Traumatic dissection of extracranial vertebral artery with massive subtentorial cerebral infarction: report of an autopsy case.

We present an extremely rare autopsy case with traumatic dissection of the extracranial vertebral artery due to blunt injury caused by a traffic accident. The patient complained of nausea and numbness of the hands at the scene of the accident. His consciousness deteriorated and he fell into a coma within 12h, then died 4 days after the collision. Brain CT/MRI disclosed massive infratentorial cerebral infarction while MRA imaged neither of the vertebral arteries. Autopsy revealed a seatbelt mark on the right side of the lower neck, with fracture of the right transverse process of the sixth cervical vertebra. The right extracranial vertebral artery (V2) showed massive medial dissection from the portion adjacent to the fracture throughout the upper end of the extracranial part of the artery and was occluded by a thrombus. An intimal tear was confirmed near the starting point of the dissection. The brain disclosed massive infarction of posterior circulation territories with changes to the so-called respirator brain. The victim's left vertebral artery was considerably hypoplastic. We concluded that a massive infratentorial infarction was caused by dissection of the right extracranial vertebral artery and consecutive thrombus formation brought about by impact with the seatbelt at the time of the collision.