Brain Dynamics Involved in Generating Tics and Controlling Voluntary Movement
This study will use electroencephalography (EEG) and electromyography (EMG) to examine how the brain generates tics and controls voluntary movement in patients with Tourette's syndrome and chronic motor tic disorder. EEG records the electrical activity of the brain. For this test, a cap with built-in electrodes is placed on the subject's head, and the electrodes are connected to a monitor that records the brain activity. EMG records muscle activity using electrodes placed on the skin over muscles on the fingers or above the outer corner of the eyes.
Healthy normal volunteers and patients with Tourette's syndrome and chronic motor tic disorder between 21 and 65 years of age may be eligible for this 2- to 3-hour study. Each candidate will be screened with a medical history, physical and neurological examinations, and a questionnaire that screens for psychiatric disorders.
During EEG and EMG recordings, participants undergo the following tasks while seated comfortably in a sound-shielded room:
- Finger task: Patients raise their index finger once every 10 seconds for about 25 minutes.
- Tic evaluation and mimicking: Patients allow their tics to occur as they do naturally. After each tic, they report whether the tic was voluntary and whether it was preceded by a sensation of urge. They then mimic tics that they normally have, at a rate of about once every 10 seconds.
- Tic suppression task: Patients suppress tics they normally have for several minutes. They then allow the tics to occur naturally, without attempting to suppress them.
- Finger task: Volunteers raise their index finger once every 10 seconds for about 25 minutes.
- Open eye task: Volunteers keep their eyes open for a minute or so, and then resume blinking as often as feels comfortable. The process is repeated several times.
|Official Title:||Spatiotemporal Dynamics of Cortical Connectivity Involved in Tics and Voluntary Movements in Patients With Tourette's Syndrome and Chronic Motor Tic Disorder: An EEG Study|
|Study Start Date:||March 2003|
|Estimated Study Completion Date:||January 2009|
This study examines the spatiotemporal dynamics of cortical functional interconnectivity involved tics and voluntary movement in patients with Tourette's syndrome or chronic motor tic disorder. By employing a combination of EEG methods that utilize analyses in the domains of both frequency (e.g., event-related desynchronization/synchronization (ERD/ERS), event-related partial coherence, phase coherence) and time (e.g., event-related partial correlation), we intend to determine
- Whether the cortical neurocircuitry involved in the performance of a simple, voluntary motor task differs in patients with tic disorders from that of healthy volunteers;
- Whether the network involved in the generation of unwanted tics differs from that of normal voluntary movement (i.e., mimicked tics); and
- What role, if any, premonitory urge and/or tic suppression plays in the modulation of this neurocircuitry.
|United States, Maryland|
|National Institutes of Health Clinical Center, 9000 Rockville Pike|
|Bethesda, Maryland, United States, 20892|