Mark Hallett, M.D.

Dr. Mark Hallett

Mark Hallett, M.D.

NIH Distinguished Investigator
Address
HUMAN MOTOR CONTROL SECTION, MEDICAL NEUROLOGY BRANCH

BG 10 RM 7D37
10 CENTER DR
BETHESDA MD 20814

Dr. Hallett obtained his A.B. and M.D. at Harvard University, had his internship in Medicine at the Peter Bent Brigham Hospital and his Neurology training at Massachusetts General Hospital. He had fellowships in neurophysiology at the NIH and in the Department of Neurology, Institute of Psychiatry in London, where he worked with C. David Marsden. Before coming to NIH in 1984, Dr. Hallett was the Chief of the Clinical Neurophysiology Laboratory at the Brigham and Women's Hospital in Boston and progressed to Associate Professor of Neurology at Harvard Medical School. He is currently Chief of the Medical Neurology Branch and Chief of its Human Motor Control Section. He is now the Inaugural President of the Functional Neurological Disorder Society and also the Past-President of the International Federation of Clinical Neurophysiology. He has been President of the International Parkinson and Movement Disorder Society and Vice-President of the American Academy of Neurology. He served as Editor in Chief of Clinical Neurophysiology. Among many awards, in 2012 he became an Honorary Member of the American Neurological Association, and in 2017 he received the degree of Doctor of Medicine Honoris Causa from the University of Hamburg, and in 2018 was made an Honorary Member of the European Academy of Neurology. In 2019, he was awarded the World Federation of Neurology’s Medal for Contributions to Neuroscience. His research activities focus on the physiology of human voluntary movement and its pathophysiology in disordered voluntary movement and involuntary movement.

The general mission of the Human Motor Control Section is to understand the physiology of normal human voluntary movement and the pathophysiology of different movement disorders. The members of the Section work together on the different projects, each bringing special expertise to the tasks. The main techniques employed are transcranial magnetic stimulation (TMS), electroencephalography (EEG), neuroimaging with positron emission tomography (PET) and functional magnetic resonance imaging (fMRI), and other techniques of clinical neurophysiology. The principal diseases studied are dystonia, Parkinson's disease, cerebellar ataxia, myoclonus, essential tremor, tic, functional movement disorders and startle disorders.

In relation to the physiology of movement, we have studied the brain processes associated with the preparation and execution of different types of movements. A special interest is the process of movement initiation and volition. We have been studying motor learning including the process of making movement automatic and the process of movement selectivity.

As one example of our work, we have been exploring the pathophysiology of functional movement disorders (FMD). There are abnormalities identifiable with functional MRI that help explain why the patients experience their movements as involuntary. The right temporo-parietal junction (TPJ) region plays a role in the sense of self-agency and it has defective connectivity even in the resting brain. 

Maps of resting state fMRI demonstrate group differences in rTPJ resting-state functional connectivity (FC) between patients with FMD and healthy controls.
Maps of resting state fMRI demonstrate group differences in rTPJ resting-state functional connectivity (FC) between patients with FMD and healthy controls. Images show decreased FC in patients with FMD between the rTPJ (seed) and the (A) bilateral supplementary motor area (SMA) (circled), (B) right precentral gyrus (circled), (C) right postcentral gyrus (circled), (D) right insula (circled), and (E) cerebellar vermis (circled). From Maurer et al. 2016; see publication list for full citation.