Pathophysiology of brain edema formation

Intracerebral hemorrhage (ICH) is a common and often fatal subtype of stroke that produces severe neurologic deficits in survivors. Although death may occur acutely after an ICH, delayed neurologic decline often occurs in patients with a large hematoma. Deterioration may be related to brain edema formation. Perihematomal edema is commonly observed during the acute and subacute stages, and it plays an important role in secondary brain injury after ICH. It appears as hypodensity around a hematoma on CT scan and as hyperintensity on T2-weighted or flair MRI. The mechanisms of perihematomal brain edema formation and the pathways of edema resolution are reviewed here.