Michael J. Fox is the latest public figure to acknowledge that he has Parkinson's disease, joining a list that includes the Rev. Billy Graham , Attorney General Janet Reno and former heavyweight champion Muhammad Ali . The disease, which affects about 1 million people in the United States, typically strikes the elderly. But the government estimates that as many as 10 percent of cases are in people under 40. Fox is 37. In patients with Parkinson's, the dopamine process is disabled, resulting in muscle tremors, stiffness, slow movement and problems with balance.
Symptoms usually start with mild tremors in a hand or limb.
Later, the disease can affect both sides of the body, causing more severe tremors and a shuffled, unbalanced walk. Everyday activities, such as washing and dressing, gradually become more difficult. There is no cure for Parkinson's disease. The most effective treatment is a drug called levodopa. The drug works by helping the brain replace missing dopamine, which in turn helps control symptoms.