maintain their stemness in suboptimal environments outside their niches.

    View details for DOI 10.1038/ng.3711

    View details for Web of Science ID 000390976600013

    View details for PubMedID 27841882

  • Stereotactic laser ablation of the splenium for intractable epilepsy. Epilepsy & behavior case reports Ho, A. L., Miller, K. J., Cartmell, S., Inoyama, K., Fisher, R. S., Halpern, C. H. 2016; 5: 23-26

    Abstract

    Partial or complete corpus callosotomies have been applied, traditionally via open surgical or radiosurgical approaches, for the treatment of epilepsy in patients with multifocal tonic, atonic, or myoclonic seizures. Minimally invasive methods, such as MRI-guided laser interstitial thermal ablation (MTLA), are being employed to functionally remove or ablate seizure foci in the treatment of epilepsy. This therapy can achieve effectiveness similar to that of traditional resection, but with reduced morbidity compared with open surgery. Here, we present a patient with a history of prior partial corpus callosotomy who continued to suffer from medically refractory epilepsy with bisynchronous onset. We report on the utilization of laser ablation of the splenium in this patient to achieve full corpus callosotomy. Adequate ablation of the splenial remnant was confirmed by postoperative MRI imaging, and at four-month follow-up, the patient's seizure frequency had dropped more than 50%. This is the first reported instance of laser ablation of the splenium to achieve full corpus callosotomy following a previous unsuccessful anterior callosotomy in a patient with intractable generalized epilepsy.

    View details for DOI 10.1016/j.ebcr.2015.12.003

    View details for PubMedID 26955518

  • Deep brain stimulation for obesity: rationale and approach to trial design NEUROSURGICAL FOCUS Ho, A. L., Sussman, E. S., Pendharkar, A. V., Azagury, D. E., Bohon, C., Halpern, C. H. 2015; 38 (6)

    Abstract

    Obesity is one of the most serious public health concerns in the US. While bariatric surgery has been shown to be successful for treatment of morbid obesity for those who have undergone unsuccessful behavioral modification, its associated risks and rates of relapse are not insignificant. There exists a neurological basis for the binge-like feeding behavior observed in morbid obesity that is believed to be due to dysregulation of the reward circuitry. The authors present a review of the evidence of the neuroanatomical basis for obesity, the potential neural targets for deep brain stimulation (DBS), as well as a rationale for DBS and future trial design. Identification of an appropriate patient population that would most likely benefit from this type of therapy is essential. There are also significant cost and ethical considerations for such a neuromodulatory intervention designed to alter maladaptive behavior. Finally, the authors present a consolidated set of inclusion criteria and study end points that should serve as the basis for any trial of DBS for obesity.

    View details for DOI 10.3171/2015.3.FOCUS1538

    View details for Web of Science ID 000355539900008

    View details for PubMedID 26030708

  • Anatomic and Thermometric Analysis of Cranial Nerve Palsy after Laser Amygdalohippocampotomy for Mesial Temporal Lobe Epilepsy. Operative neurosurgery (Hagerstown, Md.) Huang, Y., Leung, S. A., Parker, J. J., Ho, A. L., Wintermark, M., Patel, S. H., Pauly, K. B., Kakusa, B. W., Beres, S. J., Henderson, J. M., Grant, G. A., Halpern, C. H. 2019

    Abstract

    BACKGROUND: Laser interstitial thermal therapy (LITT) is a minimally invasive therapy for treating medication-resistant mesial temporal lobe epilepsy. Cranial nerve (CN) palsy has been reported as a procedural complication, but the mechanism of this complication is not understood.OBJECTIVE: To identify the cause of postoperative CN palsy after LITT.METHODS: Four medial temporal lobe epilepsy patients with CN palsy after LITT were identified for comparison with 22 consecutive patients with no palsy. We evaluated individual variation in the distance between CN III and the uncus, and CN IV and the parahippocampal gyrus using preoperative T1- and T2-weighted magnetic resonance (MR) images. Intraoperative MR thermometry was used to estimate temperature changes.RESULTS: CN III (n=2) and CN IV palsies (n=2) were reported. On preoperative imaging, the majority of identified CN III (54%) and CN IV (43%) were located within 1 to 2 mm of the uncus and parahippocampal gyrus tissue border, respectively. Affected CN III and CN IV were more likely to be found<1 mm of the tissue border (PCNIII=.03, PCNIV<.01; chi-squared test). Retrospective assessment of thermal profile during ablation showed higher temperature rise along the mesial temporal lobe tissue border in affected CNs than unaffected CNs after controlling for distance (12.9░C vs 5.8░C; P=.03; 2-sample t-test).CONCLUSION: CN palsy after LITT likely results from direct heating of the respective CN running at extreme proximity to the mesial temporal lobe. Low-temperature thresholds set at the border of the mesial temporal lobe in patients whose CNs are at close proximity may reduce this risk.

    View details for DOI 10.1093/ons/opz279

    View details for PubMedID 31555820

  • Laminectomy versus Corpectomy for Spinal Metastatic Disease-Complications, Costs, and Quality Outcomes. World neurosurgery Azad, T. D., Varshneya, K., Ho, A. L., Veeravagu, A., Sciubba, D. M., Ratliff, J. K. 2019

    View details for DOI 10.1016/j.wneu.2019.07.206

    View details for PubMedID 31404695

  • Grade II Spondylolisthesis: Reverse Bohlman Procedure with Trans-Discal S1-L5 and S2Ai Screws Placed with Robotic Guidance. World neurosurgery Ho, A. L., Varshneya, K., Medress, Z. A., Pendharkar, A. V., Sussman, E. S., Cheng, I., Veeravagu, A. 2019

    Abstract

    STUDY DESIGN: Technical Report with two illustrative cases.OBJECTIVE: Grade II spondylolisthesis remains a complex surgical pathology for which there is no consensus regarding optimal surgical strategies. Surgical strategies vary regarding extent of reduction, utilization of instrumentation/interbody support, and anterior versus posterior approaches with or without decompression. The objective of this study is to provide the first report on the efficacy of robotic spinal surgery systems in supporting the treatment of grade II spondylolisthesis.METHODS: Utilizing two illustrative cases, we provide a technical report of how a robotic spinal surgery platform can be utilized to treatment grade II spondylolisthesis with a novel instrumentation strategy.RESULTS: We describe how utilization of the "Reverse Bohlman" technique to achieve a large anterior fusion construct spanning the pathologic level and buttressed by the adjacent level above, coupled with a novel, high fidelity posterior fixation scheme with transdiscal S1-L5 and S2Ai screws placed in a minimally invasive fashion with robot guidance allows for the best chance of fusion in situ.CONCLUSIONS: The "Reverse Bohlman" technique coupled with transdiscal S1-L5 and S2Ai screw fixation accomplishes the surgical goals of creating a solid fusion construct, avoiding neurologic injury with aggressive reduction, and halting the progression of anterolisthesis. Utilization of robot guidance allows for efficient placement of these difficult screw trajectories in a minimally invasive fashion.

    View details for DOI 10.1016/j.wneu.2019.07.229

    View details for PubMedID 31398524

  • Focal Intramedullary Spinal Cord Lesion in Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome: Toxoplasmosis Versus Lymphoma WORLD NEUROSURGERY Mohole, J., Ho, A. L., Sussman, E. S., Pendharkar, A. V., Lee, M. 2019; 127: 227?31
  • Objective measures of functional impairment for degenerative diseases of the lumbar spine: a systematic review of the literature SPINE JOURNAL Stienen, M. N., Ho, A. L., Staartjes, V. E., Maldaner, N., Veeravagu, A., Desai, A., Gautschi, O. P., Bellut, D., Regli, L., Ratliff, J. K., Park, J. 2019; 19 (7): 1276?93
  • Facial Nerve Paralysis Occurring 4 Days following Stereotactic Radiosurgery for a Vestibular Schwannoma. Asian journal of neurosurgery Chow, K. K., Ajlan, A., Ho, A. L., Li, G., Soltys, S. G. ; 14 (1): 262?65

    Abstract

    Stereotactic radiosurgery (SRS) is commonly used for the treatment of vestibular schwannomas given its high rate of tumor control and low rate of complications. Facial nerve palsy has been reported several months after treatment as a rare late complication of SRS. Here, we report a case of facial weakness occurring only 4 days after treatment and discuss potential etiology and management considerations.

    View details for PubMedID 30937049

    View details for PubMedCentralID PMC6417297

  • Deep Brain Stimulation for Chronic Cluster Headache: A Review NEUROMODULATION Vyas, D. B., Ho, A. L., Dadey, D. Y., Pendharkar, A. V., Sussman, E. S., Cowan, R., Halpern, C. H. 2019; 22 (4): 388?97

    View details for DOI 10.1111/ner.12869

    View details for Web of Science ID 000471831000003

  • Effects of surgical targeting in laser interstitial thermal therapy for mesial temporal lobe epilepsy: A multicenter study of 234 patients. Epilepsia Wu, C., Jermakowicz, W. J., Chakravorti, S., Cajigas, I., Sharan, A. D., Jagid, J. R., Matias, C. M., Sperling, M. R., Buckley, R., Ko, A., Ojemann, J. G., Miller, J. W., Youngerman, B., Sheth, S. A., McKhann, G. M., Laxton, A. W., Couture, D. E., Popli, G. S., Smith, A., Mehta, A. D., Ho, A. L., Halpern, C. H., Englot, D. J., Neimat, J. S., Konrad, P. E., Neal, E., Vale, F. L., Holloway, K. L., Air, E. L., Schwalb, J., Dawant, B. M., D'Haese, P. 2019

    Abstract

    OBJECTIVE: Laser interstitial thermal therapy (LITT) for mesial temporal lobe epilepsy (mTLE) has reported seizure freedom rates between 36% and 78% with at least 1 year of follow-up. Unfortunately, the lack of robust methods capable of incorporating the inherent variability of patient anatomy, the variability of the ablated volumes, and clinical outcomes have limited three-dimensional quantitative analysis of surgical targeting and its impact on seizure outcomes. We therefore aimed to leverage a novel image-based methodology for normalizing surgical therapies across a large multicenter cohort to quantify the effects of surgical targeting on seizure outcomes in LITT for mTLE.METHODS: This multicenter, retrospective cohort study included 234 patients from 11 centers who underwent LITT for mTLE. To investigate therapy location, all ablation cavities were manually traced on postoperative magnetic resonance imaging (MRI), which were subsequently nonlinearly normalized to a common atlas space. The association of clinical variables and ablation location to seizure outcome was calculated using multivariate regression and Bayesian models, respectively.RESULTS: Ablations including more anterior, medial, and inferior temporal lobe structures, which involved greater amygdalar volume, were more likely to be associated with Engel class I outcomes. At both 1 and 2 years after LITT, 58.0% achieved Engel I outcomes. A history of bilateral tonic-clonic seizures decreased chances of Engel I outcome. Radiographic hippocampal sclerosis was not associated with seizure outcome.SIGNIFICANCE: LITT is a viable treatment for mTLE in patients who have been properly evaluated at a comprehensive epilepsy center. Consideration of surgical factors is imperative to the complete assessment of LITT. Based on our model, ablations must prioritize the amygdala and also include the hippocampal head, parahippocampal gyrus, and rhinal cortices to maximize chances of seizure freedom. Extending the ablation posteriorly has diminishing returns. Further work is necessary to refine this analysis and define the minimal zone of ablation necessary for seizure control.

    View details for DOI 10.1111/epi.15565

    View details for PubMedID 31112302

  • Expenditures and Health Care Utilization Among Adults With Newly Diagnosed LowBack and Lower Extremity Pain JAMA NETWORK OPEN Kim, L. H., Vail, D., Azad, T. D., Bentley, J. P., Zhang, Y., Ho, A. L., Fatemi, P., Feng, A., Varshneya, K., Desai, M., Veeravagu, A., Ratliff, J. K. 2019; 2 (5)
  • Image-guided Percutaneous Polymethylmethacrylate-augmented Spondylodesis for Painful Metastasis in the Veteran Population CUREUS Sussman, E. S., Ho, A., Pendharkar, A., Tharin, S. 2019; 11 (4)
  • Focal Intramedullary Spinal Cord Lesion in HIV/AIDs: Toxoplasmosis vs. Lymphoma. World neurosurgery Mohole, J., Ho, A. L., Sussman, E. S., Pendharkar, A. V., Lee, M. 2019

    Abstract

    BACKGROUND: Neurological complications are common in HIV/AIDS patients.1 While both the central nervous system (CNS) and the peripheral nervous system (PNS) can be affected, up to 80% of HIV/AIDS patients have CNS involvement during the course of their illness.2,3 The brain is the primary site of HIV/AIDS associated CNS complications. Spinal cord involvement is rare, particularly focal intramedullary spinal cord lesions without any associated cerebral lesions.4-6 Amongst various opportunistic infections and malignancies, toxoplasmosis and CNS lymphoma represent the most common cause of focal neurological disease in HIV/AIDS patients.4,5,7 However, distinguishing between toxoplasmosis and CNS lymphoma is challenging as both diseases have similar clinical presentations.CASE DESCRIPTION: This report demonstrates a case of myelopathy presenting as an isolated, single intramedullary spinal cord lesion in a newly diagnosed HIV positive female. Additionally, we discuss common methods of diagnostic distinction between the toxoplasmosis and CNS lymphoma.CONCLUSION: We suggest that there should be a high-index of suspicion for toxoplasmosis in HIV/AIDS patients presenting with a focal intramedullary spinal cord lesion.

