Brain surgery for obsessive-compulsive disorder effective but risky

Scientists from Karolinska Institutet studying obsessive-compulsive disorder (OCD) patients who have undergone a type of brain surgery called capsulotomy, have found that half of the group improved considerably, even long after the operation. A minority of patients did not improve, however, and developed side-effects.

"The surgical treatment of serious OCD is a very powerful one, but as well as being effective it also has potentially serious side-effects," says research scientist Dr Christian Rück. "In each and every case, it´s a difficult challenge to weigh the dangers against the benefits."

Capsulotomy is a neurosurgical operation that involves severing nerve fibres in the internal capsule, a deep-seated highway of nerve fibres passing between central brain nuclei and the frontal lobes, amongst other areas. These parts of the brain are also thought to play a part in OCD. The operation has been performed since the 1950s on a small number of seriously incapacitated patients who have failed to respond to pharmacological or psychological treatment.

The study, which is published in the prestigious Archives of General Psychiatry, is based on 25 patients with OCD who were operated upon between 1988 and 2000 at Karolinska University Hospital. The patients were followed for up to17 years after the operation with interviews, self-assessment instruments, and MR brain scans. The results show that roughly half of the patients responded well to surgery, an improvement that persisted for many years afterwards. A minority of patients showed signs of apathy and two developed pronounced disinhibition. Two patients became incontinent.

"I think the risks of capsulotomy might have been underestimated," says Dr Rück. "More research is needed on refined methods of determining the site of operation. Our MR analysis of these sites suggest that surgery could be safer and more effective if it was more localised. It’s essential to find efficacious and safe treatments for the most seriously ill."

(Source: Archives of General Psychiatry: Karolinska Institutet: September 2008)