Acute stress and inflammation responses are associated with worse outcomes in intracerebral hemorrhage (ICH) but the precise mechanisms involved are unclear. We evaluated the effect of neutrophil-to-lymphocyte ratio (NLR) in ICH outcome, with focus on hematoma expansion and early cerebral edema. In a retrospective study, we included all patients with primary ICH admitted to our center within 24-h from symptom onset from January 2014 to February 2015. We retrieved demographic and medical history data, Glasgow Coma Scale scores, blood cell counts, glucose, and C-reactive protein, and calculated NLR. We obtained hematoma volumes by computerized planimetry. Outcomes included independence at 90 days (modified Rankin scale 0-2), mortality at 30 days, significant hematoma expansion (> 33% or > 6 mL) and early cerebral edema causing significant midline shift (> 2.5 mm) at 24 h. We included 135 patients. NLR independently associated with independence at 90 days (adjusted odds ratio (aOR) 0.79, 95% CI 0.67-0.93, p = 0.006) significant cerebral edema (aOR 1.08, 95%CI 1.01-1.15, p = 0.016) but not hematoma expansion (aOR 0.99, 95%CI 0.94-1.04, p = 0.736). The severity of midline shift was positively correlated with NLR (adjusted beta = 0.08, 95% CI 0.05-0.11, p < 0.001). In ICH, an immediate and intense systemic inflammatory response reduces the likelihood of a better functional outcome at 90 days, which is more likely to be explained by perihematomal edema growth than due to a significant hematoma expansion. These findings could have implications in new treatment strategies and trial designs, which endpoints tend to target exclusively hematoma enlargement.
Keywords: Brain edema; Hematoma; Inflammation; Intracerebral hemorrhage; Neutrophils.