Movement Disorders
It's with a heavy heart we mark the passing of Dr. Mark Hallett November 2, 2025.
Dr. Hallett retired from civil service in December 2022, becoming a Scientist Emeritus after a stellar 38-year career at NIH. An internationally renowned expert in movement disorders, Dr. Hallett directed NINDS’s Medical Neurology Branch and was Chief of the Human Motor Control Section, which he founded in 1984. A true pioneer in his field, he played a major role in establishing movement disorders as a subspecialty of Neurology. He was one of the first to use transcranial magnetic stimulation, a technique that he employed, along with an array of brain imaging methods, to treat patients and develop a deep understanding of human functional movement and the pathophysiology of neurological disorders such as dystonia, Parkinson's disease, cerebellar ataxia, myoclonus, essential tremor, tic, and others. He was among the first to use botulinum toxin therapy for motor disorders, notably to treat hand dystonia. Through his research on motor initiation and functional tremor, Dr. Hallett studied the scientific basis of voluntary movement and free will, challenging the prevailing notion that conscious volition initiates movement.
The scope and impact of Dr. Hallett’s work transcend traditional productivity metrics, but those numbers are astounding: He published more than 1000 manuscripts and reviews, edited nearly 30 books, and served on the editorial board of over 40 journals. He held leadership positions in many professional societies, including the American Academy of Neurology and the International Federation of Clinical Neurophysiology. His clinical and scientific accomplishments were recognized by dozens of distinguished service and lifetime achievement awards, as well as honorary degrees, professorships, and society memberships around the world. He presented an engaging valedictory lecture at his last Board of Scientific Counselors review, and his career contributions were celebrated in 2022 with a symposium marking his retirement.
Dr. Hallett graduated from Harvard College in 1965 and Harvard Medical School in 1969. Following his internship in Boston, in 1970 he joined NIMH’s Laboratory of Neurobiology as a Staff Associate, a position he held for two years. He returned to Boston for a neurology residency at Massachusetts General Hospital, then performed a year-long fellowship in London with C. David Marsden, who at that time was founding the movement disorders field. He returned once again to Boston as the director of the Neurophysiology Laboratories at the Peter Bent Brigham (which became Brigham and Women’s) Hospital, where he rose to Associate Professor in Neurology at Harvard Medical School. He was recruited to NIH in 1984 as the Clinical Director of NINCDS (later NINDS), a position he held until 2000.
During his time at NINDS, Dr. Hallett contributed tremendously to its intramural program – through both the groundbreaking research within his lab and his leadership. He chaired or served on numerous committees, including the Tenure Review Committee and the Scientific Review Committee. He was deeply respected by the institute’s leaders, faculty, and staff, all of whom looked up to him and consulted him regularly for advice and wisdom. He mentored more than 150 fellows, many of whom have become international leaders in neurology, and he received numerous mentoring and clinical teaching awards.
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 was an NINDS Scientist Emeritus and previously served as the Chief of the Medical Neurology Branch and Chief of its Human Motor Control Section. He was also 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. Formerly an NIH Distinguished Investigator, Dr. Hallett became a Scientist Emeritus in 2023.
Dr. Hallett's research interests centered around human motor control, to understand the physiology of normal human voluntary movement and the pathophysiology of different movement disorders. The main techniques employed in his research were 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 were dystonia, Parkinson's disease, cerebellar ataxia, myoclonus, essential tremor, tic, functional movement disorders and startle disorders.
In relation to the physiology of movement, he and his collaborators studied the brain processes associated with the preparation and execution of different types of movements. A special interest was in the process of movement initiation and volition. Dr. Hallett was also interested in studying motor learning including the process of making movement automatic and the process of movement selectivity.