A Tribute to Mark Hallett, MD (1943–2025)

Mark Hallett, MD, a visionary neurologist and leader in movement disorders, died in 2025. His career included directing the Medical Neurology Branch at NINDS, founding the International Parkinson and Movement Disorder Society, and authoring nearly 1300 manuscripts. He made groundbreaking contributions to understanding bradykinesia, tremor, myoclonus, dystonia, and functional neurological disorders, and developed techniques like transcranial magnetic stimulation. He mentored over 280 fellows, was known for his oratory skills, and received numerous honors including the World Federation of Neurology Medal. His retirement was cut short by glioblastoma multiforme.

Study at a glance

Abstract

On November 2, 2025, the world neurological community lost a visionary leader and internationally acclaimed scientist, educator, and mentor, Mark Hallett, MD. Born on October 22, 1943, in Philadelphia, Dr. Hallett attended Harriton High School in Lower Merion Township, Pennsylvania, where he was elected senior class president. He then attended Harvard College, initially intending to study astronomy. But after learning about the controversial experiments with psilocybin conducted by psychology professor Timothy Leary and his colleagues, he became interested in the function of the human brain, and graduated Magna Cum Laude as a Biology major in 1965. While at Harvard he met Judith Peller, a fellow Philadelphian. They were married in June 1966, right after she earned her BA in Classics from Wellesley College, and right before she began graduate work at Harvard. The two worked on their advanced degrees simultaneously. (She received her PhD in Classical Philology in 1971.) After graduating Cum Laude from Harvard Medical School in 1969, Dr. Hallett completed an internship at the Peter Bent Brigham Hospital in Boston. The following year, 1970, he became a “yellow beret,” a self-deprecatory nickname for male physicians who came to do research at the National Institutes of Health (NIH) in Bethesda, Maryland, to fulfill their military service obligations during the Vietnam War. He then returned to Boston in 1972 for a 3-year residency in neurology at the Massachusetts General Hospital. In 1975–1976, Mark spent a year as a fellow in the Department of Neurology at the Institute of Psychiatry in London, UK. His work there with the legendary C. David Marsden, MD, who was instrumental in founding the field of “Movement Disorders,” fueled his passion for motor physiology. In 1976, Mark returned to Boston as Director of the Neurophysiology Laboratories Section of Neurology at the Peter Bent Brigham Hospital. Eight years later, in 1984, he was appointed Clinical Director, at the National Institute of Neurological Disorders and Stroke (NINDS) and Chief of the Human Motor Control Section, Medical Neurology Branch of NINDS. Between 1988 and 2022, Dr. Hallett served as Chief of the Medical Neurology Branch at NINDS. He retired in 2022 with the title of Distinguished NIH Investigator Emeritus. Dr. Hallett's research focused on physiology and functional neuroimaging and aimed at a better understanding of human movement and motor control. His goal was to understand the symptoms of diseases from the perspective of normal physiology. To do this, he used a broad spectrum of electrophysiological and imaging techniques. Some of these methods, such as single and repetitive transcranial motor stimulation, were developed by him and his team in their laboratory and even patented. The innovative and news-seeking atmosphere at the NIH was one of the reasons why he chose to stay there for life. He made groundbreaking contributions to the pathophysiology of different movement disorders, including bradykinesia, tremor, myoclonus, and dystonia. He later became interested in consciousness and the neurophysiology of free will. He was particularly interested in promoting understanding and a common