Deep brain stimulation of the ventral internal capsule/ventral striatum for obsessive-compulsive disorder: worldwide experience

Abstract

Psychiatric neurosurgery teams in the United States and Europe have studied deep brain stimulation (DBS) of the ventral anterior limb of the internal capsule and adjacent ventral striatum (VC/VS) for severe and highly treatment-resistant obsessive-compulsive disorder. Four groups have collaborated most closely, in small-scale studies, over the past 8 years. First to begin was Leuven/Antwerp, followed by Butler Hospital/Brown Medical School, the Cleveland Clinic and most recently the University of Florida. These centers used comparable patient selection criteria and surgical targeting. Targeting, but not selection, evolved during this period. Here, we present combined long-term results of those studies, which reveal clinically significant symptom reductions and functional improvement in about two-thirds of patients. DBS was well tolerated overall and adverse effects were overwhelmingly transient. Results generally improved for patients implanted more recently, suggesting a 'learning curve' both within and across centers. This is well known from the development of DBS for movement disorders. The main factor accounting for these gains appears to be the refinement of the implantation site. Initially, an anterior-posterior location based on anterior capsulotomy lesions was used. In an attempt to improve results, more posterior sites were investigated resulting in the current target, at the junction of the anterior capsule, anterior commissure and posterior ventral striatum. Clinical results suggest that neural networks relevant to therapeutic improvement might be modulated more effectively at a more posterior target. Taken together, these data show that the procedure can be successfully implemented by dedicated interdisciplinary teams, and support its therapeutic promise.

Figure 1

Post-implant locations (X within circles) of the two lower electrode contacts in a representative patient from the third cohort. The centers of contacts 0 (bottom) and 1 (top) in the coronal, axial and sagittal planes are shown for the right side (all implants were bilateral).

Figure 2

Average electrode positions in patient groups (see text for details). Position plotted is location of tip of distal electrode contact obtained from post-implant imaging. ML position is relative to the midline; anterior–posterior (AP) position is relative to the anterior commissure (AC); dorso–ventral (DV) position is relative to the AC–PC (posterior commissure) line; (n = 23). Two patients from group A and one patient from group B did not have immediate post-operative images that allowed for reasonable estimation of electrode position due to issues related to patient care, and/or image resolution.

Figure 3

Average voltage (left) and pulse width (right) parameter settings for the three patient subgroups.

Figure 4

Mean (±s.e.m.) Yale–Brown Obsessive Compulsive Scale (YBOCS) severity scores pretreatment and at each deep brain stimulation (DBS) treatment rating point.

Figure 5

Clinical response for the three patient subgroups: average percent Yale–Brown Obsessive Compulsive Scale (YBOCS) decrease and percentage of patients meeting responder criterion (35% reduction in YBOCS).

Figure 6

Average (±s.e.m.) Global Assessment of Functioning (GAF) scores over time.

Figure 7

Average (±s.e.m.) change in depression (left) and anxiety (right) measures over time.