Ventral Capsulotomy for Intractable OCD

Obsessive-compulsive disorder impacts 1-2 percent of the population. Unfortunately, about fifteen percent of patients fail to benefit from existing therapies. A small number of OCD patients, who have a disabling illness that does not improve after conventional treatments, have neurosurgery as a last resort. One procedure, capsulotomy, involves making pairs of lesions in an anatomically-defined part of the anterior limb of the internal capsule, a structure containing nerve fiber bundles connecting the thalamus, in the center of the brain, to the prefrontal cortex, the most anterior and outermost brain region. The investigators will examine how the therapeutic effects of capsulotomy relate to changes in the structure of these brain pathways with structural (diffusion tensor imaging, DTI) and functional (resting-state and task-based) connectivity metrics. The investigators will also utilize experimental cognitive tasks that are sensitive to the circuitry impacted by this procedure.