Ventral Capsule/Ventral Striatum Stimulation in Obsessive-Compulsive Disorder: Toward a Unified Connectomic Target for Deep Brain Stimulation?

Introduction Obsessive-compulsive disorder (OCD) is among the most disabling chronic psychiatric disorders and has a significant negative impact on multiple domains of quality of life. Deep brain stimulation (DBS) is a treatment option for severe therapy-resistant OCD. Objective To provide a detailed clinical description and treatment outcome analysis in a cohort of eight refractory OCD patients receiving ventral capsule/ventral striatum (VC/VS) stimulation with the intention to validate discriminating fiber bundles previously associated with clinical response. Materials and Methods The primary outcome measure (the Yale-Brown Obsessive Compulsive Scale [Y-BOCS]) and secondary outcomes depressive symptoms, anxiety, and quality of life were retrospectively analyzed. DBS leads were warped into standard stereotactic space. A normative connectome was used to identify the neural network associated with clinical outcome. Results With a median stimulation duration of 26 months, patients exhibited a mean Y-BOCS reduction of 10.5 resulting in a response rate of 63%. Modulation of a fiber bundle traversing the anterior limb of the internal capsule (ALIC) was associated with Y-BOCS reduction. This fiber bundle connected the frontal regions to the subthalamic nucleus (STN) and was functionally identified as the hyperdirect pathway of the basal ganglia circuitry. Conclusion Our findings show that in VC/VS stimulation, the neural network associated with clinical outcome shows overlap with that of previously described for other targets namely the anterior limb of the internal capsula, the nucleus accumbens, or the STN, which supports the evolvement from the concept of an optimal gray matter target to conceiving the target as part of a symptom modulating network.

Automated summary

Obsessive-compulsive disorder (OCD) is a disabling chronic psychiatric disorder with negative impact on quality of life. Deep brain stimulation (DBS) for severe therapy-resistant OCD shows promising results in modulating specific neural networks associated with symptom improvement.