Parkinsons disease (PD; paralysis agitans) is a neurodegenerative disease of the substantia nigra (an area in the basal ganglia of the brain). The disease was first discovered and its symptoms documented in 1817 (Essay on the Shaking Palsy) by the British physician Dr. James Parkinson the associated biochemical changes in the brain of patients were identified in the 1960s. Some genes were identified only recently others remain unknown.