    View details for PubMedID 30981796

  • Objective measures of functional impairment for degenerative diseases of the lumbar spine: a systematic review of the literature. The spine journal : official journal of the North American Spine Society Stienen, M. N., Ho, A. L., Staartjes, V. E., Maldaner, N., Veeravagu, A., Desai, A., Gautschi, O. P., Bellut, D., Regli, L., Ratliff, J. K., Park, J. 2019

    Abstract

    BACKGROUND CONTEXT: The accurate determination of a patient's functional status is necessary for therapeutic decision-making and to critically appraise treatment efficacy. Current subjective patient-reported outcome measure (PROM)-based assessments have limitations and can be complimented by objective measures of function.PURPOSE: To systematically review the literature and provide an overview on the available objective measures of function for patients with degenerative diseases of the lumbar spine.STUDY DESIGN/SETTING: Systematic review of the literature.METHODS: The PRISMA guidelines were followed. Two reviewers independently searched the PubMed, Web of Science, EMBASE and SCOPUS databases for permutations of the words "objective", "assessment", "function", "lumbar" and "spine", including articles on human subjects with degenerative diseases of the lumbar spine that reported on objective measures of function, published until September 2018. No funding was received. The authors report no conflicts of interest.RESULTS: Of 2389 identified articles, 82 were included in the final analysis. There was a significant increase of 0.12 per year in the number of publications dealing with objective measures of function since 1989 (95% CI 0.08-0.16, p<0.001). Some publications studied multiple diagnoses and objective measures. The US was the leading nation in terms of scientific output for objective outcome measures (n=21; 25.6%), followed by Switzerland (n=17; 20.7%), Canada, Germany and the United Kingdom (each n=6; 7.3%). Our search revealed 21 different types of objective measures, predominantly applied to patients with lumbar spinal stenosis (n=67 publications; 81.7%), chronic/unspecific low back pain (n=28; 34.2%) and lumbar disc herniation (n=22; 26.8%). The Timed-Up-and-Go (TUG) test was the most frequently applied measure (n=26 publications; 31.7%; cumulative number of reported subjects: 5181), followed by the Motorized Treadmill Test (MTT; n=25 publications; 30.5%, 1499 subjects) and with each n=9 publications (11.0%) the Five-Repetition Sit-To-Stand test (5R-STS; 955 subjects), as well as accelerometry analyses (336 subjects). The reliability and validity of many of the less-applied objective measures was uncertain. There was profound heterogeneity in their application and interpretation of results. Risk of bias was not assessed.CONCLUSIONS: Clinical studies on patients with lumbar degenerative diseases increasingly employ objective measures of function, which offer high potential for improving the quality of outcome measurement in patient-care and research. This review provides an overview on available options. Our findings call for an agreement and standardization in terms of test selection, conduction and analysis to facilitate comparison of results across cohorts.

    View details for PubMedID 30831316

  • Expenditures and Health Care Utilization Among Adults With Newly Diagnosed Low Back and Lower Extremity Pain. JAMA network open Kim, L. H., Vail, D., Azad, T. D., Bentley, J. P., Zhang, Y., Ho, A. L., Fatemi, P., Feng, A., Varshneya, K., Desai, M., Veeravagu, A., Ratliff, J. K. 2019; 2 (5): e193676

    Abstract

    Low back pain (LBP) with or without lower extremity pain (LEP) is one of the most common reasons for seeking medical care. Previous studies investigating costs in this population targeted patients receiving surgery. Little is known about health care utilization among patients who do not undergo surgery.To assess use of health care resources for LBP and LEP management and analyze associated costs.This cohort study used a retrospective analysis of a commercial database containing inpatient and outpatient data for more than 75 million individuals. Participants were US adults who were newly diagnosed with LBP or LEP between 2008 and 2015, did not have a red-flag diagnosis, and were opiate naive prior to diagnosis. Dates of analysis were October 6, 2018, to March 7, 2019.Newly diagnosed LBP or LEP.The primary outcome was total cost of care within the first 6 and 12 months following diagnosis, stratified by whether patients received spinal surgery. An assessment was performed to determine whether patients who did not undergo surgery received care in accordance with proposed guidelines for conservative LBP and LEP management. Costs resulting from use of different health care services were estimated.A total of 2?498?013 adult patients with a new LBP or LEP diagnosis (median [interquartile range] age, 47 [36-58] years; 1?373?076 [55.0%] female) were identified. More than half (55.7%) received no intervention. Only 1.2% of patients received surgery, but they accounted for 29.3% of total 12-month costs ($784 million). Total costs of care among the 98.8% of patients who did not receive surgery were $1.8 billion. Patients who did not undergo surgery frequently received care that was inconsistent with clinical guidelines for LBP and LEP: 32.3% of these patients received imaging within 30 days of diagnosis and 35.3% received imaging without a trial of physical therapy.The findings suggest that surgery is rare among patients with newly diagnosed LBP and LEP but remains a significant driver of spending. Early imaging in patients who do not undergo surgery was also a major driver of increased health care expenditures. Avoidable costs among patients with typically self-limited conditions result in considerable economic burden to the US health care system.

    View details for PubMedID 31074820

  • Brain abscess caused by Trueperella bernardiae in a child. Surgical neurology international Pan, J., Ho, A. L., Pendharkar, A. V., Sussman, E. S., Casazza, M., Cheshier, S. H., Grant, G. A. 2019; 10: 35

    Abstract

    Background: Recurrent intracranial abscesses secondary to refractory otitis media present a challenge which demands multidisciplinary collaboration.Case Description: We present the first known case of pediatric brain abscess caused by a polymicrobial infection of Trueperella bernardiae, Actinomyces europaeus, and mixed anaerobic species resulting from acute-on-chronic suppurative left otitis media. This patient required two separate stereotactic abscess drainages and a complex course of antibiotics for successful management.Conclusion: Surgery is essential in the management of cerebral abscess both in agent identification and therapeutic drainage. Management of abscesses secondary to unusual and polymicrobial organisms often requires consultation from other medical and surgical specialties.

    View details for DOI 10.4103/sni.sni_376_17

    View details for PubMedID 31528373

  • Optogenetic Modulation for the Treatment of Traumatic Brain Injury. Stem cells and development Delaney, S. L., Gendreau, J. L., DSouza, M., Feng, A. Y., Ho, A. 2019

    Abstract

    Although research involving traumatic brain injury (TBI) has traditionally focused on the acute clinical manifestations, new studies provide evidence for chronic and progressive neurological sequelae associated with TBI, highlighting the risk of persistent, and sometimes life-long, consequences for affected patients. Several treatment modalities to date have demonstrated efficacy in experimental models. However, there is currently no effective treatment to improve neural structure repair and functional recovery of TBI patients. Optogenetics represents a potential molecular tool for neuromodulation and monitoring cellular activity with unprecedented spatial resolution and millisecond temporal precision. In this review, we discuss the conceptual background and preclinical evidence of optogenetics for neuromodulation, and translational applications for TBI treatment are considered.

    View details for DOI 10.1089/scd.2019.0187

    View details for PubMedID 31559914

  • Graft Materials and Biologics for Spinal Interbody Fusion. Biomedicines D'Souza, M., Macdonald, N. A., Gendreau, J. L., Duddleston, P. J., Feng, A. Y., Ho, A. L. 2019; 7 (4)

    Abstract

    Spinal fusion is the most widely performed procedure in spine surgery. It is the preferred treatment for a wide variety of pathologies including degenerative disc disease, spondylolisthesis, segmental instability, and deformity. Surgeons have the choice of fusing vertebrae by utilizing cages containing autografts, allografts, demineralized bone matrices (DBMs), or graft substitutes such as ceramic scaffolds. Autografts from the iliac spine are the most commonly used as they offer osteogenic, osteoinductive, and osteoconductive capabilities, all while avoiding immune system rejection. Allografts obtained from cadavers and living donors can also be advantageous as they lack the need for graft extraction from the patient. DBMs are acid-extracted organic allografts with osteoinductive properties. Ceramic grafts containing hydroxyapatite can be readily manufactured and are able to provide osteoinductive support while having a long shelf life. Further, bone-morphogenetic proteins (BMPs), mesenchymal stem cells (MSCs), synthetic peptides, and autologous growth factors are currently being optimized to assist in improving vertebral fusion. Genetic therapies utilizing viral transduction are also currently being devised. This review provides an overview of the advantages, disadvantages, and future directions of currently available graft materials. The current literature on growth factors, stem cells, and genetic therapy is also discussed.

    View details for DOI 10.3390/biomedicines7040075

    View details for PubMedID 31561556

  • Reliability of the 6-minute walking test smartphone application. Journal of neurosurgery. Spine Stienen, M. N., Gautschi, O. P., Staartjes, V. E., Maldaner, N., Sosnova, M., Ho, A. L., Veeravagu, A., Desai, A., Zygourakis, C. C., Park, J., Regli, L., Ratliff, J. K. 2019: 1?8

    Abstract

    Objective functional measures such as the 6-minute walking test (6WT) are increasingly applied to evaluate patients with degenerative diseases of the lumbar spine before and after (surgical) treatment. However, the traditional 6WT is cumbersome to apply, as it requires specialized in-hospital infrastructure and personnel. The authors set out to compare 6-minute walking distance (6WD) measurements obtained with a newly developed smartphone application (app) and those obtained with the gold-standard distance wheel (DW).The authors developed a free iOS- and Android-based smartphone app that allows patients to measure the 6WD in their home environment using global positioning system (GPS) coordinates. In a laboratory setting, the authors obtained 6WD measurements over a range of smartphone models, testing environments, and walking patterns and speeds. The main outcome was the relative measurement error (rME; in percent of 6WD), with |rME| < 7.5% defined as reliable. The intraclass correlation coefficient (ICC) for agreement between app- and DW-based 6WD was calculated.Measurements (n = 406) were reliable with all smartphone types in neighborhood, nature, and city environments (without high buildings), as well as with unspecified, straight, continuous, and stop-and-go walking patterns (ICC = 0.97, 95% CI 0.97-0.98, p < 0.001). Measurements were unreliable indoors, in city areas with high buildings, and for predominantly rectangular walking courses. Walking speed had an influence on the ME, with worse accuracy (2% higher rME) for every kilometer per hour slower walking pace (95% CI 1.4%-2.5%, p < 0.001). Mathematical adjustment of the app-based 6WD for velocity-dependent error mitigated the rME (p < 0.011), attenuated velocity dependence (p = 0.362), and had a positive effect on accuracy (ICC = 0.98, 95% CI 0.98-0.99, p < 0.001).The new, free, spine-specific 6WT smartphone app measures the 6WD conveniently by using GPS coordinates, empowering patients to independently determine their functional status before and after (surgical) treatment. Measurements of 6WD obtained for the target population under the recommended circumstances are highly reliable.

    View details for DOI 10.3171/2019.6.SPINE19559

    View details for PubMedID 31518975

  • Analysis of Outcomes and Cost of Inpatient and Ambulatory Anterior Cervical Disk Replacement Using a State-level Database. Clinical spine surgery Purger, D. A., Pendharkar, A. V., Ho, A. L., Sussman, E. S., Veeravagu, A., Ratliff, J. K., Desai, A. M. 2019

    Abstract

    Outpatient cervical artificial disk replacement (ADR) is a promising candidate for cost reduction. Several studies have demonstrated low overall complications and minimal readmission in anterior cervical procedures.The objective of this study was to compare clinical outcomes and cost associated between inpatient and ambulatory setting ADR.Outcomes and cost were retrospectively analyzed for patients undergoing elective ADR in California, Florida, and New York from 2009 to 2011 in State Inpatient and Ambulatory Databases.A total of 1789 index ADR procedures were identified in the inpatient database (State Inpatient Databases) compared with 370 procedures in the ambulatory cohort (State Ambulatory Surgery and Services Databases). Ambulatory patients presented to the emergency department 19 times (5.14%) within 30 days of the index procedure compared with 4.2% of inpatients. Four unique patients underwent readmission within 30 days in the ambulatory ADR cohort (1% total) compared with 2.2% in the inpatient ADR group. No ambulatory ADR patients underwent a reoperation within 30 days. Of the inpatient ADR group, 6 unique patients underwent reoperation within 30 days (0.34%, Charlson Comorbidity Index zero=0.28%, Charlson Comorbidity Index>0=0.6%). There was no significant difference in emergency department visit rate, inpatient readmission rate, or reoperation rates within 30 days of the index procedure between outpatient or inpatient ADR. Outpatient ADR is noninferior to inpatient ADR in all clinical outcomes. The direct cost was significantly lower in the outpatient ADR group ($11,059 vs. 17,033; P<0.001). The 90-day cumulative charges were significantly lower in the outpatient ADR group (mean $46,404.03 vs. $80,055; P<0.0001).ADR can be performed in an ambulatory setting with comparable morbidity, readmission rates, and lower costs, to inpatient ADR.

    View details for DOI 10.1097/BSD.0000000000000840

    View details for PubMedID 31180992

  • Image-guided Percutaneous Polymethylmethacrylate-augmented Spondylodesis for Painful Metastasis in the Veteran Population. Cureus Sussman, E. S., Ho, A., Pendharkar, A. V., Tharin, S. 2019; 11 (4): e4509

    Abstract

    The treatment of painful spinal metastases in patients with limited life-expectancy, significant perioperative risks, and poor bone quality poses a surgical challenge.áRecent advances in minimal-access spine surgery allow for the surgical treatment of patients previously considered not to be operative candidates. The addition of fenestrated screws for cement augmentation to existing image-guided percutaneous pedicle screw fixation can enhance efficiency, decrease risk of hardware complications, and improve back pain in this patient population. The patient is a 70-year-old man with severe axial back pain due to metastatic prostate cancer and L5 pathologic fractures not amenable to kyphoplasty. In the setting of a 6-12-month life-expectancy, the primary goal of surgery was relief of back pain associated with instability with minimal operative morbidity and post-operative recovery time. This was achieved with an internal fixation construct including percutaneously placed cement-augmented fenestrated pedicle screws at L4 and S1. The patient was discharged to home on post-operative day 1 with substantial improvement of his low back pain. Image-guided, percutaneous placement of fenestrated, cement-augmented pedicle screws is an emerging treatment for back pain associated with metastasis. Fenestrated screws allow for integrated cement augmentation. The minimal associated blood loss and recovery time make this approach an option even for patients with limited life-expectancy. This is the first report of utilization of this technique for the veteran population.

