Positive clinical response to treatment of obsessive–compulsive disorder using dual-site transcranial magnetic stimulation

To the Editor

Transcranial magnetic stimulation (TMS) utilizes a time-varying magnetic field to non-invasively stimulate or inhibit neuronal activity. In psychiatric disorders, it is used to modulate a component of a suspected neurocircuit in order to relieve symptoms. Studies of TMS in obsessive–compulsive disorder (OCD) have reported variable but generally encouraging results (Trevizol et al., 2016). Among sites that have been targeted with TMS in OCD are the pre-supplementary motor area (SMA) and orbitofrontal cortex (OFC), both of which have been associated with increased activation in OCD (De Wit et al., 2012; Nakao et al., 2014). Historically, TMS has been used at a single site within a suspected neurocircuit, and, to our knowledge, no previous publications have reported dual-site therapy specifically for OCD. In this case, we provided inhibitory stimulation over both the SMA and OFC with significant clinical effect.

Our patient was an 18-year-old female who presented with a 5-year history of OCD. Obsessions generally revolved around contamination and fears of becoming ill. Compulsions consisted of spitting, taking showers, cleaning her hands, counting and eating according to strict rituals. Symptoms were disruptive to the point that she had stopped going to school or engaging in social activities. She had comorbid, recurrent major depressive disorder (MDD). Her symptoms had not responded to multiple medication trials or cognitive behavioral therapy. She was on escitalopram at the time of this study.

Appropriate informed consent was obtained. TMS treatment consisted of 3000 pulses daily provided in 30 sessions over 6 weeks. Each session consisted of 1800 pulses applied over the SMA at a frequency of 1 Hz followed by 1200 pulses over the OFC at a frequency of 1 Hz. This dual-site TMS treatment resulted in a 33% decrease in Yale–Brown Obsessive Compulsive Scale (YBOCS) score, a 48% improvement in Montgomery Asberg Depression Rating Scale (MADRS) score and an improvement in the Clinical Global Impression-Severity scale (CGI-S) by 33%. By the end of treatment, the patient had begun attending school again and engaging in some social activities.

Advances made in neuroimaging studies continue to improve our understanding of altered pathways associated with mental illness. The dual-site approach to TMS may achieve more robust results than targeting a single site within a suspected neurocircuit.