Alcohol consumption on unprovoked seizure and epilepsy: An updated meta-analysis

Background: Epilepsy is one of the most common neurological disorders, affecting approximately 50 million people worldwide. Although a positive association between alcohol consumption and epilepsy has been demonstrated in previous meta-analyses of case-control studies, the results of several recently published large cohort studies are contradictory. Therefore, we conducted an updated meta-analysis that included more recent data to clarify the association between alcohol consumption and epilepsy. Methods: The search was performed on 25 January 2021 using the Embase and MEDLINE databases. Cohort or case-control studies were eligible for inclusion in this study. We used restricted cubic spline analysis to perform a dose-response meta-analysis. Results: A total of eight studies, including three cohort and five case-control studies, were included in our meta-analysis. The pooled risk of epilepsy was 1.70 (1.16–2.49) in alcohol users compared to non-drinkers. Subgroup analysis of 50 g units showed that the epilepsy risk increased as alcohol intake increased. The pooled risk of cohort studies was 1.00 (0.65–1.54), and the pooled risk of case-control studies was 2.61 (1.29–5.29). According to the dose-response analysis, the regression coefficient was 1.009 (1.004–1.014), indicating a significant positive dose-response relationship. Conclusion: Unlike the case-control studies, the cohort studies did not reveal a significant association between alcohol consumption and epilepsy. Further large cohort studies for the general population are required to assert a definite causal relationship between alcohol consumption and epilepsy and to identify a potential threshold.