Clinical Characteristics Of Cognitive Impairment In The Patients With Asymptomatic Severe Internal Carotid Stenosis

Objective: The purpose of the study is to investigate the clinical characteristics of cognitive impairment in the patients with asymptomatic unilateral severe internal carotid artery stenosis(ICAS) and to provide theoretical basis for prevention and treatment.Methods: According to the inclusion and exclusion criteria, we selected hospitalized patients of neurology department of 306 th hospital of PLA and xuanwu hospital capital medical university from December 2013 to June 2015. A total of 80 patients with unilateral severe carotid stenosis(stenosis rate ≥70%) and 40 patients without carotid stenosis(control group) diagnosed by digital substract angiography(DSA) were analyzed retrospectively. According to the stenotic sides, the patients with severe ICAS were divided into a left stenosis group and a right stenosis group(n =40 in each group). The North American Symptomatic Carotid Endarterectomy Trial(NASCET) criteria were used to grade the degree of stenosis. Montreal cognitive assessment(Mo CA) was used to evaluate the cognitive function of the patients. The carotid artery stenosis and cognitive function of the patients in 3 groups were analyzed, so as to obtain the characteristics of cognitive impairment in patients with carotid artery stenosis. The SPSS17.0 medical statistical software was used for statistical analysis. The measurement data is expressed by x±s, the comparison among multiple groups mean using one-way ANOVA, the comparison between the two groups using LSD or q test, the comparison between the two independent mean using t test. Count data to constitute relative abundance ratio(%), statistical analysis of count data use χ2 test. With P<0.05 for the difference was statistically significant.Results: The Mo CA total scores, visuospatial and executive functions, and language ability, and delayed memory scores of the patients in both left and right groups were lower than those of the control group. There were significant differences(21.8 ±3.1, 3.4 ±1.3, 1.8 ±0.6, and 1.6 ±1.3, respectively in the left stenosis group; 22.6 ±2.5, 3.5 ±1.1, 1.9 ± 0.6, and 1.7 ± 1.4, respectively in the right stenosis group; and 26.4 ±1.8, 4.2 ±0.9, 2.7 ± 0.6, and 3.8 ± 1.0, respectively in the control group; all P < 0.01). The naming, attention, abstract ability, orientation ability scores of the patients in both left and right groups were no significant differences compared with those of the control group(all P > 0.05). There were no significant differences in the Mo CA total scores, visuospatial and executive functions, and language ability, and delayed memory, and naming, and attention, and abstract ability, and orientation ability scores of the patients between the left stenosis and the right stenosis groups(all P >0.05).Conclusion: The patients with asymptomatic unilateral severe ICAS have commonly cognitive impairment; it is characterized by delay memory, visuospatial and executive functions, and language dysfunction. The cognitive impairment in patients with unilateral severe carotid artery stenosis has nothing to do with the side of carotid artery stenosis. The MOCA scale can be used for asymptomatic carotid stenosis caused mild cognitive dysfunction screening.