Bio

Bio


Stroke is the leading cause of disability in the United States, drastically disrupting the lives of stroke survivors and their caretakers. Unfortunately, because of tight therapeutic time requirements, the majority of stroke patients are not eligible for the current medicines or interventions. The George Lab's research focuses on improving stroke diagnostics as well as engineering new methods to enhance stroke recovery. Our lab's primary focus is applying novel bioengineering techniques to understand the mechanisms of neural recovery (primarily in stroke) and discovering methods to improve patient recovery. We use rodent models of stroke combined with biomaterial techniques, stem cell transplants, and microfabrication to achieve these aims and evaluate our methods with behavior testing and various imaging techniques. Our ultimate goal is to translate these findings into clinical trials to help stroke patients.

Clinical Focus


  • Neurology

Academic Appointments


Professional Education


  • Board Certification: Vascular Neurology, American Board of Psychiatry and Neurology (2014)
  • Fellowship:Stanford University School of Medicine (2013) CA
  • Residency:Stanford University School of Medicine (2012) CA
  • Board Certification: Neurology, American Board of Psychiatry and Neurology (2012)
  • Internship:Stanford University Medical Center (2009) CA
  • Medical Education:Harvard Medical School (2008) MA
  • Bachelor of Engineering, Tulane University of Louisiana (1999)

Research & Scholarship

Clinical Trials


  • Imaging Collaterals in Acute Stroke (iCAS) Recruiting

    Stroke is caused by a sudden blockage of a blood vessel that delivers blood to the brain. Unblocking the blood vessel with a blood clot removal device restores blood flow and if done quickly may prevent the disability that can be caused by a stroke. However, not all stroke patients benefit from having their blood vessel unblocked. The aim of this study is to determine if special brain imaging, called MRI, can be used to identify which stroke patients are most likely to benefit from attempts to unblock their blood vessel with a special blood clot removal device. In particular, we will assess in this trial whether a noncontrast MR imaging sequence, arterial spin labeling (ASL), can demonstrate the presence of collateral blood flow (compared with a gold standard of the angiogram) and whether it is useful to predict who will benefit from treatment.

    View full details

  • Transient Ischemic Attack (TIA) Triage and Evaluation of Stroke Risk Recruiting

    Transient ischemic attack (TIA) is a transient neurological deficit (speech disturbance, weakness?), caused by temporary occlusion of a brain vessel by a blood clot that leaves no lasting effect. TIA diagnosis can be challenging and an expert stroke evaluation combined with magnetic resonance imaging (MRI) could improve the diagnosis accuracy. The risk of a debilitating stroke can be as high as 5% during the first 72 hrs after TIA. TIA characteristics (duration, type of symptoms, age of the patient), the presence of a significant narrowing of the neck vessels responsible for the patient's symptoms (symptomatic stenosis), and an abnormal MRI are associated with an increased risk of stroke. An emergent evaluation and treatment of TIA patients by a stroke specialist could reduce the risk of stroke to 2%. Stanford has implemented an expedited triage pathway for TIA patients combining a clinical evaluation by a stroke neurologist, an acute MRI of the brain and the vessels and a sampling of biomarkers (Lp-PLA2). The investigators are investigating the yield of this unique approach to improve TIA diagnosis, prognosis and secondary stroke prevention. The objective of this prospective cohort study is to determine which factors will help the physician to confirm the diagnosis of TIA and to define the risk of stroke after a TIA.

    View full details

Teaching

Stanford Advisees


Publications

All Publications


  • Inter-rater agreement analysis of the Precise Diagnostic Score for suspected transient ischemic attack INTERNATIONAL JOURNAL OF STROKE Cereda, C. W., George, P. M., Inoue, M., Vora, N., Olivot, J., Schwartz, N., Lansberg, M. G., Kemp, S., Mlynash, M., Albers, G. W. 2016; 11 (1): 85-92

    Abstract

    No definitive criteria are available to confirm the diagnosis of transient ischemic attack. Inter-rater agreement between physicians regarding the diagnosis of transient ischemic attack is low, even among vascular neurologists. We developed the Precise Diagnostic Score, a diagnostic score that consists of discrete and well-defined clinical and imaging parameters, and investigated inter-rater agreement in patients with suspected transient ischemic attack.Fellowship-trained vascular neurologists, blinded to final diagnosis, independently reviewed retrospectively identical history, physical examination, routine diagnostic studies, and brain magnetic resonance imaging (diffusion and perfusion images) from consecutive patients with suspected transient ischemic attack. Each patient was rated using the 8-point Precise Diagnostic Score score, composed of a clinical score (0-4 points) and an imaging score (0-4 points). The composite Precise Diagnostic Score determines a Precise Diagnostic Score Likelihood of Brain Ischemia Scale: 0-1?=?unlikely, 2?=?possible, 3?=?probable, 4-8?=?very likely.Three raters reviewed data from 114 patients. Using Precise Diagnostic Score, all three raters scored a similar percentage of the clinical events as being "probable" or "very likely" caused by brain ischemia: 57, 55, and 58%. Agreement was high for both total Precise Diagnostic Score (intraclass correlation coefficient of 0.94) and for the Likelihood of Brain Ischemia Scale (agreement coefficient of 0.84).Compared with prior studies, inter-rater agreement for the diagnosis of transient brain ischemia appears substantially improved with the Precise Diagnostic Score scoring system. This score is the first to include specific criteria to assess the clinical relevance of diffusion-weighted imaging and perfusion lesions and supports the added value of magnetic resonance imaging for assessing patients with suspected transient ischemic attack.

