Long-term outcomes of Gamma Knife radiosurgery for trigeminal neuralgia patients with or without concomitant continuous pain

The effectiveness of Gamma Knife radiosurgery (GKRS) in treating trigeminal neuralgia (TN) has been demonstrated by a number of previous studies. However, there is a lack of research specifically documenting the initial and long-term outcomes of paroxysmal and persistent pain respectively following GKRS for TN with concomitant continuous pain (CCP). This study retrospectively analyzed pain outcomes and complications in 46 TN patients with CCP and 112 patients without CCP who underwent GKRS as initial surgical intervention at our institution from January 2019 to January 2024. Pain outcomes were classified as excellent (BNI I), good (BNI II-IIIa), and poor (BNI IIIb-V). Demographic and clinical data, pain outcomes, and complications were compared between patients with and without CCP. Subsequently, risk factors for poor outcomes after GKRS were evaluated using univariate and multivariate Cox regression analysis. The initial rate of poor outcomes in TN patients with CCP was similar to that of patients without CCP (15.8% vs 14.4%, P = .878). Following a minimum 6-month follow-up, the rate of poor pain outcomes increased to 37.0% in patients with CCP, compared to 38.4% in those without CCP (P = .968). Notably, the rate of long-term complete pain relief in patients without CCP was significantly higher than in those with CCP (35.7% vs 15.2%, P < .001). Poor response to medication (P < .001) was identified as an independent risk factors for poor outcomes after GKRS. While most TN patients with or without CCP can achieve favorable pain outcomes after GKRS, individuals with CCP were less likely to achieve complete pain relief compared to those without CCP.