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Mark Hallett

Bio: Mark Hallett is an academic researcher from National Institutes of Health. The author has contributed to research in topics: Transcranial magnetic stimulation & Motor cortex. The author has an hindex of 186, co-authored 1170 publications receiving 123741 citations. Previous affiliations of Mark Hallett include Government of the United States of America & Armed Forces Institute of Pathology.


Papers
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TL;DR: In this article, the use of a ketogenic diet in cohorts with Parkinson's disease was explored, and while not conclusive, the data suggest non-motor symptom benefit, which is useful to understand target engagement and gauge which mechanism could lead to a testable hypothesis.

11 citations

Journal ArticleDOI
TL;DR: To determine the efficacy of levetiracetam in oromandibular or cranial dystonia, a large number of patients with these conditions have received treatment with this drug.
Abstract: Objective To determine the efficacy of levetiracetam in oromandibular or cranial dystonia. Methods We recruited seven subjects with oromandibular or cranial dystonia. Five completed the study, median age was 71 years (range 42-79 years), median disease duration was 12 years (range 2-30 years). Participants were randomized to receive levetiracetam or placebo and were then crossed over. They titrated up to a total daily dose of 4000 mg or the maximum tolerated dose over 3 weeks and maintained that dose for another 3 weeks. The primary endpoint was the percent change of the eyes, mouth, speech, and swallowing Burke–Fahn–Marsden (BFM) subscores from baseline to weeks 6 and 14. Additional endpoints included the BFM subscore at weeks 3 and 11, and the global dystonia severity (GDS) subscore at weeks 3, 6, 11, and 14, as well as all adverse side effects. Results The mean percent increase in the BFM subscore (placebo: 31.25%, levetiracetam: 12.16%) was not significantly different between the two arms according to the Friedman analysis. The Wilcoxon signed-rank test showed that these percent changes were not significant, indicating that there was no statistical clinical worsening in either arm. The mean percent change of the BFM subscore at weeks 3 and 11 and the mean percent change of the GDS subscore at weeks 3, 6, 11, and 14 were not significantly different between the two arms, and the Wilcoxon signed-rank test did not show statistical significance. Conclusion Levetiracetam does not appear to be efficacious in patients with oromandibular or cranial dystonia.

11 citations

Journal ArticleDOI
TL;DR: The reversal of inhibition observed with PPC-PMv-M1 stimulation suggests that the parietal connection to the PMv plays a role in the modulation of M1, and the described network may be important in a variety of movement disorders.

11 citations

Journal Article

11 citations

Journal ArticleDOI
TL;DR: Recent neuroscience research on FMD is reviewed to discuss how the adoption of a similar integrative framework may facilitate the identification of the mechanisms underlying FMD and could also have potential clinical applicability.

11 citations


Cited by
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TL;DR: Past observations are synthesized to provide strong evidence that the default network is a specific, anatomically defined brain system preferentially active when individuals are not focused on the external environment, and for understanding mental disorders including autism, schizophrenia, and Alzheimer's disease.
Abstract: Thirty years of brain imaging research has converged to define the brain’s default network—a novel and only recently appreciated brain system that participates in internal modes of cognition Here we synthesize past observations to provide strong evidence that the default network is a specific, anatomically defined brain system preferentially active when individuals are not focused on the external environment Analysis of connectional anatomy in the monkey supports the presence of an interconnected brain system Providing insight into function, the default network is active when individuals are engaged in internally focused tasks including autobiographical memory retrieval, envisioning the future, and conceiving the perspectives of others Probing the functional anatomy of the network in detail reveals that it is best understood as multiple interacting subsystems The medial temporal lobe subsystem provides information from prior experiences in the form of memories and associations that are the building blocks of mental simulation The medial prefrontal subsystem facilitates the flexible use of this information during the construction of self-relevant mental simulations These two subsystems converge on important nodes of integration including the posterior cingulate cortex The implications of these functional and anatomical observations are discussed in relation to possible adaptive roles of the default network for using past experiences to plan for the future, navigate social interactions, and maximize the utility of moments when we are not otherwise engaged by the external world We conclude by discussing the relevance of the default network for understanding mental disorders including autism, schizophrenia, and Alzheimer’s disease

8,448 citations

Journal ArticleDOI
TL;DR: The basal ganglia serve primarily to integrate diverse inputs from the entire cerebral cortex and to "funnel" these influences, via the ventrolateral thalamus, to the motor cortex.
Abstract: Information about the basal ganglia has accumulated at a prodigious pace over the past decade, necessitating major revisions in our concepts of the structural and functional organization of these nuclei. From earlier data it had appeared that the basal ganglia served primarily to integrate diverse inputs from the entire cerebral cortex and to "funnel" these influences, via the ventrolateral thalamus, to the motor cortex (Allen & Tsukahara 1974, Evarts & Thach 1969, Kemp & Powell 1971). In particular, the basal

8,111 citations

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TL;DR: FieldTrip is an open source software package that is implemented as a MATLAB toolbox and includes a complete set of consistent and user-friendly high-level functions that allow experimental neuroscientists to analyze experimental data.
Abstract: This paper describes FieldTrip, an open source software package that we developed for the analysis of MEG, EEG, and other electrophysiological data. The software is implemented as a MATLAB toolbox and includes a complete set of consistent and user-friendly high-level functions that allow experimental neuroscientists to analyze experimental data. It includes algorithms for simple and advanced analysis, such as time-frequency analysis using multitapers, source reconstruction using dipoles, distributed sources and beamformers, connectivity analysis, and nonparametric statistical permutation tests at the channel and source level. The implementation as toolbox allows the user to perform elaborate and structured analyses of large data sets using the MATLAB command line and batch scripting. Furthermore, users and developers can easily extend the functionality and implement new algorithms. The modular design facilitates the reuse in other software packages.

7,963 citations

Journal ArticleDOI
06 Jun 1986-JAMA
TL;DR: The editors have done a masterful job of weaving together the biologic, the behavioral, and the clinical sciences into a single tapestry in which everyone from the molecular biologist to the practicing psychiatrist can find and appreciate his or her own research.
Abstract: I have developed "tennis elbow" from lugging this book around the past four weeks, but it is worth the pain, the effort, and the aspirin. It is also worth the (relatively speaking) bargain price. Including appendixes, this book contains 894 pages of text. The entire panorama of the neural sciences is surveyed and examined, and it is comprehensive in its scope, from genomes to social behaviors. The editors explicitly state that the book is designed as "an introductory text for students of biology, behavior, and medicine," but it is hard to imagine any audience, interested in any fragment of neuroscience at any level of sophistication, that would not enjoy this book. The editors have done a masterful job of weaving together the biologic, the behavioral, and the clinical sciences into a single tapestry in which everyone from the molecular biologist to the practicing psychiatrist can find and appreciate his or

7,563 citations