Fatal thrombosis of the basilar artery due to a minor head injury.

A case is reported where a 20-year-old alcohol-intoxicated man was admitted to the hospital after a minor head injury. Initially there was no neurologic disturbances or complaints but after a few hours he became comatose, and he died 4 days later without regaining consciousness. The autopsy revealed no lesions of the upper cervical spine or the vertebral arteries, but the basilar artery was occluded in its entire length. No traumatic lesions could be seen by naked eye examination of the artery, and there was no accompanying subarachnoid haemorrhage. A thorough microscopic examination, however, using step-sectioning technique revealed a significant incomplete arterial rupture with an occluding luminal thrombosis superimposed, consisting predominantly of aggregated platelets. Only the very thin adventitia separated the vascular lumen from the subarachnoid space preventing the more well known fatal complication to a minor head injury: A subarachnoid haemorrhage. To the best of our knowledge, fatal thrombosis of the basilar artery due to a minor head injury has not previously been reported. The pathogenetic mechanism seems to be identical to that underlying fatal subarachnoid haemorrhage following a similar trauma apart from the resulting arterial rupture being incomplete instead of complete.