Vascular Dementia: Quantitative Analysis of the Cito-Angioarchitectonics of the Cerebral Cortex

Dementia is a clinical diagnosis requiring new functional dependence on the basis of progressive cognitive decline. The most common causes of cognitive impairment and dementia are Alzheimer's disease (AD) and vascular brain injury (VBI), either independently, in combination, or in conjunction with other neurodegenerative disorders. The purpose of the present study was to investigate the quantitative criteria of the brain pathology at the vascular dementia for the objectification of morphological diagnosis and differential diagnosis with other dementia diseases. Material and methods. We studied medical records of 52 patients with dementia (diagnosis based on DSM-III-R criteria; mean age of 67.8±5.2 years) and 6 cases of the control group without dementia. Autopsy included macroscopic, microscopic and morphometric study of the brain. Investigated areas of the cerebral cortex Brodmann: 10 area – frontopolar prefrontal cortex, 44 and 45 areas – the frontal lobe (Broca's area), 17 area – occipital lobe (visual center), 23/24 area – limbic region, 40 area – supramarginal gyrus, parietal lobe, 41 area – Wernicke's area, temporal lobe, in all 20 zones. As a control group for quantitative morphological studies we took pieces of tissue from the respective regions and areas of the brain in six persons killed in accidents and not suffered for the mental life (data collected through medical records). Collecting the material was carried out within 6-8 hours after death. We used modern methods. Histological sections stained by standard methods: hematoxylin and eosin, Nissl staining, Bilshovsky, Cajal's, PAS-reaction. To confirm the presence of vascular amyloidosis, amyloid angiopathy and differential diagnosis of hyalinosis of vessels we used Congo red. We also used Congo red to make a diagnosis of amyloid and state the common opinion that in polarized light, Congo red-stained amyloid showed apple-green birefringence, sometimes called apple-green dichroism. Histological examination was performed with a microscope Hund H500 (Germany). Results and discussion. The main signs of macroscopic vascular dementia are diffuse atrophy of the frontal, parietal and temporal areas. The largest percentage of the loss of neurons was noted in the fields of the frontal area – 30.1% (10 fields), 27.2% (44 fields) and 25.8% (45 fields), as well as 17 fields of occipital (28.6%) (p <0.005). The loss of neurons was in the perivascular zones of the vessels, sharp destructive changes in the basement membranes were observed in the wall of the vessels – mucoid and fibrinoidal changes, and chronic processes – fibrosis and hyalinosis. Neurofibrillary dystrophy of cytoplasmic structures of neurons was not characteristic of vascular dementia. Its specific volume of the frontal area was minimum from <0,010 to 0,013 (p <0.005). In vascular dementia, spongiosis was lacunar and topographically limited by the perivascular zone of the micro vessels. The specific volume of amyloid plaques in vascular dementia was relatively low in almost all studied areas. Conclusions. However, the basic morphological diagnostic criteria and the morphometric characteristics of brain tissue of vascular dementia are established. From the view of clinical indications this can be used in practice in department of pathology for statement of the objective diagnosis and differential diagnostics with others neurodegenerative dementive syndromes.