    View details for DOI 10.7759/cureus.4509

    View details for PubMedID 31259118

    View details for PubMedCentralID PMC6590854

  • Topical Vancomycin for Surgical Prophylaxis in Pediatric Craniofacial Surgeries. The Journal of craniofacial surgery Mohole, J., Ho, A. L., Cannon, J. G., Pendharkar, A. V., Sussman, E. S., Hong, D. S., Cheshier, S. H., Grant, G. A. 2019

    Abstract

    Topical vancomycin has been demonstrated to be safe and effective for reducing surgical site infections (SSIs) following spine surgery in both adults and children, however, there are no studies of its efficacy in reducing SSIs in craniofacial surgery. The SSIs are one of the most common complications following craniofacial surgery. The complexity of craniofacial procedures, use of grafts and implants, long operative durations and larger surgical wounds all contribute to the heightened risk of SSIs in pediatric craniofacial cases. A retrospective review of all open and endoscopic pediatric craniofacial procedures performed between May 2014 and December 2017 at a single children's hospital was conducted to examine SSI rates between patients receiving topical vancomycin and a historical control group. The treatment group received topical vancomycin irrigation before wound closure. An ad-hoc cost analysis was performed to determine the cost-savings associated with topical vancomycin use. A total of 132 craniofacial procedures were performed during the study period, with 50 cases in the control group and 82 cases in the vancomycin group. Overall, SSI rate was 3.03%. Use of topical vancomycin irrigation led to a significant reduction in SSIs (4/50 SSI or 8.0% in control group vs 0/82 or 0% in vancomycin group, P?=?0.04). No adverse events were observed with topical vancomycin use. The potential cost-savings associated with the use of topical vancomycin as SSI prophylaxis in this study was $102,152. Addition of topical vancomycin irrigation as routine surgical infection prophylaxis can be an effective and low-cost method for reducing SSI in pediatric craniofacial surgery.

    View details for DOI 10.1097/SCS.0000000000005708

    View details for PubMedID 31261326

  • Stereotactic laser ablation for completion corpus callosotomy. Journal of neurosurgery. Pediatrics Huang, Y., Yecies, D., Bruckert, L., Parker, J. J., Ho, A. L., Kim, L. H., Fornoff, L., Wintermark, M., Porter, B., Yeom, K. W., Halpern, C. H., Grant, G. A. 2019: 1?9

    Abstract

    Completion corpus callosotomy can offer further remission from disabling seizures when a prior partial corpus callosotomy has failed and residual callosal tissue is identified on imaging. Traditional microsurgical approaches to section residual fibers carry risks associated with multiple craniotomies and the proximity to the medially oriented motor cortices. Laser interstitial thermal therapy (LITT) represents a minimally invasive approach for the ablation of residual fibers following a prior partial corpus callosotomy. Here, the authors report clinical outcomes of 6 patients undergoing LITT for completion corpus callosotomy and characterize the radiological effects of ablation.A retrospective clinical review was performed on a series of 6 patients who underwent LITT completion corpus callosotomy for medically intractable epilepsy at Stanford University Medical Center and Lucile Packard Children's Hospital at Stanford between January 2015 and January 2018. Detailed structural and diffusion-weighted MR images were obtained prior to and at multiple time points after LITT. In 4 patients who underwent diffusion tensor imaging (DTI), streamline tractography was used to reconstruct and evaluate tract projections crossing the anterior (genu and rostrum) and posterior (splenium) parts of the corpus callosum. Multiple diffusion parameters were evaluated at baseline and at each follow-up.Three pediatric (age 8-18 years) and 3 adult patients (age 30-40 years) who underwent completion corpus callosotomy by LITT were identified. Mean length of follow-up postoperatively was 21.2 (range 12-34) months. Two patients had residual splenium, rostrum, and genu of the corpus callosum, while 4 patients had residual splenium only. Postoperative complications included asymptomatic extension of ablation into the left thalamus and transient disconnection syndrome. Ablation of the targeted area was confirmed on immediate postoperative diffusion-weighted MRI in all patients. Engel class I-II outcomes were achieved in 3 adult patients, whereas all 3 pediatric patients had Engel class III-IV outcomes. Tractography in 2 adult and 2 pediatric patients revealed time-dependent reduction of fractional anisotropy after LITT.LITT is a safe, minimally invasive approach for completion corpus callosotomy. Engel outcomes for completion corpus callosotomy by LITT were similar to reported outcomes of open completion callosotomy, with seizure reduction primarily observed in adult patients. Serial DTI can be used to assess the presence of tract projections over time but does not classify treatment responders or nonresponders.

    View details for DOI 10.3171/2019.5.PEDS19117

    View details for PubMedID 31374542

  • Laser interstitial thermal therapy (LITT): Seizure outcomes for refractory mesial temporal lobe epilepsy. Epilepsy & behavior : E&B Le, S., Ho, A. L., Fisher, R. S., Miller, K. J., Henderson, J. M., Grant, G. A., Meador, K. J., Halpern, C. H. 2018; 89: 37?41

    Abstract

    BACKGROUND: Laser interstitial thermal therapy (LITT) is a minimally invasive alternative with less cognitive risks compared with traditional surgery for focal drug-resistant epilepsy.OBJECTIVE: We describe seizure outcomes and complications after LITT in our cohort with intractable mesial temporal lobe epilepsy (MTLE).MATERIAL AND METHODS: We prospectively tracked Stanford's MTLE cases treated with LITT from October 2014 to October 2017. Primary endpoints were seizure outcomes by (1) Engel classification and (2) reduction in baseline seizure frequency. Secondary outcomes were postablation complications.RESULTS: A total of 30 patients underwent selective amygdalohippocampotomy via LITT. Mesial temporal sclerosis (MTS) was present in 23/30 (77%) patients. Median follow-up was 18?▒?12?months (range: 6-44?months). Almost all 28/29 (97%) patients had >50% reduction, and 22/29 (76%) patients had >90% reduction in seizure frequency. Engel Class I outcome was achieved in 18/29 (62%) patients; with complete seizure freedom in 9/29 (31%) patients (Engel Class IA). Three (10%) patients have had only focal aware seizures (Engel Class 1B). Seizures only occurred with medication withdrawal in 6/29 (21%) patients (Engel Class ID). Class II was achieved by 6/29 (21%) and Class III by 5/29 (17%) patients. Complications included perioperative seizures in 10/29 (34%) and nonseizure complaints in 6/29 (21%) patients. Three (10%) patients had neurological deficits including one permanent superior quadrantanopsia, one transient trochlear, and one transient oculomotor nerve palsy.CONCLUSIONS: Overall, Engel Class I outcome was achieved in 62% of patients with MTLE, and 97% of patients achieved >50% seizure frequency reduction. Complications were largely temporary, though there was one persistent visual field deficit. Laser ablation is well-tolerated and offers marked seizure reduction for the majority of patients.

    View details for DOI 10.1016/j.yebeh.2018.09.040

    View details for PubMedID 30384097

  • Deep Brain Stimulation for Chronic Cluster Headache: A Review. Neuromodulation : journal of the International Neuromodulation Society Vyas, D. B., Ho, A. L., Dadey, D. Y., Pendharkar, A. V., Sussman, E. S., Cowan, R., Halpern, C. H. 2018

    Abstract

    OBJECTIVES: Cluster headaches are a set of episodic and chronic pain syndromes that are sources of significant morbidity for patients. The standard of care for cluster headaches remains medication therapy, however a minority of patients will remain refractory to treatment despite changes to dosage and therapeutic combinations. In these patients, functional neuromodulation using Deep Brain Stimulation (DBS) presents the opportunity to alleviate the significant pain that is experienced by targeting the neurophysiological substrates that mediate pain.MATERIAL AND METHODS: We review the literature on chronic cluster headache, including the growing number of DBS case reports and series that describe the alleviation of pain in a majority of patients through conventional or endoventricular targeting of the posterior hypothalamus and ventral tegmental area, with a minimal side effect profile.RESULTS: In this review, the history and outcomes of DBS use for medication-refractory cluster headaches are examined, with discussion on future directions for improving this novel treatment modality and providing efficacious, longer-lasting pain relief in headache patients.CONCLUSION: In patients with chronic cluster headache, functional neuromodulation using DBS presents the opportunity to alleviate the significant pain that is experienced by targeting the neurophysiological substrates that mediate pain.

    View details for PubMedID 30303584

  • Intraoperative Cerebrospinal Fluid Leak in Extradural Spinal Tumor Surgery. Neurospine Ropper, A. E., Huang, K. T., Ho, A. L., Wong, J. M., Nalbach, S. V., Chi, J. H. 2018

    Abstract

    Objective: Patients with extradural spine tumors are at an increased risk for intraoperative cerebrospinal fluid (CSF) leaks and postoperative wound dehiscence due to radiotherapy and other comorbidities related to systemic cancer treatment. In this case series, we discuss our experience with the management of intraoperative durotomies and wound closure strategies for this complex surgical patient population.Methods: We reviewed our recent single-center experience with spine surgery for primarily extradural tumors, with attention to intraoperative durotomy occurrence and postoperative wound-related complications.Results: A total of 105 patients underwent tumor resection and spinal reconstruction with instrumented fusion for a multitude of pathologies. Twelve of the 105 patients (11.4%) reviewed had intraoperative durotomies. Of these, 3 underwent reoperation for a delayed complication, including 1 epidural hematoma, 1 retained drain, and 1 wound infection. Of the 93 uncomplicated index operations, there were a total of 9 reoperations: 2 for epidural hematoma, 3 for wound infection, 2 for wound dehiscence, and 2 for recurrent primary disease. One patient was readmitted for a delayed spinal fluid leak. The average length of stay for patients with and without intraoperative durotomy was 7.3 and 5.9 days, respectively, with a nonsignificant trend for an increased length of stay in the durotomy cases (p=0.098).Conclusion: Surgery for extradural tumor resections can be complicated by CSF leaks due to the proximity of the tumor to the dura. When encountered, a variety of strategies may be employed to minimize subsequent morbidity.

    View details for PubMedID 30531655

  • Stereoelectroencephalography in children: a review. Neurosurgical focus Ho, A. L., Feng, A. Y., Kim, L. H., Pendharkar, A. V., Sussman, E. S., Halpern, C. H., Grant, G. A. 2018; 45 (3): E7

    Abstract

    Stereoelectroencephalography (SEEG) is an intracranial diagnostic measure that has grown in popularity in the United States as outcomes data have demonstrated its benefits and safety. The main uses of SEEG include 1) exploration of deep cortical/sulcal structures; 2) bilateral recordings; and 3) 3D mapping of epileptogenic zones. While SEEG has gradually been accepted for treatment in adults, there is less consensus on its utility in children. In this literature review, the authors seek to describe the current state of SEEG with a focus on the more recent technology-enabled surgical techniques and demonstrate its efficacy in the pediatric epilepsy population.

    View details for PubMedID 30173607

  • Robot-guided pediatric stereoelectroencephalography: single-institution experience. Journal of neurosurgery. Pediatrics Ho, A. L., Muftuoglu, Y., Pendharkar, A. V., Sussman, E. S., Porter, B. E., Halpern, C. H., Grant, G. A. 2018: 1?8

    Abstract

    OBJECTIVE Stereoelectroencephalography (SEEG) has increased in popularity for localization of epileptogenic zones in drug-resistant epilepsy because safety, accuracy, and efficacy have been well established in both adult and pediatric populations. Development of robot-guidance technology has greatly enhanced the efficiency of this procedure, without sacrificing safety or precision. To date there have been very limited reports of the use of this new technology in children. The authors present their initial experience using the ROSA platform for robot-guided SEEG in a pediatric population. METHODS Between February 2016 and October 2017, 20 consecutive patients underwent robot-guided SEEG with the ROSA robotic guidance platform as part of ongoing seizure localization and workup for medically refractory epilepsy of several different etiologies. Medical and surgical history, imaging and trajectory plans, as well as operative records were analyzed retrospectively for surgical accuracy, efficiency, safety, and epilepsy outcomes. RESULTS A total of 222 leads were placed in 20 patients, with an average of 11.1 leads per patient. The mean total case time (▒ SD) was 297.95 (▒ 52.96) minutes and the mean operating time per lead was 10.98 minutes/lead, with improvements in total (33.36 minutes/lead vs 21.76 minutes/lead) and operative (13.84 minutes/lead vs 7.06 minutes/lead) case times/lead over the course of the study. The mean radial error was 1.75 (▒ 0.94 mm). Clinically useful data were obtained from SEEG in 95% of cases, and epilepsy surgery was indicated and performed in 95% of patients. In patients who underwent definitive epilepsy surgery with at least a 3-month follow-up, 50% achieved an Engel class I result (seizure freedom). There were no postoperative complications associated with SEEG placement and monitoring. CONCLUSIONS In this study, the authors demonstrate that rapid adoption of robot-guided SEEG is possible even at a SEEG-naive institution, with minimal learning curve. Use of robot guidance for SEEG can lead to significantly decreased operating times while maintaining safety, the overall goals of identification of epileptogenic zones, and improved epilepsy outcomes.

    View details for PubMedID 30117789

  • Anterior Techniques in Managing Cervical Disc Disease. Cureus Kim, L. H., D'Souza, M., Ho, A. L., Pendharkar, A. V., Sussman, E. S., Rezaii, P., Desai, A. 2018; 10 (8): e3146

    Abstract

    Surgical treatment may be indicated for select patients with cervical disc disease, whether it is cervical disc herniation or spondylosis due to degenerative changes, acute cervical injury due to trauma, or other underlying cervical pathology.Currently, there are various surgical techniques, including anterior, posterior, or combined approaches, in addition to new interventions being utilized in practice. Ideally, the surgical approach should be selected in consideration of each patient's clinical presentation, imaging findings, and overall medical comorbidities on an individual basis. But the unique advantages and disadvantages of each surgical technique often complicate the therapy choice in managing cervical disc diseases. Although anterior cervical discectomy and fusion (ACDF) is the most widely accepted procedure performed for both single and multi-level cervical disc diseases, there are multiple modifications to this technique. Surgeons have access to different types of plates, screws, and cages and can adopt newer advances in the field such as stand-alone and minimally invasive techniques when indicated. In short, no consensus exists in terms of a single approach that is preferredfor all patients. This article aims to review the standard of care for management of cervical disc disease with a focus on the surgical techniques and, in particular, the anterior approach, exploring the various surgical options within this technique.

