A specialty in the practice of medicine that focuses on caring for people with disorders, diseases, and injuries involving the brain and nervous system. A physician who specializes in neurology is a neurologist. In the United States a physician must complete medical school, a comprehensive residency in neurology (usually four years of study), which focuses on the structures, functions, and dysfunctions of the nervous system, and then pass written and oral examinations conducted by the American Board of Psychiatry and Neurology. Some neurologists subspecialize in narrowly focused areas of neurology such as neuro-muscular or movement disorders often undertaking additional training in the form of fellowships after residency. People with Parkinson’s disease should receive care through a neurologist, either directly or through close collaboration with the PRIMARY CARE PHYSICIAN.