language among scientists. There was hardly a consensus statement on movement disorders in which he was not involved, including the tremor consensus organized together with him by one of us (G.D.). Another area in which he made major contributions was in the study of botulinum toxin and its therapeutic applications. One of us (J.J.) was fortunate in working with Mark in the development of the International Neurotoxin Association, founded in 2011. We co-authored articles, edited books, and organized conferences on the topic of botulinum toxin. During his career, Dr. Hallett's leadership was central to the founding of many organizations, including the International Parkinson and Movement Disorder Society (MDS) in 1985. From 1999 to 2000, Dr. Hallett served as the fifth President of the MDS, but he was involved from the very beginning in negotiating the merger between the two original organizations and planning the annual congresses, including the 1st International Congress of Parkinson's Disease and Movement Disorders in 1990, held in Washington, DC, USA. Dr. Hallett was also instrumental in many other organizations and became president of the International Federation of Clinical Neurophysiology and the American Association of Neuromuscular and Electrodiagnostic Medicine. He was also very involved with the Blepharospasm Research Foundation and the Dystonia Medical Research Foundation. After becoming increasingly interested in “psychogenic” movement disorders, later renamed “functional” disorders, he became the Founding President of the Functional Neurological Disorder Society (FNDS) in 2018. One of us (J.J.) enjoyed the opportunity to co-organize many conferences on functional neurological disorders with him, as well as to co-author several books on this topic. Indeed, during one of the most recent FNDS conferences, held in Boston in 2022, Mark was going to room with me at the dormitory; however, because he came down with COVID, he could not attend. Despite his acute illness, he was able to give the organizers a guided tour of the Harvard campus remotely via his cell phone. Dr. Hallett also held leadership positions in many other professional organizations, including the presidency of the American Association of Neuromuscular and Electrodiagnostic Medicine. He authored almost 1300 manuscripts, edited about 30 books, served on the editorial boards of over 40 major neurology journals, and was Editor-in-Chief of Clinical Neurophysiology for 8 years. Dr. Hallett received numerous honors, including honorary memberships and lifetime achievement awards in an array of international organizations and was invited to present prestigious lectures around the world. In 2017, he received a Doctor of Medicine Honoris Causa degree from the University of Hamburg, Germany. In 2007, Dr. Hallett received the Erb Medal of the German Neurological Society and in 2019 the World Federation of Neurology Medal for Contribution to Neuroscience and the International Brain Stimulation Award from the journal Brain Stimulation. Dr. Hallett was a unique mentor and colleague to over 280 fellows and guest researchers at the NIH (see the Acknowledgments). He planned each of their projects in detail with them. Lab meetings were always inspirational, outlining the projects' main objectives. He and his wife Judy made life at the NIH easy for everyone by inviting them and their spouses to their home for parties. Many children of researchers were born in Bethesda. Close friendships and relationships developed among the fellows in this international community, many of which are lasting a lifetime. The close relationship between the fellows, friends, and Mark is also evident in the regular annual reunions held at Movement Disorder Congresses worldwide. Before his official retirement his fellows and colleagues organized “Dr. Mark Hallett's Festschrift” on December 12, 2022 at the NIH. Both of us were honored to be invited to participate