Brain Activity Associated With Tics in Patients With Tourette Syndrome

This study will examine brain activity associated with the involuntary urges or uncontrolled movements, called "tics," experienced by people who have Tourette syndrome (TS). Before people with TS actually develop a tic, whether it is a movement or a vocal tic (like a cough or bark), they feel the urge to tic. This study will look at brain activity during the time of this urge and how brain activity may differ in people with TS and without TS. Healthy normal volunteers and patients with TS between 14 and 65 years of age may be eligible for this study. Patients must have sensory tics in the facial region and must experience at least a moderate premonitory urge. Candidates are screened with a medical history, brief physical examination, and a questionnaire. Participants undergo the following procedures:

• Magnetoencephalography (MEG): This test records magnetic field changes produced by brain activity. During the test, the subjects are seated in the MEG recording room and a cone containing magnetic field detectors is lowered onto their head. Electrodes (small metal disks) are placed on both sides of the face near the jaw. The recording may be made while the subject receives small currents from the electrodes on the jaw. Subjects may be asked a few questions about what they felt during the procedure.
• Magnetic resonance imaging (MRI): This test uses a strong magnetic field and radio waves to obtain images of body organs and tissues. During the procedure, the subject lies on a table that can slide in and out of the scanner-a metal cylinder. Subjects may be asked to lie still for up to 30 minutes at a time. They can communicate with the staff at any time during the scan.
• Somatosensory evoked responses: This test examines how sensory information travels form the nerves to the spinal cord and brain in the nervous system. An electrode placed on the arm, leg, or face delivers a small electrical stimulus that may tingle and cause a twitch of a hand, foot, or face muscle. Additional electrodes may sometimes be placed on the scalp, neck, and over the collarbone to record how the impulse from the stimulus travels over nerve pathways. Patients in the study are contacted for follow-up after the study. Follow-up will be conducted by phone or email, according to the patients' convenience, and will consist of reaffirming that there were no adverse events.