Increased risk of essential tremor in migraine: A population-based retrospective cohort study

PURPOSE: To examine the long-term risk of essential tremor (ET) in migraine. METHODS: Using population-based administrative data from a subset of the National Health Insurance Research Database (NHIRD) of Taiwan, we identified 22,696 newly diagnosed migraineurs (mean age 44.5 years) and a matched migraine-free cohort of 90,784 individuals in the period 2000–2008. Multivariable Cox proportional hazards regression analysis was conducted for assessing the ET risk for the migraine cohort compared to the migraine-free cohort. RESULTS: After adjusting for covariates, the migraine cohort had a 1.83-fold increased risk (95% CI 1.50–2.23) of subsequent ET in comparison to the migraine-free cohort (8.97 vs. 4.81 per 10,000 person-years). In the subgroup analysis, patients with migraine were associated with higher risks of ET, regardless of gender, age or the existence of comorbidities. CONCLUSION: Our findings demonstrated an association between migraine and ET, suggesting a possible shared pathophysiology underpinning both disorders.