Bio

Bio


Dr. Kathleen Poston is Assistant Professor of Neurology & Neurological Sciences and (by courtesy) Neurosurgery at Stanford University Medical Center. She received her Bachelor's of Science in Bioengineering at the University of Pennsylvania, her Master's Degree in Biomedical Engineering and her MD at Vanderbilt University where she received the Medical Student Prize for Excellence in Neurology. She completed her Neurology residency training at UCSF, where she was Chief Resident. She also completed a fellowship in clinical Movement Disorders under the mentorship of Dr. Stanley Fahn at Columbia University and post-doctoral research training in Functional Neuroimaging with Dr. David Eidelberg at the Feinstein Institute.

Dr. Poston's research focuses on the development of novel neuroimaging biomarkers to improve diagnostic accuracy and monitor the efficacy of investigational treatments for Parkinson's Disease and other movement disorders. Her current studies focus on cognitive and memory problems in people with Parkinson?s disease. She has been awarded grant funding by the NIH and the Michael J. Fox Foundation for Parkinson?s disease research. She is co-investigator for the Stanford Alzheimer?s disease Center (ADRC), which is funded by the National Institute for Aging and will focus on early cognitive problems in both Parkinson?s disease and Alzheimer?s disease. She is also co-investigator for the NINDS funded Morris K. Udall Center of Excellence for Parkinson?s disease Research.

Clinical Focus


  • Neurology
  • Parkinson Disease
  • Parkinsonian Disorders
  • Multiple System Atrophy
  • Palsy, Progressive Supranuclear
  • Essential Tremor
  • Huntington Disease
  • Ataxia
  • Tics
  • Dystonia Disorders
  • Blepharospasm

Academic Appointments


Honors & Awards


  • Lysia Forno Award for Teaching Excellence, Stanford University (2009-2010)

Professional Education


  • Medical Education:Vanderbilt University School of Medicine (2002) TN
  • Internship:Univ of California San Francisco (2003) CA
  • Residency:Univ of California San Francisco (2006) CA
  • Fellowship:Columbia University Medical Center (2008) NY
  • Board Certification: Neurology, American Board of Psychiatry and Neurology (2007)
  • Post-Doc, Feinstein Institute, Functional Neuroimaging (2009)
  • BSE, University of Pennsylvania, Bioengineering
  • MS, Vanderbilt University, Bioengineering (1998)

Research & Scholarship

Current Research and Scholarly Interests


Dr. Poston’s research interests include the development, validation and application of functional and structural neuroimaging as biomarkers for the diagnosis and treatment of movement disorders. Specifically, her research focuses on using FDG PET and fMRI to understand abnormal brain networks that lead to both motor and cognitive dysfunction in patients with parkinsonism. She is also interested in the development of novel imaging analysis techniques for establishing diagnosis and monitoring disease progression in early parkinsonian disorders, such as Parkinson’s disease, multiple system atrophy, progressive supranuclear palsy, and corticobasal degeneration. Such techniques can be used in the development and testing of novel therapeutic interventions, such as gene transfer therapy in Parkinson’s disease.

Clinical Trials


  • Double-Blind, Multicenter, Sham Surgery Controlled Study of CERE-120 in Subjects With Idiopathic Parkinson's Disease Not Recruiting

    The purpose of this double blind study is to determine whether CERE-120 (adeno-associated virus serotype 2 [AAV2]-neurturin [NTN]) is effective and safe in the treatment of patients with idiopathic Parkinson's Disease. CERE-120 is administered via bilateral stereotactic injections targeting the putaminal region of the brain. The design of this study involves approximately 34 patients receiving CERE-120 treatment via stereotactic surgery and approximately 17 patients receiving sham stereotactic surgery (no CERE-120 administered).

    Stanford is currently not accepting patients for this trial.

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  • Safety and Efficacy of CERE-120 in Subjects With Parkinson's Disease Not Recruiting

    The purpose of this study is to evaluate the safety and potential benefits of CERE-120 in the treatment of Parkinson's disease. CERE-120 is an experimental drug that consists of an adeno-associated virus (AAV) that was engineered to carry the human gene for neurturin, a neurotrophic (growth) factor. Similar to other growth factors (such as GDNF), neurturin is capable of restoring function and protecting brain cells from further damage. The virus used in CERE-120 is not known to cause disease in people. CERE-120 is delivered directly to the brain cells most affected in Parkinson's disease - the dopamine producing neurons. CERE-120 is injected during brain surgery. Once in place, CERE-120 continuously produces neurturin.

