Stereotactic radiosurgery for idiopathic trigeminal neuralgia

Object. Each year a greater number of patients with trigeminal neuralgia (TN) undergo radiosurgery, including a large number of patients who are candidates for microvascular decompression (MVD). Methods. The case characteristics and outcomes of 117 consecutive patients who underwent radiosurgery were retrieved from a prospectively maintained database. The mean patient age was 67.8 years; and the majority (58%) of patients had undergone surgery previously. The dependent variable for all analyses of facial pain was complete pain relief without medication (excellent outcome). Median follow-up duration was 26 months (range 1-48 months). The actuarial rate of achieving and maintaining an excellent outcome was 57% and 55% at 1 and 3 years, respectively, after radiosurgery. A greater percentage of patients who had not previously undergone surgery achieved and maintained excellent outcomes (67% at 1 and 3 years) than that of patients who had undergone prior surgery (51% and 47% at 1 and 3 years, respectively; relative risk [RR] = 1.77, 95% confidence interval [CI] 1.01-3.13, p = 0.04). New persistent trigeminal dysfunction was noted in 43 patients (37%). Tolerable numbness or paresthesias occurred in 29 patients (25%), whereas bothersome dysesthesias developed in 14 patients (12%). Only a radiation dose of 90 Gy correlated with new trigeminal deficits or dysesthesias (RR = 3.10, 95% CI 1.64-5.81, p < 0.001). Excellent outcomes in patients with new trigeminal dysfunction were achieved and maintained at rates of 76% and 74% at 1 and 3 years, respectively, after radiosurgery, compared with respective rates of 46% and 42% in patients who did not experience postradiosurgery trigeminal dysfunction (RR = 4.53, 95% CI 2.03-9.95, p < 0.01). Conclusions. Radiosurgical treatment provides complete pain relief for the majority of patients with idiopathic TN. There is a strong correlation between the development of new facial sensory loss and achievement and maintenance of pain relief after this procedure. Because the long-term results of radiosurgery still remain unknown, MVD should continue to be the primary operation for medically fit patients with TN.