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.