Comparative Characteristics of Neuropsychological and Neurometabolic Parameters in Patients with Alzheimer’s Disease and Vascular Cognitive Impairment

Objectives. To study the features of and relationships between neuropsychological and metabolic indicators in patients with cognitive disorders (CD) of the Alzheimer’s and vascular types of different severities Materials and methods. A total of 177 patients took part, including 85 with Alzheimer’s disease (AD) and 92 with vascular CD (VCD). All patients underwent comprehensive neuropsychological examination; 18F-deoxyglucose positron emission tomography was performed in 17 patients with AD and 15 patients with VCD. Results. The greatest changes in patients with AD were noted in the mnestic domain, indicators being significantly different from those of patients with VCD even at the pre-dementia stage. Neurodynamic and dysregulatory disorders were predominant in patients with VCD. Patients with AD showed symmetrical bilateral decreases in metabolic activity in the parietal and temporal cortex, often in combination with marked hypometabolism in the hippocampal region. Patients with VCD showed areas of decreased metabolism in different locations and of different sizes, mainly in the projection of the basal ganglia and in the prefrontal and parietal areas of the cortex, as well as in the cingulate gyrus, providing indirect confi rmation of the mechanism of uncoupling of subcortical and cortical structures. In patients with AD, impaired metabolic activity in the hippocampal region correlated with impaired temporal and spatial orientation (ϱ = –0.54, p < 0.05) and memory impairment (ϱ = –0.71, p < 0.005). Hypometabolism of the parietal lobe cortex was linked with the total score on the Mini Mental State Examination (ϱ = –0.8, p < 0.001), the 10-word memory test (ϱ = –0.89, p < 0.001 and ϱ = –0.82, p < 0.001), visuospatial impairment (ϱ = –0.64, p < 0.01), and the categorical association test (ϱ = –0.73, p < 0.005). In patients with VCD, dysregulatory disorders correlated with hypometabolism in the thalamus (ϱ = –0.56, p < 0.05), prefrontal cortex (ϱ = –0.64, p < 0.05), and cingulate gyrus (anterior sections) (ϱ = –0.53, p < 0.05). Conclusions. The results obtained here indicate that there are differences in CD and cerebral metabolism between patients with AD and VCD.