Association between multiple sclerosis and epilepsy: A systematic review and meta-analysis

Background: Seizures in people with multiple sclerosis (MS) are reported; however, the risk of epilepsy in adults with MS remains poorly defined.Methods: We performed a systematic review and meta-analysis to evaluate the incidence and prevalence of epilepsy in adults (= 18 years) with MS compared to those without. We searched MEDLINE and EMBASE from inception to July 1, 2022 to include observational studies that reported the prevalence or incidence of epilepsy in adults with MS and a comparator group, consisting of adults without MS or the general population. We used the Newcastle Ottawa Scale to evaluate quality of the included studies. We performed random-effects meta-analyses to determine the prevalence and incidence of epilepsy in adults with MS compared to the non-MS group.Results: We identified 17 studies consisting of 192,850 adults with MS, across nine countries. Most studies were of moderate quality as they did not specify the MS type or type of seizures. Compared to a comparison group, both the prevalence (pooled OR 2.04; 95% confidence interval 1.59-2.63, I2 = 95.4, n = 12) and the incidence of epilepsy (pooled RR 3.34; 3.17-3.52, I2 = 4.6%, n = 6) was higher in people with MS. Heterogeneity in estimates was not explained by additional analyses.Conclusions: MS is an independent risk factor for both incident and prevalent epilepsy, suggesting variation in grey matter involvement over the disease course. Longitudinal studies are required to help identify patient and disease characteristics associated with epilepsy.