Metabolic imaging of anterior capsular stimulation in refractory obsessive-compulsive disorder: a key role for the subgenual anterior cingulate and ventral striatum.

TLDR

High‑frequency anterior capsular stimulation is a novel, reversible neuromodulatory therapy under investigation for refractory OCD, with its mechanism thought to involve disruption of the corticothalamostriatocortical circuit. The study used (18)F‑FDG PET in six OCD patients before and after stimulation, comparing results to 20 matched healthy controls with volume‑of‑interest and statistical parametric mapping analyses. High‑frequency anterior capsular stimulation reduced prefrontal metabolism, particularly in the subgenual anterior cingulate, and the magnitude of this decrease correlated inversely with Y‑BOCS and HAM‑D scores, while pre‑operative subgenual activity predicted therapeutic response, supporting a pivotal role for the subgenual anterior cingulate and ventral striatum in OCD pathophysiology and neuromodulation.

Abstract

High-frequency anterior capsular stimulation is a new, promising, and reversible neuromodulatory treatment in the research stage for patients with refractory obsessive-compulsive disorder (OCD). The mechanism of action is unknown but hypothesized to be secondary to interruption of the corticothalamostriatocortical circuit. (18)F-FDG PET was performed on 6 consecutive OCD patients preoperatively and after stimulation. The results were compared with those of 20 age- and sex-matched healthy volunteers by using both a standardized volume-of-interest-based approach for subcortical areas and statistical parametric mapping. Correlations were investigated with Yale-Brown Obsessive Compulsive Scale scores (Y-BOCS) and Hamilton Depression Rating Scale scores (HAM-D).Chronic anterior capsular electrostimulation resulted in a further decrease of prefrontal metabolic activity, especially in the subgenual anterior cingulate (P < 0.001). Correlation analysis demonstrated that decreases in Y-BOCS and HAM-D with anterior capsular electrostimulation were inversely related to the metabolic activity changes in the left ventral striatum, left amygdala, and left hippocampus (P < 0.01). Preoperative resting metabolic activity in the subgenual anterior cingulate was predictive of therapeutic response (P = 0.001).These observations provide evidence that the subgenual anterior cingulate and ventral striatum have a key role in the neuronal circuitry involved in the pathophysiology of OCD with associated major depression and in the neuromodulatory mechanism of anterior capsular stimulation.