and to speak about “Mark, the early 90s” and “Dr. Hallett – the educator.” This gave us an opportunity to highlight our long and close friendship with Mark and to pay tribute to him as a speaker and as a mentor. He has been admired for his oratory skills and was often referred to as “The Explainer in Chief” because of his ability to make complex concepts understandable. This skill became particularly evident during his lectures at the annual “Comprehensive Review of Movement Disorders for Clinical Practitioner,” also known as the “Aspen Course,” started in 1991 by the first three presidents of the MDS, Drs. Fahn, Marsden, and Jankovic. After the untimely passing of Marsden, while he was a visiting scientist at NIH, Dr. Hallett was invited to join the faculty of the week-long Aspen Course (1999–2024). During that week he took full advantage of Aspen's natural beauty, music festival, Aspen Institute, and culinary culture. He especially loved biking with his fellows to Woody Creek Tavern. During our many hikes, concerts, dinners, and other social events, at which he was often accompanied by Judy, J.J. came to appreciate Mark's encyclopedic knowledge of everything, conversational skills, and wonderful sense of humor. Dr. Hallett was a globetrotter and loved to visit numerous medical and scientific institutions around the world. He always enjoyed connecting with his fellows in their “neurological diaspora.” He rarely turned down an invitation to speak, especially if it was in some exotic place. He enjoyed planning family vacations in places like Italy, the Galapagos Islands, and the Caribbean. While traveling, he loved taking photographs and tasting local, often exotic food. He always talked about how much he enjoyed being with his family and how proud he was of the accomplishments of Judy, his children, and grandchildren. Unfortunately, as we have seen too often recently with many of our friends who were planning to travel for pleasure during their years of retirement, Dr. Hallett's retirement years were cut short after he was diagnosed in December 2024 with glioblastoma multiforme. However, Mark still fitted in a visit to his timeshare in the Virgin Islands, a trip to his 60th Harvard reunion, and a Lake Tahoe vacation. Dr. Hallett is survived by his wife Judy, children Nick and Vicky, grandchildren Flora and Celeste, and his siblings Eileen (Efron) and Bruce. There are many personal characteristics of Dr. Hallett that attracted admiration by his family, fellows, friends, and colleagues. But what has stood out most prominently for us were his intellect, curiosity, leadership, wisdom, kindness, humor, laughter, integrity, and humility. He will be missed by many around the world whom he touched with these qualities and his humanity. A towering figure, gentle giant, and a true “mensch,” Mark Hallett will continue to be an inspiration, not only to many young clinicians and scientists but also to everyone who wants to make the world a better place. May his memory be a blessing for all of us to cherish. The many fellows and guest researchers who worked with Mark Hallett at the NIH, Building 10, on their joint projects are listed in the Acknowledgments. We thank Zoltan Mari and Ejaz A. Shamim for providing their extensive list of collaborators with Mark Hallett. The following fellows and guest researchers have worked with Mark Hallett at the NIH. They are listed in alphabetical order. We have taken every effort to locate all his professional friends and apologize for any omissions. Afuh Adeck, Omar Ahmad, Emmanuel Akano, Sepideh Akbaripanahi, Murat Aksu, Michele Alexander, Yasin Al-Hadid, Muslimah Ali, Anne Alteemus, Frank Anderson, Sue Ano, Sanaz Attaripour, Miroslav Backonja, Ou Bai, William Bara, Sabrina Barhoum, Kemal Bayulkem, Sandra Beck, Patrick Bedard, Beth Belluscio, David Benninger, Alfredo Berardelli, Brian Berman, Barbara Bliem, Cathy Blumhorst, Stephan Bohlhalter, Babak