Acute spontaneous subdural hematoma: an unusual form of cerebrovacular accident.

An acute subdural hematoma is commonly regarded as a complication of a head injury, and bleeding is associated with contusion or laceration of the bridging vein in the subdural space. Occasionally, reports describe non traumatic acute subdural bleeding from the rupture of cerebral aneurysm or vascular malformation. However, acute spontaneous subdural hematomas (ASDH) of arterial origin, without any traumatic history or vascular anomaly, are rarely reported in literature. Here we describe two cases who presented with acute signs of intracranial hypertension secondary to a spontaneous acute subdural hematoma in which spontaneous bleeding from a small cortical artery was seen during operation.