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.
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. Rating scales for symptom change will be obtained at baseline, during the rTMS course, and at the end of 4 weeks of treatment. Patients who do not meet response criteria after four weeks of sham and partial responders to either active or sham will be offered an open-label, cross-over phase for an additional four weeks of daily active rTMS treatment. Patients who meet response criteria in either the randomized phase or the cross-over phase will continue routine clinical care under the supervision of their treating psychiatrist, and will be invited back for a repeat assessment at 3 and 6 months to determine the persistence of benefit. Measures of the excitability of the motor cortex have been reported to be abnormal in OCD, and may relate to dysfunction in motor pathways related to OCD circuits. We will collect measures of motor cortex excitability (performed with single pulse TMS) at baseline and after treatment to determine whether changes in these measures may be correlated with clinical improvement.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
TRIPLE
Enrollment
27
Stimulus train of 30 min duration, 1Hz frequency, and 110% of the motor threshold intensity given once a day, 5 days a week, for 4 weeks by Magstim SuperRapid Magnetic Stimulator.
Sham rTMS will be administered using the Magstim Sham coil which contains a mu-metal shield that diverts the majority of the magnetic flux such that a minimal (less than 3%) magnetic field is delivered to the cortex in order to provoke a subjective sensation similar to that obtained with the real stimulation but without inducing significant cortical stimulation.
New York State Psychiatric Institute, Experimental Therapeutics
New York, New York, United States
Clinical Improvement (Yale-Brown Obsessive Compulsive Scale/Y-BOCS)
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.
Time frame: Through study completion
Motor Cortex Excitability (Motor Threshold)
In 22 OCD patients, who completed the RCT, we applied the new customized software for acquisition and analysis of neurophysiology data that was developed to allow for automatic control of the TMS devices during motor cortex excitability measures. Specifically, the software delivers TMS pulses and automatically determines motor threshold (MT); a descending staircase method is utilized, starting at the intensity at which the optimal site selection for the MT is determined. After each stimulus in the MT experiments, the software would prompt the user to confirm the automated MEP-detection.
Time frame: Through study completion
Motor Cortex Excitability (Short Intracortical Inhibition)
In 22 OCD patients enrolled in the RCT, we applied the new customized software for acquisition and analysis of neurophysiology data that was developed to allow for automatic control of the TMS devices during motor cortex excitability measures. For the paired-pulse (PP) measurements of short intracortical inhibition (SICI) the interstimulus interval (ISI) was set to 8-12 seconds on a continuous uniform distribution. The FPGA board samples the EMG data, controls the timing of the TMS stimuli, and also controls the intensity of the devices.
Time frame: Through study completion
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