    Stanford is currently not accepting patients for this trial. For more information, please contact Sandra Dunn, (650) 724 - 8278.

    View full details

Teaching

2015-16 Courses


Stanford Advisees


Graduate and Fellowship Programs


Publications

All Publications


  • Compensatory neural mechanisms in cognitively unimpaired Parkinson disease. Annals of neurology Poston, K. L., YorkWilliams, S., Zhang, K., Cai, W., Everling, D., Tayim, F. M., Llanes, S., Menon, V. 2016; 79 (3): 448-463

    Abstract

    Cognitive impairments in Parkinson's disease (PD) are thought to be caused in part by dopamine dysregulation. However, even when nigrostriatal dopamine neuron loss is severe enough to cause motor symptoms, many patients remain cognitively unimpaired. It is unclear what brain mechanisms allow these patients to remain cognitively unimpaired despite substantial dopamine dysregulation.31 cognitively unimpaired PD participants OFF dopaminergic-medications were scanned using fMRI while they performed a working memory task, along with 23 controls. We first compared the PD_OFF medication group with controls to determine whether PD participants engage compensatory frontostriatal mechanisms during working memory. We then studied the same PD participants ON dopaminergic-medications to determine whether these compensatory brain changes are altered with dopamine.Controls and PD showed working memory load-dependent activation in the bilateral putamen, anterior-dorsal insula, supplementary motor area, and anterior cingulate cortex. Compared to controls, PD_OFF showed compensatory hyper-activation of bilateral putamen and posterior insula, and machine learning algorithms identified robust differences in putamen activation patterns. Compared to PD_OFF, PD_ON showed reduced compensatory activation in the putamen. Loss of compensatory hyper-activation ON dopaminergic-medication correlated with slower performance on the working memory task and slower cognitive speed on the Symbol Digit Modality Test.Our results provide novel evidence that PD patients maintain normal cognitive performance through compensatory hyper-activation of the putamen. Dopaminergic-medication down-regulates this hyper-activation and the degree of down-regulation predicts behavior. Identifying cognitive compensatory mechanisms in PD is important for understanding how some patients maintain intact cognitive performance, despite nigrostriatal dopamine loss. This article is protected by copyright. All rights reserved.

    View details for DOI 10.1002/ana.24585

    View details for PubMedID 26696272

  • Functional brain networks and abnormal connectivity in the movement disorders NEUROIMAGE Poston, K. L., Eidelberg, D. 2012; 62 (4): 2261-2270

    Abstract

    Clinical manifestations of movement disorders, such as Parkinson's disease (PD) and dystonia, arise from neurophysiological changes within the cortico-striato-pallidothalamocortical (CSPTC) and cerebello-thalamo-cortical (CbTC) circuits. Neuroimaging techniques that probe connectivity within these circuits can be used to understand how these disorders develop as well as identify potential targets for medical and surgical therapies. Indeed, network analysis of (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) has identified abnormal metabolic networks associated with the cardinal motor symptoms of PD, such as akinesia and tremor, as well as PD-related cognitive dysfunction. More recent task-based and resting state functional magnetic resonance imaging studies have reproduced several of the altered connectivity patterns identified in these abnormal PD-related networks. A similar network analysis approach in dystonia revealed abnormal disease related metabolic patterns in both manifesting and non-manifesting carriers of dystonia mutations. Other multimodal imaging approaches using magnetic resonance diffusion tensor imaging in patients with primary genetic dystonia suggest abnormal connectivity within the CbTC circuits mediate the clinical manifestations of this inherited neurodevelopmental disorder. Ongoing developments in functional imaging and future studies in early patients are likely to enhance our understanding of these movement disorders and guide novel targets for future therapies.

