Deep brain stimulation for severe treatment-resistant obsessive-compulsive disorder: An open-label case series

Deep brain stimulation can be of benefit in carefully selected patients with severe intractable obsessive-compulsive disorder. The aim of this paper is to describe the outcomes of the first seven deep brain stimulation procedures for obsessive-compulsive disorder undertaken at the Neuropsychiatry Unit, Royal Melbourne Hospital. The primary objective was to assess the response to deep brain stimulation treatment utilising the Yale-Brown Obsessive Compulsive Scale as a measure of symptom severity. Secondary objectives include assessment of depression and anxiety, as well as socio-occupational functioning.

Patients with severe obsessive-compulsive disorder were referred by their treating psychiatrist for assessment of their suitability for deep brain stimulation. Following successful application to the Psychosurgery Review Board, patients proceeded to have deep brain stimulation electrodes implanted in either bilateral nucleus accumbens or bed nucleus of stria terminalis. Clinical assessment and symptom rating scales were undertaken pre- and post-operatively at 6- to 8-week intervals. Rating scales used included the Yale-Brown Obsessive Compulsive Scale, Obsessive Compulsive Inventory, Depression Anxiety Stress Scale and Social and Occupational Functioning Assessment Scale.

Seven patients referred from four states across Australia underwent deep brain stimulation surgery and were followed for a mean of 31 months (range, 8-54 months). The sample included four females and three males, with a mean age of 46 years (range, 37-59 years) and mean duration of obsessive-compulsive disorder of 25 years (range, 15-38 years) at the time of surgery. The time from first assessment to surgery was on average 18 months. All patients showed improvement on symptom severity rating scales. Three patients showed a full response, defined as greater than 35% improvement in Yale-Brown Obsessive Compulsive Scale score, with the remaining showing responses between 7% and 20%.

Deep brain stimulation was an effective treatment for obsessive-compulsive disorder in these highly selected patients. The extent of the response to deep brain stimulation varied between patients, as well as during the course of treatment for each patient. The results of this series are comparable with the literature, as well as having similar efficacy to ablative psychosurgery techniques such as capsulotomy and cingulotomy. Deep brain stimulation provides advantages over lesional psychosurgery but is more expensive and requires significant multidisciplinary input at all stages, pre- and post-operatively, ideally within a specialised tertiary clinical and/or academic centre. Ongoing research is required to better understand the neurobiological basis for obsessive-compulsive disorder and how this can be manipulated with deep brain stimulation to further improve the efficacy of this emerging treatment.