Quantitative electroencephalography (qEEG) to discriminate primary degenerative dementia from major depressive disorder (depression)

Abstract

-Electroencephalography (EEG) can be a valuable technique to assess electrophysiological changes related to dementia. In patients suspected of having dementia, the EEG is often quite informative. The sensitivity of the EEG to detect correlates of psychiatric disorders has been enhanced by means of quantitative methods of analysis (quantitative EEG). Quantitative features are extracted from, at least, 2 minutes of artifact-free, eyes closed, resting EEG, log-transformed to obtain Gaussianity, age-regressed, and Z-transformed relative to population norms (Neurometrics database). Using a subset of quantitative EEG (qEEG) features, forward stepwise discriminant analyses are used to construct classifier functions. Along this vein, the main objective of this experiment is to distinguish profiles of qEEG, which differentiate depressive from demented patients (n = 125). The results showed that demented patients present deviations above the control group in variables associated to slow rhythms: Normed Monopolar Relative Power Theta for Cz and Normed Bipolar Relative Power Theta for Head. On the other hand, the deviation below the control group occurs with the variable associated to alpha rhythm: Normed Monopolar Relative Power Alpha for P3, in dementia. Using this method, the present investigation demonstrated high discriminant accuracy in separating Primary Degenerative Dementia from Major Depressive Disorder (Depression).KEY WORDS: qEEG, neurometrics, Alzheimer´s disease, depression. Eletroencefalografia quantitativa (EEGq) na discriminação entre demência degenerativa primária e transtorno depressivo maior (depressão)RESUMO -A Eletroencefalografia (EEG) pode ser utilizada como uma técnica valiosa na avaliação de mudanças eletrofisiológicas relacionadas à demência. Em pacientes com suspeita de demência, o EEG é em geral bastante informativo. A sensibilidade do EEG em detectar correlatos de desordens psiquiátricas pode ser incrementada através de métodos de análise quantitativa (EEG quantitativo). Padrões quantitativos são extraídos de pelo menos 2 minutos de dados livres de artefatos, em que os sujeitos estão com olhos fechados e em estado de repouso. São aplicados métodos quantitativos, tais como: transformação logarítmica para obtenção de uma distribuição Gaussiana, regressão por faixa etária e o escore Z relativo a normas populacionais preestabelecidas (Neurometrics). Utilizando uma amostra de padrões de EEG quantitativo (EEGq), será implementada uma análise discriminante (forward stepwise) a fim de estabelecer funções classificatórias. Neste contexto, o objetivo principal deste estudo é distinguir perfis de EEGq que diferenciem pacientes com depressão de pacientes com demência (n = 125). Os resultados demonstraram que pacientes acometidos por demência apresentam desvios acima do grupo controle em variáveis associadas a ritmos lentos: Potência Monopolar Relativa Normalizada em Teta para Cz e Potência Bipolar Relativa Normalizada em Teta para Cabeça. Por outro lado, desvios abaixo do grupo controle ocorrem em...

Quantitative electroencephalography power and coherence measurements in the diagnosis of mild and moderate Alzheimer's disease

“…In the present casuistry, the finding of an increase in theta power, and to a lesser extent of the delta band, is similar to that reported in the literature [13][14][15] . No significant decreases in the alpha and beta powers were found, probably because the greater part of the patients was in the mild stage of AD.…”

Describing Brain Activity of Persons With AD and Depressive Symptoms

“…An increase in theta activity has also been one of the electrophysiological changes associated with major depression along with an increase in relative delta activity and a decrease in activity for relative alpha and beta (Deslandes et al, 2004). This increase in slow brain activity with a decrease in fast brain activity (or an inverse relationship) was reported in other studies.…”

“…Relative theta activity increased with a decrease in relative alpha in depressed persons with AD (Pozzi, Golimstock, Petracchi, Garcia, & Starkstein, 1995;Pozzi et al, 1993). Relative theta activity increased in the central area of the brain with relative alpha decreasing in the posterior area (Deslandes et al, 2004). However, in these 4 studies, depressive symptoms are assessed as the disease process of a depression disorder (a co-morbid feature) and not a symptom of AD over the progression of AD.…”

Effect of aerobic training on EEG alpha asymmetry and depressive symptoms in the elderly: a 1-year follow-up study

“…Electroencephalography (EEG) is a valuable tool used to assess electrophysiological changes associated with mental illness, and has shown increasing utility in assessing brain function in clinical studies of depression (17,18). The effects of exercise on the reduction of mood symptoms are observed by analyzing cortical hemispherical activity (19)(20)(21)(22)(23), especially in the alpha band (8)(9)(10)(11)(12)(13).…”