[Structural features of the brain in amnestic mild cognitive impairment and their correlation with mild behavioral...

To determine the structural features of the brain in elderly patients with amnestic syndrome of mild cognitive decline (aMCI) and to identify correlations of these features with mild behavioral disorders.

Fifty-three patients with aMCI (age 73.0±8.5 years, 9 males) and 34 mentally healthy subjects (66.8±9.6 years, 4 males) were examined. Cognitive status was assessed according to the Montreal Cognitive Assessment (MoCA) scale, and the severity of mild behavioral impairment was assessed according to the Mild Behavioral Impairment Checklist (MBI-C). Structural MRI images were obtained using a 3T Philips Ingenia. Cortical gray matter thickness, volumes of subcortical structures, and their correlation with MBI-C and MoCA scores were analyzed.

In patients with aMCI, a smaller cortical thickness was found in the left superior frontal gyrus and right precuneus (p<0.05), as well as negative correlations of these indicators with MBI-C scores. Also, this group showed smaller volumes of the amygdala and hippocampus of the left hemisphere (p<0.05) and a positive correlation between the volume of the left amygdala and MoCA scores.

The identified changes in structural MRI indicators and their correlation with neuropsychiatric and neurocognitive symptoms reflect the complex nature of the brain substrate of cognitive and behavioral impairment in aMCI. The results indicate the need for further search for clinically significant phenotypes in patients with aMCI, including those associated with an increased risk of Alzheimer's disease.