Prevalence of epilepsy and seizures in frontotemporal dementia: a systematic review and meta-analysis.

Seizures and epilepsy are increasingly recognized in neurodegenerative diseases, yet their burden in frontotemporal dementia (FTD) remains poorly defined. We conducted a systematic review and meta-analysis to estimate the prevalence of epilepsy or seizures in FTD, assess comparative risk versus controls, and explore variation across clinical subtypes. MEDLINE/PubMed, Embase, Cochrane Library, LILACS, and ClinicalTrials.gov were searched from inception to August 15, 2025, without language restrictions. Observational studies reporting epilepsy or clinical seizures in adults with FTD were included. Two reviewers independently screened and extracted data following PRISMA 2020 guidelines, with risk of bias assessed using Joanna Briggs Institute checklists. Random-effects meta-analyses were used to pool prevalence estimates. Eleven studies with 3,182 individuals were included; 5 were at low and 6 at high risk of bias. The pooled prevalence of epilepsy or seizures was 7% (95% CI, 4%-11%), but heterogeneity was substantial (I² = 82.3%). Prevalence varied across clinical variants (P = .04), including 3% (95% CI, 1%-11%) in behavioral-variant FTD and 9% (95% CI, 0%-69%) in primary progressive aphasia. Comparative data were sparse: the 2 studies with control counts showed increased odds in FTD but were too heterogeneous to pool, and an exploratory synthesis of all 3 gave a ratio measure of 3.72 (95% CI, 1.38-10.06). Epilepsy and seizures occur in a nontrivial proportion of individuals with FTD. However, substantial heterogeneity, variable methodological quality, and inconsistent definitions compromise the reliability of prevalence estimates. Prospective studies with standardized seizure phenotyping are needed.