    View details for DOI 10.1016/j.neuroimage.2011.12.021

    View details for Web of Science ID 000308265200010

    View details for PubMedID 22206967

  • Network correlates of disease severity in multiple system atrophy NEUROLOGY Poston, K. L., Tang, C. C., Eckert, T., Dhawan, V., Frucht, S., Vonsattel, J., Fahn, S., Eidelberg, D. 2012; 78 (16): 1237-1244

    Abstract

    Multiple system atrophy (MSA), the most common of the atypical parkinsonian disorders, is characterized by the presence of an abnormal spatial covariance pattern in resting state metabolic brain images from patients with this disease. Nonetheless, the potential utility of this pattern as a MSA biomarker is contingent upon its specificity for this disorder and its relationship to clinical disability in individual patients.We used [(18)F]fluorodeoxyglucose PET to study 33 patients with MSA, 20 age- and severity-matched patients with idiopathic Parkinson disease (PD), and 15 healthy volunteers. For each subject, we computed the expression of the previously characterized metabolic covariance patterns for MSA and PD (termed MSARP and PDRP, respectively) on a prospective single-case basis. The resulting network values for the individual patients were correlated with clinical motor ratings and disease duration.In the MSA group, disease-related pattern (MSARP) values were elevated relative to the control and PD groups (p < 0.001 for both comparisons). In this group, MSARP values correlated with clinical ratings of motor disability (r = 0.57, p = 0.0008) and with disease duration (r = -0.376, p = 0.03). By contrast, MSARP expression in the PD group did not differ from control values (p = 1.0). In this group, motor ratings correlated with PDRP (r = 0.60, p = 0.006) but not with MSARP values (p = 0.88).MSA is associated with elevated expression of a specific disease-related metabolic pattern. Moreover, differences in the expression of this pattern in patients with MSA correlate with clinical disability. The findings suggest that the MSARP may be a useful biomarker in trials of new therapies for this disorder.

    View details for DOI 10.1212/WNL.0b013e318250d7fd

    View details for Web of Science ID 000302933200010

    View details for PubMedID 22491861

  • AAV2-GAD gene therapy for advanced Parkinson's disease: a double-blind, sham-surgery controlled, randomised trial LANCET NEUROLOGY LeWitt, P. A., Rezai, A. R., Leehey, M. A., Ojemann, S. G., Flaherty, A. W., Eskandar, E. N., Kostyk, S. K., Thomas, K., Sarkar, A., Siddiqui, M. S., Tatter, S. B., Schwalb, J. M., Poston, K. L., Henderson, J. M., Kurlan, R. M., Richard, I. H., Van Meter, L., Sapan, C. V., During, M. J., Kaplitt, M. G., Feigin, A. 2011; 10 (4): 309-319

    Abstract

    Gene transfer of glutamic acid decarboxylase (GAD) and other methods that modulate production of GABA in the subthalamic nucleus improve basal ganglia function in parkinsonism in animal models. We aimed to assess the effect of bilateral delivery of AAV2-GAD in the subthalamic nucleus compared with sham surgery in patients with advanced Parkinson's disease.Patients aged 30-75 years who had progressive levodopa-responsive Parkinson's disease and an overnight off-medication unified Parkinson's disease rating scale (UPDRS) motor score of 25 or more were enrolled into this double-blind, phase 2, randomised controlled trial, which took place at seven centres in the USA between Nov 17, 2008, and May 11, 2010. Infusion failure or catheter tip location beyond a predefined target zone led to exclusion of patients before unmasking for the efficacy analysis. The primary outcome measure was the 6-month change from baseline in double-blind assessment of off-medication UPDRS motor scores. This trial is registered with ClinicalTrials.gov, NCT00643890.Of 66 patients assessed for eligibility, 23 were randomly assigned to sham surgery and 22 to AAV2-GAD infusions; of those, 21 and 16, respectively, were analysed. At the 6-month endpoint, UPDRS score for the AAV2-GAD group decreased by 8·1 points (SD 1·7, 23·1%; p<0·0001) and by 4·7 points in the sham group (1·5, 12·7%; p=0·003). The AAV2-GAD group showed a significantly greater improvement from baseline in UPDRS scores compared with the sham group over the 6-month course of the study (RMANOVA, p=0·04). One serious adverse event occurred within 6 months of surgery; this case of bowel obstruction occurred in the AAV2-GAD group, was not attributed to treatment or the surgical procedure, and fully resolved. Other adverse events were mild or moderate, likely related to surgery and resolved; the most common were headache (seven patients in the AAV2-GAD group vs two in the sham group) and nausea (six vs two).The efficacy and safety of bilateral infusion of AAV2-GAD in the subthalamic nucleus supports its further development for Parkinson's disease and shows the promise for gene therapy for neurological disorders.Neurologix.

