Gamma Knife surgery anterior capsulotomy for severe and refractory obsessive-compulsive disorder

Abstract

Obsessive-compulsive disorder (OCD) is a challenging psychiatric condition associated with anxiety and ritualistic behaviors. Although medical management and psychiatric therapy are effective for many patients, severe and extreme cases may prove refractory to these approaches. The authors evaluated their experience with Gamma Knife (GK) capsulotomy in treating patients with severe OCD. A retrospective review of an institutional review board-approved prospective clinical GK database was conducted for patients treated for severe OCD. All patients were evaluated preoperatively by at least one psychiatrist, and their condition was deemed refractory to pharmacological and psychiatric therapy. Five patients were identified. Gamma Knife surgery with the GK Perfexion unit was used to target the anterior limb of the internal capsule bilaterally. A single 4-mm isocenter was used; maximum radiation doses of 140-160 Gy were delivered. All 5 patients were preoperatively and postoperatively assessed for clinical response by using both subjective and objective metrics, including the Yale-Brown Obsessive Compulsive Scale (YBOCS); 4 of the 5 patients had postoperative radiological follow-up. The median clinical follow-up was 24 months (range 6-33 months). At the time of radiosurgery, all patients had YBOCS scores in the severe or extreme range (median 32, range 31-34). At the last follow-up, 4 (80%) of the 5 patients showed marked clinical improvement; in the remaining patient (20%), mild improvement was seen. The median YBOCS score was 13 (range 12-31) at the last follow-up. Neuroimaging studies at 6 months after GK treatment demonstrated a small area of enhancement corresponding to the site of the isocenter and some mild T2 signal changes in the internal capsule. No adverse clinical effects were noted from the radiosurgery. For patients with severe OCD refractory to medications and psychiatric therapy, GK capsulotomy afforded clinical improvement. Further study of this approach seems warranted.