Deep Transcranial Magnetic Stimulation of the Anterior Cingulate Cortex in Obsessive Compulsive Disorder Patients

Journal: Brain Stimulation 2(4): 188-200 (2009)

Authors: Y Levkovitz, E.V. Harel, Y Roth, Y Braw, D Most, L.N Katz, A Sheer, R Gersner, A Zangen

Background:

Converging evidence points toward the involvement of a dysfunctional cortico-striato-thalamo-cortical (CSTC) circuit in obsessive compulsive disorder (OCD). Transcranial magnetic stimulation (TMS) has been applied to treat and investigate OCD. However, conventional TMS coils lack the ability to target the CSTC circuits directly and treatment protocols for OCD showed diversified results. The use of dTMS coils allows direct stimulation of deeper neuronal pathways relative to those affected by conventional TMS coils. We evaluated whether dTMS targeting the medial prefrontal and the anterior cingulate cortices may influence symptom severity.

Objective:

Evaluate whether dTMS targeting the medial prefrontal and the anterior cingulate cortices influences symptom severity in OCD.

Methods:

Forty OCD patients were treated with either dTMS H7 high (20 Hz) or low (1 Hz) stimulation frequencies or sham coil daily for five weeks in a double blind controlled study. OCD symptoms were provoked in each patient in order to activate the OCD circuitry before treatment. EEG measurements were taken at baseline and at the end of treatment.

Results:

The active 20 Hz dTMS group improved significantly in YBOCS score compared to the 1 Hz and sham groups (26 vs. 6% reduction), {t (93)=-2.29 (p=0.0243)} with three month durability. EEG evoked responses over the anterior cingulate cortex correlated with clinical response, providing an objective measure, or biomarker of dTMS efficacy.

Conclusions:

High frequency dTMS treatment with the H7 coil, targeting the medial prefrontal and anterior cingulate cortices, is a promising therapeutic intervention in OCD.

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