Holly Shill, MD, is director of the Muhammad Ali Parkinson Center at Barrow Neurological Institute at Dignity Health St. Josephs Hospital and Medical Center in Phoenix. She is board certified by the American Board of Psychiatry and Neurology. Dr. Shill’s expertise includes the diagnosis and treatment of involuntary movements, essential tremor, Parkinson’s disease, Huntington’s disease, dystonia, and ataxia. She is a member of the Arizona Neurological Society, the American Academy of Neurology, the Movement Disorder Society, and the International Neurotoxin Association. Dr. Shill received her medical degree from the University of Arizona College of Medicine in Tucson. She completed her internship at Dignity Health St. Joseph’s in internal medicine. Dr. Shill completed her residency in neurology at Barrow Neurological Institute and a fellowship in movement disorders at the National Institutes of Health. Dr. Shill’s research studies include risk factors for the development and progression of Parkinson’s disease and innovative treatments for Parkinson’s. She also studies pathogenesis of essential tremor.