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

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. 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. 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. 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.