    View details for DOI 10.1016/S1474-4422(11)70039-4

    View details for Web of Science ID 000289185000014

    View details for PubMedID 21419704

  • Differential diagnosis of parkinsonism: a metabolic imaging study using pattern analysis LANCET NEUROLOGY Tang, C. C., Poston, K. L., Eckert, T., Feigin, A., Frucht, S., Gudesblatt, M., Dhawan, V., Lesser, M., Vonsattel, J., Fahn, S., Eidelberg, D. 2010; 9 (2): 149-158

    Abstract

    Idiopathic Parkinson's disease can present with symptoms similar to those of multiple system atrophy or progressive supranuclear palsy. We aimed to assess whether metabolic brain imaging combined with spatial covariance analysis could accurately discriminate patients with parkinsonism who had different underlying disorders.Between January, 1998, and December, 2006, patients from the New York area who had parkinsonian features but uncertain clinical diagnosis had fluorine-18-labelled-fluorodeoxyglucose-PET at The Feinstein Institute for Medical Research. We developed an automated image-based classification procedure to differentiate individual patients with idiopathic Parkinson's disease, multiple system atrophy, and progressive supranuclear palsy. For each patient, the likelihood of having each of the three diseases was calculated by use of multiple disease-related patterns with logistic regression and leave-one-out cross-validation. Each patient was classified according to criteria defined by receiver-operating-characteristic analysis. After imaging, patients were assessed by blinded movement disorders specialists for a mean of 2.6 years before a final clinical diagnosis was made. The accuracy of the initial image-based classification was assessed by comparison with the final clinical diagnosis.167 patients were assessed. Image-based classification for idiopathic Parkinson's disease had 84% sensitivity, 97% specificity, 98% positive predictive value (PPV), and 82% negative predictive value (NPV). Imaging classifications were also accurate for multiple system atrophy (85% sensitivity, 96% specificity, 97% PPV, and 83% NPV) and progressive supranuclear palsy (88% sensitivity, 94% specificity, 91% PPV, and 92% NPV).Automated image-based classification has high specificity in distinguishing between parkinsonian disorders and could help in selecting treatment for early-stage patients and identifying participants for clinical trials.National Institutes of Health and General Clinical Research Center at The Feinstein Institute for Medical Research.

    View details for DOI 10.1016/S1474-4422(10)70002-8

    View details for Web of Science ID 000273922000012

    View details for PubMedID 20061183

  • Abnormalities in Metabolic Network Activity Precede the Onset of Motor Symptoms in Parkinson's Disease JOURNAL OF NEUROSCIENCE Tang, C. C., Poston, K. L., Dhawan, V., Eidelberg, D. 2010; 30 (3): 1049-1056

    Abstract

    Imaging studies show that Parkinson's disease (PD) alters the activity of motor- and cognition-related metabolic brain networks. However, it is not known whether the network changes appear at or before symptom onset. In this study, we examined 15 hemiparkinsonian patients who underwent serial metabolic imaging with [(18)F]-fluorodeoxyglucose (FDG) PET at baseline and again 2.1 +/- 0.6 (mean +/- SD) and 3.9 +/- 0.7 years later. We assessed longitudinal changes in network activity in each cerebral hemisphere, focusing specifically on the "presymptomatic" hemisphere--ipsilateral to the initially involved body side. At the network level, the activity of the PD motor-related pattern (PDRP) increased symmetrically in both hemispheres over time (p < 0.001), with significant bilateral elevations at each of the three time points. Hemispheric expression of the PD cognition-related pattern likewise increased symmetrically (p < 0.001), although significant elevations were not evident on either side until 4 years. At the regional level, putamen metabolism contralateral to the initially affected body side was elevated at all three time points, without longitudinal change. In contrast, in the initially presymptomatic hemisphere, putamen metabolic activity increased steadily over time, reaching abnormal levels only at 4 years. Metabolic activity in the contralateral precuneus fell to subnormal levels by the final time point. These findings suggest that abnormal PDRP activity antecedes the appearance of motor signs by approximately 2 years. The timing and laterality of symptom onset relates to focal asymmetric metabolic changes at the putamenal node of this network.

