Parkinson Disease

Parkinson disease (PD) is a disease in which cells in regions of the brain involved with muscular coordination and control suffer in impaired ability to synthesize the neurotransmitter dopamine.

Parkinson disease or Parkinsonism is named for the English physician James Parkinson. His description of the various manifestations of the disease was published in 1817, in a work entitled "An Essay on the Shaking Palsy." He used the terms" shaking palsy" or "paralysis agitans" to describe a group of related symptoms, which he carefully observed and recorded. It is now known that this neurological disorder is caused by damage to the brain. The main symptoms of the disease are tremor while at rest and abnormal movements of the arms and legs while standing or walking. These are accompanied by a number of other symptoms, including speech problems, a stiff, bent-over position, insomnia, and constipation.

All related disorders are attributed to a malfunction of the basal ganglia (which contain a rich array of neurotransmitters and receptors controlling muscular movements) and of the substantia nigra (where dopamine is produced). Dopamine is one of the brain chemicals involved in the control of physical movement, and Parkinsonism is characterized by dopamine depletion. Secondary Parkinsonism, in which symptoms are of a passing nature, is due to temporary dopamine depletion, induced most commonly by antipsychotic drugs.