    View details for PubMedID 30410821

  • Rapid-sequence brain magnetic resonance imaging for Chiari I abnormality JOURNAL OF NEUROSURGERY-PEDIATRICS Pan, J., Quon, J. L., Johnson, E., Lanzman, B., Chukus, A., Ho, A. L., Edwards, M. B., Grant, G. A., Yeom, K. W. 2018; 22 (2): 158?64

    Abstract

    OBJECTIVE Fast magnetic resonance imaging (fsMRI) sequences are single-shot spin echo images with fast acquisition times that have replaced CT scans for many conditions. Introduced as a means of evaluating children with hydrocephalus and macrocephaly, these sequences reduce the need for anesthesia and can be more cost-effective, especially for children who require multiple surveillance scans. However, the role of fsMRI has yet to be investigated in evaluating the posterior fossa in patients with Chiari I abnormality (CM-I). The goal of this study was to examine the diagnostic performance of fsMRI in evaluating the cerebellar tonsils in comparison to conventional MRI. METHODS The authors performed a retrospective analysis of 18 pediatric patients with a confirmed diagnosis of CM-I based on gold-standard conventional brain MRI and 30 controls without CM-I who had presented with various neurosurgical conditions. The CM-I patients were included if fsMRI studies had been obtained within 1 year of conventional MRI with no surgical intervention between the studies. Two neuroradiologists reviewed the studies in a blinded fashion to determine the diagnostic performance of fsMRI in detecting CM-I. For the CM-I cohort, the fsMRI and T2-weighted MRI exams were randomized, and the blinded reviewers performed tonsillar measurements on both scans. RESULTS The mean age of the CM-I cohort was 7.39 years, and 50% of these subjects were male. The mean time interval between fsMRI and conventional T2-weighted MRI was 97.8 days. Forty-four percent of the subjects had undergone imaging after posterior fossa decompression. The sensitivity and specificity of fsMRI in detecting CM-I was 100% (95% CI 71.51%-100%) and 92.11% (95% CI 78.62%-98.34%), respectively. If only preoperative patients are considered, both sensitivity and specificity increase to 100%. The authors also performed a cost analysis and determined that fsMRI was significantly cost-effective compared to T2-weighted MRI or CT. CONCLUSIONS Despite known limitations, fsMRI may serve as a useful diagnostic and surveillance tool for CM-I. It is more cost-effective than full conventional brain MRI and decreases the need for sedation in young children.

    View details for PubMedID 29749883

  • Frameless stereotactic dual lead placement through single burr hole: A technical report. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia Cartmell, S. C., Miller, K. J., Ho, A. L., Halpern, C. H. 2018

    Abstract

    Deep Brain Stimulation (DBS) surgery is a neurosurgical procedure involving the placement of stimulatory leads in subcortical structures. Rarely, DBS requires placement of dual ipsilateral leads. Previously, techniques for placing dual ipsilateral leads through a single burr hole were reported using a traditional stereotactic frame. Here, we demonstrate that dual ipsilateral leads can be safely and effectively placed through a single burr hole using a frameless stereotactic DBS system (NexFrame) with only simple modifications to existing equipment.

    View details for DOI 10.1016/j.jocn.2018.06.053

    View details for PubMedID 30007524

  • Topical vancomycin for surgical prophylaxis in non-instrumented pediatric spinal surgeries. Child's nervous system : ChNS : official journal of the International Society for Pediatric Neurosurgery Cannon, J. G., Ho, A. L., Mohole, J., Pendharkar, A. V., Sussman, E. S., Cheshier, S. H., Grant, G. A. 2018

    Abstract

    STUDY DESIGN: Retrospective cohort study.OBJECTIVE: To determine if topical vancomycin irrigation reduces the incidence of post-operative surgical site infections following pediatric spinal procedures. Surgical site infections (SSIs) following spinal procedures performed in pediatric patients represent a serious complication. Prophylactic use of topical vancomycin prior to closure has been shown to be effective in reducing incidence of SSIs in adult spinal procedures. Non-instrumented cases make up the majority of spinal procedures in pediatric patients, and the efficacy of prophylactic topical vancomycin in these procedures has not previously been reported.METHODS: This retrospective study reviewed all non-instrumented spinal procedures performed over a period from 05/2014-12/2016 for topical vancomycin use, surgical site infections, and clinical variables associated with SSI. Topical vancomycin was utilized as infection prophylaxis, and applied as a liquid solution within the wound prior to closure.RESULTS: Ninety-five consecutive, non-instrumented, pediatric spinal surgeries were completed between 01/2015 and 12/2016, of which the last 68 utilized topical vancomycin. There was a 11.1% SSI rate in the non-topical vancomycin cohort versus 0% in the topical vancomycin cohort (P=0.005). The number needed to treat was 9. There were no significant differences in risk factors for SSI between cohorts. There were no complications associated topical vancomycin use.CONCLUSIONS: Routine topical vancomycin administration during closure of non-instrumented spinal procedures can be a safe and effective tool for reducing SSIs in the pediatric neurosurgical population.

    View details for PubMedID 29955942

  • Quantitative analysis of the safety and efficacy of microvascular decompression for patients with trigeminal neuralgia above and below 65?years of age. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia Wallach, J., Ho, A. L., Kim, L. H., Chaudhuri, A. A., Chaudhary, N., Vaz-Guimaraes, F., Chang, S. D. 2018

    Abstract

    For medically-refractory trigeminal neuralgia (TN), microvascular decompression (MVD) is the first-line treatment, and has demonstrated the greatest efficacy and durability. However, due to potential surgical complications, a bias may exist against performing MVD in elderly patients. We sought to determine through a quantitative analysis whether MVD in the elderly is a safe and effective procedure for TN. We completed a Pubmed/SCOPUS literature search up to 12/2016 for eligible studies on MVD for TN. Only research articles with age stratification of results were included. In this quantitative analysis, we analyzed the data for the six articles identified in the literature comparing MVD for a group of patients ?65?years with an elderly group <65?years. A total of 1483 were included. 455 patients were ?65?years (mean 70.8?years, range 65-89?years) and 1028 patients were <65?years (mean 53.4?years, range 19-64?years). Composite mean follow-up time was 51.6?months for the elderly group, and 55.1?months for the young group. Following MVD, each group had 1 mortality (p?=?0.43). There were 21 serious morbidities in the elderly group (4.62%) and 32 in the young group (3.11%) (p?=?0.11). In addition, 15 patients (1.46%) in the elderly group and 24 patients (1.62%) in the young group experienced a cerebrospinal fluid leak (p?=?0.23). TN recurrence rates 9.23% in the young group and 13.33% in the elderly group (p?=?0.070). In conclusion, for properly-selected surgical candidates, MVD should not be ruled out on the basis of age ?65?years.

    View details for PubMedID 29954647

  • Neuromodulatory Treatments for Alcohol Use Disorder: A Review. Brain sciences Salib, A. N., Ho, A. L., Sussman, E. S., Pendharkar, A. V., Halpern, C. H. 2018; 8 (6)

    Abstract

    Alcohol use disorder (AUD) is a prevalent condition characterized by chronic alcohol-seeking behaviors and has become a significant economic burden with global ramifications on public health. While numerous treatment options are available for AUD, many are unable to sustain long-term sobriety. The nucleus accumbens (NAcc) upholds an integral role in mediating reward behavior and has been implicated as a potential target for deep brain stimulation (DBS) in the context of AUD. DBS is empirically thought to disrupt pathological neuronal synchrony, a hallmark of binge behavior. Pre-clinical animal models and pilot human clinical studies utilizing DBS for the treatment of AUD have shown promise for reducing alcohol-related cravings and prolonging abstinence. In this review, we outline the various interventions available for AUD, and the translational potential DBS has to modulate functionality of the NAcc as a treatment for AUD.

    View details for PubMedID 29843426

  • Minimally invasive approaches to craniosynostosis. Journal of neurosurgical sciences Pendharkar, A. V., Shahin, M. N., Cavallo, C., Zhao, X., Ho, A. L., Sussman, E. S., Grant, G. A. 2018

    Abstract

    Craniosynostosis (CS) is defined as the premature fusion of one or more calvarial sutures. This carries several consequences, including abnormal/asymmetric cranial vault development, increased intracranial pressure, compromised neurocognitive development, and craniofacial deformity. Definitive management is surgical with the goal of protecting cerebral development by re-establishing normal cranial vault expansion and correcting cosmetic deformity. In today's practice, CS surgery has advanced radically from simple craniectomies to major cranial vault reconstructive (CVR) procedures. More recently there has been considerable interest in endoscopic assisted surgery (EAS). Theoretical benefits include decreased operative time, morbidity, blood loss, postoperative pain, cost and faster recovery times. In this focused review, we summarize the current body of literature reporting clinical outcomes in EAS and review the data comparing EAS and CVR.

    View details for PubMedID 29790726

  • Outpatient spine surgery: defining the outcomes, value, and barriers to implementation. Neurosurgical focus Pendharkar, A. V., Shahin, M. N., Ho, A. L., Sussman, E. S., Purger, D. A., Veeravagu, A., Ratliff, J. K., Desai, A. M. 2018; 44 (5): E11

    Abstract

    Spine surgery is a key target for cost reduction within the United States health care system. One possible strategy involves the transition of inpatient surgeries to the ambulatory setting. Lumbar laminectomy with or without discectomy, lumbar fusion, anterior cervical discectomy and fusion, and cervical disc arthroplasty all represent promising candidates for outpatient surgeries in select populations. In this focused review, the authors clarify the different definitions used in studies describing outpatient spine surgery. They also discuss the body of evidence supporting each of these procedures and summarize the proposed cost savings. Finally, they examine several patient- and surgeon-specific considerations to highlight the barriers in translating outpatient spine surgery into actual practice.

    View details for PubMedID 29712520

  • Propensity-matched comparison of outcomes and cost after macroscopic and microscopic lumbar discectomy using a national longitudinal database. Neurosurgical focus Pendharkar, A. V., Rezaii, P. G., Ho, A. L., Sussman, E. S., Purger, D. A., Veeravagu, A., Ratliff, J. K., Desai, A. M. 2018; 44 (5): E12

    Abstract

    OBJECTIVE There has been considerable debate about the utility of the operating microscope in lumbar discectomy and its effect on outcomes and cost. METHODS A commercially available longitudinal database was used to identify patients undergoing discectomy with or without use of a microscope between 2007 and 2015. Propensity matching was performed to normalize differences between demographics and comorbidities in the 2 cohorts. Outcomes, complications, and cost were subsequently analyzed using bivariate analysis. RESULTS A total of 42,025 patients were identified for the "macroscopic" group, while 11,172 patients were identified for the "microscopic" group. For the propensity-matched analysis, the 11,172 patients in the microscopic discectomy group were compared with a group of 22,340 matched patients who underwent macroscopic discectomy. There were no significant differences in postoperative complications between the groups other than a higher proportion of deep vein thrombosis (DVT) in the macroscopic discectomy cohort versus the microscopic discectomy group (0.4% vs 0.2%, matched OR 0.48 [95% CI 0.26-0.82], p = 0.0045). Length of stay was significantly longer in the macroscopic group compared to the microscopic group (mean 2.13 vs 1.83 days, p < 0.0001). Macroscopic discectomy patients had a higher rate of revision surgery when compared to microscopic discectomy patients (OR 0.92 [95% CI 0.84-1.00], p = 0.0366). Hospital charges were higher in the macroscopic discectomy group (mean $19,490 vs $14,921, p < 0.0001). CONCLUSIONS The present study suggests that the use of the operating microscope in lumbar discectomy is associated with decreased length of stay, lower DVT rate, lower reoperation rate, and decreased overall hospital costs.

    View details for PubMedID 29712527

  • Nurse Telephonic Triage Service for After-hour Patient Calls in Neurosurgery. Annals of surgery Escobedo-Wu, E. L., Dhebar, F., Harsh, G., Steinberg, G., Vyas, A., Katznelson, L., Ho, A. L., Pendharkar, A. V., Sussman, E. S., Rohatgi, N. 2018; 267 (4): e67?e68

    Abstract

    OBJECTIVE: The aim of this study was to report the utilization and experience of the nurse telephonic triage service for after-hour patient calls in Neurosurgery.BACKGROUND: It is challenging for patients to reach their clinicians after-hours in a timely manner. This may result in worse health outcomes for the patients, or inappropriate utilization of emergency rooms and urgent care facilities. Physicians continue to remain overwhelmed with frequent after-hours calls in addition to other clinical responsibilities while on-call.METHODS: In August 2015, our institution launched the Clinical Advice Service (CAS) to provide a patient-centric, nurse-run telephone triage service for after-hour calls from Neurosurgery patients. Clinical protocols were created for use by CAS staff by Neurosurgery clinicians.RESULTS: Between July 2016 and June 2017, CAS has accepted 1021 after-hours calls from Neurosurgery patients. A total of 71.4% of these calls were clinical, and the remaining nonclinical (directions, appointments, general information). CAS escalated 37.3% of the calls to the on-call Neurosurgery physician; 4.8% Neurosurgery patients were triaged to the emergency room by CAS.CONCLUSION: CAS has been able to provide well-coordinated care to Neurosurgery patients while reducing physician workload.

    View details for PubMedID 29064895

  • Stereotactic radiosurgery for central nervous system hemangioblastoma: systematic review and meta-analysis JOURNAL OF NEURO-ONCOLOGY Pan, J., Jabarkheel, R., Huang, Y., Ho, A., Chang, S. D. 2018; 137 (1): 11?22

    Abstract

    Hemangioblastomas are rare, benign, vascular tumors of the central nervous system (CNS), often associated with von-hippel lindau (VHL) disease. Current therapeutic options include microsurgical resection or stereotactic radiosurgery (SRS). With no randomized controlled studies and minimal data beyond single-institution reviews, the optimal management approach for patients with CNS hemangioblastomas is unclear. We completed a Pubmed/SCOPUS literature search from January 1990 to January 2017 for eligible studies on SRS for CNS hemangioblastomas. Relevant articles were identified and reviewed in accordance to the Preferred Reporting Items for Systematic Review and Meta-Analysisá(PRISMA) guidelines. 26 studies met eligibility criteria for qualitative synthesis, representing 596 subjects and 1535 tumors. The Gamma Knife was the most published SRS method for CNS hemangioblastomas. After critical study appraisal for intra-study bias, 14 studies were used for quantitative meta-analysis of 5-year progression free survival (PFS). The pooled 5-year PFS across all eligible studies was 88.4%. No difference was observed between spine versus intracranial studies. Individual patient data (IPD) was extracted from 14 studies, representing 322 tumors. Univariate analysis of IPD revealed that VHL patients were younger, and had smaller tumors compared to those with sporadic disease. Adverse events were associated with increasing marginal dose, independent of tumor volume. VHL status, sex, radiosurgical method, tumor location, and tumor volume were not found to be significantly associated with tumor progression. Multiple studies show excellent tumor control at 5-year follow up, however, the long-term efficacy of SRS for CNS hemangioblastomas still needs to be investigated, and the studies exploring the role of SRS for early treatment of asymptomatic lesions is wanting.

