[Acute subdural hemorrhage of arterial origin: report of three cases]

Three cases of acute subdural hematoma without head injury, but associated with bleeding from cortical artery are described. Case 1: a 74-year-old male had sudden headache during a bronchial asthma attack followed by deterioration of consciousness. He was deeply comatose on admission, and CT scans revealed a huge subdural hematoma. Evacuation of the large hematoma revealed a spurting cortical branch of the middle cerebral artery beneath it. Case 2: Four days before admission, a 69-year-old male developed headache during a fit of coughing. His CT scans on admission showed a thin subdural hematoma. Because it was increasing in volume, the hematoma was removed surgically. A spurting cortical branch of the middle cerebral artery was seen on the surface of the temporal lobe. Case 3: a 80-year-old male, who had had an operation for inguinal hernia under spinal anesthesia ten days before, suffered a sudden headache just after he stood up. CT scans revealed a thick subdural hematoma. As the clot was being removed a spurting artery was seen in the Sylvian region. In a review of 116 surgical cases of acute subdural hematoma at our institute, the incidence of acute spontaneous subdural hemorrhage was 2.6%. The etiology of nontraumatic hematoma is a matter of controversy. Our three cases suggested that the etiology might be the rupture of a cortical artery at the site of adhesion with the dura mater. This would predispose the artery to tearing with minor trauma. Hematoma evacuation by craniotomy and treatment of the ruptured cortical artery were necessary for favorable outcome.