Association of epileptiform abnormalities and seizures in Alzheimer disease

Alice D. Lam, Rani A. Sarkis, Kyle R. Pellerin, Jin Jing, Barbara A. Dworetzky, Daniel B. Hoch, Claire S. Jacobs, Jong Woo Lee, Daniel S. Weisholtz, Rodrigo Zepeda, M. Brandon Westover, Andrew J. Cole, Sydney S. Cash

Research output: Contribution to journalArticlepeer-review

76 Scopus citations


ObjectiveTo examine the relationship between scalp EEG biomarkers of hyperexcitability in Alzheimer disease (AD) and to determine how these electric biomarkers relate to the clinical expression of seizures in AD.MethodsIn this cross-sectional study, we performed 24-hour ambulatory scalp EEGs on 43 cognitively normal elderly healthy controls (HC), 41 participants with early-stage AD with no history or risk factors for epilepsy (AD-NoEp), and 15 participants with early-stage AD with late-onset epilepsy related to AD (AD-Ep). Two epileptologists blinded to diagnosis visually reviewed all EEGs and annotated all potential epileptiform abnormalities. A panel of 9 epileptologists blinded to diagnosis was then surveyed to generate a consensus interpretation of epileptiform abnormalities in each EEG.ResultsEpileptiform abnormalities were seen in 53% of AD-Ep, 22% of AD-NoEp, and 4.7% of HC. Specific features of epileptiform discharges, including high frequency, robust morphology, right temporal location, and occurrence during wakefulness and REM, were associated with clinical seizures in AD. Multiple EEG biomarkers concordantly demonstrated a pattern of left temporal lobe hyperexcitability in early stages of AD, whereas clinical seizures in AD were often associated with bitemporal hyperexcitability. Frequent small sharp spikes were specifically associated with epileptiform EEGs and thus identified as a potential biomarker of hyperexcitability in AD.ConclusionEpileptiform abnormalities are common in AD but not all equivalent. Specific features of epileptiform discharges are associated with clinical seizures in AD. Given the difficulty recognizing clinical seizures in AD, these EEG features could provide guidance on which patients with AD are at high risk for clinical seizures.

Original languageEnglish (US)
Pages (from-to)E2259-E2270
Issue number16
StatePublished - Oct 20 2020

ASJC Scopus subject areas

  • Clinical Neurology


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