Early Stereotactic Radiosurgery for Medically Refractory Trigeminal Neuralgia

OBJECTIVE: To evaluate effectiveness of early Gamma Knife radiosurgery (GKRS) in treatment of medically refractory trigeminal neuralgia (TN). METHODS: This retrospective review comprised 108 consecutive patients with medically refractory idiopathic TN between 2006 and 2014. All patients underwent GKRS targeting the root entry zone with a median maximum dose of 90 Gy and isodose line of 20%. Outcomes pertaining to pain and facial numbness were scored using Barrow Neurological Institute scales. RESULTS: Following a median latency period of 4 weeks, we observed complete or adequate pain relief (Barrow Neurological Institute scores of I-IIIB) in 86 of 108 patients (90%). At a median time of 17 months, 22 patients (26%) experienced pain recurrence. New-onset facial numbness was reported by 59 patients (55%). Treatment failure rates were highest among patients with a longer history of pain. Compared with patients with pain history of <= 5 years, patients with pain history of >5 years experienced longer latency before pain relief (P = 0.027). Univariate and multivariate analyses demonstrated that pain history of <= 5 years was a significant predictor of pain relief (P = 0.049 and P = 0.045, respectively). CONCLUSIONS: GKRS achieves a high rate of pain relief among patients with medically refractory idiopathic TN. Pain history of <= 5 years is a reliable predictor of pain relief and appears to be associated with shorter latency to pain relief after GKRS. Therefore, early GKRS for patients with medically refractory idiopathic TN is recommended.