Epilepsy Prevalence Higher in Frontotemporal Dementia Than Alzheimer Disease
Epilepsy diagnoses and the use of antiseizure medications were significantly higher among patients with frontotemporal dementia (FTD) compared with patients with Alzheimer disease (AD) and healthy controls in a case-control study published in JAMA Neurology.
“Previous studies have proposed that epilepsy is a more common comorbidity of AD than of other neurodegenerative diseases. In the present study, the results indicated the opposite, as the prevalence of epilepsy was similar or higher among patients with FTD compared with patients with AD,” wrote corresponding author Eino Solje, MD, PhD, of the University of Eastern Finland, Kuopio, Finland, and study coauthors.
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The analysis compared the prevalence of epilepsy, and antiseizure medication purchases, among 245 patients with FTD, 2416 matched healthy controls, and 1326 patients with AD from a pair of early-onset dementia diagnostics centers in Finland.
“The risk of epilepsy increased several years before the clinical onset of FTD symptoms,” researchers reported, “which could be due to overlapping neuropathologic and neurophysiologic changes between epilepsy and early FTD.”
Specifically, 10 years before FTD diagnosis, the prevalence of epilepsy was 3.3% in the FTD group, 0.8% in the HC group, and 1.4% in the AD group, according to the study. Five years before FTD diagnosis, the prevalence was 4.9% in the FTD group, 1.3% in the HC group, and 1.7% in the AD group.
The year of FTD diagnosis, the prevalence of epilepsy was 6.5% in the FTD group, 1.8% in the HC group, and 5.0% the AD group. (The difference between the FTD and AD groups at this time point, researchers noted, did not significantly differ.) Five years after FTD diagnosis, the prevalence of epilepsy was 11.2% in the FTD group, 2.2% in the HC group, and 6.9% in the AD group.
Antiseizure medication purchases were significantly more common in the FTD group compared with the other groups during the prediagnostic period, with a notable increase approximately 2 years before FTD diagnosis, the study found.
“The observed association between FTD and epilepsy was not limited to any specific seizure type,” researchers wrote, “and comorbid epilepsy did not increase mortality among the patients with FTD.”
The research team advised the need for further investigation into the potential overlap of the pathophysiologic mechanisms of epilepsy and FTD.
