It is indicated that all subjects who had acute grade I radiation sick
ness of the Chernobyl accident showed disorders of the brain functions
5-6 years later. They evidence involvement of all brain structures bu
t especially the subcortical brainstem portions. Marked memory reducti
on was also noted. The neurological deficit was not pronounced but the
patients developed a syndrome of significant disadaptation, which had
a progressive character. The authors propose to term these changes as
postradiation encephalopathy of primary-radiation and intoxication ge
nesis.