Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Jul 1;82(7):715-721.
doi: 10.1001/jamaneurol.2025.1358.

Prevalence of Epilepsy in Frontotemporal Dementia and Timing of Dementia Diagnosis

Annemari Kilpeläinen  1   2 , Mikko Aaltonen  3 , Kalle Aho  1 , Sami Heikkinen  1 , Ave Kivisild  1 , Adolfina Lehtonen  4 , Laura Leppänen  4 , Iina Rinnankoski  4 , Helmi Soppela  1 , Laura Tervonen  4   5   6 , Päivi Hartikainen  2 , Annakaisa Haapasalo  7 , Reetta Kälviäinen  1   2 , Kasper Katisko  1 , Johanna Krüger  4   5   6 , Eino Solje  1   2
Affiliations

Prevalence of Epilepsy in Frontotemporal Dementia and Timing of Dementia Diagnosis

Annemari Kilpeläinen et al. JAMA Neurol. .

Abstract

Importance: Previous studies have described a potential association between epilepsy and frontotemporal dementia (FTD), but no systematic data are available.

Objective: To determine whether epilepsy is more prevalent in patients with FTD than in healthy controls (HCs) or patients with Alzheimer disease (AD).

Design, setting, and participants: In this case-control study, we compared the prevalence of epilepsy and purchases of antiseizure medicines (ASMs) among patients with FTD, matched HCs, and patients with AD from 2 early-onset dementia diagnostics centers in the same geographic regions of Finland. AD or FTD diagnoses were made between January 1, 2010, and December 31, 2021. Data were analyzed from January 26, 2024, to January 16, 2025.

Main outcomes and measures: The primary outcome was to describe the prevalence of epilepsy in patients with FTD, covering the time period from 10 years before to 5 years after the FTD diagnosis. We used International Statistical Classification of Diseases, Tenth Revision codes to identify all patients with epilepsy and tracked purchases of ASMs.

Results: The study cohort included 245 patients with FTD (121 female [49.4%], 124 male [50.6%]; mean [SD] age, 65.2 [8.7] years), 2416 matched HCs (1190 female [49.3%], 1226 male [50.7%]; mean [SD] age, 65.0 [8.5] years), and 1326 patients with AD (777 female [58.6%], 549 male [41.4%]; mean [SD] age, 71.7 [9.8] years). The prevalence of epilepsy was higher in the FTD group compared with the HC group (3.3% vs 0.8%, respectively; P = .002) and AD group (3.3% vs 1.4%, respectively; P = .01) 10 years before FTD diagnosis. At the year of the diagnosis, the prevalence was 6.5% in patients with FTD, 1.8% in HCs (FTD vs HC difference, 4.7 percentage points [ppt] [95% CI, 2.2-8.6 ppt]; P < .001), and 5.0% in patients with AD (FTD vs AD difference, 1.6 ppt [95% CI, -1.2 to 5.5 ppt]; P = .32); at 5 years after the diagnosis, the prevalence was 11.2% in patients with FTD, 2.2% in HCs (FTD vs HC difference, 9.0 ppt [95% CI, 5.0-14.6 ppt]; P < .001), and 6.9% in patients with AD (FTD vs AD difference, 4.2 ppt [95% CI, 0-10.0 ppt]; P = .05). ASM purchases were made significantly more often among patients with FTD (10.2%) compared with HCs (1.8%) and patients with AD (4.2%) (FTD vs HC difference, 8.4 ppt [95% CI, 5.2-12.9 ppt]; P < .001; FTD vs AD difference, 6.1 ppt [95% CI, 2.6-10.6 ppt]; P < .001) at all time points and increased during the study period.

Conclusions and relevance: This case-control study found a higher prevalence of epilepsy and increased ASM use among patients with FTD compared with HCs and patients with AD , suggesting an association between epileptic abnormalities and the pathophysiology of FTD. Further studies are warranted to investigate a potential overlap in the pathophysiologic mechanisms of epilepsy and FTD.

