The association between dementia and epilepsy: A systematic review and meta-analysis

Objective: Dementia is among the top 15 conditions with the most substantial increase in burden of disease in the past decade, and along with epilepsy, among the top 25 causes of years lived with disability worldwide. The epidemiology of dementia in persons with epilepsy, and vice versa, is not well characterized. The purpose of this systematic review was to examine the prevalence, incidence, and reported risk factors for dementia in epilepsy and epilepsy in dementia. Methods: Embase, PsycINFO, MEDLINE, and the Cochrane databases were searched from inception. Papers were included if they reported the incidence and/or prevalence of dementia and epilepsy. Two individuals independently performed duplicate abstract and full-text review, data extraction, and quality assessment. Random-effects models were used to generate pooled estimates when feasible. Results: Of the 3,043 citations identified, 64 were reviewed in full text and 19 articles were included. The period prevalence of dementia ranged from 8.1 to 17.5 per 100 persons among persons with epilepsy (insufficient data to pool). The pooled period prevalence of epilepsy among persons with dementia was 5 per 100 persons (95% confidence interval [CI] 1–9) in population-based settings and 4 per 100 persons (95% CI 1–6) in clinic settings. There were insufficient data to report a pooled overall incidence rate and only limited data on risk factors. Significance: There are significant gaps in knowledge regarding the epidemiology of epilepsy in dementia and vice versa. Accurate estimates are needed to inform public health policy and prevention, and to understand health resource needs for these populations.