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

Abstract

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.

Association between EEG Abnormalities and CSF Biomarkers in a Memory Clinic Cohort

“…Decreased EEG coherence and global field synchronization in α-band as well as frontal shift of generators of α-activity have been reported already in the MCI stage of AD supporting the hypothesis that AD develops as a neocortical disconnection syndrome [13,15,16,17]. Various EEG parameters were correlated in previous studies with measures of general cognition, neuropsychological test scores, clinical rating scales, regional cerebral blood flow and glucose metabolism as measured by SPECT and PET, respectively [13,18,19,20,21,22]. …”

Resting EEG sources correlate with attentional span in mild cognitive impairment and Alzheimer's disease

“…As an exception, our procedure could not disclose EEG changes at beta frequencies in AD vs. Nold subjects (Claus et al ., 2000, 1998). This may be due to the use of quite large frequency bands for beta 1 (13–20 Hz) and beta 2 (20–30 Hz), together with the average of LORETA solutions across large cortical regions.…”

Medical Big Data: Neurological Diseases Diagnosis Through Medical Data Analysis

“…Numerous studies have been conducted on the CAD system to deal with EEG changes associated with dementia. The researchers developed CAD methods to identify the degree of severity of dementia, and some studies support the possibility for EEG to detect dementia in early stages [46][47][48][49][50]. For example, Henderson et al [51] detected early dementia presence in EEGs with high sensitivity and specificity [46,51].…”