Obsessive compulsive disorder (OCD) affects 2-3% of the population. It consists of persistent thoughts (obsessions), uncontrollable repetitive behaviours (compulsions) and anxiety. More than 20% of cases are resistant to medical treatments but would improve with surgery or "radiosurgery". Disconnecting some of the circuits between the frontal lobe and the rest of the brain has shown to improve OCD symptoms.
OCD can be treated with magnetic resonance-guided (MRI) stereotactic surgery. Patients are examined using functional tests and MRIs to locate the regions to be treated that give rise to a patient's OCD. An instrument is placed on the head. An MRI is performed and the patient is transferred to the operating room. Under general anaesthetic, two holes are made in the frontal region through which a heated probe is inserted, making lesions the size of a grain of rice that disconnect different brain regions. The approximate duration of the procedure is four hours.
After OCD surgery, patients are somewhat disoriented and experience moderate headaches. They may also suffer from fever, nausea and vomiting, though they are relaxed and calm. They usually stay in hospital for three days. OCD obsessions start disappearing quickly, but the complete improvement appears after a year when the patient will find themselves noticeably less obsessive and compulsive.
Another treatment is radiosurgery with Gamma Knife. The patient is fitted with a stereotactic instrument and enters the Gamma Knife, which consists of a radiation system similar to an MRI, and which does not require anaesthesia. The patient remains in this machine for about three hours and leaves the hospital within two hours after the procedure. The patient experiences no discomfort and obsessive behaviour improves from six months to a year, progressively and slowly.
OCD obsessions and compulsions improve in 71% of cases, with an improvement in the quality of life of the patient in 75%. The results are similar in the group treated with "radiosurgery". No long-term adverse effects have been observed.