Vertebral Artery Occlusion Following Hyperextension and Rotation of the Head

Abstract

This is a case report of a lateral medullary syndrome of Wallenberg following occlusion of one vertebral artery and stenosis of the opposite artery precipitated by combined motion of hyperextension, rotation, and lateral flexion of the head within physiological limits. Sufficient duration of such head position appeared to initiate thrombus formation following stenosis or occlusion of the vertebral artery at the level of the atlanto-occipital joint. Propagation of this thrombus obstructed the posterior inferior cerebellar artery causing infarction of the lateral medullary region. The pathogenesis of this mechanism is discussed.