Fatal dissecting aneurysm of the internal carotid artery with delayed symptoms following facial impact.

A fatal dissecting aneurysm of the internal carotid artery occurred in a 16-year-old male following facial impact in an automobile accident. The patient showed no neurologic deficit until two days after the automobile accident, when he suddenly started having seizures and developed right-sided hemiparesis. There was no evidence of direct trauma to the neck externally or internally. The only injuries observed in the head and face were two skin lacerations in the chin area. His condition rapidly deteriorated, and he expired on the fourth hospital day. The gross and microscopic findings for the internal carotid artery are presented. The possible mechanisms for the vascular lesion and a review of the literature are discussed.