Author
Helen Bronte-Stewart
Other affiliations: Hospital of the University of Pennsylvania, University of California, San Francisco
Bio: Helen Bronte-Stewart is an academic researcher from Stanford University. The author has contributed to research in topics: Deep brain stimulation & Subthalamic nucleus. The author has an hindex of 40, co-authored 102 publications receiving 8105 citations. Previous affiliations of Helen Bronte-Stewart include Hospital of the University of Pennsylvania & University of California, San Francisco.
Papers published on a yearly basis
Papers
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Rush University Medical Center1, Medical University of South Carolina2, Columbia University3, Innsbruck Medical University4, University of Lisbon5, University of Pennsylvania6, University of Marburg7, University of Paris8, University of Rochester9, Baylor College of Medicine10, Autonomous University of Barcelona11, University of Toronto12, University College London13, Wayne State University14, University of Illinois at Chicago15, Icahn School of Medicine at Mount Sinai16, University of Toulouse17, Leiden University18, University of Massachusetts Medical School19
TL;DR: The combined clinimetric results of this study support the validity of the MDS‐UPDRS for rating PD.
Abstract: We present a clinimetric assessment of the Movement Disorder Society (MDS)-sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS). The MDS-UDPRS Task Force revised and expanded the UPDRS using recommendations from a published critique. The MDS-UPDRS has four parts, namely, I: Non-motor Experiences of Daily Living; II: Motor Experiences of Daily Living; III: Motor Examination; IV: Motor Complications. Twenty questions are completed by the patient/caregiver. Item-specific instructions and an appendix of complementary additional scales are provided. Movement disorder specialists and study coordinators administered the UPDRS (55 items) and MDS-UPDRS (65 items) to 877 English speaking (78% non-Latino Caucasian) patients with Parkinson's disease from 39 sites. We compared the two scales using correlative techniques and factor analysis. The MDS-UPDRS showed high internal consistency (Cronbach's alpha = 0.79-0.93 across parts) and correlated with the original UPDRS (rho = 0.96). MDS-UPDRS across-part correlations ranged from 0.22 to 0.66. Reliable factor structures for each part were obtained (comparative fit index > 0.90 for each part), which support the use of sum scores for each part in preference to a total score of all parts. The combined clinimetric results of this study support the validity of the MDS-UPDRS for rating PD.
4,589 citations
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TL;DR: There is insufficient evidence to support or refute the efficacy of DBS of the GPi or VIM nucleus of the thalamus in reducing off time, dyskinesia, or medication usage, or to improve motor function.
Abstract: Objective: To make evidence-based treatment recommendations for the medical and surgical treatment of patients with Parkinson disease (PD) with levodopa-induced motor fluctuations and dyskinesia. To that end, five questions were addressed. 1. Which medications reduce off time? 2. What is the relative efficacy of medications in reducing off time? 3. Which medications reduce dyskinesia? 4. Does deep brain stimulation (DBS) of the subthalamic nucleus (STN), globus pallidus interna (GPi), or ventral intermediate (VIM) nucleus of the thalamus reduce off time, dyskinesia, and antiparkinsonian medication usage and improve motor function? 5. Which factors predict improvement after DBS? Methods: A 10-member committee including movement disorder specialists and general neurologists evaluated the available evidence based on a structured literature review including MEDLINE, EMBASE, and Ovid databases from 1965 through June 2004. Results, Conclusions, and Recommendations: 1. Entacapone and rasagiline should be offered to reduce off time (Level A). Pergolide, pramipexole, ropinirole, and tolcapone should be considered to reduce off time (Level B). Apomorphine, cabergoline, and selegiline may be considered to reduce off time (Level C). 2. The available evidence does not establish superiority of one medicine over another in reducing off time (Level B). Sustained release carbidopa/levodopa and bromocriptine may be disregarded to reduce off time (Level C). 3. Amantadine may be considered to reduce dyskinesia (Level C). 4. Deep brain stimulation of the STN may be considered to improve motor function and reduce off time, dyskinesia, and medication usage (Level C). There is insufficient evidence to support or refute the efficacy of DBS of the GPi or VIM nucleus of the thalamus in reducing off time, dyskinesia, or medication usage, or to improve motor function. 5. Preoperative response to levodopa predicts better outcome after DBS of the STN (Level B).
