Deep brain stimulation (DBS) is an effective treatment option for patients with refractory obsessivecompulsive disorder (OCD). However, clinical experience with DBS for OCD remains limited. The authors examined the tolerability and effectiveness of DBS in an open study of patients with refractory OCD.Methods: Seventy consecutive patients, including 16 patients from a previous trial, received bilateral DBS of the ventral anterior limb of the internal capsule (vALIC) between April 2005 and October 2017 and were followed for 12 months. Primary effectiveness was assessed by the change in scores on the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) from baseline until the 12-month follow-up. Response was defined by a $35% decrease in Y-BOCS score, partial response was defined by a 25%234% decrease, and nonresponse was defined by a ,25% decrease. Secondary effectiveness measures were the Hamilton Anxiety Rating Scale (HAM-A) and the Hamilton Depression Rating Scale (HAM-D).Results: Y-BOCS, HAM-A, and HAM-D scores all decreased significantly during the first 12 months of DBS. Twelve months of DBS resulted in a mean Y-BOCS score decrease of 13.5 points (SD=9.4) (40% reduction; effect size=1.5). HAM-A scores decreased by 13.4 points (SD=9.7) (55%; effect size= 1.4), and HAM-D scores decreased by 11.2 points (SD= 8.8) (54%; effect size=1.3). At the 12-month follow-up, 36 of the 70 patients were categorized as responders (52%), 12 patients as partial responders (17%), and 22 patients as nonresponders (31%). Adverse events included transient symptoms of hypomania, agitation, impulsivity, and sleeping disorders.Conclusions: These results confirm the effectiveness and safety of DBS of the vALIC for patients with treatmentrefractory OCD in a regular clinical setting.

Background: The ventral anterior limb of the internal capsule (vALIC) is a target for deep brain stimulation (DBS) in obsessive-compulsive disorder (OCD). Conventional surgical planning is based on anatomical landmarks. Objective/hypothesis: We hypothesized that treatment response depends on the location of the active DBS contacts with respect to individual white matter bundle trajectories. This study thus aimed to elucidate whether vALIC DBS can benefit from bundle-specific targeting. Methods: We performed tractography analysis of two fiber bundles, the anterior thalamic radiation (ATR) and the supero-lateral branch of the medial forebrain bundle (MFB), using diffusion-weighted magnetic resonance imaging (DWI) data. Twelve patients (10 females) who had received bilateral vALIC DBS for at least 12 months were included. We related the change in OCD symptom severity on the Yale-Brown obsessive-compulsive scale (Y-BOCS) between baseline and one-year follow-up with the distances from the active contacts to the ATR and MFB. We further analyzed the relation between treatment response and stimulation sites in standard anatomical space. Results: We found that active stimulation of the vALIC closer to the MFB than the ATR was associated with better treatment outcome (p ¼ 0.04; r 2 ¼ 0.34). In standard space, stimulation sites were largely overlapping between treatment (non)responders, suggesting response is independent of the anatomically defined electrode position. Conclusion: These findings suggest that vALIC DBS for OCD may benefit from MFB-specific implantation and highlight the importance of corticolimbic connections in OCD response to DBS. Prospective investigation is necessary to validate the clinical use of MFB targeting.