[Bilateral vertebral artery occlusion associated with atlantoaxial dislocation due to os odontoideum]

A 17-year-old boy was hospitalized with transient consciousness disturbance on extension of the neck. At seven years of age, the patient developed delayed-onset posterior circulation stroke after the door struck him a mild blow on his forehead. A computed tomography scan revealed right cerebellar infarction with unknown etiology. He had been followed up without stroke recurrence and CT change until this hospitalization. Cerebral angiography disclosed bilateral vertebral artery occlusion at the C-2 level with the well-developed muscular collateral artery bypassing the occluded left vertebral artery. A cervical X-ray showed a posterior atlanto-axial subluxation with os odontoideum. Compression of the vertebral arteries due to mild trauma aggravating an atlanto-axial subluxation may have caused the bilateral vertebral artery thrombosis resulting in occlusion, and disturbance of the muscular collateral circulation on extension of the neck may have led to the recurrence of vertebrobasilar insufficiency. This is the first report of the angiographically confirmed bilateral vertebral artery occlusion with an established etiology in childhood.