[A dynamic comparison of the interhemispheric asymmetry in the coherence of the human EEG in tumorous lesions of the diencephalic and hemispheric brain structures under different conditions of cerebral compensation].

In patients with diencephalic (30 persons) and hemispheric tumors (17 persons with the left-side and 18 ones with the right-side localization) EEG coherence was studied before and in early terms (12 days) after surgery in comparison with the right-handed healthy subjects. It was shown that integral coherence asymmetry coefficient before surgery were informative for a prognosis of the postsurgery treatment. Changes of absolute coherence levels in the central-frontal cortical areas were also informative. In patients with the light postsurgery course of treatment coherence levels were higher than those in the healthy subjects and increased after surgery. They decreased in patients with aggravated character of postsurgery period. Recovery terms were shorter in patients with the left hemispheric tumor localization than those with the right hemispheric one. The similarity of EEG coherence changes was observed in patients with the diencephalic and right hemispheric tumor localization. These results suppose the functional connections between these structures which are significant for compensatory processes in early terms of postsurgery period after brain tumor ablation.