Brain Activity Associated With Tics in Patients With Tourette Syndrome
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.
OBJECTIVES:

 This study will examine the spatiotemporal dynamics of sensory tics in patients with Tourette
 syndrome (TS). We will also investigate the possible existence of a sensory gating problem.
 By investigating somatosensory evoked responses from stimulation of the trigeminal nerve
 (tSERs) on affected versus unaffected sides of the face, we hope to identify differences in
 the SER waveforms that suggest sensory abnormalities. We will use a series of short trains of
 stimulations on the affected side to examine habituation, subsequently performing a time-

 frequency analysis to seek indicators of decreased sensory gating. This study will examine,
 specifically:

 Whether the cortical neurocircuitry involved in the elicitation of tSERs differs in patients
 with tic disorders from controls.

 If SERs differ in a sensory tic facial region of patients, compared to the same spot on an
 unaffected side of the face.

 Whether in controls and patients with sensory tics on both sides of their body, tSERs on both
 sides of the face are symmetrical.

 If there is a lack of habituation in tic patients to tSERs in a short-train click paradigm,
 compared to controls.

 The location for sources of abnormalities in either paradigm.

 STUDY POPULATION:

 Twenty patients and 10 control subjects will be studied. Subjects can be of any race, gender,
 handedness, or age between 14 and 65 years.

 DESIGN:

 This study will compare tSERs in normal volunteers to those in TS patients. Patients with
 bilateral sensory tics will be contrasted with those who have unilateral sensory tics,
 comparing power of the response at latencies on affected versus unaffected sides. Subjects
 will be seated in the MEG and instructed to "feel the delivered sensation, and try not to tic
 for seventy seconds, without counting". The trigeminal nerve will be electrically stimulated
 at 0.25 Hz for 30 seconds, which will be followed by head localization and subsequent rest
 for tic release. To evaluate sensory gating, the design is similar except the trigeminal
 stimulation will occur in short trains. Patients will be surveyed to determine if the
 instructions intensified sensory tics.

 OUTCOME MEASURES:

 We will compare the power of averaged tSERs at latencies, comparing face sides in patients
 and comparing patients' active face side with controls' dominant face side. The power of
 frequency components at latencies will be considered. We will locate the sources of
 differential tSER activity.
-  INCLUSION CRITERIA FOR NORMAL VOLUNTEERS:

 Subjects will be normal volunteers with no history of neurological disorders; they will be
 screened in the NINDS Movement Disorders Outpatient Clinic, and will have a neurological
 and physical examination.

 Subjects will be male or female, in age ranges 14 to 65 years old.

 INCLUSION CRITERIA FOR PATIENTS:

 Patients ages 14 to 65 with a clinical diagnosis of tourette syndrome or chronic motor tic
 disorder as defined by DSM-IV-TR and evaluation of tic severity using the Yale Tic Scale
 (YGTSS). This criterion will be established by preliminary screening in the NINDS Movement
 Disorders Outpatient Clinic. Structure Clinical Interview for (DSMIV SCID) will be
 administered to all subjects to ensure that strict DSM-IV criteria for Tourette syndrome
 have been met and to assess for possible comorbid psychiatric disorders.

 Patients with at least moderate premonitory urge, as evaluated with the PUTS.

 Patients with sensory tics, either bilaterally or unilaterally, in the facial region.

 EXCLUSION CRITERIA FOR PATIENTS AND NORMAL VOLUNTEERS:

 Cardiac pacemaker / cardiac or neural defibrillators.

 Metal fragments in the eyes.

 Metal plates, pins, or bolts in the head.

 Any magnetic implantation / implantations made from iron (ferrous products).

 Hearing problems.

 Problems using response devices.

 Subjects younger than 14 or older than 65 years.

 Subjects with 1 ) major depression, 2) bipolar disorder, or 3) psychotic disorder.

 Subjects taking benzodiazepines, anti-depressant or neuroleptic medications.

 Subjects with major acute or chronic illness, or subjects for whom sitting in a still
 position for an extended period of time would trigger or exacerbate a preexisting condition
 or cause any undue harm or discomfort.

 Pregnant women (steroidal hormones have been shown to influence EEG (Rupprecht et al.,
 2001).

 Patients with severe head tics or subjects who are unable to hold their head still in a
 scanner for at least 70 seconds.