[Effects of long-term action of direct electric field on brain slices].

An attempt of modeling of experimental paradigm of long-term transcranial direct current stimulation (ltDCS) ofa human brain by constant electric field was undertaken on rat hippocampal slices. At anodal or cathodal direction of electric field (14 min, 250 mV/mm) statistically significant changes of population spikes (pop-spikes) amplitude in the field CAl towards increase or decrease respectively occurred in reply to stimulation of Schaffer collaterals (1/30). Long-lasting aftereffects were not observed.

[The comparison of clustering methods of EEG independent components in healthy subjects and patients with post concussion syndrome after traumatic brain injury].

The comparison of three different clustering methods of 19-channels EEG independent components in 518 healthy subjects and 87 patients with post concussion syndrome after traumatic brain injury was performed to define more exact the location of sources of pathologic brain activity. Following methods of grouping were used: clustering of independent components topographies, clustering of coordinates of equivalent dipole sources corresponding to independent components topographies and sorting of independent components using extremes of equivalent source current density computed by Standardized Low Resolution Electromagnetic Tomography (sLORETA).The comparison of power spectra of independent components revealed statically significant increase of EEG power located in frontal and temporal brain areas in delta, theta and alpha frequency bands in patients with post concussion syndrome after traumatic brain injury.

[Methods of localization of equivalent EEG sources in the diagnostics of protracted loss of consciousness].

Results of EEG study of patients in a protracted unconscious state due to severe cranial trauma using different methods of source localization (independent component analysis, the LORETA method) are presented in order to compare their diagnostic value. Also the results of the study of somatosensory evoked potentials (SSEP) to median nerve stimulation of and EEG are compared. The independent higher frequency components of the EEG power spectrum had the higher activity in the delta-band, were localized predominantly in the frontal brain hemispheres (frontal, temporal regions), positively correlated with pathological neurodynamic SSEP changes (r=0,69; p=0,003) and negatively with the scores on the Glasgow outcome scale (r=-0,66; p=0,005).