Pathophysiology, assessment, and treatment of Parkinson's disease.

Parkinson's disease (PD) is a slowly progressing neurologic movement disorder affecting nearly 1% of the population over age 65. PD is the fourth most common neurodegenerative disease of patients. Incidence is greater in men with a ratio of 3:2--men to women. Because PD is so complex, diagnosis and treatment are often very challenging. While the cause of PD is unknown, research has concentrated on genetics, exogenous toxins, and endogenous toxins from cellular oxidative reactions. The presenting symptoms of a patient with PD include muscle rigidity, tremors, bradykinesia, and postural instability. Treatment for PD has been primarily pharmacologic: levodopa, carbidopa, anticholinergics, and selegiline (a monoamine oxidase inhibitor to reestablish an equilibrium between dopamine and acetylcholine). surgical procedures (e.g., pallidotomy, thalamotomy, and tissue implants) are a possible choice of treatment for patients who have failed to respond satisfactorily to drugs.