Transcranial Magnetic Stimulation (TMS) Studies of Dystonia

Study Summary

This study will use transcranial magnetic stimulation to examine how the brain controls muscle movement in focal and generalized types of dystonia. Dystonia is a movement disorder in which involuntary muscle contractions cause uncontrolled twisting or abnormal postures. Dystonia may be focal, involving just one region of the body, such as the hand, neck or face. Focal dystonia usually begins in adulthood. Generalized dystonia, on the other hand, generally begins in childhood or adolescence. Symptoms begin in one area and then become more widespread. Healthy normal volunteers and patients with focal or generalized dystonia 8 years of age and older may be eligible for this study. First-degree relatives of patients will also be enrolled. In transcranial magnetic stimulation, an insulated wire coil is placed on the subject's scalp and brief electrical currents are passed through the coil, creating magnetic pulses that pass into the brain. These pulses generate very small electrical currents in the cortex-the outer part of the brain-briefly disrupting the function of the brain cells in the stimulated area. The stimulation may cause muscle twitching or tingling in the scalp, face and limbs. During the stimulation, the subject will be asked to either keep the hand relaxed or to slightly tense certain muscles in the hand or arm. The test will last about 1.5 hours. The cause of dystonia is unknown. It is hoped that a comparison of brain activity in normal volunteers, patients and their relatives not affected by dystonia will help scientists learn why some people develop dystonic movements.

Conditions Studied

Study Locations (1)