Abstract 166: Spleen Contraction in Patients With Ischemic Stroke and Brain Hemorrhage: Validating Animal Studies
Objectives: Animal models have shown that the spleen contracts and contributes to post-ischemic inflammation that may exacerbate brain injury and impair recovery. Translation of these findings in patients is challenging because of a lack of normative spleen volume (SV) data. We created normograms of SV for an adult at-risk population, quantified splenic contraction (SC) in stroke patients, and characterized patients with SC. Methods: We enrolled 158 healthy volunteers (HV) with matching age and gender distribution with that of our stroke center registry. Spleen ultrasounds were performed on 5 consecutive days. We used quantile regression models to identify predictors of SV for HV. Gender and body surface area (BSA) were used to construct percentile based normograms of SV, and the expected pre-stroke SV were calculated, from which SC was quantified. We also enrolled a cohort of 170 patients with acute stroke and intracerebral hemorrhage within 24 hours of symptom onset and performed serial spleen ultrasound measurements during hospitalization. Logistic regression was used to determine factors associated with SC. Results: Normograms for SV in healthy males and females based on BSA were created (Figure 1). Over a 5-day consecutive period of daily spleen measurements, the maximum day to day variation was 10.6 cm3. Based on these findings, stroke patients with a normalized SV below 20 cm3 of their expected SV, were classified as having SC. Excluding stroke mimics, 158 patients were included in the analyses, of which 64 (40.5%) had SC detected within 24 hrs of symptom onset. African-American race, older age, and history of previous stroke were significantly associated with SC (Table 1). Conclusion: The spleen does appear to reduce in size after stroke in some specific subgroups of patients with acute stroke and brain hemorrhage. The biological relevance of SC to the inflammatory response and functional outcomes of stroke patients are currently being studied in our study cohorts.