Natural History of Perihematomal Edema After Intracerebral Hemorrhage Measured by Serial Magnetic Resonance Imaging

Background and Purpose—Knowledge on the natural history and clinical impact of perihematomal edema (PHE) associated with intracerebral hemorrhage is limited. We aimed to define the time course, predictors, and clinical significance of PHE measured by serial magnetic resonance imaging. Methods—Patients with primary supratentorial intracerebral hemorrhage 5 cm3 underwent serial MRIs at prespecified intervals during the first month. Hematoma (Hv) and PHE (Ev) volumes were measured on fluid-attenuated inversion recovery images. Relative PHE was defined as Ev/Hv. Neurologic assessments were performed at admission and with each MRI. Barthel Index, modified Rankin scale, and extended Glasgow Outcome scale scores were assigned at 3 months. Results—Twenty-seven patients with 88 MRIs were prospectively included. Median Hv and Ev on the first MRI were 39 and 46 cm3, respectively. Median peak absolute Ev was 88 cm3. Larger hematomas produced a larger absolute Ev (r20.6) and a smaller relative PHE (r20.7). Edema volume growth was fastest in the first 2 days but continued until 123 days. In multivariate analysis, a higher admission hematocrit was associated with a greater delay in peak PHE (P0.06). Higher admission partial thromboplastin time was associated with higher peak rPHE (P0.02). Edema volume growth was correlated with a decline in neurologic status at 48 hours (81 vs 43 cm3, P0.03) but not with 3-month functional outcome