Effects of intracranial artery stenosis of anterior circulation on cognition—A CT perfusion‐based study

Background Intracranial atherosclerotic stenosis (ICAS) is one of the most important independent risk factors for stroke that is closely related to the occurrence of cognitive impairment. The relationship between ICAS and vascular cognitive impairment (VCI) remains unclear. Cerebral hemodynamic changes are one of the main causes of cognitive impairment. Computed tomographic perfusion (CTP) imaging can quantitatively analyze cerebral blood perfusion and quantify cerebral hemodynamic changes. Previous research on the relationship between hypoperfusion induced by ICAS and cognitive impairment, as well as its underlying mechanisms, remains relatively insufficient. This study is dedicated to elucidating the characteristics and potential mechanisms of cognitive impairment in ICAS patients with abnormal perfusion, utilizing CTP imaging as our primary investigative tool. Methods This study recruited 82 patients who suffer from non‐disabling ischemic stroke (IS group) and 28 healthy controls. All participants underwent comprehensive neuropsychological assessments both collectively and individually, in addition to CTP imaging. Within the patient group, we further categorized individuals into two subgroups: the ischemic penumbra group (IP, N = 28) and the benign oligemia group (BO, N = 54), based on CTP parameters—Tmax. The correlations between cognitive function and abnormal perfusion were explored. Results The cognitive function, including the overall cognitive, memory, attention, executive functions, and language, was significantly impaired in the IS group compared with that in the control group. Further, there are statistical differences in the stroop color–word test‐dot (Stroop‐D) and Montreal Cognitive Assessment (MoCA) sub‐items (memory + language) between the BO and IP groups. In the BO group, the score of Stroop‐D is lower, and the MoCA sub‐items are higher than the IP group. There is no correlation between CTP parameters and cognitive function. Conclusion Cognitive function is significantly impaired in patients with ICAS, which is related to cerebral perfusion. Executive, memory, and language function were better preserved in ICAS patients without IP. Hence, this study posits that managing hypoperfusion induced by ICAS may play a pivotal role in the development of VCI. The results elucidate that executive, memory, and language function were better in ICAS patients without ischemic penumbra compared with the ischemic penumbra group. “b” and “c” show that the