[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.