EP 22. Deep brain stimulation of ventral internal capsule for refractory obsessive compulsive disorder

Abstract

OCD is generally believed to be one of the most distressing of all anxiety disorders. Some OCD patients remain refractory and run a chronic deteriorating course. Therapeutic option in this group was initially limited to ablative surgery like anterior capsulotomy or anterior cingulotomy. Current study is aimed to see the effect of deep brain stimulation of posterior and ventral part of internal capsule on severity of OCD symptoms after three months, six months and then yearly follow-ups. Present series consisted of two patients having intractable OCD. Two psychiatrists independently assessed each patient. Both the patients full filled the criteria for OCD (33.30) according to the Diagnostic and Statistical Manual of Psychiatric Disorders 4th edition (DSM IV). Both failed to improve following treatment with at least 3 selective serotonin reuptake inhibitors (SSRIs) and have completed Cognitive Behavior Therapy (CBT) Outcome of both the patients was measured by Y-BOCS scale (Yale-Brown Obsessive-Compulsive Scale), BDI (Beck Depression Inventory) and MMSE (Mini mental scale examination). The pre and post operative assessment was done by two clinical psychologists who independently assessed both the patients Target for stimulation was deep ventral at anterior limb of internal capsule just posterior to anterior commissure 5–6 mm from midline. Leads were implanted stereotactically on both sides under local anaesthesia and sedation. Quadripolar stimulating electrode (Model 3387 Medtronic) were used on both sides and they are connected to Pulse Generator (Medtronic) by connecting leads under general anaesthesia. In the first case non rechargeable pulse generator (Kinetra) was used while in the second case rechargeable pulse generator (Activa RC) was used. Programming of device was started after six weeks and continued for six to eight months till patient show significant improvement. Medications were kept unchanged. Neuropsychiatric evaluation was done after three months and six months. Afterwards yearly follow-up was done. Our primary aim of this study is to determine the efficacy of DBS for OCD and to compare its result to traditional anterior capsulotomy. The literature indicates that anterior capsulotomy produces a 35% improvement in OCD symptoms in about 45% of operated patients. Present series of two patients showed very significant improvement in both cases. Our first case reported 68.42% improvement in her OCD symptoms as her Y-BOCS score reduced from 38 to 12 and (45.45%) of improvement in BDI score after one year. Similar finding was observed in second patient where Y-BOCS reduced from 38 to 10 (73.68% improvement) and BDI improved to 70.83%. There was no change in MMSE score in both cases that signifies no adverse effect on mental status. Both the patients showed more than 35% improvement that was much superior to results achieved by bilateral capsulotomy. Very significant improvements in present series relates to the placement of leads that were more posterior and ventral. There was recurrence of symptoms of OCD in first patient after nineteen months related to depletion of battery that improved after replacement with newer one. This problem was rectified in second patient where rechargeable DBS system was used that has long battery life. Conclusion We conclude that DBS of VC/VS complex is very safe and effective in refractory OCD and the shows considerable promise for future. The long term result of this small controlled study is much better as compared to lesioning (capsulotomy).