    View details for PubMedID 29204841

  • In Reply: The Use of Vancomycin Powder for Surgical Prophylaxis Following Craniotomy NEUROSURGERY Ho, A. L., Li, G. H. 2018; 82 (2): E71

    View details for DOI 10.1093/neuros/nyx537

    View details for Web of Science ID 000424225800017

    View details for PubMedID 29149292

  • Practical Pearl: Use of MRI to Differentiate Pseudo-subarachnoid Hemorrhage from True Subarachnoid Hemorrhage. Neurocritical care Ho, A. L., Sussman, E. S., Pendharkar, A. V., Iv, M., Hirsch, K. G., Fischbein, N. J., Dodd, R. L. 2018

    View details for PubMedID 29948997

  • Mild traumatic brain injury and concussion: terminology and classification. Handbook of clinical neurology Sussman, E. S., Pendharkar, A. V., Ho, A. L., Ghajar, J. 2018; 158: 21?24

    Abstract

    Traumatic brain injury (TBI) is a major cause of morbidity and mortality throughout the world. Mild TBI, which is typically defined by Glasgow Coma Scale score ?13, accounts for the vast majority of all TBIs, particularly in the setting of sports-related injuries. The terms concussion and TBI are often used interchangeably, both in the medical literature and in clinical care of this patient population. However, the lack of clearly defined definitions of these terms often leads to confusion, and this confusion may lead to delayed diagnosis and inconsistent management of affected patients. Here, we review the current terminology and classification of mild TBI and concussion. We will also discuss recent efforts to stratify these injuries into clinically relevant subtypes or profiles that are both diagnostic- and treatment-targeted.

    View details for PubMedID 30482349

  • Topical vancomycin surgical prophylaxis in pediatric open craniotomies: an institutional experience. Journal of neurosurgery. Pediatrics Ho, A. L., Cannon, J. G., Mohole, J., Pendharkar, A. V., Sussman, E. S., Li, G., Edwards, M. S., Cheshier, S. H., Grant, G. A. 2018: 1?6

    Abstract

    OBJECTIVE Topical antimicrobial compounds are safe and can reduce cost and complications associated with surgical site infections (SSIs). Topical vancomycin has been an effective tool for reducing SSIs following routine neurosurgical procedures in the spine and following adult craniotomies. However, widespread adoption within the pediatric neurosurgical community has not yet occurred, and there are no studies to report on the safety and efficacy of this intervention. The authors present the first institution-wide study of topical vancomycin following open craniotomy in the pediatric population. METHODS In this retrospective study the authors reviewed all open craniotomies performed over a period from 05/2014 to 12/2016 for topical vancomycin use, SSIs, and clinical variables associated with SSI. Topical vancomycin was utilized as an infection prophylaxis and was applied as a liquid solution following replacement of a bone flap or after dural closure when no bone flap was reapplied. RESULTS Overall, 466 consecutive open craniotomies were completed between 05/2014 and 12/2016, of which 43% utilized topical vancomycin. There was a 1.5% SSI rate in the nontopical cohort versus 0% in the topical vancomycin cohort (p = 0.045). The number needed to treat was 66. There were no significant differences in risk factors for SSI between cohorts. There were no complications associated with topical vancomycin use. CONCLUSIONS Routine topical vancomycin administration during closure of open craniotomies can be a safe and effective tool for reducing SSIs in the pediatric neurosurgical population.

    View details for PubMedID 30141749

  • Cervical Stenosis in Adult Arthrogryposis: A Case Report and Review of the Literature. Journal of neurological surgery reports Ho, A. L., Mohole, J., Sussman, E. S., Pendharkar, A. V., Singh, H. 2018; 79 (1): e19?e22

    Abstract

    Arthrogryposis multiplex congenita is a rare, nonprogressive congenital disorder that describes a constellation of conditions characterized by multiple joint contractures. Spinal pathology and deformity are common; however, the majority of the literature on arthrogryposis is focused on pediatric management. There exist very few reports on long-term outcomes and management of adults with arthrogryposis. We present a case of cervical spinal stenosis in an adult female with arthrogryposis that underwent posterior cervical decompression and fusion. A review of spine-related sequelae seen in adults with arthrogryposis and considerations for spinal surgery for these patients is discussed.

    View details for PubMedID 29581933

    View details for PubMedCentralID PMC5860911

  • Diffusion Tensor Imaging in an Infant Undergoing Functional Hemispherectomy: A Surgical Aid. Cureus Ho, A. L., Pendharkar, A. V., Sussman, E. S., Casazza, M., Grant, G. A. 2017; 9 (9): e1697

    Abstract

    Hemispherectomy is a highly effective treatment option for children with severe, unilateral, medically refractory epilepsy. Many patients undergoing hemispherectomy are younger patients with dysmorphic brains, making accomplishing a complete disconnectionchallenging due to anatomic distortion, even with the aid of intraoperative navigation. Diffusion tensor imaging (DTI) has been proposed as a valuable imaging adjunct perioperatively to help guide surgeons intraoperatively, as well as for post-surgical evaluation and confirmation of complete hemispheric disconnection.We present a case of an infant with Otoharra syndrome and hemimegencephaly who underwent a functional hemispherectomy for treatment of severe, refractory seizures. We demonstrate how DTI was utilized both pre-, intra-, and postoperatively to help plan, guide, and confirm surgical disconnection. The application of exquisite DTI for this child led to her being seizure-free, which is a life-changing event with long-lasting benefits and will become even more critical as we now perform these disconnection procedures with a more minimally invasive approach.

    View details for PubMedID 29167751

  • Outpatient vs Inpatient Anterior Cervical Discectomy and Fusion: A Population-Level Analysis of Outcomes and Cost. Neurosurgery Purger, D. A., Pendharkar, A. V., Ho, A. L., Sussman, E. S., Yang, L., Desai, M., Veeravagu, A., Ratliff, J. K., Desai, A. 2017

    Abstract

    Outpatient anterior cervical discectomy and fusion (ACDF) is a promising candidate for US healthcare cost reduction as several studies have demonstrated that overall complications are relatively low and early discharge can preserve high patient satisfaction, low morbidity, and minimal readmission.To compare clinical outcomes and associated costs between inpatient and ambulatory setting ACDF.Demographics, comorbidities, emergency department (ED) visits, readmissions, reoperation rates, and 90-d charges were retrospectively analyzed for patients undergoing elective ACDF in California, Florida, and New York from 2009 to 2011 in State Inpatient and Ambulatory Databases.A total of 3135 ambulatory and 46 996 inpatient ACDFs were performed. Mean Charlson comorbidity index, length of stay, and mortality were 0.2, 0.4 d, and 0% in the ambulatory cohort and 0.4, 1.8 d, and 0.04% for inpatients ( P < .0001). Ambulatory patients were younger (48.0 vs 53.1) and more likely to be Caucasian. One hundred sixty-eight ambulatory patients (5.4%) presented to the ED within 30 d (mean 11.3 d), 51 (1.6%) were readmitted, and 5 (0.2%) underwent reoperation. Among inpatient surgeries, 2607 patients (5.5%) presented to the ED within 30 d (mean 9.7 d), 1778 (3.8%) were readmitted (mean 6.3ád), and 200 (0.4%) underwent reoperation. Higher Charlson comorbidity index increased rate of ED visits (ambulatory operating room [OR] 1.285, P < .05; inpatient OR 1.289, P < .0001) and readmission (ambulatory OR 1.746, P < .0001; inpatient OR 1.685, P < .0001). Overall charges were significantly lower for ambulatory ACDFs ($33 362.51 vs $74 667.04; P < .0001).ACDF can be performed in an ambulatory setting with comparable morbidity and readmission rates, and lower costs, to those performed in an inpatient setting.

    View details for DOI 10.1093/neuros/nyx215

    View details for PubMedID 28498922

  • The Use of Vancomycin Powder for Surgical Prophylaxis Following Craniotomy. Neurosurgery Ravikumar, V., Ho, A. L., Pendhakar, A. V., Sussman, E. S., Kwong-Hon Chow, K., Li, G. 2017; 80 (5): 754-758

    Abstract

    Intrawound vancomycin powder has been studied extensively in spinal fusion surgeries and been found to reduce rates of surgical site infections (SSIs) significantly. Despite its success in spinal surgeries, topical vancomycin has not been extensively studied with respect to cranial neurosurgery.To evaluate the efficacy of intrawound topical vancomycin for prevention of SSIs following open craniotomies.We retrospectively analyzed a large series of 350 patients from 2011 to 2015 in a pre/postintervention study of use of topical vancomycin to reduce postoperative craniotomy infection rates. We had a preintervention control group of 225 patients and a postintervention group of 125 patients that received intrawound topical vancomycin.Our preintervention incidence of SSI was 2.2% and this was significantly reduced to 0% following introduction of topical vancomycin ( P < .5). An ad hoc cost analysis suggested a cost savings of $59 965 with the use of topical vancomycin for craniotomies.Our study found a significant reduction in SSI rates after introduction of topical vancomycin. Thus, this simple intervention should be considered in all open craniotomy patients as both infection prophylaxis and a potential cost saving intervention.

    View details for DOI 10.1093/neuros/nyw127

    View details for PubMedID 28327930

  • Interventional therapy for brain arteriovenous malformations before and after ARUBA JOURNAL OF CLINICAL NEUROSCIENCE Sussman, E. S., Iyer, A. K., Teo, M., Pendharkar, A. V., Ho, A. L., Steinberg, G. K. 2017; 37: 54-56

    Abstract

    The ARUBA trial (2014) concluded that medical management alone is superior to medical management plus interventional therapy for the treatment of unruptured brain arteriovenous malformations (bAVMs). This sparked considerable controversy among involved healthcare providers. Here, we evaluated the impact of ARUBA on the volume, type, and treatment modality of bAVMs referred to a large tertiary care center. This was achieved by conducting a retrospective review of a prospectively maintained database of all bAVMs treated at Stanford Health Care and Stanford Children's Health from January 2012 through July 2015. The case volume of bAVMs treated at Stanford has been relatively unchanged in the period of time leading up to and after ARUBA. Furthermore, there has been no significant change in the proportion of unruptured AVMs treated. Although differences existed in types of interventions administered, these differences are best explained by variations in the SM grades of AVMs treated during each study period, rather than by underlying changes in treatment strategy. Additional research is warranted to more thoroughly characterize the impact of ARUBA on the treatment patterns of bAVMS.

    View details for DOI 10.1016/j.jocn.2016.10.036

    View details for Web of Science ID 000394396400015

  • Stereotactic radiosurgery for non-vestibular cranial nerve schwanommas JOURNAL OF NEURO-ONCOLOGY D'Astous, M., Ho, A. L., Pendharkar, A., Choi, C. Y., Soltys, S. G., Gibbs, I. C., Tayag, A. T., Thompson, P. A., Adler, J. R., Chang, S. D. 2017; 131 (1): 177-183

    Abstract

    Non-vestibular cranial nerve schwannomas (NVCNS) are rare lesions, representing <10?% of cranial nerve schwannomas. The optimal treatment for NVCNS is often derived from vestibular schwannomas experience. Surgical resection has been referred to as the first line treatment for those benign tumors, but significant complication rates are reported. Stereotactic radiosurgery (SRS) has arisen as a mainstay of treatment for many benign tumors, including schwanommas. We retrospectively reviewed the outcomes of NVCNS treated by SRS to characterize tumor control, symptom relief, toxicity, and the role of hypo-fractionation of SRS dose. Eighty-eight (88) patients, with ninety-five (95) NVCNS were treated with either single or multi-session SRS from 2001 to 2014. Local control was achieved in 94?% of patients treated (median follow-up of 33 months, range 1-155). Complications were seen in 7.4?% of cases treated with SRS. At 1-year, 57?% of patients had improvement or resolution of their symptoms, while 35?% were stable and 8?% had worsening or increased symptoms. While 42?% received only one session, results on local control were similar for one or multiple sessions (p?=?0.424). SRS for NVCNS is a treatment modality that provides excellent local control with minimal complication risk compared to traditional neurosurgical techniques. Tumor control obtained with a multi-session treatment was not significantly different from single session treatment. Safety profile was also comparable for uni or multi-session treatments. We concluded that, as seen in VS treated with CK SRS, radiosurgery treatment can be safely delivered in cases of NVCNS.

    View details for DOI 10.1007/s11060-016-2286-7

    View details for Web of Science ID 000393065400019

  • DNA methylation analysis for the treatment of meningiomas. Journal of visualized surgery Gendreau, J. L., Chow, K. K., Sussman, E. S., Iyer, A., Pendharkar, A. V., Ho, A. L. 2017; 3: 178

    View details for PubMedID 29302454

  • Laser interstitial thermal therapy for the treatment of epilepsy: evidence to date NEUROPSYCHIATRIC DISEASE AND TREATMENT Shukla, N. D., Ho, A. L., Pendharkar, A. V., Sussman, E. S., Halpern, C. H. 2017; 13: 2469?75

    Abstract

    Medically intractable epilepsy is associated with increased morbidity and mortality. For those with focal epilepsy and correlated electrophysiological or radiographic features, open surgical resection can achieve high rates of seizure control, but can be associated with neurologic deficits and cognitive effects. Recent innovations have allowed for more minimally invasive methods of surgical seizure control such as magnetic resonance-guided laser interstitial therapy (MRgLITT). MRgLITT achieves the goal of ablating seizure foci while preserving neuropsycho-logical function and offering real-time feedback and monitoring of tissue ablation. This review summarizes the utilization of MRgLITT for mesial temporal lobe epilepsy and other seizure disorders. Overall, the efficacy of MRgLITT is comparable to that of open surgery and offers a less invasive approach in patients with significantly less morbidity.