Boroojerdi, Joaquim Brasil-Neto, David Brody, Claudette Brooks, Michiko Bruno, Ashura Buckley, Khalaf Bushara, Catherine Bushnell, Maria-Jose Catalan, Chi-Chao Chao, Li Chen, Robert Chen, Sophie Cho, Alexander Choi, Andrew Clark, Joseph Classen, Helena Cockx, Leonardo Cohen, Denis Cortese, Diane Damiano, Deepa Dash, Marie-Pierre Deiber, Luigi DeLuca, Mehmet Demirci, Günther Deuschl, Mrinal Dewanjee, Bozhidar Dimitrov, Tzvetelina Dimitrova, Pierre Diomi, Richard Dubinsky, Irene Dustin, Jeff Duyn, Debra Ehrlich, Aviva Ellenstein, Susan Factor, Mirella Fernandez, Ed Fine, Edmond FitzGibbon, Henrik Foltys, Lucy Forrest, Eleni Frangos, Walter Friedli, William Frazier, R. Benjamin Free, Peter Fuhr, Harold Gainer, Cecile Gallea, Martha Garcia Garcia, Gaetan Garraux, Marjorie Garvey, Plamen Gatev, Christian Gerloff, Pritha Ghosh, Andy Goldfine, Susanne Goldstein, Stephen Gonsalves, Taichi Goto, Allison Griffin, Stephen Grill, Ute Gschandtner, Christopher Grunseich, Fady Guirguis, Patrick Haggard, Oday Halhouli, Wenyan Han, Takashi Hanakawa, Noriaki Hattori, Takaaki Hattori, Dietrich Haubenberger, Rick Helmich, Priyantha Herath, Janet Hieshetter, Michele Hindi-Alexander, Angela Holmes, Rebecca Hommer, Manabu Honda, Silvina Horovitz, Elise Houdayer, Renzo Huber, Laryssa Huryn, Diego Iacono, Vincente Ibanez, Katsunari Ikoma, Kazumi Iseki, Lucrezia Islam, Nobue K. Iwata, Avanti Iyer, Sadhana Jackson, S.-H. Jin, Jerri Johnson, Alan Kaelin-Lang, Suk-Yun Kang, Dimitrios Kapogiannis, Anke Karabanov, Barbara Karp, Panagiotis Kassavetis, Matthias Keidel, Omar Khan, Shahram Khoshbin, Gottfried Kranz, Sharif Kronemer, Sahana Kukke, David Kupferschmidt, Kathrin Lafaver, Mark Latash, Lawrence Latour, Peter Lauro, Bennett Lavenstein, Justine Lely, Letizia Leocani, Giorgio Leodori, Fidias Leon-Sarmiento, Alicja Lerner, K.-K. Liao, Hsin-Pin Lin, Peter Lin, Sarah Lisanby, Irene Litvan, Alicia Livinski, Grisel Lopez, Jau-Shin Lou, Codrin Lungu, Feng Luo, Nicholas Madian, Ava Mandel, Paolo Manganotti, Arun Mani, Zoltan Mari, C. David Marsden, Steve Massaquoi, Masao Matsuhashi, Sarah Matteson, Carine Maurer, Anne Mayfield, Gayle McCrossin, Patrick McGurrin, Jennifer Mehren, Karin Mente, Shabbir Merchant, Sabine Meunier, Jin Miao, Tatsuya Mima, Fiona Molloy, Paul Morrell, Wolf Muellbacher, Fatta Nahab, Govind Nair, Christopher Nguyen, Jan Nilsson, Zahid Noor, Allison Nugent, Lindsay Oberman, Joan Ohayon, Mike Orquiza, Leslie Osborne, Fernando Pagan, Rainer Paine, Ming-Kai Pan, Sepideh Panahi, Sanjay Pandey, Marcela Panizza, Pattamon Panyakaew, Maryland Pao, Jung E. Park, Alvaro Pascual-Leone, Elizabeth Peckham, Laura Pesantez Pacheco, Nicole Peterkin, Ajay Pillai, Daniel Pine, Sarah Pirio Richardson, Traian Popa, Brach Poston, Ingrid Pretzer-Aboff, Vesper Ramos, Ravi (Arippa) Ravindran, Ali Raza, Haniya Raza, Joel Reyes, Katherine Roche, Stephen Rojcewicz, Lorna Role, Alex Ross, Heike Russmann, Norihiro Sadato, Leorey Saligan, Jerome Sanes, Ulisses Santamaria, Mohammed Saqib, Joelle Sarlls, Noa Sasson, Lumy Sawaki-Adams, Rachael Schacherer, Kaya Scheman, David Schessel, Enas Shahine, Ejaz Shamim, Smita Sharma, Carolyn Sherer, Jessica Shields, Holly Shill, Jau Shin Lou, Kristina Simonyan, Young Sohn, Martin Sommer, Primavera Spagnolo, Prachaya Srivanitchapoom, Tripthi Sugumar, Kenton Swartz, David Talmage, Yohei Tamura, Ina Tarkka, Nivethida Thirugnanasambandam, Sule Tinaz, Helge Topka, Marlene Topka, Camilo Toro, Antonio Triggiani, L. Christine Turtzo, Yoshino Ueki, Josep Valls-Sole, Susanne van der Veen, Peter van Gelderen, Nora Vanegas, Jessica Vaughan, Felipe Vial, Khorana Vikram, Bernhard Voller, Valerie Voon, Mark Wagner, Daniel Waldvogel, Brian Walitt, Judith Walters, Han Wang, Eric Wasserman, Rebecca Waugh, Konrad Werhahn, Karl Wessel, Lewis Wheaton, Miguel Wilken, George Wittenberg, Tao Wu, Dan Xi, Weizhen Xie, Richard Young, Hengameh Zahed, Maryamnaz Hosseinzadeh Zaribaf, Kirsten Zeuner, Ping Zhuang, Ulf Ziemann.