PubMed Disclaimer

Conflict of interest statement

Conflict of Interest Disclosures: Dr Heikkinen reported receiving grants from the Finnish Medical Foundation, the Finnish Parkinson Foundation, and the Finnish Brain Foundation during the conduct of the study and receiving personal fees from the Finnish Neuro Society and Nordic Infucare outside the submitted work. Dr Kälviäinen reported receiving grants from the Saastamoinen Foundation, the Vaajasalo Foundation, the government of Finland, the Research Council of Finland, and the Jane and Aatos Erkko Foundation and receiving personal fees from Orion Pharma, UCB Pharma, Jazz Pharma, Angelini Pharma, Takeda, Marinus Pharmaceuticals, and Eisai outside the submitted work. Dr Katisko reported receiving grants from the Finnish Brain Foundation, the Finnish Medical Foundation, the Päivikki & Sakari Sohlberg Foundation, the Finnish Cultural Foundation, and the Uulo Arhio Foundation during the conduct of the study. Dr Krüger reported receiving grants from the Wihuri Foundation and state research funding via Kuopio University Hospital during the conduct of the study; serving on the advisory board of Novartis, Nutricia, EISAI, Lilly, and Roche; receiving honoraria from Bioarctic and Lilly; and receiving support for conference participation from Merck. Dr Solje reported receiving grants from the Wihuri Foundation, state research funding via Kuopio University Hospital, and the Sigrid Juselius Foundation during the conduct of the study and receiving personal fees from Novartis, EISAI, Roche, Novo Nordisk, Lundbeck, and Bioarctic outside the submitted work. No other disclosures were reported.

Figures

Figure 1.
Figure 1.. Prevalence of Epilepsy Among the Study Groups at Different Time Points
Error bars represent 95% CIs. AD indicates Alzheimer disease; HC, healthy control; FTD, frontotemporal dementia.
Figure 2.
Figure 2.. Prevalence of the Most Common Epilepsy Diagnosis Codes
Diagnosis codes are from the International Statistical Classification of Diseases, Tenth Revision (ICD-10). G40.1 = Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures. G40.2 = Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures. G40.9 = Epilepsy, unspecified, not intractable. Error bars represent 95% CIs. AD indicates Alzheimer disease; HC, healthy control; FTD, frontotemporal dementia.
Figure 3.
Figure 3.. Prevalence of Antiseizure Medicine Purchases Before FTD Diagnosis
Error bars represent 95% CIs. AD indicates Alzheimer disease; HC, healthy control; FTD, frontotemporal dementia.
See this image and copyright information in PMC

References

    1. Bang J, Spina S, Miller BL. Frontotemporal dementia. Lancet. 2015;386(10004):1672-1682. doi: 10.1016/S0140-6736(15)00461-4 - DOI - PMC - PubMed
    1. Majounie E, Renton AE, Mok K, et al. ; Chromosome 9-ALS/FTD Consortium; French Research Network on FTLD/FTLD/ALS; ITALSGEN Consortium . Frequency of the C9orf72 hexanucleotide repeat expansion in patients with amyotrophic lateral sclerosis and frontotemporal dementia: a cross-sectional study. Lancet Neurol. 2012;11(4):323-330. doi: 10.1016/S1474-4422(12)70043-1 - DOI - PMC - PubMed
    1. Olney NT, Spina S, Miller BL. Frontotemporal dementia. Neurol Clin. 2017;35(2):339-374. doi: 10.1016/j.ncl.2017.01.008 - DOI - PMC - PubMed
    1. Antonioni A, Raho EM, Lopriore P, et al. Frontotemporal dementia, where do we stand? a narrative review. Int J Mol Sci. 2023;24(14):11732. doi: 10.3390/ijms241411732 - DOI - PMC - PubMed
    1. Seltman RE, Matthews BR. Frontotemporal lobar degeneration: epidemiology, pathology, diagnosis and management. CNS Drugs. 2012;26(10):841-870. doi: 10.2165/11640070-000000000-00000 - DOI - PubMed

Substances