Mark Hallett | |
---|---|
Born | 1943 |
Alma mater | Harvard |
Known for | Physiology of motor control and movement disorders |
Scientific career | |
Institutions | NIH Intramural Research Program |
Doctoral advisor | C. David Marsden |
Notable students | Alvaro Pascual-Leone |
Mark Hallett is an American neurologist who researched the physiology of human movement and movement disorders including functional motor disorders at the NIH, and currently serves as Distinguished NIH Investigator Emeritus. [1] [2] [3] Hallett worked at NIH for 40 years in the federal government, with several decades at the Human Motor Control Section and was previously chief of the Clinical Neurophysiology Laboratory at Brigham and Women's Hospital. [1]
Hallett has contributed work "to the principles of normal human voluntary movement, understanding the motor system and movement disorders including dystonia, parkinsonism and myoclonus, and the use of transcranial magnetic stimulation (TMS) and botulinum toxin to treat movement disorders." [1] He is noted for his prolific research output throughout his career and is the 96th most cited scientist in the United States, according to Research.com, by h-index. [1] Hallett has suggested that education, awareness, and availability of the latest treatment programs remains a key challenge for motor diseases. [3] His work is considered to be pioneering in the field of functional motor disorders. [4]
Hallett is also considered a pioneer of the field of TMS and helped create the first conferences on TMS safety guidelines, as well as providing additional foundational research around principles of brain stimulation; he was awarded the 2019 International Brain Stimulation Award as a result. [5]
Hallett graduated from Harvard with an AB and MD and trained at Peter Bent Brigham hospital and Massachusetts General Hospital. [2] Hallett also founded the Functional Neurological Disorder Society in 2003 and served as an editor in chief of Clinical Neurophysiology. [6] [2] He has also served as President of the International Parkinson and Movement Disorder Society and Vice-President of the American Academy of Neurology. [2] He retired from NIH and serves as professor emeritus as of 2023 after 40 years of federal service. [1] Hallett pioneered experimental botulinum injections to treat Leon Fleisher's hand dystonia. [7] In the wake of diplomats suffering Havana Syndrome, Hallett was among the physicians asked to examine the diplomats. [4]
Hallett has worked on topics of volition and free will through a neurophysiological lens, including reformulations of the Libet clock experiment. [8] [9]
Transcranial magnetic stimulation (TMS) is a noninvasive neurotherapy, a form of brain stimulation in which a changing magnetic field is used to induce an electric current at a specific area of the brain through electromagnetic induction. An electric pulse generator, or stimulator, is connected to a magnetic coil connected to the scalp. The stimulator generates a changing electric current within the coil which creates a varying magnetic field, inducing a current within a region in the brain itself.
The National Institute of Neurological Disorders and Stroke (NINDS) is a part of the U.S. National Institutes of Health (NIH). It conducts and funds research on brain and nervous system disorders and has a budget of just over US$2.03 billion. The mission of NINDS is "to reduce the burden of neurological disease—a burden borne by every age group, every segment of society, and people all over the world". NINDS has established two major branches for research: an extramural branch that funds studies outside the NIH, and an intramural branch that funds research inside the NIH. Most of NINDS' budget goes to fund extramural research. NINDS' basic science research focuses on studies of the fundamental biology of the brain and nervous system, genetics, neurodegeneration, learning and memory, motor control, brain repair, and synapses. NINDS also funds clinical research related to diseases and disorders of the brain and nervous system, e.g. AIDS, Alzheimer's disease, epilepsy, muscular dystrophy, multiple sclerosis, Parkinson's disease, spinal cord injury, stroke, and traumatic brain injury.
Myoclonus is a brief, involuntary, irregular twitching of a muscle, a joint, or a group of muscles, different from clonus, which is rhythmic or regular. Myoclonus describes a medical sign and, generally, is not a diagnosis of a disease. It belongs to the hyperkinetic movement disorders, among tremor and chorea for example. These myoclonic twitches, jerks, or seizures are usually caused by sudden muscle contractions or brief lapses of contraction. The most common circumstance under which they occur is while falling asleep. Myoclonic jerks occur in healthy people and are experienced occasionally by everyone. However, when they appear with more persistence and become more widespread they can be a sign of various neurological disorders. Hiccups are a kind of myoclonic jerk specifically affecting the diaphragm. When a spasm is caused by another person it is known as a provoked spasm. Shuddering attacks in babies fall in this category.
Dystonia is a neurological hyperkinetic movement disorder in which sustained or repetitive muscle contractions occur involuntarily, resulting in twisting and repetitive movements or abnormal fixed postures. The movements may resemble a tremor. Dystonia is often intensified or exacerbated by physical activity, and symptoms may progress into adjacent muscles.
Chorea-acanthocytosis is a rare hereditary disease --evidence suggests that only 500 to 1,000 people worldwide have the condition. It is caused by a mutation in a gene that directs structural proteins in red blood cells. It belongs to a group of four diseases characterized under the name neuroacanthocytosis. When a patient's blood is viewed under a microscope, some of the red blood cells appear thorny. These thorny cells are called acanthocytes.
