Parkinson's damages the heart as well as the brain Sep 05,

               Parkinson's disease may go far beyond the brain in its damage to nerve cells, researchers have
               discovered. While it has long been known that the disease involves a loss of nerve endings in part of
               the brain, new research shows that it also damages related nerves in the heart.

               This discovery could lead to new ways of predicting or even preventing Parkinson's, according to
               investigators at the National Institute of Neurological Disorders and Stroke (NINDS). In a study of 29
               Parkinson's patients, Dr. David S. Goldstein and his colleagues found that most had lost heart nerve
               endings that produce the chemical norepinephrine. Norepinephrine is related to dopamine, the chemical
               that declines in the brains of Parkinson's patients. This suggests, according to Goldstein's team, that
               whatever triggers the loss of dopamine-producing nerve endings in the brain also depletes nerve
               endings in the heart.

Their findings were published in the September 5 issue of the Annals of Internal Medicine.

               Parkinson's is a chronic, progressive disease that strikes the motor system, gradually robbing patients
               of muscle control, balance and coordination. Many patients also experience a drop in blood pressure
               when they stand--a condition called orthostatic hypotension. Doctors had believed the Parkinson's drug
               levodopa was behind this blood pressure abnormality.

               But according to the NINDS researchers, the explanation may instead lie in nerve damage to the heart.
               Among their study patients, nine had orthostatic hypotension. All nine, as well as 11 without the blood
               pressure condition, showed a loss of nerve endings in the heart. When the researchers looked at a
               group of patients with a disorder similar to Parkinson's--multiple system atrophy--they found normal
               heart nerve endings.

               Goldstein's team is currently studying whether other organs show similar nerve-ending loss in
               Parkinson's. According to Goldstein, damage to the hearts of Parkinson's patients may involve a toxin in
               the blood that prematurely wears out nerve endings. Because this hypothesis may also apply to the
               brain, according to NINDS, the new findings could "point to a way of predicting and ultimately preventing
               the disorder."

About 500,000 Americans have Parkinson's. The disease usually appears when people are in their 50s
and 60s, but it can also strike young adults.

SOURCE: Annals of Internal Medicine 2000;133:338-347, 382-384.

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