Systemic Inflammation and White Matter Hyperintensities Associated with Cognitive Impairment in Intracranial Atherosclerotic Stenosis: A Retrospective Observational Study.

BACKGROUND AND PURPOSE: Cognitive impairment is a common clinical symptom in individuals with intracranial atherosclerotic stenosis (ICAS), but the underlying mechanisms have not been completely elucidated. This study aimed to identify factors associated with cognitive impairment in ICAS and explore their interrelationships. METHODS: A total of 129 consecutive patients with ICAS and 31 healthy controls were enrolled in this research. Among the patients with ICAS, 96 completed the Montreal Cognitive Assessment (MoCA), as did all healthy controls. Cognitive impairment was defined as MoCA <23, with scores ≥23 indicating normal function. Differences between these subgroups in peripheral blood inflammatory markers and neuroimaging features were assessed. Multivariate regression models identified independent predictors of cognitive impairment and evaluated their interrelationships. RESULTS: Patients with ICAS exhibited significantly lower MoCA scores than the controls (18.08 vs 25.10; P < 0.001). Within the ICAS cohort, individuals with cognitive impairment were older. They demonstrated greater systemic immune dysregulation, characterized by lower lymphocyte-to-monocyte ratio (LMR), higher white matter hyperintensities volume (WMHV), increased prevalence of plaque enhancement, and symptomatic ICAS (all P < 0.05). Multivariate analysis established LMR (OR: 0.65, 95% CI: 0.45-0.93) and lnWMHV (OR: 2.50, 95% CI: 1.54-4.06) as independent factors associated with cognitive impairment (both P < 0.05). LMR showed a positive linear correlation with MoCA scores, whereas lnWMHV displayed a negative correlation (both P < 0.05). Furthermore, moderate-to-severe WMH (overall, deep, or periventricular) was significantly associated with lower LMR (P < 0.05), suggesting an association between systemic inflammatory status and WMH in patients with ICAS. CONCLUSION: Cognitive impairment in ICAS was associated with lower LMR and greater WMH burden, suggesting potential involvement of inflammatory dysregulation and white matter injury in cognitive dysfunction among patients with ICAS.