Transcranial Direct Current Stimulation to Treat Symptoms of Parkinson's Disease

This study will examine the effects of transcranial direct current stimulation (tDCS) on gait (walking) problems and rigidity in patients with Parkinson's disease. tDCS is a method of brain stimulation that may be able to change the electrical activity of the nerves of the brain, possibly causing Parkinson's disease symptoms to improve. Patients between 40 and 80 years of age with moderately severe Parkinson's disease whose main symptoms are problems with walking, including freezing, or rigidity, may be eligible for this study. Candidates must be taking Sinemet or another L-DOPA drug and not have too much tremor. Participants will be assigned to receive either real or sham (placebo) tDCS. Both groups will have eight treatments over 3-1/2 weeks. For the tDCS, electrodes are placed on wet pads on the scalp. An electrical current passes through the electrodes, travels through the scalp and skull, and causes small electrical currents in the cortex-the outer part of the brain. Participants will have a neurological examination, including an evaluation of walking, just before and just after each tDCS session. Patients' motor function will be re-evaluated at 1, 3, and 6 months after the last tDCS treatment. ...