Changes of intrahemispheric integration in patients with vertebrobasilar transient ischemic attacks

To determine the dynamics of changes of intrahemispheric integration, 26 patients with vertebrobasilar (VB) transient ischemic attacks (TIA), aged 48-62 years, were examined using EEG coherence spectral analysis. A control group included 24 age-matched volunteers. An absence of changes of the level of integration between the majority of hemispheric regions in the 8-band and a decrease of this level between the hemispheric regions located at some distance from each other in the 8-band were revealed on the 2-4(th) day after TIA. A disintegration of the alpha-band activity was observed mostly between occipital regions of hemispheres and regions located at some distance from them with the absence of signs characteristic of focal cerebral lesions. The disintegration in the beta(1)-band was very similar to that of alpha-activity. The decrease of the level of integration in the beta(2)-band was much less in severity and distribution as compared to the beta(1)-band. The positive dynamics of clinical symptoms in patients was correlated with the positive dynamics of changes of integration in the majority of EEG bands on the 10-14(th) day after TIA. The bidirectional changes of intrahemispheric integration in the beta(2)-band were likely to show a qualitatively new state of pathogenic and sanogenetic processes in the CNS of patients on the 10-14(th) day after TIA. Estimated changes of intrahemispheric integration gave evidence for a reversible and functional CNS damage in patients with VB TIA.