"Hyperacute" subdural hematoma: CT mimic of recurrent episodes of bleeding in the setting of child abuse.

Mixed density extraaxial hematomae on computed tomography (CT) scanning generally represent recurrent episodes of bleeding (chronic subdural hematoma with rebleeding). Hyperacute hemorrhages in which the patient is actively bleeding or has a coagulopathy have also been described as mixed density. We report a case of child abuse in a fourteen month old child who presented with a CT scan showing a mixed density subdural hematoma which was originally interpreted as recurrent episodes of hemorrhage, but who had evidence of only acute, active bleeding at surgery and by histologic examination. There is a proportionally high incidence of subdural hematoma in cases of child abuse, due in part to the increased susceptibility of the immature brain to trauma. Because the mechanism of injury is different for hemorrhage due to hyperacute subdural hematoma (SDH) and that of acute bleeding within a chronic SDH, the distinction between these entities has potentially important legal implications in cases of suspected child abuse. This potential pitfall in interpretation of the CT scan has not to our knowledge been reported in the forensic literature.