484 citations
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TL;DR: The finding that longer periods of DBS attenuated beta power for a longer time suggests that there may be long-acting functional changes to networks in the STN in PD after chronic DBS.
278 citations
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TL;DR: This study shows for the first time that STN DBS attenuates the power in the prominent beta band recorded in the STN of patients with PD, raising the interesting possibility of using this biomarker for closed loop DBS or neuromodulation.
266 citations
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TL;DR: The results indicate that the rate of CSF production in patients with PD is normal, and that the number of patients with dementia of the Alzheimer’s type is markedly reduced.
Abstract: Objective: To evaluate the production rate of CSF in patients with differing disease states. Methods: The authors measured the production rate of CSF in three groups of patients: five patients with PD below age 60 (aged 51 ± 4 years, mean ± SD), nine with PD over age 60 (aged 69 ± 6 years, mean ± SD), and seven with dementia of the Alzheimer’s type (AD) (aged 72 ± 9 years, mean ± SD). This method, based on the Masserman technique, employs ventricular rather than a lumbar access to the CSF space. Furthermore, the volume of CSF removed during the procedure is only 3 mL rather than 10 mL. Results: These measurements indicate that the mean rate of CSF production in patients with PD under age 60 was 0.47 ± 0.13 mL/minute, in patients with PD aged 60 or older the mean rate was 0.40 ± 0.12 mL/minute, and in patients with AD the mean rate was 0.20 ± 0.06 mL/minute. Conclusion: These results indicate that the rate of CSF production in patients with PD is normal, and that the rate of CSF production in patients with AD is markedly reduced.
225 citations
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TL;DR: A thorough understanding of the broad spectrum of clinical manifestations of PD is essential to the proper diagnosis of the disease and genetic mutations or variants, neuroimaging abnormalities and other tests are potential biomarkers that may improve diagnosis and allow the identification of persons at risk.
Abstract: Objective: Parkinson’s disease (PD) is a progressive neurological disorder characterised by a large number of motor and non-motor features that can impact on function to a variable degree. This review describes the clinical characteristics of PD with emphasis on those features that differentiate the disease from other parkinsonian disorders. Methods: A MedLine search was performed to identify studies that assess the clinical characteristics of PD. Search terms included “Parkinson’s disease”, “diagnosis” and “signs and symptoms”. Results: Because there is no definitive test for the diagnosis of PD, the disease must be diagnosed based on clinical criteria. Rest tremor, bradykinesia, rigidity and loss of postural reflexes are generally considered the cardinal signs of PD. The presence and specific presentation of these features are used to differentiate PD from related parkinsonian disorders. Other clinical features include secondary motor symptoms (eg, hypomimia, dysarthria, dysphagia, sialorrhoea, micrographia, shuffling gait, festination, freezing, dystonia, glabellar reflexes), non-motor symptoms (eg, autonomic dysfunction, cognitive/neurobehavioral abnormalities, sleep disorders and sensory abnormalities such as anosmia, paresthesias and pain). Absence of rest tremor, early occurrence of gait difficulty, postural instability, dementia, hallucinations, and the presence of dysautonomia, ophthalmoparesis, ataxia and other atypical features, coupled with poor or no response to levodopa, suggest diagnoses other than PD. Conclusions: A thorough understanding of the broad spectrum of clinical manifestations of PD is essential to the proper diagnosis of the disease. Genetic mutations or variants, neuroimaging abnormalities and other tests are potential biomarkers that may improve diagnosis and allow the identification of persons at risk.
