Parkinson disease is a gradually progressive degenerative disorder of the central nervous system. Parkinson disease belongs to a group of conditions called movement disorders. There are four characteristic problems caused by Parkinson disease, including tremor at rest, balance problems, stiffness, and slowness of movement. Parkinson disease.
Parkinson's disease is a degenerative neurological disease that affects approximately one million persons in the United States. It primarily impacts the specific part of the brain that controls movement called the substantia nigra.