[The cases of acute spontaneous subdural hematoma].

In this paper, 10 cases of acute spontaneous subdural hematoma (ASSDH) among 149 cases of all acute subdural hematoma (ASDH) were reported with a review of 36 cases in the literature. The age of the patients with ASSDH ranged from 48 to 90 years (mean age of 71.9 years), and the average age of ASDH patients was 52.4 years. The male to female ratio of ASSDH and ASDH was 3:7 and 5:2, respectively. ASSDH patients were older than ASDH patients, and ASSDH patient tended to be female. Four cases of ASSDH patients had the past history of dementia. The outcome of 5 cases of ASSDH with general complications was fatal. During operation in all cases except one, spurting arterial rupture from a branch of the cortical artery adjacent to the Sylvian fissure was observed. It was presumed in the literature that the mechanism of the arterial rupture is gliding movement of the brain, tearing an arterial twig with dural attachment, or the existence of the junction of an arterial twig as an anatomically weak point. Hypertension, alcoholism, dementia, past history of subdural hematoma or subarachnoid hemorrhage may be important influencing factors in this mechanism.