Objective: The purpose of this study was to compare clinical features, long-term surgical outcomes between patients with idiopathic and tumor-related trigeminal neuralgia (TN), and to identify factors associated with the maintenance of permanent pain-free state.
Methods: Between January 2003 and December 2013, 360 patients with idiopathic TN and 39 patients with tumor-related TN who had undergone microsurgery were retrospectively studied. Kaplan-Meier survival curves were generated and compared by Log-rank test, and the possible prognostic factors were analyzed by the Cox proportional-hazards regression.
Results: Patients with tumor-related TN exhibited a younger age of pain onset (46.28 ± 18.18y vs. 53.03 ± 11.90y, p = .006), a briefer symptom duration (3.20 ± 4.38y vs. 7.01 ± 6.04y, p = .000), and much more preoperative neuropathic deficits (61.54%% vs. 24.17%%, p = .000), as compared with patients with idiopathic TN. Using Kaplan-Meier analysis, we found microsurgery was effective in 72.3% of patients with idiopathic TN, and in 86.4% of cases with tumor-related TN at six years follow-up postoperatively. Prognostic analysis suggested that a clear-cut neurovascular compression in patients with idiopathic TN (HR = 3.098, 95%CI: 1.800-5.311; p = .000) and total tumor removal in patients with tumor secondary TN (HR = 7.662, 95%CI: 0.098-36.574; p = .044) were positively correlated with excellent long-term outcomes.
Conclusions: The occurrences of TN at younger age, a shorter duration and preponderance of preclinical neuropathic symptoms are the characteristics of TN patients secondary to intracranial tumor, in contrast to patients with TN caused by a compressed vessel. Microsurgery is an effective and safe treatment modality for TN regardless of the disease etiology, the involvement of a clear-cut vascular offender and total tumor resection are the most important predictors of excellent outcome for microsurgery in idiopathic and tumor-related TN patients, respectively.
Keywords: Trigeminal neuralgia; microsurgery; neurovascular compression; outcome; tumor.