[Evaluation of functional brain condition by EEG biopotential power asymmetry]

The fluctuations of functional brain condition level are evaluated by interhemispheric asymmetry of bioelectric activity power that is a consequence of both hemispheres interplay and involvement of nonspecific brain system in this process. Using neurological examination and electroencephalography, functional CNS condition analysis in patients with chronic brain ischemia and healthy controls was carried out. The results were compared to the indices of interhemispheric asymmetry of biopotential power (IHABP). Different functional CNS condition of both the patients and controls was characterized by different ratio of IHABP for fore- and back brain cortical regions. Controls exhibited a predominance of IHABP for frontal neocortex areas comparing to back ones. In the patients, the identical IHABP indices were detected for both neocortex areas.