Long-Term Effectiveness of Early Versus Late Microvascular Decompression for Trigeminal Neuralgia Secondary to Arterial Compression.

Background: The relationship between the duration of trigeminal neuralgia (TN) symptoms prior to initial microvascular decompression (MVD) and long-term outcomes is unclear. We evaluated whether the pre-operative symptom duration is associated with complete freedom from pain when MVD is performed as the initial procedure in TN secondary to arterial compression.

Methods: Patients with purely paroxysmal TN who underwent MRI were retrospectively classified as cTN or iTN. Patients in each subtype of TN were categorized into pre-operative symptom duration groups of ≤ 24 months, 24-48 months, 48-72 months, or ≥ 72 months. Univariate and multivariate analyses were conducted for each subtype of TN. The first subgroup (i.e., ≤ 24 months) was treated as the reference subgroup for multivariate analysis.

Results: At a median follow-up of 62.9 months (28.9-97.6 months), 15 (71.4%), 18 (100%), 12 (80.0%), and 13 (76.5%) MVDs for cTN with morphological changes resulted in pain freedom without medication in the ≤ 24, 24-48, 48-72, and ≥ 72 months symptom duration groups, respectively. At a median follow-up of 71.4 months (21.2-71.4 months), 8 (100%), 16 (94.1%), 10 (90.9%), and 8 (80.0%) MVDs for iTN morphological changes resulted in pain freedom without medication in the ≤ 24, 24-48, 48-72, and ≥ 72 months symptom duration groups, respectively. Multivariate analysis showed no difference in outcomes between groups.

Discussion: MVD performed later in the disease course is equally effective when compared to early MVD as the initial surgical procedure for the management of cTN with morphological changes and iTN without morphological changes.