Supplementary Material for: Migraine Risk in Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorder: A Nationwide Cohort Study in South Korea

Introduction: Although the relationship between migraine and multiple sclerosis (MS) has been reported, the risk of migraine in MS and neuromyelitis optica spectrum disorder (NMOSD) is unclear. Therefore, this study investigated the risk of migraine in the Korean MS and NMOSD populations.
Methods: This study analyzed claims data from 1492 patients with MS and 1551 patients with NMOSD based on diagnostic codes in the Korean National Health Insurance Service. Migraine risk was compared with a control group (matched 1:5 for age, sex, and comorbidities) using Cox proportional hazards analysis. Patients aged <20 years and with previous migraine were excluded.
Results: Migraine risk was higher in patients with MS (adjusted hazard ratio [aHR] 1.37; 95% confidence interval [CI]: 1.15−1.62) but did not differ significantly in patients with NMOSD (aHR 1.05; 95%CI: 0.87−1.27) compared to controls. No significant sex-based differences in migraine risk were observed. Patients with NMOSD showed decreasing risk with age (p for interaction=0.040). Comorbidities like hypertension, diabetes, or dyslipidemia did not significantly alter migraine risk in either group.
Conclusion: The study results revealed an increased risk of migraines in patients with MS but not in patients with NMSOD compared with matched controls.