These clinical trials are part of larger multi-center studies that are evaluating the effectiveness of several medications, including rasagiline, entacapone and levodopa ethyl ester. Parkinson's disease is one of the most common movement disorders. It is a lifelong neurological condition that increasingly affects a person's ability to perform the normal activities of daily living. It is characterized by a tremor at rest, a general slowing of pace and a slow shuffling gait that may be associated with loss of balance. Speech can become soft and difficult to understand.
Symptoms progress slowly over time.
Celebrities like Michael J. Fox, Janet Reno, Muhammad Ali and Pope John Paul II have fostered a global appreciation of Parkinson's disease, but there is still no known cause or cure for this disorder. Treatments that offer relief from symptoms often become less effective as the disease progresses. The irony is that drugs currently used to treat Parkinson's contribute to the development of yet another symptom known as dyskinesia, or drug-related involuntary movements. These movements resemble restless wriggling or even gyrating movements that at times can cause as much trouble as the Parkinson's itself. The onset of Parkinson's disease is often when people are in their 50s and 60s.