Hematoma expansion following acute intracerebral hemorrhage

Abstract

Intracerebral hemorrhage (ICH), the most devastating form of stroke, has no specific therapy proven to improve outcome by randomized controlled trial. Location and baseline hematoma volume are strong predictors of mortality, but are nonmodifiable by the time of diagnosis. Expansion of the initial hematoma is a further marker of poor prognosis that may be at least partly preventable. Several risk factors for hematoma expansion have been identified, including baseline ICH volume, early presentation after symptom onset, anticoagulation, and the CT angiography spot sign. Although the biological mechanisms of hematoma expansion remain unclear, accumulating evidence supports a model of ongoing secondary bleeding from ruptured adjacent vessels surrounding the initial bleeding site. Several large clinical trials testing therapies aimed at preventing hematoma expansion are in progress, including aggressive blood pressure reduction, treatment with recombinant factor VIIa guided by CT angiography findings, and surgical intervention for superficial hematomas without intraventricular extension. Hematoma expansion is so far the only marker of outcome that is amenable to treatment and thus a potentially important therapeutic target.

Figure 1. CT Angiography Spot Sign And Hematoma Expansion

Computed tomography (CT) and CT angiography of a 78-year-old male, showing an acute intracerebral hemorrhage. (A) The baseline CT shows an 18 mL intracerebral hemorrhage centered within the left parietal lobe without intraventriculair extension. (B) CT angiography demonstrates multiple spot signs within the anterior portion of the hematoma. (C) A follow-up CT after seven hours shows significant expansion of the hemorrhage (final volume 119 mL). The patient passed away the day after admission.

Figure 2. Computational Model Hematoma Expansion

Snapshots of a computational simulation of the “avalanche model” for hematoma expansion. The initially ruptured small vessel is shown in red and the secondary mechanical shearing of adjacent vessels is shown in different shades of blue. (From Greenberg et al. PLoS One 2012;7:e48458)