Genetic liability to migraine and functional outcome after ischemic stroke.

BACKGROUND AND PURPOSE: To evaluate the association of genetic liability to migraine with functional outcome after ischemic stroke using Mendelian randomization.

METHODS

Genetic proxies for migraine were obtained from the largest genome-wide association study meta-analysis of 102,084 migraine cases and 771,257 controls. Genetic associations with functional outcome after ischemic stroke were obtained from the Genetics of Ischemic Stroke Functional Outcome network study (N = 6021). Poor functional outcome after ischemic stroke was defined as a score of 3-6 on the modified Rankin scale at 3 months (N = 2280). The inverse-variance weighted method was used to estimate the association of genetic liability to migraine with functional outcome, and we performed sensitivity analyses to assess the robustness of results.

RESULTS

Genetic liability to migraine was associated with poor functional outcome after ischemic stroke (odds ratio of poor functional outcome per doubling in migraine odds 1.22, 95% confidence interval 1.02-1.45, p = 0.031). This association remained directionally consistent across sensitivity analyses.

CONCLUSIONS

This study provides genetic support that migraine is associated with poor functional outcome after ischemic stroke. These findings warrant further follow-up and, if replicated, may have clinical implications for post-stroke recovery.