Objectives. To identify the significance of cerebral microbleeds (CMB) in the diagnosis of the main cerebrovascular and neurodegenerative diseases with cognitive impairments (CI). Materials and methods. MRI scans (1.5 T, T2* regime, gradient echo) were performed in 120 patients with Alzheimer’s disease (AD), Lewy body dementia (LBD), and vascular dementia to study CMB, their influence on the state of cognitive functions, and links with signs of vascular and neurodegenerative brain lesions. Neuropsychological studies were performed using the Montreal and Addenbrooke scales, including assessment of speech activity, the clock drawing test, and the pictures test. Results and discussion. CMB were detected in more than 1/3 patients with neurodegenerative and cerebrovascular pathologies; cortical CMB were mostly seen in neurodegenerative pathology and subcortical in cerebrovascular pathology, and these locations can be used for differential diagnosis. Single subcortical CMB were seen in 48% of patients with LBD, and these were accompanied by smaller numbers of lacunar infarcts and a lower severity of leukoaraiosis. In AD with additional signs of LBD and cerebrovascular disease, CMB was encountered more frequently (60%) and was a criterion for mixed pathology. Conclusions. Leukoaraiosis has great clinical significance in neurodegenerative and cerebrovascular diseases with CI, if accompanied by CMB. The presence of CMB is a marker for severe CI and a predictor for mixed pathology in CMB located cortically-subcortical and the corresponding neuropsychological profile.
