[Quantitative EEG correlates of the human frontal lobe dysfunction]. / Kolichestvennye EEG-korreliaty disfunktsii lobnykh dolei kory golovnogo mozga cheloveka.

Increased central-parietal EEG theta-2 activity (about 6.5 per sec) was found in children with cognitive disorders (in Rett's syndrome, fragile X-syndrome, infantile autism) and in elderly patients with Alzheimer-type dementia (with prevalence of neuropsychological "frontal" disorders) in the presence of suppressed alpha rhythm. This theta-activity was closely associated with cognitive deficits and possessed a specific functional topography, namely it focused in the parietal region and suppressed by both visual stimulation and motor tests. The similar EEG pattern was observed in some patients treated with neuroleptics and/or during hyperventilation. By taking into account the data available in the literature on motor, oculomotor, regional cerebral blood flow and the probability prediction in frontal lobar dysfunction, it is suggested that the theta-activity described appears in the visuomanual coordination system and is a physiological correlate of decreased functional status of frontal lobes.

[Quantitative EEG in early and differential diagnosis of mild dementia of different genesis]. / Kolichestvennaia élektroéntsefalografiia v rannei i differentsial'noi diagnostike "miagkikh" dementsii raznogo geneza.

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.