    View details for PubMedID 29026310

  • Image-guided stereotactic radiosurgery for treatment of spinal hemangioblastoma NEUROSURGICAL FOCUS Pan, J., Ho, A. L., D'Astous, M., Sussman, E. S., Thompson, P. A., Tayag, A. T., Pangilinan, L., Soltys, S. G., Gibbs, I. C., Chang, S. D. 2017; 42 (1)

    Abstract

    OBJECTIVE Stereotactic radiosurgery (SRS) has been an attractive treatment option for hemangioblastomas, especially for lesions that are surgically inaccessible and in patients with von Hippel-Lindau (VHL) disease and multiple lesions. Although there has been a multitude of studies examining the utility of SRS in intracranial hemangioblastomas, SRS has only recently been used for spinal hemangioblastomas due to technical limitations. The purpose of this study is to provide a long-term evaluation of the effectiveness of image-guided radiosurgery in halting tumor progression and providing symptomatic relief for spinal hemangioblastomas. METHODS Between 2001 and 2011, 46 spinal hemangioblastomas in 28 patients were treated using the CyberKnife image-guided radiosurgery system at the authors' institution. Fourteen of these patients also had VHL disease. The median age at treatment was 43.5 years (range 19-85 years). The mean prescription radiation dose to the tumor periphery was 21.6 Gy (range 15-35 Gy). The median tumor volume was 0.264 cm(3) (range 0.025-70.9 cm(3)). Tumor response was evaluated on serial, contrast-enhanced CT and MR images. Clinical response was evaluated by clinical and imaging evaluation. RESULTS The mean follow-up for the cohort was 54.3 months. Radiographic follow-up was available for 19 patients with 34 tumors; 32 (94.1%) tumors were radiographically stable or displayed signs of regression. Actuarial control rates at 1, 3, and 5 years were 96.1%, 92.3%, and 92.3%, respectively. Clinical evaluation on follow-up was available for 13 patients with 16 tumors; 13 (81.2%) tumors in 10 patients had symptomatic improvement. No patient developed any complications related to radiosurgery. CONCLUSIONS Image-guided SRS is safe and effective for the primary treatment of spinal hemangioblastomas and is an attractive alternative to resection, especially for those with VHL disease.

    View details for DOI 10.3171/2016.10.FOCUS16361

    View details for Web of Science ID 000392113200012

    View details for PubMedID 28041328

  • Interventional therapy for brain arteriovenous malformations before and after ARUBA. Journal of clinical neuroscience Sussman, E. S., Iyer, A. K., Teo, M., Pendharkar, A. V., Ho, A. L., Steinberg, G. K. 2016

    Abstract

    The ARUBA trial (2014) concluded that medical management alone is superior to medical management plus interventional therapy for the treatment of unruptured brain arteriovenous malformations (bAVMs). This sparked considerable controversy among involved healthcare providers. Here, we evaluated the impact of ARUBA on the volume, type, and treatment modality of bAVMs referred to a large tertiary care center. This was achieved by conducting a retrospective review of a prospectively maintained database of all bAVMs treated at Stanford Health Care and Stanford Children's Health from January 2012 through July 2015. The case volume of bAVMs treated at Stanford has been relatively unchanged in the period of time leading up to and after ARUBA. Furthermore, there has been no significant change in the proportion of unruptured AVMs treated. Although differences existed in types of interventions administered, these differences are best explained by variations in the SM grades of AVMs treated during each study period, rather than by underlying changes in treatment strategy. Additional research is warranted to more thoroughly characterize the impact of ARUBA on the treatment patterns of bAVMS.

    View details for DOI 10.1016/j.jocn.2016.10.036

    View details for PubMedID 27810415

  • Stereotactic radiosurgery for non-vestibular cranial nerve schwanommas. Journal of neuro-oncology D'Astous, M., Ho, A. L., Pendharkar, A., Choi, C. Y., Soltys, S. G., Gibbs, I. C., Tayag, A. T., Thompson, P. A., Adler, J. R., Chang, S. D. 2016: -?

    Abstract

    Non-vestibular cranial nerve schwannomas (NVCNS) are rare lesions, representing <10?% of cranial nerve schwannomas. The optimal treatment for NVCNS is often derived from vestibular schwannomas experience. Surgical resection has been referred to as the first line treatment for those benign tumors, but significant complication rates are reported. Stereotactic radiosurgery (SRS) has arisen as a mainstay of treatment for many benign tumors, including schwanommas. We retrospectively reviewed the outcomes of NVCNS treated by SRS to characterize tumor control, symptom relief, toxicity, and the role of hypo-fractionation of SRS dose. Eighty-eight (88) patients, with ninety-five (95) NVCNS were treated with either single or multi-session SRS from 2001 to 2014. Local control was achieved in 94?% of patients treated (median follow-up of 33 months, range 1-155). Complications were seen in 7.4?% of cases treated with SRS. At 1-year, 57?% of patients had improvement or resolution of their symptoms, while 35?% were stable and 8?% had worsening or increased symptoms. While 42?% received only one session, results on local control were similar for one or multiple sessions (p?=?0.424). SRS for NVCNS is a treatment modality that provides excellent local control with minimal complication risk compared to traditional neurosurgical techniques. Tumor control obtained with a multi-session treatment was not significantly different from single session treatment. Safety profile was also comparable for uni or multi-session treatments. We concluded that, as seen in VS treated with CK SRS, radiosurgery treatment can be safely delivered in cases of NVCNS.

    View details for PubMedID 27752881

  • Vocal Tremor: Novel Therapeutic Target for Deep Brain Stimulation. Brain sciences Ravikumar, V. K., Ho, A. L., Parker, J. J., Erickson-DiRenzo, E., Halpern, C. H. 2016; 6 (4)

    Abstract

    Tremulous voice is characteristically associated with essential tremor, and is referred to as essential vocal tremor (EVT). Current estimates suggest that up to 40% of individuals diagnosed with essential tremor also present with EVT, which is associated with an impaired quality of life. Traditional EVT treatments have demonstrated limited success in long-term management of symptoms. However, voice tremor has been noted to decrease in patients receiving deep brain stimulation (DBS) with the targeting of thalamic nuclei. In this study, we describe our multidisciplinary procedure for awake, frameless DBS with optimal stimulation targets as well as acoustic analysis and laryngoscopic assessment to quantify tremor reduction. Finally, we investigate the most recent clinical evidence regarding the procedure.

    View details for PubMedID 27735866

  • Pituitary Apoplexy Associated with Carotid Compression and a Large Ischemic Penumbra. World neurosurgery Sussman, E. S., Ho, A. L., Pendharkar, A. V., Achrol, A. S., Harsh, G. R. 2016; 92: 581 e7-581 e13

    Abstract

    Pituitary apoplexy is an acute clinical syndrome caused by pituitary gland hemorrhage or infarction. Rarely, this clinical syndrome is associated with cerebral infarction secondary to compression of an internal carotid artery. We report an unusual case of pituitary apoplexy associated with a cerebral infarct with a large ischemic penumbra.The patient presented with headaches and visual disturbance and was found to have pituitary apoplexy. Findings of his neurologic examination showed he had rapidly deteriorated, with obtundation, ophthalmoplegia, and left hemiplegia. Computed tomography perfusion images revealed a right hemispheric infarct with a large ischemic penumbra. Emergent decompressive transsphenoidal resection was performed. The patient had dramatic neurologic recovery, and postoperative imaging revealed salvage of most of the previously identified penumbra.Cerebral perfusion imaging is a useful diagnostic tool for identifying the subset of pituitary apoplexy patients that may benefit from emergent surgical intervention.

    View details for DOI 10.1016/j.wneu.2016.06.040

    View details for PubMedID 27319311

  • CyberKnife Stereotactic Radiosurgery for Atypical and Malignant Meningiomas. World neurosurgery Zhang, M., Ho, A. L., D'Astous, M., Pendharkar, A. V., Choi, C. Y., Thompson, P. A., Tayag, A. T., Soltys, S. G., Gibbs, I. C., Chang, S. D. 2016; 91: 574-581 e1

    Abstract

    Recurrent World Health Organization (WHO) grade II and III meningiomas have traditionally been treated by surgery alone, but early literature suggests that adjuvant stereotactic radiosurgery may greatly improve outcomes. We present the long-term tumor control and safety of a hypofractionated stereotactic radiosurgery regimen.Prospectively collected data of 44 WHO grade II and 9 WHO grade III meningiomas treated by CyberKnife for adjuvant or salvage therapy were reviewed. Patient demographics, treatment parameters, local control, regional control, locoregional control, overall survival, radiation history, and complications were documented.For WHO grade II patients, recurrence occurred in 41%, with local, regional, and locoregional failure at 60 months recorded as 49%, 58%, and 36%. For WHO grade III patients, recurrence occurred in 66%, with local, regional, and locoregional failure at 12 months recorded as 57%, 100%, and 43%. The 60-month locoregional control rates for radiation na´ve and experienced patients were 48% and 0% (Pá=á0.14). Overall, 7 of 44 grade II patients and 8 of 9 grade III patients had died at last follow-up. The 60-month and 12-month overall survival rates for grade II and III meningiomas were 87% and 50%, respectively. Serious complications occurred in 7.5% of patients.Stereotactic radiosurgery for adjuvant and salvage treatment of WHO grade II meningioma using a hypofractionated plan is a viable treatment strategy with acceptable long-term tumor control, overall survival, and complication rates. Future studies should focus on radiation-na´ve patients and local management of malignant meningioma.

    View details for DOI 10.1016/j.wneu.2016.04.019

    View details for PubMedID 27108030

  • Optogenetic modulation in stroke recovery NEUROSURGICAL FOCUS Pendharkar, A. V., Levy, S. L., Ho, A. L., Sussman, E. S., Cheng, M. Y., Steinberg, G. K. 2016; 40 (5)

    Abstract

    Stroke is one of the leading contributors to morbidity, mortality, and health care costs in the United States. Although several preclinical strategies have shown promise in the laboratory, few have succeeded in the clinical setting. Optogenetics represents a promising molecular tool, which enables highly specific circuit-level neuromodulation. Here, the conceptual background and preclinical body of evidence for optogenetics are reviewed, and translational considerations in stroke recovery are discussed.

    View details for DOI 10.3171/2016.2.FOCUS163

    View details for Web of Science ID 000375119300003

    View details for PubMedID 27132527

  • Sports-related brain injuries: connecting pathology to diagnosis NEUROSURGICAL FOCUS Pan, J., Connolly, I. D., Dangelmajer, S., Kintzing, J., Ho, A. L., Grant, G. 2016; 40 (4)

    Abstract

    Brain injuries are becoming increasingly common in athletes and represent an important diagnostic challenge. Early detection and management of brain injuries in sports are of utmost importance in preventing chronic neurological and psychiatric decline. These types of injuries incurred during sports are referred to as mild traumatic brain injuries, which represent a heterogeneous spectrum of disease. The most dramatic manifestation of chronic mild traumatic brain injuries is termed chronic traumatic encephalopathy, which is associated with profound neuropsychiatric deficits. Because chronic traumatic encephalopathy can only be diagnosed by postmortem examination, new diagnostic methodologies are needed for early detection and amelioration of disease burden. This review examines the pathology driving changes in athletes participating in high-impact sports and how this understanding can lead to innovations in neuroimaging and biomarker discovery.

    View details for DOI 10.3171/2016.1.FOCUS15607

    View details for Web of Science ID 000373476500004

    View details for PubMedID 27032917

  • Clinical evaluation of concussion: the evolving role of oculomotor assessments NEUROSURGICAL FOCUS Sussman, E. S., Ho, A. L., Pendharkar, A. V., Ghajar, J. 2016; 40 (4)

    Abstract

    Sports-related concussion is a change in brain function following a direct or an indirect force to the head, identified in awake individuals and accounting for a considerable proportion of mild traumatic brain injury. Although the neurological signs and symptoms of concussion can be subtle and transient, there can be persistent sequelae, such as impaired attention and balance, that make affected patients particularly vulnerable to further injury. Currently, there is no accepted definition or diagnostic criteria for concussion, and there is no single assessment that is accepted as capable of identifying all patients with concussion. In this paper, the authors review the available screening tools for concussion, with particular emphasis on the role of visual function testing. In particular, they discuss the oculomotor assessment tools that are being investigated in the setting of concussion screening.

    View details for DOI 10.3171/2016.1.FOCUS15610

    View details for Web of Science ID 000373476500006

    View details for PubMedID 27032924

  • Impact of histopathological transformation and overall survival in patients with progressive anaplastic glioma. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia Ho, A. L., Koch, M. J., Tanaka, S., Eichler, A. F., Batchelor, T. T., Tanboon, J., Louis, D. N., Cahill, D. P., Chi, A. S., Curry, W. T. 2016; 31: 99?105

    Abstract

    Progression of anaplastic glioma (World Health Organization [WHO] grade III) is typically determined radiographically, and transformation to glioblastoma (GB) (WHO grade IV) is often presumed at that time. However, the frequency of actual histopathologic transformation of anaplastic glioma and the subsequent clinical impact is unclear. To determine these associations, we retrospectively reviewed all anaplastic glioma patients who underwent surgery at our center at first radiographic progression, and we examined the effects of histological diagnosis, clinical history, and molecular factors on transformation rate and survival. We identified 85 anaplastic glioma (39 astrocytoma, 24 oligodendroglioma, 22 oligoastrocytoma), of which 38.8% transformed to GB. Transformation was associated with shorter overall survival (OS) from the time of diagnosis (3.4 vs. 10.9years, p=0.0005) and second surgery (1.0 vs. 3.5years, p<0.0001). Original histologic subtype did not significantly impact the risk of transformation or OS. No other factors, including surgery, adjuvant therapy or molecular markers, significantly affected the risk of transformation. However, mutations in isocitrate dehydrogenase 1 (IDH1) was associated with longer time to progression (median 4.6 vs. 1.4years, p=0.008) and OS (median 10.0 vs. 4.2years, p=0.046). At radiographic progression, tissue diagnosis may be warranted as histologic grade may provide valuable prognostic information and affect therapeutic clinical trial selection criteria for this patient population.