    View details for DOI 10.1523/JNEUROSCI.4188-09.2010

    View details for Web of Science ID 000273779200026

    View details for PubMedID 20089913

  • The effects of dopamine on digit span in Parkinson's disease. Journal of clinical movement disorders Warden, C., Hwang, J., Marshall, A., Fenesy, M., Poston, K. L. 2016; 3: 5-?

    Abstract

    Parkinson's disease patients are at an elevated risk of developing cognitive impairment. Although cognitive impairment is one of the strongest predictors of quality of life, dopaminergic anti-parkinsonian medications are designed to target motor symptoms. However, there is substantial evidence that dopamine also impacts cognition, in particular working memory. It is therefore critical for movement disorders physicians to understand the potential dopaminergic effects on working memory when prescribing these medications. Verbal digit span tasks offer a potentially straightforward and quick assessment of baseline working memory. Moreover, Digit Span Backward was recently validated as a screening tool for mild cognitive impairment in Parkinson's disease when participants were medicated. Research indicates that the interaction between dopamine and working memory follows an Inverted-U shaped curve, but the effect of dopamine on Digit Span has not been well studied. Our study seeks to: (1) determine the validity of verbal Digit Spans for detecting cognitive impairment in Parkinson's disease patients both ON and OFF medications; and (2) ascertain the effects of dopaminergic medications on verbal Digit Span.We recruited 64 Parkinson's disease patients and 22 age-and education-matched controls. Parkinson's patients completed Digit Span Backward and Digit Span Forward ON and OFF medications, while healthy controls completed them once. All participants were categorized by cognitive diagnosis using level-II consensus criteria.Digit Span Backward successfully identified mild cognitive impairment in Parkinson's disease, both ON and OFF medications. Combining patients with and without cognitive impairment, we found that dopamine significantly improved performance on Digit Span Backward, but not Forward. In a secondary analysis, we found this dopaminergic improvement was restricted to the Low baseline working memory group; the High baseline working memory group was unaffected.This study provides evidence for Digit Span Backward as a screening tool for working memory impairment in Parkinson's disease and for its utility in measuring baseline working memory. Moreover, it reveals a partial beneficial effect of dopamine on Digit Span in Parkinson's disease patients.

    View details for DOI 10.1186/s40734-016-0033-z

    View details for PubMedID 26955482

  • Task-rest modulation of basal ganglia connectivity in mild to moderate Parkinson's disease. Brain imaging and behavior Müller-Oehring, E. M., Sullivan, E. V., Pfefferbaum, A., Huang, N. C., Poston, K. L., Bronte-Stewart, H. M., Schulte, T. 2015; 9 (3): 619-638

    Abstract

    Parkinson's disease (PD) is associated with abnormal synchronization in basal ganglia-thalamo-cortical loops. We tested whether early PD patients without demonstrable cognitive impairment exhibit abnormal modulation of functional connectivity at rest, while engaged in a task, or both. PD and healthy controls underwent two functional MRI scans: a resting-state scan and a Stroop Match-to-Sample task scan. Rest-task modulation of basal ganglia (BG) connectivity was tested using seed-to-voxel connectivity analysis with task and rest time series as conditions. Despite substantial overlap of BG-cortical connectivity patterns in both groups, connectivity differences between groups had clinical and behavioral correlates. During rest, stronger putamen-medial parietal and pallidum-occipital connectivity in PD than controls was associated with worse task performance and more severe PD symptoms suggesting that abnormalities in resting-state connectivity denote neural network dedifferentiation. During the executive task, PD patients showed weaker BG-cortical connectivity than controls, i.e., between caudate-supramarginal gyrus and pallidum-inferior prefrontal regions, that was related to more severe PD symptoms and worse task performance. Yet, task processing also evoked stronger striatal-cortical connectivity, specifically between caudate-prefrontal, caudate-precuneus, and putamen-motor/premotor regions in PD relative to controls, which was related to less severe PD symptoms and better performance on the Stroop task. Thus, stronger task-evoked striatal connectivity in PD demonstrated compensatory neural network enhancement to meet task demands and improve performance levels. fMRI-based network analysis revealed that despite resting-state BG network compromise in PD, BG connectivity to prefrontal, premotor, and precuneus regions can be adequately invoked during executive control demands enabling near normal task performance.

