THE ROLE OF MELATONIN IN THE DEVELOPMENT OF POST-STROKE COGNITIVE IMPAIRMENT IN ELDERLY PATIENTS IN COMPARISON WITH MIDDLE-AGED PATIENTS
In the acute phase of ischemic stroke 73 patients aged from 61 to 86 years and 47 patients aged 36 to 60 years underwent a comprehensive neuropsychological testing, evaluation of the concentration of 6-sulfatoximelatonin 6-sulfatoximelatonin in the night urine and brain MRI morphometry in some patients. The control group consisted of 14 persons without cerebrovascular disease. Younger and middle-aged patients had higher levels of 6-sulfatoximelatonin compared to both controls and elderly patients. The level of the metabolite in patients older than 60 years and the control group did not differ. In the group of patients older than 60 years we revealed a direct correlation with the severity of the stroke and concentration of 6-sulfatoximelatonin. Metabolite concentration was inversely correlated with the results of the Mini Mental State Examination, Frontal Assessment Battery, verbal ﬂuency, clock drawing test and directly - with the Shulte tables result. High concentrations of 6-sulfatoximelatonin was also associated with a large size of acute ischemic lesion and hippocampal volume. The highest concentration of the metabolite was observed in patients with dysexecutive cognitive impairment and the lowest in patients with normal cognitive status and amnestic deﬁcit. Thus, in elderly patients a high concentration of 6-6-sulfatoximelatonin is a marker «pure» post-stroke cognitive impairment, whereas a low concentration of metabolite in the presence of cognitive deﬁcits may be indicative of its mixed, that is, in part, of hippocampal type.