Studies of Capsulotomy, Cingulotomy

Two neurosurgical lesion procedures under investigation for use with patients with psychiatric disorders are cingulotomy for intractable obsessive-compulsive disorder (OCD) and depression and capsulotomy for intractable OCD.

In cingulotomy, historically the most-performed psychosurgical procedure in the United States, probes are inserted through the top of the skull into the cingulum bundle and overlying cingulate cortex. Surgeons heat the tips of the probe to burn portions of tissue selectively.

Capsulotomy originally involved the insertion of probes through the top of the skull and into the internal capsule. But more recent work in the United States has focused on gamma knife capsulotomy, a radiosurgical device that makes precise lesions in tissue without the need for craniotomy.

Both procedures are guided by magnetic resonance imaging.

A study on cingulotomy, “Magnetic Resonance Image-Guided Stereotactic Cingulotomy for Intractable Psychiatric Disease” by researchers at Harvard Medical School, appeared in June 1996 in the journal Neurosurgery.

In the study, a retrospective analysis of outcome was performed for 34 patients who had intractable major affective disorder and/or OCD and underwent MR image-guided stereotactic cingulotomy since 1991. Fourteen patients underwent multiple cingulotomies. Overall, 38 percent of the patients were classified as responders, 23 percent as possible responders, and 38 percent as nonresponders. Of the patients who did not respond to initial cingulotomies and who underwent multiple cingulotomies, 36 percent became responders, 36 percent possible responders, and 28 percent nonresponders. There were no deaths or long-term side effects related to the procedure.

A study by the same research group, “Prospective Long-Term Follow-Up of 44 Patients Who Received Cingulotomy for Treatment-Refractory Obsessive-Compulsive Disorder” was published in the February 2002 American Journal of Psychiatry.

In that study, open preoperative and follow-up assessments were conducted at multiple time points for 44 patients undergoing one or more cingulotomies for treatment-refractory OCD.

At a mean follow-up of 32 months after one or more cingulotomies, 14 patients (32 percent) met criteria for treatment response, and six others (14 percent) were partial responders. Few adverse effects were reported. These included memory deficits, apathy and decreased energy, urinary disturbances, and—in one patient—seizure disorder.

Finally, Greenberg noted that preliminary findings from an ongoing study of anterior capsulotomy performed using the gamma knife are also encouraging, with just over half of the patients meeting response criteria two years after surgery.

Anecdotally, adherence to and success of behavior therapy—which all patients had attempted prior to surgery—appeared much enhanced after surgery in responders.

Publication of the results of this study are expected in 2004, Greenberg said.