Gamma knife radiosurgery for the treatment of trigeminal neuralgia.

One hundred and ten patients with trigeminal neuralgia were treated with the Gamma Knife using a single isocenter, the 4 mm secondary collimator helmet and a radiosurgical dose maximum of 70 or 80-Gy. The isocenter was placed at the trigeminal sensory root adjacent to the pons as identified on stereotactic MRI scans. Follow-up periods range from 4-49 months (mean 19.8 months). Initial pain relief was achieved in 95.5% of patients with typical trigeminal neuralgia symptoms, who had not had prior surgical intervention, and only 3.3% of these patients experienced recurrent pain during the follow-up period. Patients with atypical features to their pains or who had prior unsuccessful surgical attempts to relieve their pains achieved initial and long-term pain relief in 88 and 69%, respectively. Three patients (2.7%) developed delayed loss of facial sensation following treatment, but no other complications of any kind were noted. We believe that Gamma Knife radiosurgery is the safest and most effective form of treatment which is currently available for trigeminal neuralgia. We recommend early radiosurgical treatment of trigeminal neuralgia once the diagnosis is clearly established.