Natural history of perihematomal edema after intracerebral hemorrhage measured by serial magnetic resonance imaging

Abstract

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 cm(3) underwent serial MRIs at prespecified intervals during the first month. Hematoma (H(v)) and PHE (E(v)) volumes were measured on fluid-attenuated inversion recovery images. Relative PHE was defined as E(v)/H(v). 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 H(v) and E(v) on the first MRI were 39 and 46 cm(3), respectively. Median peak absolute E(v) was 88 cm(3). Larger hematomas produced a larger absolute E(v) (r(2)=0.6) and a smaller relative PHE (r(2)=0.7). Edema volume growth was fastest in the first 2 days but continued until 12 ± 3 days. In multivariate analysis, a higher admission hematocrit was associated with a greater delay in peak PHE (P=0.06). Higher admission partial thromboplastin time was associated with higher peak rPHE (P=0.02). Edema volume growth was correlated with a decline in neurologic status at 48 hours (81 vs 43 cm(3), P=0.03) but not with 3-month functional outcome.

Conclusions: PHE volume measured by MRI increases most rapidly in the first 2 days after symptom onset and peaks toward the end of the second week. The timing and magnitude of PHE volume are associated with hematologic factors. Its clinical significance deserves further study.

Figures

Figure 1

A representative slice from the FLAIR sequence at 48 hours (Panels A & B) and at 7 days (C) from a patient with a spontaneous left putaminal ICH demonstrating the method of outlining hematoma, perihematomal edema and total lesion volumes.

Figure 2. Temporal profile of perihematomal edema growth after spontaneous intracerebral hemorrhage

Panel A: Growth curves (n=22 patients with 78 MRIs) of perihematomal edema in the first three weeks after ICH onset. Perihematomal edema peaks at a mean of 12 ± 3 days. Peak rPHE varies from 100-650%. Panel B: Timing of peak perihematomal edema (n=22 patients with 78 MRIs). Panel C: Boxplots of the rate and magnitude of perihematomal edema volume (Ev) growth in the first month after ICH. Edema growth is fastest in the first 48 hours after ICH onset.

Figure 3. Relationship between hematoma and perihematomal edema volumes during the first month after spontaneous intracerebral hemorrhage

A larger hematoma volume is associated with larger perihematomal edema volume (Ev), but inversely correlated with relative perihematomal edema (rPHE).