    View details for DOI 10.1007/s11682-014-9317-9

    View details for PubMedID 25280970

  • Gene delivery of neurturin to putamen and substantia nigra in Parkinson disease: A double-blind, randomized, controlled trial ANNALS OF NEUROLOGY Olanow, C. W., Bartus, R. T., Baumann, T. L., Factor, S., Boulis, N., Stacy, M., Turner, D. A., Marks, W., Larson, P., Starr, P. A., Jankovic, J., Simpson, R., Watts, R., Guthrie, B., Poston, K., Henderson, J. M., Stern, M., Baltuch, G., Goetz, C. G., Herzog, C., Kordower, J. H., Alterman, R., Lozano, A. M., Lang, A. E. 2015; 78 (2): 248-257

    Abstract

    A 12-month double-blind sham-surgery-controlled trial assessing adeno-associated virus type 2 (AAV2)-neurturin injected into the putamen bilaterally failed to meet its primary endpoint, but showed positive results for the primary endpoint in the subgroup of subjects followed for 18 months and for several secondary endpoints. Analysis of postmortem tissue suggested impaired axonal transport of neurturin from putamen to substantia nigra. In the present study, we tested the safety and efficacy of AAV2-neurturin delivered to putamen and substantia nigra.We performed a 15- to 24-month, multicenter, double-blind trial in patients with advanced Parkinson disease (PD) who were randomly assigned to receive bilateral AAV2-neurturin injected bilaterally into the substantia nigra (2.0 × 10(11) vector genomes) and putamen (1.0 × 10(12) vector genomes) or sham surgery. The primary endpoint was change from baseline to final visit performed at the time the last enrolled subject completed the 15-month evaluation in the motor subscore of the Unified Parkinson's Disease Rating Scale in the practically defined off state.Fifty-one patients were enrolled in the trial. There was no significant difference between groups in the primary endpoint (change from baseline: AAV2-neurturin, -7.0?±?9.92; sham, -5.2?±?10.01; p?=?0.515) or in most secondary endpoints. Two subjects had cerebral hemorrhages with transient symptoms. No clinically meaningful adverse events were attributed to AAV2-neurturin.AAV2-neurturin delivery to the putamen and substantia nigra bilaterally in PD was not superior to sham surgery. The procedure was well tolerated, and there were no clinically significant adverse events related to AAV2-neurturin. Ann Neurol 2015;78:248-257.

    View details for DOI 10.1002/ana.24436

    View details for Web of Science ID 000358501600009

    View details for PubMedID 26061140

  • A disease-specific metabolic brain network associated with corticobasal degeneration BRAIN Niethammer, M., Tang, C. C., Feigin, A., Allen, P. J., Heinen, L., Hellwig, S., Amtage, F., Hanspal, E., Vonsattel, J. P., Poston, K. L., Meyer, P. T., Leenders, K. L., Eidelberg, D. 2014; 137: 3036-3046

