[A case of subarachnoid hemorrhage with acute subdural hematoma due to head injury: a case report].

Acute intracranial hemorrhages can be caused by cerebrovascular disease or head injury. Diagnostic imaging is in both cases sometimes similar, so it is difficult to make an exact diagnosis. We report a case of acute subdural hematoma due to head injury after loss of consciousness due to an aneurysmal rupture. A 52-year-old male was found out fallen on the floor in a state of unconsciousness and was brought to the nearest hospital. CT scan showed subarachnoid hemorrhage with left acute subdural hematoma and he was transported to our hospital. Angiography revealed a left MCA aneurysm. The next day, a clipping operation was performed but brain contusion was observed in the left frontal lobe. Postoperative CT scan showed contusional hematoma at the left frontal lobe and plain skull X-ray films demonstrated a diastatic fracture of the right lambdoid suture. Acute subdural hematoma due to the rupture of a cerebral aneurysm is sometimes recognized, but the first CT findings are similar to those observed after head injury. When the clinical course of onset is unclear, we must keep in mind that the cause of acute subdural hematoma may be head injury, even if angiography demonstrates abnormal vessels.