BACKGROUND: Obsessive compulsive disorder (OCD), in its severe form, can cause 
tremendous disability for affected patients.
OBJECTIVE: To evaluate the results following bilateral radiosurgical anterior 
capsulotomy for severe medically refractory OCD.
METHODS: We performed gamma knife anterior capsulotomy (GKAC) on 3 patients with 
extreme, medically intractable OCD. According to our protocol, all patients were 
evaluated by at least 2 psychiatrists who recommended surgery. The patient had 
to request the procedure, and had to have severe OCD according to the Yale-Brown 
Obsessive Compulsive Scale (YBOCS). Patient ages were 37, 55, and 40 years, and 
pre-radiosurgery YBOCS scores were 34/40, 39/40, and 39/40. Bilateral lesions 
were created with 2 4-mm isocenters to create an oval volume in the ventral 
internal capsule at the putaminal midpoint. A maximum dose of 140 or 150 Gy was 
used.
RESULTS: There was no morbidity after the procedure, and all patients returned 
immediately to baseline function. All patients noted significant functional 
improvements, and reduction in OCD behavior. Follow-up was at 55, 42, and 28 
months. The first patient reduced her YBOCS score from 34 to 24. One patient 
with compulsive skin picking and an open wound had later healing of the chronic 
wound and a reduction in the YBOCS score from 39 to 8. At 28 months, the third 
patient is living and working independently, and her YBOCS score is 18.
CONCLUSION: Within a strict protocol, gamma knife radiosurgery provided 
improvement of OCD behavior with no adverse effects. This technique should be 
evaluated further in patients with severe and disabling behavioral disorders.