[The characteristics of the late reaction of the human brain to radiation exposure: the EEG and neuropsychological study (the sequelae of the accident at the Chernobyl Atomic Electric Power Station)].

We examined 23 patients (participants in the clean-up of the consequences of the Chernobyl accident in 1986-1987) using neuropsychological and electrophysiological approaches. The results obtained by means of EEG coherence analysis, three-dimensional source localization, and dichotic listening test were compared. All the patients showed some common dysfunctions such as disturbances of hemispheric interaction which resulted in deterioration of the brain functional state in comparison with the control group. Neuropsychological evidence and source localization of the epileptiform EEG suggested predominantly subcortical damage at the limbic-reticular and, especially, diencephalic level. The observed signs of the left-hemispheric dysfunction depended on the brainstem damage while the right-hemispheric dysfunction were explained by the diencephalic damage. The observed symptoms were considered as a result of subcortical brain lesions at different levels rather than the primary cortical hemispheric damage.