Ventral striatal/ventral capsular Gamma capsulotomy for obsessive-compulsive disorder: a randomized controlled trial

Abstract

Up to 40% of obsessive-compulsive disorder (OCD) patients do not respond to conventional therapies. For them, stereotactic neurosurgery is usually indicated. An improved radiosurgical technique was recently developed, called ventral striatal/ventral capsular (VC/VS) Gamma capsulotomy. On the other hand, there are no randomized controlled trials (RCT) assesing the efficacy and adverse events of radiosurgical procedures, including this one. The first RCT in the world is now being conducted in our center. Preliminary results with patients randomized to receive (in a double-blind method)either true or false radiosurgery suggest that this procedure is possibly efficacious and has a low profile of adverse events. However, definite conclusions can only be drawn with a larger sample size. On the other hand, efficacy and safety of smaller ventral lesions in the internal capsule are still unknown. The aims of this study are: a)to confirm, with an increased sample for the double-blind RCT, that VC/VS Gamma capsulotomy is efficacious and safe for treatment refractory OCD patients; b)to assess efficacy and safety of smaller (single-shot bilateral ventral) VC/VS Gamma capsulotomy lesions.We intend to randomize the next 10 treatment refractory OCD patients in two groups: true radiosurgery and false radiosurgery ("sham operation"). Five patients who do not accept to take part in the RCT will be offered single-shot bilateral ventral lesions. All patients will be subjected, both pre-operatively and at several post-operative time points, to a detailed clinical/psychiatric assessment, and to extensive psychiatric batteries, including diagnostic tests, OCD severity tests, depression/anxiety scales, tics scales, psychosocial impairment assessments and quality of life and family accomodation instruments. Neuropsychological and personality changes will be assessed, as well as structural and functional neuroimaging findings.