[Mathematical analysis of EEG in consciousness recovery after traumatic brain injuries].

The clinical and EEG study of 20 patients with post-comatose consciousness disturbances caused by severe traumatic brain injuries (9 patients with autonomic state and 11 with Korsakoff syndrome), applying a statistical method of analysis of EEG spectrum and coherent connections developed by the authors, has revealed pathological features of the EEG interhemispheric connections. Patients with consciousness disturbances exhibited (1) total functional disconnections of hemispheres which was characteristic of the autonomic state and (2) disconnection in frontal areas of the brain in patients with Korsakoff syndrome as compared to the normal spatial distribution of coherence observed in 40 healthy people. Consciousness recovery has been accompanied by interhemispheric connections normalization, at first in the posterior regions of the hemispheres and then in the anterior ones as well as by transforming of coherence profile in the shape of "envelope" being most typical for the normal pattern of coherence distributation.

[Intercentral EEG relationships in regressive and chronic post-traumatic Korsakoff syndrome].

Dynamic EEG study of patients with posttraumatic Korsakoff's syndrome (KS) with the application of complex analysis methods revealed a complicated pathological structure of the intercentral relations of cortical electrical activity. The interhemispheric EEG coherence between symmetrical frontal cortical areas are sharply reduced, while the intrahemispheric coherence are increased in comparison with the normal values. The proposed technique of segregation of statistically homogeneous spectro-coherent characteristics made it possible to reveal the earlier intercentral EEG relations formed by stable and variable coherence spectra.