[Quantitative EEG in early and differential diagnosis of mild dementia of different genesis]

Quantitative EEG was used to reveal the specific features of its amplitude-frequency parameters and topography in patients with mild dementia of different genesis versus healthy elderly individuals. All four study groups of patients differ in EEC relative spectral density, they also differ from the healthy persons while alpharhythm was suppressed in Alzheimer's disease (AD) and vascular dementia (VD) and there was slower alpha-rhythm and higher theta-activity in senile AD (SAD). Patients with VD were characterized by desynchronized EEG. Factorial and stepwise discriminant analyses of EEG parameters showed that the control group greatly differed from patients with mild dementias. Patient groups mainly with atrophic atrophic AD and SAD or vascular (VD and mixed) dementia were also different whereas the mixed vascular-atrophic group is intermediate in EEC parameters between the VD group and the partially overlapped AD and SDA patient groups. Quantitative EEC data may be thus used for differential diagnosis to optimize therapy and prognosis even in mild dementia.