Long-term Outcomes and the Predictors Following Microvascular Decompression and Gamma Knife Radiosurgery for Drug Refractory Primary Trigeminal Neuralgia: A Single-Center Experience with a Large Cohort

BACKGROUND: We analyze our results and outcome multimodality management of idiopathic trigeminal neuralgia (TN). OBJECTIVE: To evaluate long-term outcomes and the predictors following microvascular decompression (MVD) and gamma-knife radiosurgery (GKRS). METHODS: A retrospective review of patients with drug-refractory primary TN treated between 2015 and 2024, with a minimum follow-up of 12 months. Treatment outcomes were assessed using Barrow Neurological Institute (BNI) pain scores at follow-up. Complete pain relief (CPR) was defined as BNI 1 or 2, adequate pain relief (APR) as BNI 3, and treatment failure as BNI 4 or 5. RESULTS: Of 263 patients, 175 underwent MVD and 88 underwent GKRS. The mean duration of follow-up was 58.3 ± 30.2 months (MVD) and 68 ± 34.5 months (GKRS). CPR was achieved in 86.8% (MVD) and 56.8% (GKRS) patients. The recurrence rate was 12% (MVD) and 20.45% (GKRS), with a median time to recurrence of 4 and 21 months, respectively. Incomplete immediate postoperative pain relief after MVD predicted treatment failure and recurrence (P < 0.001; P = 0.005). Involvement of multiple trigeminal divisions and failure of more than two preoperative medications were associated with higher recurrence (P = 0.05; P = 0.018). Multiple prior failed procedures predicted recurrence after GKRS (P = 0.013). CONCLUSION: MVD provides excellent immediate (94%) and durable (86%) pain relief in surgically fit patients, with early response predicting sustained outcomes; recurrence is associated with multisegment involvement and higher preoperative pharmacological requirement. GKRS offers a reasonable alternative (71% short-term, 57% long-term relief) and is especially useful in patients either unfit for surgery or unwilling for surgery.