Clinical Trial: Transcranial Magnetic Stimulation (TMS) and Obsessive Compulsive Disorder (OCD)

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Treatment of Obsessive Compulsive Disorder (OCD) With Transcranial Magnetic Stimulation (TMS)

Brief Summary:

This study will evaluate the clinical efficacy of functional Magnetic Resonance Imaging (fMRI) guided 1 Hz repetitive Transcranial Magnetic Stimulation (rTMS) applied to the Supplementary Motor Area (SMA) in OCD patients who have not fully responded to conventional therapies. The investigators will collect TMS measures of motor cortex excitability to test whether rTMS restores normal levels of intracortical inhibition found to be deficient in OCD. The investigators hypothesize that:

1. Compared to sham (placebo), active rTMS will improve symptoms of OCD as assessed with the Yale Brown Obsessive Compulsive Scale (Y-BOCS) and Clinical Global Impression (CGI).
2. Active (but not sham) rTMS will normalize levels of motor cortex excitability, as reflected by increased intracortical inhibition, motor threshold, and cortical silent period, and by decreased intracortical facilitation, relative to pre-treatment baseline.

Detailed Summary:

This study tests the efficacy of functional Magnetic Resonance Imaging (fMRI) guided repetitive Transcranial Magnetic Stimulation (rTMS) in the treatment of Obsessive Compulsive Disorder (OCD). This study also examines measures of brain function that may inform us about the brain basis underlying OCD.

Despite major advances in the study and treatment of OCD, patients often do not respond or experience only partial remission from pharmacotherapy or cognitive behavioral therapy. rTMS is a non-invasive procedure that allows stimulation of the brain using magnetic fields. Some studies have reported that rTMS may be helpful in reducing obsessive and compulsive symptoms. While promising, prior research has several limitations (e.g., relatively small sample sizes, stimulation of sub-optimal target areas, relatively short durations of treatment, and lack of sham (placebo) comparison).

This study addresses the drawbacks of prior work, and will provide data that will be important in determining whether rTMS can be useful for OCD patients resistant to conventional therapies. In this trial, 32 adult outpatients with OCD, that have been only partially responsive to conventional therapies, will be randomly assigned to one of two treatment groups (active low frequency (1 Hz) rTMS or sham-placebo) applied to the Supplementary Motor Area (SMA) daily for up to four weeks. If rTMS will be added onto ongoing pharmacotherapy, the doses must have been stable for 3 months prior to study entry. The SMA was selected because of its connections with areas of the brain, especially motor areas, implicated in OCD. Pilot work indicates that stimulation of SMA with low frequency rTMS was beneficial in OCD patients. Low frequency rTMS has the added benefit of a better safety profile (i.e. no risk of seizure) compared to high frequency rTMS.

Response rate was defined as a decrease >25% on the YBOCS-SR. Y-BOCS-Self Report (Baer et al. 1993) is very similar to the clinician-administered one, and has shown excellent internal consistency and test-retest reliability, performing somewhat better than the interview (Steketee et al., 1996); subjects are asked to focus on the main obsessions and main compulsions and to answer five questions: time spent, interference, distress, resistance, and control. Consistent with the interview format, subjects rate each item on a 0 (none) to 4 (extreme) scale.