Supratentorial arachnoid cysts and seizures/epilepsy: A population study in community dwellers aged ≥20 years

Literature on the association between arachnoid cysts and seizures/epilepsy is inconsistent, and most series have been flawed due to recruitment bias. In this study, we aimed to assess the prevalence of supratentorial arachnoid cysts ( SAC s) in Atahualpa residents aged ≥20 years, and to estimate whether these lesions were associated with seizures/epilepsy. A total of 1157 individuals were included. Computed tomography revealed SAC s in 25 individuals (2.2%). Most had middle cranial fossa SAC s (n = 19). Recurrent nonprovoked seizures were diagnosed in 28 individuals and a single seizure in 4. Only 1 of 25 (4%) individuals with SAC s had seizures/epilepsy as opposed to 31 of 1132 (2.7%) who did not have SAC s ( P  =   0.508). A logistic regression model showed no association between SAC s and seizures/epilepsy, after taking into account the effect of relevant confounders (odds ratio [ OR ] 1.71; 95% confidence interval [95% CI] 0.22‐13.3; P  =   0.607). This study provides evidence of lack of association between SAC s and seizures/epilepsy.