Clinically unidentified dissection of vertebral artery as a cause of cerebellar infarction.

Background and Purpose-Dissection of vertebral arteries has been reported in association with minor neck movements without signs of trauma on the surface of the neck. In addition, injury of a vertebral artery can cause brain infarctions. However, few cases have been reported in which fatal brain infarction was due to nonocclusive, clinically undetected, traumatic thrombus formation in a vertebral artery. Case Description-A 62-year-old man was hit by a car, and a right cerebellar infarction was found the day after the accident. The cause of the infarction could not be detected by angiography. Although the patient recovered favorably after surgical removal of the right lateral hemisphere of the cerebellum, he died suddenly 2 weeks after the accident. An autopsy and a microscopic study revealed pulmonary thromboembolism and organizing traumatic lesions of the right vertebral artery without occlusion or noteworthy stenosis of the artery. Conclusions-We concluded that the patient sustained traumatic lesions of the right vertebral artery during the traffic accident 2 weeks before death and that his cerebellar infarction was due to a thrombus resulting from these traumatic lesions.