    View details for DOI 10.1177/1747493015607507

    View details for Web of Science ID 000368703300021

    View details for PubMedID 26763024

  • Novel TIA biomarkers identified by mass spectrometry-based proteomics INTERNATIONAL JOURNAL OF STROKE George, P. M., Mlynash, M., Adams, C. M., Kuo, C. J., Albers, G. W., Olivot, J. 2015; 10 (8): 1204-1211

    View details for DOI 10.1111/ijs.12603

    View details for Web of Science ID 000367673700011

  • Novel Stroke Therapeutics: Unraveling Stroke Pathophysiology and Its Impact on Clinical Treatments NEURON George, P. M., Steinberg, G. K. 2015; 87 (2): 297-309

    Abstract

    Stroke remains a leading cause of death and disability in the world. Over the past few decades our understanding of the pathophysiology of stroke has increased, but greater insight is required to advance the field of stroke recovery. Clinical treatments have improved in the acute time window, but long-term therapeutics remain limited. Complex neural circuits damaged by ischemia make restoration of function after stroke difficult. New therapeutic approaches, including cell transplantation or stimulation, focus on reestablishing these circuits through multiple mechanisms to improve circuit plasticity and remodeling. Other research targets intact networks to compensate for damaged regions. This review highlights several important mechanisms of stroke injury and describes emerging therapies aimed at improving clinical outcomes.

    View details for DOI 10.1016/j.neuron.2015.05.041

    View details for Web of Science ID 000361144200007

  • Aortic arch atheroma: a plaque of a different color or more of the same? Stroke; a journal of cerebral circulation George, P. M., Albers, G. W. 2014; 45 (5): 1239-1240

    View details for DOI 10.1161/STROKEAHA.114.004827

    View details for PubMedID 24699053

  • Three-dimensional conductive constructs for nerve regeneration. Journal of biomedical materials research. Part A George, P. M., Saigal, R., Lawlor, M. W., Moore, M. J., LaVan, D. A., Marini, R. P., Selig, M., Makhni, M., Burdick, J. A., Langer, R., Kohane, D. S. 2009; 91 (2): 519-527

    Abstract

    The unique electrochemical properties of conductive polymers can be utilized to form stand-alone polymeric tubes and arrays of tubes that are suitable for guides to promote peripheral nerve regeneration. Noncomposite, polypyrrole (PPy) tubes ranging in inner diameter from 25 microm to 1.6 mm as well as multichannel tubes were fabricated by electrodeposition. While oxidation of the pyrrole monomer causes growth of the film, brief subsequent reduction allowed mechanical dissociation from the electrode mold, creating a stand-alone, conductive PPy tube. Conductive polymer nerve guides made in this manner were placed in transected rat sciatic nerves and shown to support nerve regeneration over an 8-week time period.

    View details for DOI 10.1002/jbm.a.32226

    View details for PubMedID 18985787

  • Electrically Controlled Drug Delivery from Biotin-Doped Conductive Polymer Advanced Materials George, P. M., LaVan, D., Burdick, J., Chen, C. Y., Liang, E., Langer, R. 2006; 18 (5)
  • Fabrication and biocompatibility of polypyrrole implants suitable for neural prosthetics BIOMATERIALS George, P. M., Lyckman, A. W., LaVan, D. A., Hegde, A., Leung, Y., Avasare, R., Testa, C., Alexander, P. M., Langer, R., Sur, M. 2005; 26 (17): 3511-3519

    Abstract

    Finding a conductive substrate that promotes neural interactions is an essential step for advancing neural interfaces. The biocompatibility and conductive properties of polypyrrole (PPy) make it an attractive substrate for neural scaffolds, electrodes, and devices. Stand-alone polymer implants also provide the additional advantages of flexibility and biodegradability. To examine PPy biocompatibility, dissociated primary cerebral cortical cells were cultured on PPy samples that had been doped with polystyrene-sulfonate (PSS) or sodium dodecylbenzenesulfonate (NaDBS). Various conditions were used for electrodeposition to produce different surface properties. Neural networks grew on all of the PPy surfaces. PPy implants, consisting of the same dopants and conditions, were surgically implanted in the cerebral cortex of the rat. The results were compared to stab wounds and Teflon implants of the same size. Quantification of the intensity and extent of gliosis at 3- and 6-week time points demonstrated that all versions of PPy were at least as biocompatible as Teflon and in fact performed better in most cases. In all of the PPy implant cases, neurons and glial cells enveloped the implant. In several cases, neural tissue was present in the lumen of the implants, allowing contact of the brain parenchyma through the implants.

    View details for DOI 10.1016/j.biomaterials.2004.09.037

    View details for Web of Science ID 000226968200016

    View details for PubMedID 15621241

  • Simple, three-dimensional microfabrication of electrodeposited structures ANGEWANDTE CHEMIE-INTERNATIONAL EDITION LaVan, D. A., George, P. M., Langer, R. 2003; 42 (11): 1262-1265

    View details for Web of Science ID 000181872300008

    View details for PubMedID 12645058

Footer Links:

Stanford Medicine Resources: