The goal of this proposal is to provide therapy to patients with severe, treatment-refractory obsessive-compulsive disorder (OCD) by stimulating in two separate, but related, brain regions, the dorsolateral prefrontal cortex (dlPFC) and the ventral anterior limb of the internal capsule and adjacent ventral striatum (VC/VS) with a novel Medtronic PC+S deep brain stimulation (DBS) system. While providing this DBS therapy, use of this new, recording-capable device will allow collection of data about brain activity in these two regions. This data will enable researchers to further elucidate the exact mechanisms of DBS therapy, as well as the neuropathophyisiology of OCD. This study aims to 1) gather evidence for corticostriatal changes in OCD in response to acute and chronic VC/VS DBS treatment and 2) specifically disrupt or enhance synchrony in the cortico-striato-thalamo-cortical (CSTC) circuit.~Deep Brain stimulation involves bilateral stereotactic placement of stimulating leads into specific brain structures. Leads are attached to permanent subcutaneous wires and battery-powered implantable neurostimulators (INSs). Noninvasive INS programming can achieve a balance between maximal benefit (reduction in disabling OCD symptoms), while minimizing adverse effects (eg sensorimotor effects such as dysarthria or paresthesias; as well as behavioral side effects, e.g., hypomania, insomnia, or increased anxiety). HDE approval was granted in February 2009, and IDE approval was granted in February 2016. Multiple hospitals around the country have established HDE protocols to implant patients with intractable OCD who have failed conventional therapies, and some hospitals, like us, have obtained Investigational Device Exemption (IDE) approval to conduct pilot clinical trials. The existing model of DBS for OCD only addresses one aspect of the brain circuit implicated in the CSTC circuit, the VC/VS target. Therapy with this device, under this protocol, will also be able to provide stimulation to the cortical part of this circuit. Single-site VC/VS DBS may not adequately target the putative circuit. If OCD symptoms do arise from CSTC loop dysfunction, this implies that the problem is one of improper information flow between connected brain areas. Thus, modifying circuit activity may require coordinated intervention at multiple points to effectively synchronize or de-synchronize the full loop. Stimulation that specifically interrupts reverberant activity between prefrontal cortex and striatum will be superior to VC/VS DBS alone at relieving symptoms of OCD. We will test this by simultaneously implanting stimulating/recording electrodes at both VC/VS and a dorsolateral prefrontal cortex (dlPFC) target bilaterally.
This study involves the use of the Medtronic PC+S deep brain stimulation for the treatment of intractable OCD.