Index of Alpha/Theta Ratio of the Electroencephalogram: A New Marker for Alzheimer’s Disease

Abstract

Objective: We evaluated quantitative EEG measures to determine a screening index to discriminate Alzheimer’s disease (AD) patients from normal individuals.Methods: Two groups of individuals older than 50 years, comprising a control group of 57 normal volunteers and a study group of 50 patients with probable AD, were compared. EEG recordings were obtained from subjects in a wake state with eyes closed at rest for 30 min. Logistic regression analysis was conducted.Results: Spectral potentials of the alpha and theta bands were computed for all electrodes and the alpha/theta ratio calculated. Logistic regression of alpha/theta of the mean potential of the C3 and O1 electrodes was carried out. A formula was calculated to aid the diagnosis of AD yielding 76.4% sensitivity and 84.6% specificity for AD with an area under the ROC curve of 0.92.Conclusion: Logistic regression of alpha/theta of the spectrum of the mean potential of EEG represents a good marker discriminating AD patients from normal controls.

Precuneus Failures in Subjects of the PSEN1 E280A Family at Risk of Developing Alzheimer’s Disease Detected Using Quantitative Electroencephalography

“…Comparing the accuracy to discriminate E280A symptomatic carriers from healthy people, only Rodriguez had presented results with an AUC of 0.98 using data from the Alpha or Theta band. Our results, sensitivity = 76%, specificity = 90% and AUC = 0.9, seems to be close to the current finding in classification in AD using EEG source markers [74]: sensitivity = 73%, specificity = 78% and AUC = 0.8; or even using a scalp Alpha/Theta ratio [75]: sensitivity = 76%, specificity = 85% and AUC = 0.9. It is important to highlight that the symptomatic subjects were mainly, 15 of them, in MCI stage and the remaining in mild dementia.…”

EEG and Clinical Factors Associated with Mild Cognitive Impairment in Coronary Artery Disease Patients

“…Previously, it had been found that the theta/alpha ratio is increased in patients with Alzheimer’s disease [14]. However, there is a lack of evidence supporting the diagnostic potential of the theta/alpha ratio for MCI patients with severe CAD.…”

“…Particularly, mild cognitive impairment (MCI), an early stage of VCI, is not always accurately detected by the results of a neuropsychological assessment [13, 14]. One way to more precisely detect MCI is by quantitative electroencephalography (EEG) [15, 16].…”

“…A quantitative EEG has been used effectively to assess brain functions in both normal and various pathological conditions, including MCI, to facilitate and improve diagnostic accuracy [17, 18]. Quantitative EEG ratios not only can be used to study the neurophysiological mechanisms of cognitive functional impairment but may also be useful as potential diagnostic markers of cognitive disorders [14, 18]. …”

Investigating the ability of post-stroke EEG measures of brain dysfuntion to inform early prediction of cognitive impairment or depression outcomes

“…One study used an alpha/theta ratio to screen for Alzheimer's dementia (Schmidt et al, 2013). In a group of 50 patients with probable Alzheimer's dementia (MMSE scores 12-25) and 57 healthy participants (MMSE score over 25) aged 50 years and older resting state EEG was recorded (Schmidt et al, 2013).…”