Time from Migraine Onset to Surgery Predicts Postoperative Headache Frequency: A Retrospective Cohort Study.

BACKGROUND: Migraine trigger-site surgery has been proposed for medically refractory migraine, yet predictors of postoperative outcome remain incompletely defined. The influence of the interval between migraine onset and surgical intervention has not been systematically evaluated. METHODS: A retrospective cohort study of consecutive patients undergoing migraine trigger-site surgery in Taiwan (2019-2024) was conducted. The primary endpoint was postoperative headache frequency per month; Migraine Headache Index (MHI) was the secondary endpoint. Time-to-surgery (years from migraine onset to operation) was evaluated using Spearman correlation, group comparison, and multivariable regression adjusted for age, sex, preoperative frequency, trigger-site number, and nerve block status. RESULTS: Among 54 patients (70.4% female; mean age 38.0 years), 47 (87.0%) achieved successful treatment (≥50% frequency reduction) and 16 (29.6%) achieved frequency elimination. Median time-to-surgery was 15 years. Longer time-to-surgery was significantly correlated with higher postoperative frequency (Spearman ρ = 0.397; p = 0.003) and remained an independent predictor in multivariable regression (β = 0.342; 95% CI 0.107-0.577; p = 0.005), alongside preoperative frequency (β = 0.270; p = 0.011). Patients with time-to-surgery at or below the cohort median (15 years) achieved a 96% success rate with 43% complete elimination, compared with 77% success and 15% elimination among those with longer durations (p = 0.047 and p = 0.038, respectively). CONCLUSIONS: Time-to-surgery is an independent predictor of postoperative headache frequency, with each additional year of disease duration associated with 0.34 more headache days per month. These findings suggest that early surgery in appropriately selected patients may improve frequency outcomes.