This study will use transcranial magnetic stimulation (TMS) to study the function of the
cerebral cortex (outer layer of the brain) in people with obsessive compulsive disorder
(OCD) and related disorders. A non-invasive procedure, TMS activates areas of the brain with
magnetic pulses that travel through the scalp and head and cause small electrical currents
in the brain.
People 18 years of age and older with OCD and disorders that may be related-tic disorders,
such as Tourette's syndrome, focal dystonia (localized muscle cramps), body dysmorphic
disorder (hypersensitivity to changes in appearance), eating disorders, such as anorexia
nervosa, trichotillomania (compulsive hair-pulling)-may be eligible for this study. Healthy
normal volunteers will also be enrolled. Candidates will be screened by telephone interview.
Participants will undergo TMS. For this procedure, an insulated wire coil is placed on the
subject's head. A brief electrical current passes through the coil, creating a magnetic
pulse that travels through the scalp and skull and causes small electrical currents in the
outer part of the brain. The stimulation may cause muscle, hand or arm twitching, or may
affect movement or reflexes. During the stimulation, the subject may be asked to tense
certain muscles slightly or perform other simple actions. The electrical activity of muscles
during stimulation is recorded with a computer or other recording device, using electrodes
attached to the skin with tape.
Subjects will receive fewer than 500 magnetic pulses, and the study will take less than 3
hours. Participants may repeat the procedure on several occasions, if they agree.
Transcranial magnetic stimulation (TMS), a noninvasive means of stimulating the brain
through the scalp and skull, has become an important tool in neurophysiology and
neuropsychiatry. The purpose of this project is (1) to use TMS as a probe of cortical
excitability to investigate the physiology of the cerebral cortex in Obsessive-Compulsive
Disorder (OCD) and OCD-related disorders (including the "OCD spectrum"), which we believe to
be disorders involving alterations in the excitability of the cortex; (2) to compare those
findings to results in healthy individuals, and (3) to evaluate the possible effects of
various pharmacological treatments on TMS parameters in individuals with OCD and OCD-related
disorders. This protocol seeks to evaluate the hypothesis that TMS may provide a sensitive
measure of cortical function that is relevant to the underlying pathology in OCD and
OCD-related disorders. The identification of possible anomalies of TMS measures in these
patient groups and changes elicited by pharmaceutical agents will be useful in orienting
research towards investigations of the cortical neurotransmitter systems.
Subjects will be screened for history of significant medical and non-OCD-related
neuropsychiatric illnesses by means of a phone screening and interview with a trained
screener (nurse, physician, social worker or psychologist).
Each patient and healthy volunteer entered into the study must be free of significant
medical or psychiatric illness and not taking any medications with neurological or
The presence of neurological abnormalities will not be an exclusionary criterion because
of the existence of lesional OCD & OCD spectrum disorders that may co-exist with
The only exclusionary criteria for this study are subjects who have a pacemaker, an
implanted medication pump, a metal plate in the skull, metal objects inside the eye or
skull (for example, after brain surgery or a shrapnel wound) or any recent (less than 3
months) brain lesions.
Subjects under 18 years of age will be excluded.