Hyperkinesia refers to an increase in muscular activity that can result in excessive abnormal movements, excessive normal movements, or a combination of both. Hyperkinesia is a state of excessive restlessness which is featured in a large variety of disorders that affect the ability to control motor movement, such as Huntington's disease. It is the opposite of hypokinesia, which refers to decreased bodily movement, as commonly manifested in Parkinson's disease.
Focal dystonia, also called focal task-specific dystonia, is a neurological condition that affects a muscle or group of muscles in a specific part of the body during specific activities, causing involuntary muscular contractions (spasms) and abnormal postures. There are many different types of focal dystonia, each affecting a different region of the body. For example, in focal hand dystonia, or writer's cramp, the fingers either curl into the palm or extend outward without control. In musicians, the condition is called musician's focal dystonia, or simply, musician's dystonia. In sports, it may be involved in what is commonly referred to as the yips. The condition appears to be associated with over-training, and individualized treatment strategies may involve medications, retraining techniques, and procedures.
Blepharospasm is a neurological disorder characterized by intermittent, involuntary spasms and contractions of the orbicularis oculi (eyelid) muscles around both eyes. These result in abnormal twitching or blinking, and in the extreme, sustained eyelid closure resulting in functional blindness.
Spasmodic torticollis is an extremely painful chronic neurological movement disorder causing the neck to involuntarily turn to the left, right, upwards, and/or downwards. The condition is also referred to as "cervical dystonia". Both agonist and antagonist muscles contract simultaneously during dystonic movement. Causes of the disorder are predominantly idiopathic. A small number of patients develop the disorder as a result of another disorder or disease. Most patients first experience symptoms midlife. The most common treatment for spasmodic torticollis is the use of botulinum toxin type A.
Myoclonic dystonia or Myoclonus dystonia syndrome is a rare movement disorder that induces spontaneous muscle contraction causing abnormal posture. The prevalence of myoclonus dystonia has not been reported, however, this disorder falls under the umbrella of movement disorders which affect thousands worldwide. Myoclonus dystonia results from mutations in the SGCE gene coding for an integral membrane protein found in both neurons and muscle fibers. Those suffering from this disease exhibit symptoms of rapid, jerky movements of the upper limbs (myoclonus), as well as distortion of the body's orientation due to simultaneous activation of agonist and antagonist muscles (dystonia).
Avindra "Avi" Nath, is a physician-scientist who specializes in neuroimmunology. Nath is a senior investigator, and intramural clinical director of the National Institute of Neurological Disorders and Stroke (NINDS) at the National Institutes of Health (NIH) in the United States. At NINDS, Nath also leads the Section of Infections of the Nervous System and plans to institute a translational research center. He previously served in several research and administrative positions at the Johns Hopkins Hospital and the Johns Hopkins University School of Medicine.
Dyskinetic cerebral palsy (DCP) is a subtype of cerebral palsy (CP) and is characterized by impaired muscle tone regulation, coordination and movement control. Dystonia and choreoathetosis are the two most dominant movement disorders in patients with DCP.
(Charles) David Marsden, FRS was a British neurologist who made a significant contribution to the field of movement disorders. He was described as 'arguably the leading academic neurologist and neuroscientist of his generation in the UK'.
Non-invasive cerebellar stimulation is the application of non-invasive neurostimulation techniques on the cerebellum to modify its electrical activity. Techniques such as transcranial magnetic stimulation (TMS) or transcranial direct current stimulation (tDCS) can be used. The cerebellum is a high potential target for neuromodulation of neurological and psychiatric disorders due to the high density of neurons in its superficial layer, its electrical properties, and its participation in numerous closed-loop circuits involved in motor, cognitive, and emotional functions.
Konrad Karl Erich Bodo Wilhelm Dirk Dressler is a German neurologist and psychiatrist. He is Full Professor of Neurology at Hannover Medical School. His research focus is neurological movement disorders and the development and introduction of the botulinum toxin therapy.
Jerrold Lee Vitek is an American neurologist. He is the Head of the Neurology Department, Director of the Neuromodulation Research Program, and Center Director of the University of Minnesota Udall Center of Excellence for Parkinson's Research. Vitek's clinical interests include movement disorders and evaluation for deep brain stimulation (DBS) and his current research activities focus on Parkinson's disease, dystonia, tremor and deep brain stimulation.
Friedhelm Christoph Hummel is a German neuroscientist and neurologist. A full professor at École Polytechnique Fédérale de Lausanne, he is the Defitech Chair of Clinical Neuroengineering, and the head of the Hummel Laboratory at EPFL's School of Life Sciences. He also is an associate professor of clinical neuroscience at the University of Geneva.
Nina Felice Schor is an American physician-scientist and pediatric neurologist. She has served as director of the NIH Intramural Research Program since the Fall of 2022. Schor was the deputy director of National Institute of Neurological Disorders and Stroke from 2018 to 2022. She was the William H. Eilinger Chair of the Department of Pediatrics at University of Rochester and Pediatrician-in-Chief of the Golisano Children’s Hospital from 2006 to January 2018.
Judith Richmond Walters is an American neuropharmacologist serving as chief of the neurophysiological pharmacology section at the National Institute of Neurological Disorders and Stroke.
Raffaele Nardone is an Italian medical doctor, neurologist, and neuroscientist, known for his contributions in the field of clinical neurophysiology. He is the chair of the Department of Neurology at the Franz Tappeiner Hospital in Merano, Italy.