AUTHOR=Hadar Peter N. , Westmeijer Mike , Sun Haoqi , Meulenbrugge Erik-Jan , Jing Jin , Paixao Luis , Tesh Ryan A. , Da Silva Cardoso Madalena , Arnal Pierrick , Au Rhoda , Shin Chol , Kim Soriul , Thomas Robert J. , Cash Sydney S. , Westover M. Brandon TITLE=Epilepsy is associated with the accelerated aging of brain activity in sleep JOURNAL=Frontiers in Physiology VOLUME=Volume 15 - 2024 YEAR=2024 URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2024.1458592 DOI=10.3389/fphys.2024.1458592 ISSN=1664-042X ABSTRACT=Although seizures are the cardinal problem, epilepsy is associated with other forms of brain dysfunction including impaired cognition, abnormal sleep, and increased risk of developing dementia. We hypothesized that, given widespread neurologic dysfunction in epilepsy, accelerated brain aging would be seen. We set out to measure the sleep-based Brain Age Index (BAI) in a diverse group of patients with epilepsy. BAI is a machine learning-based biomarker that measures how much the brain activity of a person during overnight sleep deviates from chronological age-based norms.This case-control study drew age-matched controls without epilepsy from home sleep monitoring volunteers and from non-epilepsy patients with sleep lab testing. Patients with epilepsy underwent in-patient monitoring and were classified by epilepsy type and seizure burden. The primary outcomes measured were BAI, processed from electroencephalograms, and epilepsy severity metrics (years with epilepsy, seizure frequency standardized by year, and seizure burden [number of seizures in life]). Subanalyses were conducted on a subset with NIH Toolbox cognitive testing for total, fluid, and crystallized composite cognition. Results: 138 patients with epilepsy (32 exclusively focal, 106 generalizable [focal seizures with secondary generalization]) underwent in-patient monitoring and age-matched, non-epilepsy controls were analyzed. Mean BAI was higher in epilepsy patients vs. controls and differed by epilepsy type: -0.05 years (controls) versus 5.02 years (all epilepsy, p<0.001), 5.53 years (generalizable, p<0.001), and 3.34 years (focal, p=0.03). Sleep architecture was disrupted in epilepsy, especially in generalizable epilepsy. Higher BAI was positively associated with increased lifetime seizure burden in focal and generalizable epilepsies, and associated with lower crystallized cognition. Lifetime seizure burden inversely correlated with fluid, crystallized, and composite cognition. Significance: Epilepsy is associated with accelerated brain aging. Higher brain age indices are associated with poorer cognition and more severe epilepsy, specifically generalizability and higher seizure burden. These findings strengthen the use of the sleep-derived, electroencephalography-based BAI as a biomarker for cognitive dysfunction in epilepsy.