Inferior thalamic peduncle deep brain stimulation for treatment-refractory obsessive-compulsive disorder: A phase 1 pilot trial.

BACKGROUND: Several different surgical procedures targeting the limbic circuit have been utilized for severe, treatment resistant obsessive-compulsive disorder; however, there has only been limited exploration of the inferior thalamic peduncle (ITP). The aim of this study was to determine the safety and initial efficacy of ITP deep brain stimulation (DBS) in patients with severe obsessive-compulsive disorder.

METHODS: Patients with severe, treatment-refractory obsessive-compulsive disorder were enrolled into this open-label phase 1 DBS pilot study. Bilateral ITP DBS devices were implanted between November 2010 and December 2015. The primary outcome was safety. The initial efficacy was determined by Yale-Brown Obsessive-Compulsive scale (YBOCs) scores. Component Y-BOCs scores, Hamilton Depression Severity Scale, Quality of Life Assessment (SF-36), Oxford Happiness Questionnaire, Warwick-Edinburgh Mental Well-Being Scale, and Sheehan Disability Scale were also analyzed for a minimum of 2 years after surgery. Additionally, preoperative and three-month postoperative FDG-PET studies were performed on two patients.

RESULTS: Five patients (2 males, 3 females; age range 25-48 years) received ITP DBS. All five patients were considered responders at one year (52% improvement in YBOCs scores compared to baseline (range 39-73%, p < 0.01) and last follow-up (54% improvement; range 38-85%; p < 0.01). At two years follow-up, there were three adverse events that occurred in two patients. One patient had his DBS system removed after one year due to the device becoming the object of his obsession. The other two adverse events were not related to the device. Post-operative FDG-PET imaging in two patients demonstrated decreased glucose uptake within the right caudate, right putamen, right supplementary motor area, and right cingulum and increased glucose uptake in bilateral motor areas, left temporal pole, and left orbitfrontal cortex.

CONCLUSIONS: ITP DBS has a favorable safety profile and is potentially an efficacious treatment for severe obsessive-compulsive disorder. Larger clinical trials are necessary to determine efficacy.