The arteriograms and other findings in 42 patients with the subclavian steal syndrome were statistically evaluated to determine which factors predisposed to vertebrobasilar ischemia. Evidence of disconnection of the circle of Willis between the territories of the carotid and vertebral arteries was found in a significantly higher proportion of the patients with vertebrobasilar insufficiency. Thi...

Simultaneous ischemia of the vertebrobasilar and anterior spinal artery territory is rare. Cheshire et al. [1] did not find evidence of brainstem symptoms in any of their 44 patients with spinal cord infarction nor in the additionally reviewed 155 cases. However, in 1966 Boudin et al. [2] reported on 2 patients with combined brainstem and spinal cord lesions who had vertebral-artery stenosis do...

The objective of this review paper is to borrow Virchow’s Triad as a conceptual framework to examine the state of the art in research on thrombosis, specifically in the vertebrobasilar system as a consequence of high velocity, low amplitude spinal manipulation of the cervical spine. A revised Virchow’s Triad is presented which emphasizes the interactions between various risk factors, as a tool ...