    View details for PubMedID 27279154

  • Attitudes Toward Treating Addiction With Deep Brain Stimulation. Brain stimulation Ali, R., DiFrancesco, M. F., Ho, A. L., Kampman, K. M., Caplan, A. L., Halpern, C. H. 2016; 9 (3): 466?68

    View details for PubMedID 27066935

  • Integrating Cerebrospinal Fluid Shunt Quality Checks into the World Health Organization's Safe Surgery Checklist: A Pilot Study. World neurosurgery Wong, J. M., Perry, W. R., Greenberg, Y., Ho, A. L., Lipsitz, S. R., Goumnerova, L. C., Laws, E. R., Berry, W. R., Gawande, A. A., Bader, A. M. 2016; 92: 491?98.e3

    Abstract

    Despite efforts for improvement, cerebrospinal fluid (CSF) shunt failure rates remain high. Recent studies have shown promising reductions in failure rates and infection rates with the routine use of perioperative checklists. This study was conducted to pilot test the feasibility and efficacy of integrating specific CSF shunt surgery quality checks into the World Health Organization (WHO) Surgical Safety Checklist.We designed CSF shunt checklist quality items according to a previously established methodology, including solicitation of best practices by a national multidisciplinary expert panel. We examined adherence to key processes before and after implementation as a measure of the efficacy of the integrated checklist. We then surveyed users regarding perceived checklist utility.Overall adherence to shunt-specific key processes increased from 8.6 (95% confidence interval [CI], 7.9-9.2) to 9.9 (95% CI, 9.3-10.4; Pá= 0.0070) per 12 items, driven by the infection control items (4.7 [95% CI, 4.1-5.3] to 6.0 [95% CI, 5.4-6.4] per 8 items; Pá= 0.0056). All of the survey respondents indicated that the checklist was easy to use. The majority stated that it helped them feel better prepared to perform the procedure consistently according to evidence-based practice, and that if they were to adhere to the checklist consistently, their rate of shunt failure would be expected to decrease.The integration of specialty-specific checks into the WHO Safe Surgery Checklist improved adherence to quality processes and generally was well accepted in our pilot study. A larger clinical trial is needed to assess whether this approach could improve shunt outcomes.

    View details for PubMedID 27350301

  • National trends in inpatient admissions following stereotactic radiosurgery and the in-hospital patient outcomes in the United States from 1998 to 2011. Journal of radiosurgery and SBRT Ho, A. L., Li, A. Y., Sussman, E. S., Pendharkar, A. V., Iyer, A., Thompson, P. A., Tayag, A. T., Chang, S. D. 2016; 4 (3): 165-176

    Abstract

    This study sought to examine trends in stereotactic radiosurgery (SRS) and in-hospital patient outcomes on a national level by utilizing national administrative data from the Nationwide Inpatient Sample (NIS) database.Using the NIS database, all discharges where patients underwent inpatient SRS were included in our study from 1998 - 2011 as designated by the ICD9-CM procedural codes. Trends in the utilization of primary and adjuvant SRS, in-hospital complications and mortality, and resource utilization were identified and analyzed.Our study included over 11,000 hospital discharges following admission for primary SRS or for adjuvant SRS following admission for surgery or other indication. The most popular indication for SRS continues to be treatment of intracranial metastatic disease (36.7%), but expansion to primary CNS lesions and other non-malignant pathology beyond trigeminal neuralgia has occurred over the past decade. Second, inpatient admissions for primary SRS have declined by 65.9% over this same period of time. Finally, as inpatient admissions for SRS become less frequent, the complexity and severity of illness seen in admitted patients has increased over time with an increase in the average comorbidity score from 1.25 in the year 2002 to 2.29 in 2011, and an increase in over-all in-hospital complication rate of 2.8 times over the entire study period.As the practice of SRS continues to evolve, we have seen several trends in associated hospital admissions. Overall, the number of inpatient admissions for primary SRS has declined while adjuvant applications have remained stable. Over the same period, there has been associated increase in complication rate, length of stay, and mortality in inpatients. These associations may be explained by an increase in the comorbidity-load of admitted patients as more high-risk patients are selected for admission at inpatient centers while more stable patients are increasingly being referred to outpatient centers.

    View details for PubMedID 27795870

    View details for PubMedCentralID PMC5081223

  • Deep brain stimulation for obesity: rationale and approach to trial design. Neurosurgical focus Ho, A. L., Sussman, E. S., Pendharkar, A. V., Azagury, D. E., Bohon, C., Halpern, C. H. 2015; 38 (6): E8-?

    Abstract

    Obesity is one of the most serious public health concerns in the US. While bariatric surgery has been shown to be successful for treatment of morbid obesity for those who have undergone unsuccessful behavioral modification, its associated risks and rates of relapse are not insignificant. There exists a neurological basis for the binge-like feeding behavior observed in morbid obesity that is believed to be due to dysregulation of the reward circuitry. The authors present a review of the evidence of the neuroanatomical basis for obesity, the potential neural targets for deep brain stimulation (DBS), as well as a rationale for DBS and future trial design. Identification of an appropriate patient population that would most likely benefit from this type of therapy is essential. There are also significant cost and ethical considerations for such a neuromodulatory intervention designed to alter maladaptive behavior. Finally, the authors present a consolidated set of inclusion criteria and study end points that should serve as the basis for any trial of DBS for obesity.

    View details for DOI 10.3171/2015.3.FOCUS1538

    View details for PubMedID 26030708

  • Deep brain stimulation for vocal tremor: a comprehensive, multidisciplinary methodology. Neurosurgical focus Ho, A. L., Erickson-DiRenzo, E., Pendharkar, A. V., Sung, C., Halpern, C. H. 2015; 38 (6): E6-?

    Abstract

    Tremulous voice is a characteristic feature of a multitude of movement disorders, but when it occurs in individuals diagnosed with essential tremor, it is referred to as essential vocal tremor (EVT). For individuals with EVT, their tremulous voice is associated with significant social embarrassment and in severe cases may result in the discontinuation of employment and hobbies. Management of EVT is extremely difficult, and current behavioral and medical interventions for vocal tremor result in suboptimal outcomes. Deep brain stimulation (DBS) has been proposed as a potential therapeutic avenue for EVT, but few studies can be identified that have systematically examined improvements in EVT following DBS. The authors describe a case of awake bilateral DBS targeting the ventral intermediate nucleus for a patient suffering from severe voice and arm tremor. They also present their comprehensive, multidisciplinary methodology for definitive treatment of EVT via DBS. To the authors' knowledge, this is the first time comprehensive intraoperative voice evaluation has been used to guide microelectrode/stimulator placement, as well as the first time that standard pre- and post-DBS assessments have been conducted, demonstrating the efficacy of this tailored DBS approach.

    View details for DOI 10.3171/2015.3.FOCUS1537

    View details for PubMedID 26030706

  • Deep brain stimulation for vocal tremor: a comprehensive, multidisciplinary methodology NEUROSURGICAL FOCUS Ho, A. L., Erickson-DiRenzo, E., Pendharkar, A. V., Sung, C., Halpern, C. H. 2015; 38 (6)

    Abstract

    Tremulous voice is a characteristic feature of a multitude of movement disorders, but when it occurs in individuals diagnosed with essential tremor, it is referred to as essential vocal tremor (EVT). For individuals with EVT, their tremulous voice is associated with significant social embarrassment and in severe cases may result in the discontinuation of employment and hobbies. Management of EVT is extremely difficult, and current behavioral and medical interventions for vocal tremor result in suboptimal outcomes. Deep brain stimulation (DBS) has been proposed as a potential therapeutic avenue for EVT, but few studies can be identified that have systematically examined improvements in EVT following DBS. The authors describe a case of awake bilateral DBS targeting the ventral intermediate nucleus for a patient suffering from severe voice and arm tremor. They also present their comprehensive, multidisciplinary methodology for definitive treatment of EVT via DBS. To the authors' knowledge, this is the first time comprehensive intraoperative voice evaluation has been used to guide microelectrode/stimulator placement, as well as the first time that standard pre- and post-DBS assessments have been conducted, demonstrating the efficacy of this tailored DBS approach.

    View details for DOI 10.3171/2015.3.FOCUS1537

    View details for Web of Science ID 000355539900006

    View details for PubMedID 26030706

  • Dual-trajectory Approach for Simultaneous Cyst Fenestration and Endoscopic Third Ventriculostomy for Treatment of a Complex Third Ventricular Arachnoid Cyst. Cureus Ho, A. L., Pendharkar, A. V., Sussman, E. S., Ravikumar, V. K., Li, G. H. 2015; 7 (3)

    Abstract

    We present a case of a multiloculated third ventricular arachnoid cyst to describe a novel technique for definitive management of these lesions via direct endoscopic fenestration and CSF diversion utilizing separate trajectories that offers superior visualization and avoids forniceal injury.We present a case of a 33-year-old woman with progressive headache and worsened vision, a known history of a multiloculated third-ventricular arachnoid cyst, and imaging findings consistent with cyst expansion and worsened obstructive hydrocephalus. We then describe the dual-trajectory approach for simultaneous cyst fenestration and endoscopic third ventriculostomy that ultimately resulted in successful treatment of her cyst and hydrocephalus.Dual-trajectory endoscopic approach utilizing double burr holes should be considered when addressing lesions of the third ventricle causing obstructive hydrocephalus.

    View details for DOI 10.7759/cureus.253

    View details for PubMedID 26180677

  • Deep Brain Stimulation for Essential Vocal Tremor: A Technical Report. Cureus Ho, A. L., Choudhri, O., Sung, C. K., DiRenzo, E. E., Halpern, C. H. 2015; 7 (3)

    Abstract

    Essential vocal tremor (EVT) is the presence of a tremulous voice that is commonly associated with essential tremor. Patients with EVT often report a necessary increase in vocal effort that significantly worsens with stress and anxiety and can significantly impact quality of life despite optimal medical and behavioral treatment options. Deep brain stimulation (DBS) has been proposed as an effective therapy for vocal tremor, but very few studies exist in the literature that comprehensively evaluate the efficacy of DBS for specifically addressing EVT. We present a technical report on our multidisciplinary, comprehensive operative methodology for treatment of EVT with frameless, awake deep brain stimulation (DBS).

    View details for DOI 10.7759/cureus.256

    View details for PubMedID 26180680

  • Deep Brain Stimulation for Obesity. Cureus Ho, A. L., Sussman, E. S., Zhang, M., Pendharkar, A. V., Azagury, D. E., Bohon, C., Halpern, C. H. 2015; 7 (3)

    Abstract

    Obesity is now the third leading cause of preventable death in the US, accounting for 216,000 deaths annually and nearly 100 billion dollars in health care costs. Despite advancements in bariatric surgery, substantial weight regain and recurrence of the associated metabolic syndrome still occurs in almost 20-35% of patients over the long-term, necessitating the development of novel therapies. Our continually expanding knowledge of the neuroanatomic and neuropsychiatric underpinnings of obesity has led to increased interest in neuromodulation as a new treatment for obesity refractory to current medical, behavioral, and surgical therapies. Recent clinical trials of deep brain stimulation (DBS) in chronic cluster headache, Alzheimer's disease, and depression and obsessive-compulsive disorderáhave demonstrated the safety and efficacy of targeting the hypothalamus and reward circuitry of the brain with electrical stimulation, and thus provide the basis for a neuromodulatory approach to treatment-refractory obesity. In this study, we review the literature implicating these targets for DBS in the neural circuitry of obesity. We will also briefly review ethical considerations for such an intervention, and discuss genetic secondary-obesity syndromes that may also benefit from DBS. In short, we hope to provide the scientific foundation to justify trials of DBS for the treatment of obesity targeting these specific regions of the brain.

    View details for DOI 10.7759/cureus.259

    View details for PubMedID 26180683

  • Cushing's disease: predicting long-term remission after surgical treatment NEUROSURGICAL FOCUS Pendharkar, A. V., Sussman, E. S., Ho, A. L., Gephart, M. G., Katznelson, L. 2015; 38 (2)

    Abstract

    Cushing's disease (CD) is a state of excess glucocorticoid production resulting from an adrenocorticotropic hormone (ACTH)-secreting pituitary adenoma. The gold-standard treatment for CD is transsphenoidal adenomectomy. In the hands of an experienced neurosurgeon, gross-total resection is possible in the majority of ACTH-secreting pituitary adenomas, with early postoperative remission rates ranging from 67% to 95%. In contrast to the strong data in support of resection, the clinical course of postsurgical persistent or recurrent disease remains unclear. There is significant variability in recurrence rates, with reports as high as 36% with a mean time to recurrence of 15-50 months. It is therefore important to develop biochemical criteria that define postsurgical remission and that may provide prognosis for long-term recurrence. Despite the use of a number of biochemical assessments, there is debate regarding the accuracy of these tests in predicting recurrence. Here, the authors review the various biochemical criteria and assess their utility in predicting CD recurrence after resection.

    View details for DOI 10.3171/2014.10.FOCUS14682

    View details for Web of Science ID 000349263300013

    View details for PubMedID 25639315

  • Association Between Vascular Anatomy and Posterior Communicating Artery Aneurysms. World neurosurgery Can, A., Ho, A. L., Emmer, B. J., Dammers, R., Dirven, C. M., Du, R. 2015; 84 (5): 1251?55

    Abstract

    Hemodynamic stress, conditioned by the geometry and morphology of the vessel trees, plays an important role in the formation of intracranial aneurysms. The aim of this study was to identify image-based location-specific morphologic parameters that are associated with posterior communicating artery (PCoA) aneurysms.Morphologic parameters obtained from computed tomography angiography of 56 patients with PCoA aneurysms and 23 control patients were evaluated with 3D Slicer, an open-source image analysis software, to generate 3-dimensional models of the aneurysms and surrounding vasculature. Segment lengths, diameters, and vessel-to-vessel angles were examined. To control for genetic and clinical risk factors, the unaffected contralateral side of patients with unilateral PCoA aneurysms was used as a control group for internal carotid artery (ICA)-related parameters. A separate control group with visible PCoAs and aneurysms elsewhere was used as a control group for PCoA-related parameters.Internal carotid artery-related parameters were not statistically different between the PCoA aneurysm and control groups. Univariate and multivariate subgroup analysis for patients with visualized PCoAs demonstrated that a larger PCoA diameter was significantly associated with the presence of a PCoA aneurysm (odds ratio = 12.1, 95% confidence interval = 1.3-17.1, P = 0.04) after adjusting for other morphologic parameters.Larger PCoA diameters are associated with the presence of PCoA aneurysms. These parameters may provide objective metrics to assess aneurysm formation and growth risk stratification in high-risk patients.

