Determinants of Quantitative Spectral Electroencephalography in Early Alzheimer’s Disease: Cognitive Function, Regional Cerebral Blood Flow, and Computed Tomography

• Published in: Dementia and geriatric cognitive disorders 2000-03, Vol.11 (2), p.81-89
• Main Authors: Claus, J.J., Ongerboer de Visser, B.W., Bour, L.J., Walstra, G.J.M., Hijdra, A., Verbeeten Jr, B., van Royen, E.A., Kwa, V.I.H., van Gool, W.A.
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Alzheimer Disease - diagnostic imaging; Alzheimer Disease - physiopathology; Alzheimer Disease - psychology; Atrophy; Biological and medical sciences; Cerebrovascular Circulation - physiology; Cognition - physiology; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; Electroencephalography; Female; Humans; Male; Medical sciences; Neurology; Original Research Article; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed
• ISSN: 1420-8008; 1421-9824
• DOI: 10.1159/000017219

Electroencephalography (EEG) bands may have different clinical or physiological correlates at initial diagnosis of Alzheimer’s disease (AD). We studied 163 consecutive patients with probable (n = 105) and possible (n = 58) AD with measurements of cognitive function (CAMCOG), regional cerebral blood flow (rCBF) with single photon emission computed tomography using technetium-99m-labeled hexamethylpropylene amine oxime, and computed tomography (CT). Lower CAMCOG scores were significantly and most strongly associated with lower parieto-occipital and fronto-central alpha power. In a separate analysis of cognitive domains, disturbances in language, praxis, attention, and abstraction were also significantly and most consistently related to decrease in alpha power. Presence of cortical atrophy as measured on CT showed some statistically significant relations with EEG bands, but these associations were not consistent. Lower temporal and parietal rCBF were significantly related to lower parieto-occipital alpha activity. Presence of leukoaraiosis was significantly associated with lower beta values, but also with higher absolute theta and delta activity. The results suggest that alpha on EEG is most closely linked to cognitive function and rCBF, while beta and theta activity more likely reflect lower cortical or subcortical changes. Our study thus provides evidence that the EEG bands reflect differential pathophysiologic changes in AD.