Cognitive impairment can be a consequence of direct and indirect brain injury, hypoxia, edema, metabolic disorders, neurodegenerative processes, metabolic encephalopathies, electrolyte abnormalities, organ failure, the effects of pesticides, toxins, drugs, and infectious processes. The results are presented from the study on correlations between cognitive functioning and syndromic characteristics and neuroimaging changes in patients with chronic post-traumatic (CTE), chronic vascular (CVE), chronic alcohol-induced (CAIE) and post-infectious (PIE) encephalopathies. The data of 520 medical records of patients with CTE (n = 145), CVE (n = 145), CAIE (n = 102) and PIE (n = 128) were analyzed. Neuroimaging was performed using multislice computed tomography. Cognitive functions were examined using the Montreal Cognitive Assessment. Statistical analysis of data was carried out with the help of computer software Microsoft Excel and Statistica 13.0. There was a probable relationship between cognitive functioning and extrapyramidal syndrome in patients with CVE; cognitive impairment and emotional lability disorder in patients with CAIE; cephalalgia syndrome, motor disorder syndrome and cerebellar ataxia syndrome in patients with PIE. In participants with CTE and CAIE, there was a significant correlation between cognitive functioning and ventricular enlargement; in patients with PIE — between cognitive functioning and the enlargement of the subarachnoid spaces.