    Abstract

    Corticobasal degeneration is an uncommon parkinsonian variant condition that is diagnosed mainly on clinical examination. To facilitate the differential diagnosis of this disorder, we used metabolic brain imaging to characterize a specific network that can be used to discriminate corticobasal degeneration from other atypical parkinsonian syndromes. Ten non-demented patients (eight females/two males; age 73.9 ± 5.7 years) underwent metabolic brain imaging with (18)F-fluorodeoxyglucose positron emission tomography for atypical parkinsonism. These individuals were diagnosed clinically with probable corticobasal degeneration. This diagnosis was confirmed in the three subjects who additionally underwent post-mortem examination. Ten age-matched healthy subjects (five females/five males; age 71.7 ± 6.7 years) served as controls for the imaging studies. Spatial covariance analysis was applied to scan data from the combined group to identify a significant corticobasal degeneration-related metabolic pattern that discriminated (P < 0.001) the patients from the healthy control group. This pattern was characterized by bilateral, asymmetric metabolic reductions involving frontal and parietal cortex, thalamus, and caudate nucleus. These pattern-related changes were greater in magnitude in the cerebral hemisphere opposite the more clinically affected body side. The presence of this corticobasal degeneration-related metabolic topography was confirmed in two independent testing sets of patient and control scans, with elevated pattern expression (P < 0.001) in both disease groups relative to corresponding normal values. We next determined whether prospectively computed expression values for this pattern accurately discriminated corticobasal degeneration from multiple system atrophy and progressive supranuclear palsy (the two most common atypical parkinsonian syndromes) on a single case basis. Based upon this measure, corticobasal degeneration was successfully distinguished from multiple system atrophy (P < 0.001) but not progressive supranuclear palsy, presumably because of the overlap (? 24%) that existed between the corticobasal degeneration- and the progressive supranuclear palsy-related metabolic topographies. Nonetheless, excellent discrimination between these disease entities was achieved by computing hemispheric asymmetry scores for the corticobasal degeneration-related pattern on a prospective single scan basis. Indeed, a logistic algorithm based on the asymmetry scores combined with separately computed expression values for a previously validated progressive supranuclear palsy-related pattern provided excellent specificity (corticobasal degeneration: 92.7%; progressive supranuclear palsy: 94.1%) in classifying 58 testing subjects. In conclusion, corticobasal degeneration is associated with a reproducible disease-related metabolic covariance pattern that may help to distinguish this disorder from other atypical parkinsonian syndromes.

    View details for DOI 10.1093/brain/awu256

    View details for Web of Science ID 000346760900025

    View details for PubMedID 25208922

  • What light have resting state fMRI studies shed on cognition and mood in Parkinson's disease? Journal of clinical movement disorders YorkWilliams, S., Poston, K. L. 2014; 1: 4-?

    Abstract

    Much remains unknown about non-motor symptoms of Parkinson's disease (PD), which have variable occurrence, progression, and severity among patients. The existing suite of neuroimaging tools has yielded insight that cannot be garnered by traditional methods such as behavioral and post-mortem assessment. They provide information on brain activity and structure that is invaluable to understanding abnormalities associated with neurodegeneration in PD. Among these tools, functional magnetic resonance imaging (fMRI) is often favored for its safety and spatial resolution. Resting state fMRI research capitalizes on the wealth of information that the brain offers when a person is not performing a motor or cognitive task. It is also a good means to study impaired and heterogeneous populations, such as people with PD. The present article reviews research that applies resting state fMRI to the ongoing hunt for biomarkers of PD non-motor symptoms. Thus far, research in this subfield has focused on two of the most common and significant non-motor symptoms: cognitive impairment and depression. These studies support resting state fMRI as a valid and practical tool for the study of these symptoms, but discrepancies among findings highlight the importance of further research with standardized procedures.

    View details for DOI 10.1186/2054-7072-1-4

    View details for PubMedID 26788330

  • Fragile X-Associated Tremor/Ataxia Syndrome (FXTAS) with Myoclonus MOVEMENT DISORDERS Poston, K. L., McGovern, R. A., Goldman, J. S., Caccappolo, E., Mazzoni, P. 2010; 25 (4): 514-516

    View details for DOI 10.1002/mds.22929

    View details for Web of Science ID 000276337400027

    View details for PubMedID 20063436

  • FDG PET in the Evaluation of Parkinson's Disease. PET clinics Poston, K. L., Eidelberg, D. 2010; 5 (1): 55-64

    Abstract

    Network analysis of (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) is an innovative approach for the study of in movement disorders, such as Parkinson's disease (PD). Spatial covariance analysis of imaging data acquired from PD patients has revealed characteristic regional patterns associated with the motor and cognitive features of disease. Quantification of pattern expression in individual patients can be used for diagnosis, assessment of disease severity, and evaluation of novel medical and surgical therapies. Identification of disease-specific patterns in other parkinsonian syndromes, such as multiple system atrophy and progressive supranuclear palsy, has improved diagnostic accuracy in patients with difficult to diagnose parkinsonism. Further developments of these techniques are likely to enhance the role of functional imaging in investigating underlying abnormalities and potential new therapies in these neurodegenerative diseases.

