Results of the study of the late cognitive impairments in chronically exposed persons

The objective of the paper is to study cognitive impairments in residents of the Techa riverside villages who were affected by chronic radiation exposure in low to intermediate dose range. Materials and methods. The study involved 52 people subdivided into 2 groups depending on the accumulated dose to red bone marrow (RBM). The following diagnostic techniques were used: clinical (examination by psychiatrist, neurologist), clinical-psychological (MMSE, WAIS test, method of proverb interpretation and clock drawing test), and neurophysiological (EEG). Results and Conclusions. Signs of pre-dementia cognitive impairments and dementia that manifest in impairment of several cognitive functions (thinking, attention, speech) were revealed in persons affected by chronic radiation exposure. The most frequently occurring type of impairment is weakness of memory. Full-scale intelligence quotient (IQ) in studied persons of the main group is equal to average score (94.9±2.6), as well as the values of the non-verbal IQ (103.6±2.1). Verbal IQ score is equal to low average (88.9±3.3). Out of all dose groups statistically significant decrease in the average score of full-scale and verbal IQ was revealed in the group with dose to RBM ranging from 0.5 to 0.99 Gy (p=0.07). Cerebrovascular disorders occur predominately in the left mesencephalic artery. The data of EEG examination demonstrate that the processes of CNS excitation predominate over those of inhibition in members of the main group.