GAMMA-KNIFE RADIOSURGERY FOR TREATMENT OF TRIGEMINAL NEURALGIA - IDIOPATHIC AND TUMOR-RELATED

Sixty patients with trigeminal neuralgia who did not have a response t o pharmacologic treatment (including 22 who had no response to convent ional surgical treatment) underwent stereotactic radiosurgical treatme nt with the Leksell Gamma Knife. A radiosurgical maximum dose of 70 Gy was delivered to the trigeminal nerve root adjacent to the pens via a 4-mm collimator helmet in 51 patients who presented with trigeminal n euralgia unrelated to tumors. In these patients, the root was localize d by stereotactic MRI. Follow-up assessment of pain relief was accompl ished by a third party not involved in the patients' clinical care. Wi thin a latency period of 1 day to 4 months following the treatment, 38 of 51 patients (74.545) were completely free of pain and eventually a ll medications were tapered off. An additional seven patients (13.7%) experienced reductions in pain from 50 to 90% and utilized little or n o medications. Patients who had no prior surgical intervention fared m uch better than those who had previous surgery to relieve their facial pains. At last follow-up, a mean of 16.3 months (range 6-36 months) a fter treatment, 41 patients (80.4%) remained pain-free or had marked p ain reduction. There were four patients with recurrent pain. All 26 pa tients with classical symptoms of trigeminal neuralgia with no atypica l features who had no prior surgery, had complete or nearly complete p ain relief, and none of these patients had recurrent pain. Nine patien ts with trigeminal neuralgia due to tumors received standard radiosurg ical treatment directed at their tumors, and eight of nine (88.8%) had pain relief. Of the total of 60 patients treated for trigeminal neura lgia, 49 (81.7%) experienced complete or nearly complete relief of pai n at last follow-up. Only one patient with pre-existing facial sensory loss due to a tumor had a mild increase in facial numbness. No other patient experienced either loss of facial sensation or any other compl ication. Gamma Knife radiosurgery appears to be a minimally invasive, safe, and effective therapy of trigeminal neuralgia.