    View details for PubMedID 20689674

  • Action tremor of the legs in essential tremor: Prevalence, clinical correlates, and comparison with age-matched controls PARKINSONISM & RELATED DISORDERS Poston, K. L., Rios, E., Louis, E. D. 2009; 15 (8): 602-605

    Abstract

    The hallmark feature of essential tremor (ET) is action tremor of the arms. Leg tremor may also occur yet it has not been the central focus of previous studies. Its prevalence has only rarely been reported, its clinical correlates have yet to be explored. Our aims were to report the prevalence and analyze the clinical correlates of leg action tremor in patients with ET and, given the propensity for normal elderly individuals to manifest mild limb tremors, compare the prevalence with that in age-matched controls. Kinetic leg tremor rated > or =1 occurred in 28/63 (44.4%) ET cases and in only 9/63 (14.3%) controls (p<0.001); moderate leg tremor occurred in 14.3% of cases. Leg tremor severity modestly correlated with disease duration (r=0.31, p=0.02). However, the severity and laterality of leg tremor did not correlate with those of arm tremor. The pathophysiological implications of this finding deserve further exploration.

    View details for DOI 10.1016/j.parkreldis.2008.11.006

    View details for Web of Science ID 000270122500011

    View details for PubMedID 19103506

  • Network biomarkers for the diagnosis and treatment of movement disorders NEUROBIOLOGY OF DISEASE Poston, K. L., Eidelberg, D. 2009; 35 (2): 141-147

    Abstract

    Functional brain networks provide a set of useful biomarkers for the assessment of movement disorders such as Parkinson's disease (PD). Spatial covariance analysis of imaging data from PD patients has led to the identification of abnormal metabolic patterns associated with the motor and cognitive features of this disease. Measurements of pattern expression have been used for diagnosis, assessment of rates of disease progression, and objective evaluation of the efficacy of therapeutic interventions. For instance, the recent identification of new disease-specific patterns for Multiple System Atrophy (MSA) and Progressive Supranuclear Palsy (PSP) has improved diagnostic accuracy in patients with parkinsonian syndromes. Further, disease-related networks have been found to be modulated by novel treatment strategies such as gene therapy. Finally, the application of network analysis to the study of inherited movement disorders such as Huntington's disease can aid in the assessment of disease-modifying therapies in pre-symptomatic gene mutation carriers.

    View details for DOI 10.1016/j.nbd.2008.09.026

    View details for Web of Science ID 000268078300004

    View details for PubMedID 19013242

  • Movement disorder emergencies JOURNAL OF NEUROLOGY Poston, K. L., Frucht, S. J. 2008; 255: 2-13

    Abstract

    Movement disorder emergencies include any movement disorder which evolves over hours to days, in which failure to appropriately diagnose and manage can result in patient morbidity or mortality. It is crucial that doctors recognize these emergencies with accuracy and speed by obtaining the proper history and by being familiar with the phenomenology of frequently encountered movements. These disorders will be discussed based on the most common associated involuntary movement, either parkinsonism, dystonia, chorea, tics or myoclonus, and, when available, review the workup and treatment options based on the current literature.

    View details for DOI 10.1007/s00415-008-4002-9

    View details for Web of Science ID 000259034000002

    View details for PubMedID 18821080

  • Zydis selegilline in the management of Parkinson's disease EXPERT OPINION ON PHARMACOTHERAPY Poston, K. L., Waters, C. 2007; 8 (15): 2615-2624

    Abstract

    Selegiline, a selective monoamine oxidase-B inhibitor, has been used for decades in the treatment of Parkinson's disease. The recent development of an orally disintegrating dosage form using Zydis technology allows pregastric drug absorption and, thus, greatly improving the pharmacodynamic and pharmacokinetic drug profiles. This new formulation provides higher drug bioavailability and a substantially reduced concentration of active metabolites. As an adjunct to levodopa, Zydis selegiline is shown to be a safe and effective therapy in patients with motor fluctuations and wearing off. This review outlines the advantages of a Zydis formulation in Parkinson's disease and the evidence supporting the use of Zydis selegiline for motor fluctuations.

    View details for DOI 10.1517/14656566.8.15.2615

    View details for Web of Science ID 000250426000014

    View details for PubMedID 17931095

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