In Memorium Mark Hallett, MD

On November 2, 2025, our friend, mentor, and colleague, Mark Hallett, died peacefully at home surrounded by his family. An internationally recognized expert in neurology and neurophysiology, Mark, as he was known to all, was a legendary clinician and prolific researcher. He was an extremely effective teacher and mentored hundreds of clinicians and researchers nationally and internationally. He was unpretentious, open, and always accessible to his family, students, colleagues, and even strangers. When contacted, Mark always seemed to respond within an hour or two, even when he was in a distant location or time zone. For his fellows, his email response time was legendary, as exemplified by fellows proud of their late working time sending emails at 8 pm and receiving an answer back before they could even log off the computer. His engagement with his fellows' work, as well as his innate curiosity, drove him to respond quickly to keep the momentum of projects moving forward. The depth and breadth of his knowledge and his impact on the fields of neurology and neurophysiology cannot be overstated. During his long, productive career he published over 1200 scientific papers and edited 30 or more textbooks, with many of his works being extensively cited. Mark was a committed, involved member of the AANEM and ABEM, serving on the Boards of both organizations, on the Editorial Board of Muscle and Nerve and as an ABEM examiner. During his career, he served on nearly every committee at the AANEM. He was the President of number of associations including the AANEM (1992) and received numerous awards including the AANEM's prestigious Distinguished Clinician Award (2002) and Lifetime Achievement Award (2014). Some of Mark's other leadership positions included President of the International Parkinsons and Movement Disorders Society, Vice President of the American Academy of Neurology, and President of the Functional Neurological Disorder Society. He was also an awardee of an AAN Presidential lecture. Mark was raised in Philadelphia, Pennsylvania where he excelled in academics, public speaking, and tennis. He moved to Cambridge Massachusetts to attend Harvard College (1965) then Harvard Medical School (1969). After completing an internship in Boston in 1970, he moved to Bethesda, Maryland to the National Institutes of Health (NIH) where he served for 2 years as a Staff Associate in the Laboratory of Neurobiology. He then returned to Boston to complete a neurology residency at Massachusetts General Hospital where he served as Chief Resident. His illustrious career in the field of movement disorders began with a fellowship in London with C. David Marsden, a founding father of this sub-specialty. Following this fellowship, Mark once again returned to Boston as the director of the Neurophysiology Laboratories at the Peter Bent Brigham Hospital (now Brigham and Women's) and as an Associate Professor in Neurology at Harvard Medical School. In 1984, he returned to the NIH as the Clinical Director of NINCDS (later NINDS), a position he held until 2000. He was the Chief of the Human Motor Control Section at NINDS for over 30 years, running a highly respected and productive research laboratory that carried out groundbreaking research in neurophysiology and movement disorders. An astute clinician, he also provided much sought after consultation services to patients and clinicians from around the globe. In addition to his leadership positions in many professional associations, Mark chaired and served on numerous committees at NIH, advising many scientists in training. His enduring legacy is his impact on the hundreds of colleagues and clinical and research fellows he mentored over the years, many of whom have gone on to become international leaders in neurology, movement disorders, and neurophysiology themselves. Outside of his career, Mark was devoted to his personal as well as work families. He had a ready smile and wicked sense of humor. This included a talent for haiku which often showcased his sense of humor. A favorite haiku that he often shared with his fellows who were growing their families during their time with him at NIH was “I said to fellows/Be fruitful and multiply/I meant manuscripts.” His passion for travel was legendary as was his love of photography. Mark is survived by Judith, his wife of 59 years, his children Nicholas (Brock Monroe) and Victoria (Jeffrey Miller), grandchildren Celeste Miller and Flora Miller, and younger siblings, Eileen (Efron) and Bruce. Dr. Gipi Shiavo PhD, Mark's colleague at the International Neurotoxins Association, so aptly summarized our feelings on Mark's passing: “A truly remarkable colleague and friend, with an astonishing ability to be a natural leader without any overt alpha male behavior. And a tremendous wit that made any task and chore just a natural next step to take with a laugh. His laugh. Farewell, my friend.” Mark, from all of us at your work family, we thank you for who you were and what you gave to each of us. All authors contributed to the writing and editing of this memorium. This work was supported by NIH Clinical Center. and National Institute of Neurological Disorders and Stroke. The authors declare no conflicts of interest. Data sharing not applicable to this article as no datasets were generated or analyzed during the current study.