The Effect of Low-Frequency Repetitive Transcranial Magnetic Stimulation at Orbitofrontal Cortex in the Treatment of Patients With Medication-Refractory Obsessive-Compulsive Disorder

Abstract

Obsessive-compulsive disorder (OCD) is a chronic debilitating psychiatric disorder, with significant proportion of patients failing to respond with current first-line treatments. The present study assesses the safety and effectiveness of low-frequency repetitive transcranial magnetic stimulation (LF-rTMS) over left-orbitofrontal cortex (Lt-OFC) as a potential augmentation strategy in treatment of patients with medication-refractory OCD in real-world clinical setting. The present report also aims to examine the factors affecting response to rTMS and the durability of effects produced by rTMS over 1 month of follow-up period. Retrospective review and analysis of clinical case files of 25 patients with medication-refractory OCD, all of whom had received 20 sessions of LF-rTMS over Lt-OFC as part of routine clinical care. A reduction of 25% and 35% in Yale-Brown Obsessive Compulsive Scale scores was used to determine the proportion of partial and complete responders, respectively. There was a significant decrease in mean Yale-Brown Obsessive Compulsive Scale score at the end of 20 sessions of rTMS compared with baseline (7.04 ± 5.07; P < 0.001), with no further significant change during the subsequent 1-month follow-up period (0.20 ± 1.38; P = 0.47). Thirteen patients (52%) met criteria for partial response, of which 11 patients (44%) showed complete response. Furthermore, higher number of failed medication trials was found to be significantly associated with greater chances of nonresponse to rTMS treatment. There is a role of applying LF-rTMS over Lt-OFC as an augmentation strategy in ameliorating clinical symptoms among patients with medication-refractory OCD.