Abstract TP535: Degree of Cognitive Impairment Based on Subarachnoid Hemorrhage-Associated Early Brain Injury

Introduction: Cognitive impairment is common after aneurysmal subarachnoid hemorrhage (aSAH), however differences between low and high grade aSAH is less well defined. In this study we investigated the contribution of aSAH-associated early brain injury (EBI) to neurocognitive decline. Methods: We retrospectively studied aSAH patients admitted to a tertiary referral center (group 1). EBI was defined as mild, moderate, or severe based on baseline Hunt and Hess score (1-2 vs. 3 vs. 4-5, respectively). Cognition was assessed by the Montreal Cognitive Assessment (MoCA) administered by blinded personnel prior to hospital discharge. Sociodemographic characteristics and pertinent complications, including use of ventricular diversion, vasospasm, delayed neurologic deterioration, and cerebral infarct were recorded. Ischemic stroke (group 2) and non-neurological patients (group 3) served as controls. MoCA scores were compared using ANCOVA adjusting for baseline differences. Results: Groups 1, 2, and 3 included 84, 43, and 25 patients, respectively. There was no difference in sex but there was a difference in age (52.2±12.2, 60.5±14.9, 52.2±7.0 years, p=0.008). MoCA scores (mean±SD) for groups 1, 2, and 3 were 20.0±5.2, 20.0±5.4, and 23.6±5.0. These differences were statistically different after adjustment for age and level of education (p=0.001). In pairwise analysis, MoCA scores for aSAH patients were similar to ischemic stroke but lower than for non-neurologic patients. Among aSAH patients, the rate of mild, moderate, and severe EBI were 71%, 21%, and 8% (MoCA scores 20.7±5.3, 18.2±4.9 and 18.3±4.2, respectively). No significant differences in MoCA scores were noted based on EBI severity. Also, the scores of aSAH patient with mild EBI were comparable to ischemic stroke but lower than for non-neurological controls. Conclusion: Cognitive decline is commonly seen in aSAH survivors irrespective of the EBI severity. The cognitive decline observed in mild EBI patients highlights an underappreciated degree of cognitive decline in individuals who are otherwise expected to have good outcomes. Cognitive screening in low-grade aSAH patients is warranted.