435 Internal Neurolysis for Trigeminal Neuralgia: Systematic Review

Abstract

INTRODUCTION: Trigeminal neuralgia (TN) remains a challenging disease with debilitating symptoms and variable efficacy of treatment options. Internal neurolysis (IN) is a technique to dissect out the cisternal portion of the trigeminal nerve into multiple “fascicles”, and has shown potential as a treatment option. METHODS: Studies from 2000-2021 that assessed IN for TN were aggregated and independently reviewed. Outcomes evaluated included post-operative pain scores as defined by the BNI-PS or UCSF-PS, recurrence rates, hypesthesia scores as defined by the BNI-HS, and complications. Outcome were stratified as either excellent (BNI-PS: I or UCSF: excellent), good (BNI-PS: I/II or UCSF: excellent) or fair (BNI-PS: I-III and UCSF: excellent/good). Recurrence rates were considered for any pain recurrence and for significant recurrence defined as BNI-PS I/II transitioning to III-V. Weighted averages for demographics, outcomes and complications were generated. RESULTS: A total of 520 patients in 12 studies were identified with 384 patients undergoing IN. The mean follow-up was 36.5 months (range 12-90 months). Overall, an excellent to good outcome was seen in 83.7% of patients. Pain outcomes at 1 year were excellent: 58-78.4%, good: 77-93.75%, and fair: 80-93.75%. Overall pain outcomes were excellent: 47-82.1%, good: 62.5-87.1% and fair: 80-100%. Hypesthesia following IN was seen in as many as 96% post-operatively, however at follow-up remained in only 1.75-10%. The 1-year and overall recurrence rates of any pain were: 3.92-42% and 3.6-50%. The 1-year and overall rates for significant recurrence of pain were: 3.92-17% and 3.6-25%. CONCLUSION: IN represents a potentially promising approach for the surgical treatment of TN in the absence of vascular compression and cases of recurrence. It may also be an adjunct option to MVD in cases of low grade vascular compression. Further study is required to evaluate the impact of IN.