EEG Theta Power Is an Early Marker of Cognitive Decline in Dementia due to Alzheimer’s Disease

Article type: Research Article

Authors: Musaeus, Christian Sandøe^{a; *} | Engedal, Knut^b | Høgh, Peter^{c; i} | Jelic, Vesna^{d; e} | Mørup, Morten^f | Naik, Mala^g | Oeksengaard, Anne-Rita^d | Snaedal, Jon^h | Wahlund, Lars-Olof^d | Waldemar, Gunhild^a | Andersen, Birgitte Bo^a

Affiliations: [a] Department of Neurology, Danish Dementia Research Centre (DDRC), Rigshospitalet, University of Copenhagen, Copenhagen, Denmark | [b] Norwegian National Advisory Unit on Ageing and Health (Ageing and Health), Vestfold Hospital Trust and Oslo University Hospital, Ullevaal, Oslo, Norway | [c] Regional Dementia Research Center, Department of Neurology, Zealand University Hospital, Roskilde, Denmark and Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark | [d] Department of Neurobiology, Division of Clinical Geriatrics, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden | [e] Clinic for Cognitive Disorders, Theme Aging, Karolinska University Hospital-Huddinge, Sweden | [f] Section for Cognitive Systems, DTU Compute, Technical University of Denmark, Lyngby, Denmark | [g] Department of Geriatric Medicine, Haraldsplass Deaconess Hospital, Bergen, Norway | [h] Department of Geriatric Medicine, Landspítali University Hospital, Reykjavik, Iceland | [i] Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark

Correspondence: [*] Correspondence to: Christian Sandøe Musaeus, Rigshospitalet, University of Copenhagen, Blegdamsvej 9 – section 6911, 2100 Copenhagen, Denmark. E-mail: [email protected].

Abstract: Background:Quantitative EEG (qEEG) power could potentially be used as a diagnostic tool for Alzheimer’s disease (AD) and may further our understanding of the pathophysiology. However, the early qEEG power changes of AD are not well understood. Objective:To investigate the early changes in qEEG power and the possible correlation with memory function and cerebrospinal fluid biomarkers. In addition, whether qEEG power could discriminate between AD, mild cognitive impairment (MCI), and older healthy controls (HC) at the individual level. Methods:Standard EEGs from 138 HC, 117 MCI, and 117 AD patients were included from six Nordic memory clinics. All EEGs were recorded consecutively before the diagnosis and were not used for the consensus diagnosis. Absolute and relative power was calculated for both eyes closed and open condition. Results:At group level using relative power, we found significant increases globally in the theta band and decreases in high frequency power in the temporal regions for eyes closed for AD and, to a lesser extent, for MCI compared to HC. Relative theta power was significantly correlated with multiple neuropsychological measures and had the largest correlation coefficient with total tau. At the individual level, the classification rate for AD and HC was 72.9% for relative power with eyes closed. Conclusion:Our findings suggest that the increase in relative theta power may be the first change in patients with dementia due to AD. At the individual level, we found a moderate classification rate for AD and HC when using EEGs alone.

Keywords: Alzheimer’s disease, dementia, diagnostic, EEG, mild cognitive impairment, power

DOI: 10.3233/JAD-180300

Journal: Journal of Alzheimer's Disease, vol. 64, no. 4, pp. 1359-1371, 2018