Effects of asymptomatic cerebral artery stenosis of anterior circulation and establishment of collateral circulation on cognition

The purpose of this study is to investigate how cognition is affected by asymptomatic cerebral artery stenosis (CAS) of the anterior circulation and its related collateral circulation. 102 patients with CAS of the anterior circulation and 52 controls were enrolled from January 1, 2019 to June 30, 2022. Patients with CAS of anterior circulation were further divided into different subgroups according to the degree of stenosis, cerebral perfusion, and collateral circulation. A series of neuropsychological scales were used to evaluate the participant’s cognitive function, activities of daily living, and neuropsychiatric symptoms (such as memory, execution, psychomotor speed, etc.). The data were analyzed using T-test, F-test, chi-square test, rank sum test, and other statistical methods, moreover, the quantitative data were further examined for trends. The relationship between the degree of CAS, cerebral perfusion, collateral circulation, and the outcome of the cognitive test was investigated using Spearman correlation analysis. Compared to controls, there were severe impairments of global cognition, psychomotor speed/execution, memory, attention, activities of daily living, and more neuropsychiatric symptoms in patients with anterior circulation CAS (p < 0.05), and these impairments got worsened with the aggravation of CAS (p < 0.05). The global cognition, psychomotor speed / executive function, memory function, and daily living ability were impaired both in the cerebral perfusion-compensated group and decompensated group(p < 0.05), while there was no statistically significant difference between the two groups (p > 0.05). With the aggravation of CAS, the proportion of poor collateral formation increased, and this difference was statistically significant (P < 0.01). The degree of stenosis, cerebral perfusion, and collateral circulation establishment of anterior circulation CAS was correlated with global cognition, memory, psychomotor speed, execution, attention, activities of daily living, and neuropsychiatric symptoms (all p < 0.01). Cognitive impairment and the percentage of inadequate collateral circulation development rise as stenosis progresses in patients with anterior circulation CAS. The decline in global cognitive function was accompanied by impairments in psychomotor speed / executive function, memory function, attention, and daily living skills, as well as the aggravation of neuropsychiatric symptoms, especially in patients with impaired cerebral perfusion and poor collateral circulation formation.