    View details for PubMedID 26074436

  • Morphological parameters associated with middle cerebral artery aneurysms. Neurosurgery Can, A., Ho, A. L., Dammers, R., Dirven, C. M., Du, R. 2015; 76 (6): 721?26; discussion 726?27

    Abstract

    Morphological factors contribute to the hemodynamics of the middle cerebral artery (MCA).To identify image-based morphological parameters that correlated with the presence of MCA aneurysms.Image-based anatomic parameters obtained from 110 patients with and without MCA bifurcation aneurysms were evaluated with Slicer, an open-source image analysis software, to generate 3-dimensional models of the aneurysms and surrounding vascular architecture. We examined segment lengths, diameters, and vessel-to-vessel angles of the parent and daughter vessels at the MCA bifurcation. In order to reduce confounding by genetic and clinical risk factors, 2 control groups were selected: group A (the unaffected contralateral side of patients with unilateral MCA bifurcation aneurysms) and group B (patients without intracranial aneurysms or other vascular malformations). Univariate and multivariate analyses were performed to determine statistical significance.One hundred ten patients who were evaluated from 2007 to 2014 were analyzed (73 patients with MCA aneurysms and 37 control patients). Multivariate analysis revealed that a smaller parent artery diameter (group A: odds ratio [OR] 0.20, P < .01, group B: OR 0.23, P < .01) and a larger daughter-to-daughter branch angle (group A: OR 1.01, P = .04, group B: OR 1.02, P = .04) were most strongly associated with MCA aneurysm presence after adjusting for other morphological factors.Smaller parent artery diameter and larger daughter-to-daughter branch angles are associated with the presence of MCA bifurcation aneurysms. These easily measurable parameters may provide objective metrics to assess aneurysm formation and growth risk stratification in high-risk patients.

    View details for PubMedID 25734323

  • Effect of vascular anatomy on the formation of basilar tip aneurysms. Neurosurgery Can, A., Mouminah, A., Ho, A. L., Du, R. 2015; 76 (1): 62-66

    Abstract

    The pathogenesis of intracranial aneurysms is multifactorial and includes genetic, environmental, and anatomic influences. Hemodynamic stress plays a particular role in the formation of intracranial aneurysms, which is conditioned by the geometry and morphology of the vessel trees.To identify image-based morphological parameters that correlated with the formation of basilar artery tip aneurysms (BTAs) in a location-specific manner.Morphological parameters obtained from computed tomographic angiographies of 33 patients with BTAs and 33 patients with aneurysms at other locations were evaluated with Slicer, an open-source image analysis software, to generate 3-dimensional models of the aneurysms and surrounding vascular architecture. We examined the diameters and vessel-to-vessel angles of the main vessels at the basilar bifurcation in patients with and without BTAs. To control for genetic and other risk factors, only patients with at least 1 aneurysm were included. Univariate and multivariate analyses were performed to determine statistical significance.Sixty-six patients (33 with BTAs, 33 with other aneurysms) who were evaluated from 2008 to 2013 were analyzed. Multivariate logistic regression revealed that a larger angle between the posterior cerebral arteries (odds ratio, 1.04; P = 1.42 Î 10(-3)) and a smaller basilar artery diameter (odds ratio, 0.23; P = .02) were most strongly associated with BTA formation after adjustment for other morphological and clinical variables.Larger posterior cerebral artery angles and smaller basilar artery diameters are associated with the formation of basilar tip aneurysms. These parameters are easily measurable by the clinician and will aid in screening strategies in high-risk patients.

    View details for DOI 10.1227/NEU.0000000000000564

    View details for PubMedID 25255256

  • Surgical Management of Sacral Chordomas: Illustrative Cases and Current Management Paradigms. Cure»us Pendharkar, A. V., Ho, A. L., Sussman, E. S., Desai, A. 2015; 7 (8)

    Abstract

    Sacral chordomas represent more than 50% of all sacral tumors. These slow-growing, malignant lesions present insidiously and are often large and intimately involved with sacral neurovascular and pelvic structures. En bloc resection is the only well-established predictor of progression-free survival. Optimal surgical management requires a complex multi-disciplinary approach. Here, we describe two cases of sacral chordoma and review current management paradigms.

    View details for DOI 10.7759/cureus.301

    View details for PubMedID 26430575

  • Posterior cerebral artery angle and the rupture of basilar tip aneurysms. PloS one Ho, A. L., Mouminah, A., Du, R. 2014; 9 (10): e110946

    Abstract

    Since the initial publication of the International Study of Unruptured Intracranial Aneurysms (ISUIA), management of unruptured intracranial aneurysms has been mainly based on the size of the aneurysm. The contribution of morphological characteristics to treatment decisions of unruptured aneurysms has not been well studied in a systematic and location specific manner. We present a large sample of basilar artery tip aneurysms (BTA) that were assessed using a diverse array of morphological variables to determine the parameters associated with ruptured aneurysms. Demographic and clinical risk factors of aneurysm rupture were obtained from chart review. CT angiograms (CTA) were evaluated with Slicer, an open source visualization and image analysis software, to generate 3-D models of the aneurysms and surrounding vascular architecture. Morphological parameters examined in each model included aneurysm volume, aspect ratio, size ratio, aneurysm angle, basilar vessel angle, basilar flow angle, and vessel to vessel angles. Univariate and multivariate analyses were performed to determine statistical significance. From 2008-2013, 54 patients with BTA aneurysms were evaluated in a single institution, and CTAs from 33 patients (15 ruptured, 18 unruptured) were available and analyzed. Aneurysms that underwent reoperation, that were associated with arteriovenous malformations, or that lacked preoperative CTA were excluded. Multivariate logistic regression revealed that a larger angle between the posterior cerebral arteries (P1-P1 angle, p = 0.037) was most strongly associated with aneurysm rupture after adjusting for other morphological variables. In this location specific study of BTA aneurysms, the larger the angle formed between posterior cerebral arteries was found to be a new morphological parameter significantly associated with ruptured BTA aneurysms. This is a physically intuitive parameter that can be measured easily and readily applied in the clinical setting.

    View details for PubMedID 25353989

    View details for PubMedCentralID PMC4212997

  • Morphological parameters associated with ruptured posterior communicating aneurysms. PloS one Ho, A., Lin, N., Charoenvimolphan, N., Stanley, M., Frerichs, K. U., Day, A. L., Du, R. 2014; 9 (4): e94837

    Abstract

    The rupture risk of unruptured intracranial aneurysms is known to be dependent on the size of the aneurysm. However, the association of morphological characteristics with ruptured aneurysms has not been established in a systematic and location specific manner for the most common aneurysm locations. We evaluated posterior communicating artery (PCoA) aneurysms for morphological parameters associated with aneurysm rupture in that location. CT angiograms were evaluated to generate 3-D models of the aneurysms and surrounding vasculature. Univariate and multivariate analyses were performed to evaluate morphological parameters including aneurysm volume, aspect ratio, size ratio, distance to ICA bifurcation, aneurysm angle, vessel angles, flow angles, and vessel-to-vessel angles. From 2005-2012, 148 PCoA aneurysms were treated in a single institution. Preoperative CTAs from 63 patients (40 ruptured, 23 unruptured) were available and analyzed. Multivariate logistic regression revealed that smaller volume (p?=?0.011), larger aneurysm neck diameter (0.048), and shorter ICA bifurcation to aneurysm distance (p?=?0.005) were the most strongly associated with aneurysm rupture after adjusting for all other clinical and morphological variables. Multivariate subgroup analysis for patients with visualized PCoA demonstrated that larger neck diameter (p?=?0.018) and shorter ICA bifurcation to aneurysm distance (p?=?0.011) were significantly associated with rupture. Intracerebral hemorrhage was associated with smaller volume, larger maximum height, and smaller aneurysm angle, in addition to lateral projection, male sex, and lack of hypertension. We found that shorter ICA bifurcation to aneurysm distance is significantly associated with PCoA aneurysm rupture. This is a new physically intuitive parameter that can be measured easily and therefore be readily applied in clinical practice to aid in the evaluation of patients with PCoA aneurysms.

    View details for PubMedID 24733151

    View details for PubMedCentralID PMC3986342

  • Analysis of morphological parameters to differentiate rupture status in anterior communicating artery aneurysms. PloS one Lin, N., Ho, A., Charoenvimolphan, N., Frerichs, K. U., Day, A. L., Du, R. 2013; 8 (11): e79635

    Abstract

    In contrast to size, the association of morphological characteristics of intracranial aneurysms with rupture has not been established in a systematic manner. We present an analysis of the morphological variables that are associated with rupture in anterior communicating artery aneurysms to determine site-specific risk variables. One hundred and twenty-four anterior communicating artery aneurysms were treated in a single institution from 2005 to 2010, and CT angiograms (CTAs) or rotational angiography from 79 patients (42 ruptured, 37 unruptured) were analyzed. Vascular imaging was evaluated with 3D Slicerę to generate models of the aneurysms and surrounding vasculature. Morphological parameters were examined using univariate and multivariate analysis and included aneurysm volume, aspect ratio, size ratio, distance to bifurcation, aneurysm angle, vessel angle, flow angle, and parent-daughter angle. Multivariate logistic regression revealed that size ratio, flow angle, and parent-daughter angle were associated with aneurysm rupture after adjustment for age, sex, smoking history, and other clinical risk factors. Simple morphological parameters such as size ratio, flow angle, and parent-daughter angle may thus aid in the evaluation of rupture risk of anterior communicating artery aneurysms.

    View details for PubMedID 24236149

    View details for PubMedCentralID PMC3827376

  • Molecular basis of intervertebral disc degeneration. Advances in experimental medicine and biology Gopal, D., Ho, A. L., Shah, A., Chi, J. H. 2012; 760: 114-133

    Abstract

    Intervertebral disc (IVD) degeneration is a disease of the discs connecting adjoining vertebrae in which structural damage leads to degeneration of the disc and surrounding area. Degeneration of the disc is considered to be a normal process of aging, but can accelerate faster than expected or be precipitated by other factors. The scientific community has come a long way in understanding the biological basis and interpreting the lifestyle implications of IVD degeneration. Of all the diseases of the intervertebral disc, degeneration is the most common and has earned much attention due to its diversity in presentation and potential multiorgan involvement. We will provide a brief overview of the anatomic, cellular, and molecular structure of the IVD, and delve into the cellular and molecular pathophysiology surrounding IVD degeneration. We will then highlight some of the newest developments in stem cell, protein, and genetic therapy for IVD degeneration.

    View details for PubMedID 23281517

  • Exploitation of genetically modified neural stem cells for neurological disease. Advances in experimental medicine and biology Ho, A. L., Keshavarzi, S., Levy, M. L. 2010; 671: 74?92

    Abstract

    The successful treatment and potential treatment of the central nervous system (CNS) pathology remains the most challenging frontier in medical science. The clinical modalities presently available are mostly of limited efficacy and with the aging population, neurodegerative diseases and CNS neoplasms are increasingly prevalent. Neural stem cells (NSCs) have provided optimism for the horizon of therapeutic progress in treating neurological diseases. These mutipotent (able to differentiate into neurons, astrocytes and oligodendrocytes) cells can be obtained directly from the CNS or derived from of embryonic stem cells (ESCs). NSCs can be genetically manipulated in vitro to express desired transgenes for improved expandability, as well as for delivery of toxic payloads. NSCs also demonstrate the ability to engraft within the CNS, migrate to CNS pathology and in certain scenarios to reconstitute the injured or diseased nervous system.

    View details for PubMedID 20455497

  • Stem cells and the origin of gliomas: A historical reappraisal with molecular advancements. Stem cells and cloning : advances and applications Levy, M. L., Ho, A. L., Hughes, S., Menon, J., Jandial, R. 2009; 1: 41-47

    Abstract

    The biology of both normal and tumor development clearly possesses overlapping and parallel features. Oncogenes and tumor suppressors are relevant not only in tumor biology, but also in physiological developmental regulators of growth and differentiation. Conversely, genes identified as regulators of developmental biology are relevant to tumor biology. This is particularly relevant in the context of brain tumors, where recent evidence is mounting that the origin of brain tumors, specifically gliomas, may represent dysfunctional developmental neurobiology. Neural stem cells are increasingly being investigated as the cell type that originally undergoes malignant transformation - the cell of origin - and the evidence for this is discussed.

    View details for PubMedID 24198504

  • Stem cell horizons in intervertebral disc degeneration. Stem cells and cloning : advances and applications Ciacci, J., Ho, A., Ames, C. P., Jandial, R. 2009; 1: 31-39

    Abstract

    Intervertebral disc degeneration remains a pervasive and intractable disease arising from a combination of aging and stress on the back and spine. The growing field of regenerative medicine brings the promise of stem cells in the treatment of disc disease. Scientists and physicians hope to employ stem cells not only to stop, but also reverse degeneration. However, there are many important outstanding issues, including the hostile avascular, apoptotic physiological environment of the intervertebral disc, and the difficulty of obtaining mesenchymal stem cells, and directing them towards chondrocytic differentiation and integration within the nucleus pulposus of the disc. Given the recent advances in minimally invasive spine surgery, and developing body of work on stem cell manipulation and transplantation, stem cells are uniquely poised to bring about large-scale improvements in treatment and outcomes for degenerative disc disease. In this review we will first discuss the cellular and molecular factors influencing degeneration, and then examine the efficacy and difficulties of stem cell transplantation.

    View details for PubMedID 24198503

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