Systematic review of coexistent epileptic seizures and Alzheimer's disease: Incidence and prevalence.

BACKGROUND/OBJECTIVES: Coexistent seizures add complexity to the burden of Alzheimer's disease (AD). We aim to estimate the incidence and prevalence of coexistent seizures and AD and summarize characteristics.

DESIGN

A systematic review and meta-analysis (PROSPERO protocol registration CRD42020150479).

SETTING

Population-, community-, hospital-, or nursing home-based.

PARTICIPANTS AND MEASUREMENTS

Thirty-nine studies reporting on seizure incidence and prevalence in 21,198 and 380,777 participants with AD, respectively, and AD prevalence in 727,446 participants with seizures. When statistical heterogeneity and inconsistency (assessed by Q statistic and I ) were not shown, rates were synthesized using random effect.

RESULTS

Studies were conducted in Australia, Brazil, Finland, France, Ireland, Italy, Japan, Netherlands, Portugal, Sweden, Taiwan, United Kingdom, and United States. The incidence of seizures among people with clinically diagnosed AD ranged from 4.2 to 31.5 per 1000 person-years. Prevalence of seizures among people with clinically diagnosed AD ranged from 1.5% to 12.7% generally, but it rose to the highest (49.5% of those with early-onset AD) in one study. Meta-analysis reported a combined seizure prevalence rate among people with pathologically verified AD at 16% (95% confidence interval [CI] 14-19). Prevalence of seizure in autosomal dominant AD (ADAD) ranged from 2.8% to 41.7%. Being younger was associated with higher risk of seizure occurrence. Eleven percent of people with adult-onset seizures had AD (95%CI, 7-14).

CONCLUSION

Seizures are common in those with AD, and seizure monitoring may be particularly important for younger adults and those with ADAD.