Most cases of obsessive-compulsive disorder (OCD) respond well to medication or psychotherapy, but as many as 20% of cases remain resistant to these forms of treatment. Doctors have been looking for effective ways to treat these resistant cases of OCD for decades, and one promising approach involves a surgical technique called deep brain stimulation (DBS). A recent survey of DBS studies suggests that the technique could provide long-term relief for the majority of treatment-resistant OCD sufferers.
Searching for the Heart of OCD in the Brain
Deep brain stimulation (DBS) uses electrodes to deliver electrical pulses directly to the brain. The electrodes are connected to a device that’s implanted under the skin of the chest, and the device controls the pattern of the pulses in much the same way that a pacemaker delivers electrical pulses to the heart. The technique has been used successfully to treat movement disorders such as Parkinson’s disease, and it’s more recently been used to treat depression that doesn’t respond to traditional treatments.
The challenge in using DBS to treat OCD is in finding the correct part of the brain to target. Early studies targeted a part of the brain called the anterior limb of the internal capsule. Imaging studies had indicated that this part of the brain was associated with OCD symptoms, and another surgical procedure called an anterior capsulotomy had produced positive results as a treatment for the disorder.
Targeting DBS at the anterior limb of the internal capsule reduced symptoms in many OCD patients, but researchers continued to look for other areas of the brain that might also be effective targets. Other studies have targeted the subthalamic nucleus, the nucleus accumbens, the ventral capsule/ventral striatum, and the inferior thalamic peduncle.
Although the results of targeting these five different areas of the brain varied, the improvement in OCD symptoms have been significant overall. About 60% of participants in the studies fully responded to the treatment, meaning they saw more than a 35% decrease in their symptoms as measured by a commonly used assessment scale.