4,349 citations
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McGill University1, New York University2, Mayo Clinic3, French Institute of Health and Medical Research4, Federal Institute for Drugs and Medical Devices5, University of New South Wales6, Rush University Medical Center7, University of California, Los Angeles8, Vancouver Hospital and Health Sciences Centre9, University of Pittsburgh10, Ludwig Maximilian University of Munich11, VU University Medical Center12, Women's College, Kolkata13, Case Western Reserve University14, Karolinska Institutet15
TL;DR: Mild cognitive impairment can be regarded as a risk state for dementia, and its identification could lead to secondary prevention by controlling risk factors such as systolic hypertension.
3,962 citations
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Montreal General Hospital1, German Center for Neurodegenerative Diseases2, University of Pennsylvania3, Innsbruck Medical University4, Mount Sinai Hospital5, University of Marburg6, University of Navarra7, University of California, San Diego8, Toronto Western Hospital9, Neuroscience Research Australia10, Rush University Medical Center11, Capital Medical University12, Radboud University Nijmegen13, Mayo Clinic14, University of Kiel15
TL;DR: The Movement Disorder Society PD Criteria retain motor parkinsonism as the core feature of the disease, defined as bradykinesia plus rest tremor or rigidity, and two levels of certainty are delineated: clinically established PD and probable PD.
Abstract: This document presents the Movement Disorder Society Clinical Diagnostic Criteria for Parkinson's disease (PD). The Movement Disorder Society PD Criteria are intended for use in clinical research but also may be used to guide clinical diagnosis. The benchmark for these criteria is expert clinical diagnosis; the criteria aim to systematize the diagnostic process, to make it reproducible across centers and applicable by clinicians with less expertise in PD diagnosis. Although motor abnormalities remain central, increasing recognition has been given to nonmotor manifestations; these are incorporated into both the current criteria and particularly into separate criteria for prodromal PD. Similar to previous criteria, the Movement Disorder Society PD Criteria retain motor parkinsonism as the core feature of the disease, defined as bradykinesia plus rest tremor or rigidity. Explicit instructions for defining these cardinal features are included. After documentation of parkinsonism, determination of PD as the cause of parkinsonism relies on three categories of diagnostic features: absolute exclusion criteria (which rule out PD), red flags (which must be counterbalanced by additional supportive criteria to allow diagnosis of PD), and supportive criteria (positive features that increase confidence of the PD diagnosis). Two levels of certainty are delineated: clinically established PD (maximizing specificity at the expense of reduced sensitivity) and probable PD (which balances sensitivity and specificity). The Movement Disorder Society criteria retain elements proven valuable in previous criteria and omit aspects that are no longer justified, thereby encapsulating diagnosis according to current knowledge. As understanding of PD expands, the Movement Disorder Society criteria will need continuous revision to accommodate these advances.
3,421 citations
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TL;DR: In this article, the potential functional role of the beta-band oscillations in cognitive processing, on the motor system and on the pathophysiology of movement disorders is discussed. But the authors focus on the maintenance of the current sensorimotor or cognitive state.
1,900 citations
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TL;DR: It is hypothesized that beta oscillations and/or coupling in the beta-band are expressed more strongly if the maintenance of the status quo is intended or predicted, than if a change is expected.
Abstract: In this review, we consider the potential functional role of beta-band oscillations, which at present is not yet well understood. We discuss evidence from recent studies on top-down mechanisms involved in cognitive processing, on the motor system and on the pathophysiology of movement disorders that suggest a unifying hypothesis: beta-band activity seems related to the maintenance of the current sensorimotor or cognitive state. We hypothesize that beta oscillations and/or coupling in the beta-band are expressed more strongly if the maintenance of the status quo is intended or predicted, than if a change is expected. Moreover, we suggest that pathological enhancement of beta-band activity is likely to result in an abnormal persistence of the status quo and a deterioration of flexible behavioural and cognitive control.
1,837 citations