Study of the Cognitive Evoked Potentials and Bioelectrical Brain Activity in Patients with Mild Cognitive Impairment Associated with Chronic Cerebral Ischemia

Yokudhon N. Madjidova, PhD, ScD¹*; Dildora K. Khaydarova²

¹Tashkent Medical Pediatric Institute; ²Tashkent Medical Academy, Tashkent, Uzbekistan

*Corresponding author:  Prof. Yokudhon N. Madjidova, MD, PhD. Head of Department of Neurology, Pediatric Neurology and Medical Genetics of Tashkent Medical Pediatric Institute. Tashkent, Uzbekistan. E-mail:

Published: September 24, 2013


Chronic cerebral ischemia (CCI), as a manifestation of age-related pathology shows strong parameters of the morbidity rate among the elderly. Cognitive impairments are one of main expressions of this pathology. The aim of this study was to evaluate the neurophysiological parameters of the cognitive impairments in patients with various stages of discirculatory encephalopathy (DE) in the comparative aspect. The cognitive functions were studied in 60 patients (main group) possessing various degrees of CCI (stages I-III DE) on a comparative basis. Among them, 20 patients had stage I DE (Group 1), 22 patients had stage II DE (Grope 2), and 18 patients had stage III DE (Group 3). The control group included 15 volunteers of comparable age without any manifestations of CCI. The mean age was 62.4±12.4 years. The etiological factors of DE in our observations were arterial hypertension and atherosclerosis of the cerebral vessels, without occlusion of the major artery of head. Based on the neuropsychological tests in 49 patients (81.6%) of the main group, we found cognitive impairments in various degrees of severity. Normal age-related memory loss was observed in 14.9% while mild cognitive impairment (MCI) was seen in 66.7% of the cases. Among the types of MCI, the disregulatory type was observed in 51.6% of patients with stage II-III DE, and the combined type was observed in 45.4% of patients with stage III DE. The EEG-pattern in patients with DE has some peculiarities that are expressed in the predominance of rhythmical slow wave activity and the reduction in the coherence of alpha rhythmic activity that results in a consequent disturbance of the integrated brain activity. Changes in cognitive evoked potentials (CEP P300) were expressed in the shortening of P300 peak latency and an increase in P300 peak amplitude and consequently, a reduction the latency/amplitude ratio in patients having MCI associated with DE.

chronic cerebral ischemia; mild cognitive impairment; cognitive evoked potentials.
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Int J Biomed. 2013; 3(3):188-191. © 2013 International Medical Research and Development Corporation. All rights reserved.