SEPT. 8, 2000

Health Happenings
Parkinson's: More Than a Brain Disorder

For many years, researchers have known that the movement problems associated with Parkinson’s disease result from a loss of neurons that produce a nerve-signaling chemical called dopamine in one part of the brain. A new study suggests that Parkinson’s also affects nerve endings that produce a related chemical, norepinephrine, in the heart. The finding improves understanding about how Parkinson’s develops and may lead to a way of predicting the disorder and possibly preventing it.

The study also improves understanding of orthostatic hypotension, or a fall in blood pressure when a person stands up, which is a common complication of Parkinson’s disease. This condition can cause dizziness, lightheadedness, and fainting.

According to the study, Parkinson’s patients tend to have decreased numbers of norepinephrine-producing nerve endings in the heart. This finding suggests that Parkinson’s is more than just a brain disease and may be caused by an abnormality that affects the peripheral nervous system, which includes the sympathetic nervous system, as well as the brain.