Glutamatergic neurotransmission is affected by low-frequency repetitive transcranial magnetic stimulation over the supplemental motor cortex of patients with obsessive-compulsive disorder

Objective: In obsessive-compulsive disorder (OCD), glutamatergic neurotransmission dysfunction played key roles in pathophysiology. The current research assessed changes of neurometabolites in the bilateral striatum of OCD patients receiving low-frequency repetitive transcranial magnetic stimulation (rTMS) using 1H proton magnetic resonance spectroscopy (1H-MRS). Methods: 52 OCD patients were divided into rTMS treatment group (29) and the control group (medication only) (22). The levels of neurometabolites in the bilateral striatum of patients with OCD were measured using MRS before and after treatment. All participants were taking medication prior to the treatment and the process. Results: Following rTMS treatment, Yale-Brown Obsessive-Compulsive Scale (YBOCS) score was significantly decreased in the rTMS group compared with the control group. Glutamate (Glu) and glutamate and glutamine complexes (Glx) in the bilateral striatum of the rTMS treatment response group increased significantly with the improvement of OCD. Glu in the bilateral striatum and Glx in the right striatum were positively correlated with compulsion after the treatment. Conclusions: The physiopathological mechanism of OCD may be related to the glutamatergic dysfunction, and the low-frequency repetitive transcranial magnetic stimulation applied to the supplementary motor area can improve OCD symptoms by modulating glutamatergic levels in the bilateral striatum of patients with OCD.