Intraventricular hemorrhage and brain injury in the premature infant. Neuropathology and pathogenesis.

Intraventricular hemorrhage of the premature infant originates in the subependymal germinal matrix. Important neuropathological complications of the hemorrhage are post-hemorrhagic hydrocephalus and periventricular hemorrhagic infarction. The latter infarction and the ischemic lesion, periventricular leukomalacia, are the most important forms of brain injury in the premature infant. Pathogenesis of intraventricular hemorrhage relates to intravascular, vascular, and extravascular factors.