PARKINSON'S DISEASE [ back to Glossary Index ]
Parkinson's Disease is a brain-based movement disorder of unknown cause which afflicts approximately 1.5 million people in the United States. Something (be it a virus, an environmental toxin, head trauma or other agent) causes dopamine-producing cells in the substantia nigra to die off. On 5/30/00 a team of french researchers led by Dr. Yves Agid reported they had identified a defective gene called "parkin" which appeared in more than half of young patients they studies who had come down with "early onset" Parkinson's (people like Michael J. Fox, who are symptomatic under age 45). Dr. Agid's team will study whether the parkin gene mutation causes or contributes to the death of dopamine producing cells, at least in some PD patients. Whatever kills those cells, when they die, the supply of dopamine in the brain gradually drops towards zero. As the supply dwindles, symptoms increase. These include resting tremor of the arm; slow, shuffling gait with tiny steps; bodily stiffness; difficulty initiating movement; loss of facial expressiveness; micro-graphia (incredibly tiny handwriting); very soft, low-decibel speech; hallucinations; dementia; and depression.

The first breakthrough in treatment was L-dopa (the chemical pre-cursor to dopamine) which temporarily reversed Parkinsonian symptoms, quieting their tremors and enabling patients to walk and talk more normally. Unfortunately patients tend to become dose-tolerant and require increasing doses of ever larger amounts to gain the same benefits. Still worse, too much L-dopa can cause frightening auditory and visual hallucinations and bizarre facial grimacing. In the late 1980s and early 1990s, collaborating groups American and Swedish researchers pioneered the technique of harvesting fetal substantial nigra cells from aborted fetuses, and then transplanting them directly into the brains of adult Parkinson's patients. This fueled a firestorm of political-religious debate over abortion rights with a temporary moratorium on such transplants ordered by then President Bush.

Eventually the moratorium was lifted and such transplants have continued rather quietly on a much smaller scale than the research community wanted. Some patients have continued to maintain partially improved status 10 years post-transplant. Because fetal transplantation is expensive, difficult, highly controversial and works only some of the time, scientists are looking for new sources of dopamine producing cells. Sources include primative stem cells, cells from the neck of the patient which are super-efficient at transmitting dopamine and bacteria cloned with the genes to make dopamine. Celebrities with Parkinson's who have courageously spoken out for improved treatments include Muhammad Ali, Janet Reno and Michael J. Fox.  Remarkably, something in coffee may help prevent PD. A study of 8,004 Japanese American men living in Hawaii between 1965 and 1996, found that men who did not drink coffee were 5 times more likely to get PD than those who drank it, and that the men least likely to get PD were the ones who drank the most coffee, about 4.5 to 5.5 cups a day. The reason for this statistical correlation is not yet known, but will surely be studied by others in the future.