Christopher D. Stephen is a Neurologist, a Clinician-Scientist, and an Epidemiologist with the Movement Disorders Unit, Ataxia Center; Dystonia Clinic, Department of Neurology, Massachusetts General Hospital (MGH); and the Performing Arts Clinic, Department of Neurology, Brigham and Women’s Hospital. He is an Instructor in neurology with the Harvard Medical School. His clinical interests include rare movement disorders (particularly ataxia and dystonia and their overlap), motor functional movement disorders (FND), and neurological problems in musicians. Closely associated with his clinical expertise, his research interests include the quantitative assessment of movement disorders, with a view to their use as potential motor biomarkers of disease severity and progression. Utilizing movement analysis techniques, he has quantitatively studied eye movements, static posture, and motion sensor-based analysis in movement disorders, as part of his highly collaborative research. He is a member of the MGH Center for Rare Neurological Diseases and has also been involved in imaging and other clinical research in the rare ataxias, late-onset GM2 gangliosidosis; and within the Ataxia Center, on MRI imaging biomarkers in the sporadic ataxia multiple system atrophy of the cerebellar type (MSA-C). He is also a member of the MGH Collaborative Center for X-Linked Dystonia Parkinsonism (XDP) Clinical Research Team, where he is also a Co-Lead Investigator of the Coordinating Center for the XDP-TRACK Natural History of XDP. He is a key member of the MGH FND Research Program and has led or contributed to multiple publications with the goal of advancing FND patient care. As an epidemiologist, he studies movement disorders and FND, utilizing large longitudinal cohort studies, large databases, and health services research. He is a member of the International Parkinson and Movement Disorders Society Rare Movement Disorders, Functional Movement Disorders, and Ataxia Study Groups.