EEG findings in senile dementia and normal aging

Abstract

EEG findings in 62 patients with senile dementia of alzheimer type (SDA), 22 patients with multi-infarct dementia (MID) and 90 controls of same age and sex were studied. The SDA patients differed significantly from the controls in EEG normality, over-all disturbance, dominant occipital, rhythm, accentuation of theta and delta, fluctuations in alertness, paroxysmal activity and H-reaction. Even the least severely affected SDA patients differed significantly from the controls in all EEG variables except paroxysmal activity. With increasing degree intellectual impairment in the SDA group the dominant occipital rhythm became slower. The MID group differed from the controls in all EEG parameters including asymmetric findings. The EEG findings of the SDA patients differed significantly from those of the MID patients only in asymmetric findings which were more common in the MID patients. 29% of the normal elderly people had EEG alterations, Abnormalities were mild. Asymmetric findings, mainly theta activity in left temporal region were common. H-reaction (occipital driving response greater than or equal to 18 c/s) was well preserved in the controls. EEG is valuable in differentiation of dementia patients from normal elderly people, but differentiation between MID and SDA is not reliable by using EEG, only.

Abnormal EEG Slow Activity in Left Temporal Areas in Senile Dementia of the Alzheimer Type

“…Asymmetric EEG slow activity has been reported to be prevalent in the elderly in qualitative EEG studies of cerebrovascular disease (6,25). However, the one qualitative study (25) which documented the locality of these abnormalities suggests that they are more right temporal and more diffuse than those of the mild-to-moderate SDAT patients of the present study.…”

Eletrencefalograma digital com mapeamento em demência de Alzheimer e doença de Parkinson: estudo prospectivo controlado

“…A demência senil de tipo Alzheimer (DA) é a mais freqüente etiologia desta síndrome, correspondendo a aproximadamente 50% dos casos em várias séries clínicas 2 . Os achados eletrencefalográficos na DA podem incluir lentificação do ritmo posterior dominante, aumento difuso da atividade lenta (delta e teta) e/ou surtos de atividade lenta com maior amplitude anterior 11 *- 21,22 . Os achados de análise espectral são similares aos relatos de análise visual em vários estudos 1,3,4 , e o grau de gravidade da doença correlaciona-se com o grau de anormalidades tanto no EEG visual como na análise espectral.…”

Topographic EEG changes with normal aging and SDAT

“…Obrist and Busse (1965) described 4 trends in the aging EEG: slowing of the alpha rhythm, increased fast activity, diffuse slowing, and focal disturbances. Over the past two decades, these general trends have been further refined (Obrist 1978) and attempts have been made to associate specific EEG abnormalities with unique pathological developments (Drachman and Hughes 1971;Johannesson et al 1979;Stigsby et al 1981;Soininen et al 1982). With the application of quantitative methods to EEG analysis, investigators have measured the changes in frequency and amplitude of the EEG recording.…”