Introduction: Perihematomal edema (PHE) expansion rate may be an independent predictor of poor functional outcome following spontaneous intracerebral hemorrhage (ICH). We examined whether this association varies by ICH location.
Hypothesis: The effect size of PHE expansion rate on mortality and poor functional outcome will be greater for deep ICH compared to lobar ICH.
Methods: Subjects (n=139) were retrospectively identified from a prospective ICH cohort enrolled from 2000-2013. Inclusion criteria: ≥18 years of age, spontaneous supratentorial ICH, and known time of onset. Exclusion criteria: infratentorial or primary intraventricular hemorrhage, subsequent surgery, trauma, or warfarin-related ICH. ICH, PHE, and intraventricular hemorrhage (IVH) volumes were measured from CT scans. PHE expansion rates were calculated from serial PHE volume measurements. Logistic regression assessed the association between PHE expansion rate and mortality or poor functional outcome (modified Rankin Scale >2) at 90 days. Odds ratios are per 0.04 mL/h.
Results: PHE expansion rate from baseline to 24 hours (PHE24) predicts mortality for deep (p=0.03, OR 1.13[1.02-1.26]) and lobar ICH (p=0.02, OR 1.03[1.00-1.06]) in unadjusted regression, and in models adjusted for age (Deep: p=0.02; Lobar: p=0.03), blood pressure (Deep: p=0.02; Lobar: p=0.04), IVH volume (Deep: p=0.02; Lobar: p=0.05), Glasgow Coma Scale (Deep: p=0.03; Lobar: p=0.02), or time to baseline CT (Deep: p=0.05; Lobar: p=0.05). PHE24 also predicts mortality for lobar ICH adjusting for ICH volume (p=0.05, OR 1.03[1-1.06]). A significant interaction exists between ICH location and PHE expansion rate from baseline to 72 hours (PHE72) in models predicting mRS>2 (p=0.04). PHE72 predicts mRS>2 for deep but not lobar ICH (p-values not shown) in models that are unadjusted (p=0.02, OR 4.04[1.25-13.04]) or adjusted for ICH volume (p=0.02, OR 4.3[1.25-14.98]), age (p=0.03, OR 5.4[1.21-24.11]), blood pressure (p=0.05, OR 3.28[1.02-10.57]), IVH volume (p=0.02, OR 4.59[1.28-16.41]), GCS (p=0.02, OR 4.19[1.2-14.55]), or time to first CT (p=0.03, OR 4.02[1.19-13.56]).
Conclusion: PHE72 predicts poor functional outcomes exclusively after deep ICH, whereas PHE24 predicts mortality for deep and lobar ICH.