Cognitive Impairment After Aneurysmal Subarachnoid Hemorrhage: Risk Factors, Efficacy of Lumbar Drainage and Prognostic Utility of the Montreal Cognitive Assessment.

Abstract

This study aimed to identify risk factors for cognitive impairment after aneurysmal subarachnoid hemorrhage (aSAH), evaluate the efficacy of lumbar drainage (LD), and assess the prognostic utility of the Montreal Cognitive Assessment (MoCA). In this retrospective cohort study, 75 aSAH patients aged 18 to 75 years underwent cognitive (MoCA), neurological (modified Rankin Scale, mRS), and functional (functional activities questionnaire, FAQ) assessments at 3 months postoperatively. Multivariate regression and receiver operating characteristic analyses were used to identify predictors. The incidence of cognitive impairment (MoCA <26) was 53.3% (40/75). Multivariate analysis identified the following independent risk factors: education level <5 years (odds ratio [OR] = 4.644, 95% confidence interval [CI] 1.151-18.743, P = 0.031), Fisher grade 3-4 (OR = 9.176, 95% CI 1.997-42.163, P = 0.004), delayed cerebral infarction (OR = 7.867, 95% CI 1.932-32.039, P = 0.004), and chronic hydrocephalus (OR = 4.219, 95% CI 1.128-15.783, P = 0.032). LD reduced the risk of impairment (OR = 0.211, 95% CI 0.047-0.954, P = 0.043), particularly in severe subgroups (Hunt-Hess IV-V, WFNS IV-V, modified Fisher 3-4). The incidence of unfavorable clinical outcomes (mRS ≥3) was 25.3%, and that of impaired daily living ability (FAQ >5) was 41.3%. MoCA scores correlated strongly with both mRS (P < 0.001) and FAQ (P < 0.001), and effectively predicted unfavorable outcomes (area under the curve = 0.860, optimal cutoff ≈<23) and impaired daily living (area under the curve = 0.910, optimal cutoff ≈<25). Cognitive impairment in aSAH patients is significantly associated with lower educational attainment, greater initial hemorrhage severity, and secondary brain injury. Our findings suggest that early LD intervention, particularly in high-grade cases, may be a promising therapeutic strategy. MoCA demonstrates robust prognostic value for functional recovery, supporting its clinical utility in early risk stratification.