Increased risk of Bell palsy in patient with migraine: A longitudinal follow-up study.

Migraine is thought to be associated with Bell palsy. This study aimed to investigate the risk of Bell palsy in migraine patients.The Korean National Health Insurance Service-National Sample Cohort was collected from 2002 to 2013. A total of 45,164 migraine patients were matched for age, sex, income, region of residence, hypertension, diabetes, and dyslipidemia and compared with 180,656 controls. The migraine group included participants diagnosed with migraine [International Classification of Disease (ICD)-10: G43] who underwent treatment more than once. Participants with Bell palsy were included on the basis of the ICD-10 (G510) and treatment with steroids. A history of hypertension, diabetes, and dyslipidemia was determined using ICD-10 codes. Crude (simple) and adjusted hazard ratios (HRs) of Bell palsy in migraine patients were analyzed using the Cox proportional hazards model. Subgroup analyses were conducted based on age and sex.Bell palsy occurred in 0.6% (262/44,902) of the migraine group and 0.5% (903/179,753) of the control group. The adjusted HR of Bell palsy was 1.16 in the migraine group compared with the control group [95% confidence interval (95% CI) = 1.01-1.33, P = .34]. Among age-related subgroups, participants ≥30 and <60 years old in the migraine subgroup demonstrated a 1.28-times higher risk of Bell palsy than the control group (95% CI = 1.05-1.57, P = .014).Migraine increased the risk of Bell palsy in the total population. Among age subgroups, migraine patients ≥30 and <60 years old had an increased risk of Bell palsy.