Stereotactic Radiosurgery for Type 1 versus Type 2 Trigeminal Neuralgias

INTRODUCTION: It remains unclear whether stereotactic radiosurgery (SRS) offers the same benefit for patients with type 2 trigeminal neuralgia (TN2) as for those with type 1 trigeminal neuralgia (TN1). The objective of this study is to compare the outcomes of patients with TN1 and TN2 after SRS. METHODS: SRS outcomes of patients with trigeminal neuralgia treated at a single center from 1994 to 2016 were analyzed. Patients with TN1 were matched to those with TN2 in a 1: 1 ratio based on sex, age, pretreatment Barrow Neurological Institute (BNI) pain score, previous treatment, previous facial numbness, and maximum dose. The primary outcome was defined as a BNI pain score of <= 3. RESULTS: The matched TN1 and TN2 cohorts each comprised 56 patients. There were no differences in BNI pain scores at last follow-up, new/worse facial numbness, or pain recurrence, or time to recurrence. Time to initial pain relief after SRS was longer for patients with TN2 (5.4 vs. 4.4 months; P = 0.0016). Actuarial initial pain relief rates were 75%, 90%, and 90% for TN1 and 47%, 77%, and 87% for TN2 at 5, 10, and 15 months, respectively. Actuarial pain relief maintenance rates were 72%, 67%, and 52% for TN1 and 53%, 32%, and 32% for TN2 at 1, 2, and 3 years, respectively. CONCLUSIONS: SRS offers similar rates of initial pain relief, pain score distribution, pain recurrence, and time to pain recurrence between patients with TN1 and TN2. The time to initial pain relief was longer for patients with TN2.