Hemodynamic Features of Symptomatic Vertebrobasilar Disease

Abstract

Background and Purpose Atherosclerotic vertebrobasilar (VB) disease is an important etiology of posterior circulation stroke. To examine the role of hemodynamic compromise, a prospective multi-center study, Vertebrobasilar Flow Evaluation and Risk of Transient Ischemic Attack and Stroke (VERiTAS), was conducted. Here we report clinical features and vessel flow measurements from the study cohort. Methods Patients with recent VB TIA or stroke and ≥50% atherosclerotic stenosis or occlusion in vertebral (VA) and/or basilar (BA) arteries were enrolled. Large vessel flow in the VB territory was assessed using quantitative MRA. Results The cohort (n=72, 44% female) had a mean age of 65.6 years; 72% presented with ischemic stroke. Hypertension (93%) and hyperlipidemia (81%) were the most prevalent vascular risk factors. BA flows correlated negatively with percentage stenosis in the affected vessel, and positively to the minimal diameter at the stenosis site (p<0.01). A relative threshold effect was evident, with flows dropping most significantly with ≥80% stenosis/occlusion (p<0.05). Tandem disease involving the BA and either/both VAs had the greatest negative impact on immediate downstream flow in the BA (43 ml/min vs. 71 ml/min, p=0.01). Distal flow status assessment, based on an algorithm incorporating collateral flow by examining distal vessels (BA and posterior cerebral arteries), correlated neither with multifocality of disease nor severity of the maximal stenosis. Conclusions Flow in stenotic posterior circulation vessels correlates with residual diameter, and drops significantly with tandem disease. However, distal flow status, incorporating collateral capacity, is not well predicted by the severity or location of the disease.

Guidelines for the Prevention of Stroke in Patients With Stroke and Transient Ischemic Attack

“…379 Aggressive medical therapy may or may not be as effective for patients with symptoms caused by hemodynamic compromise from ECVAS. Efforts are under way to define a population that may benefit from revascularization procedures because of the high risk of recurrent vertebrobasilar stroke from hemodynamic compromise caused by ECVAS, 380 but at present, there are no studies specifically addressing this situation.…”

Evaluating the morphological changes of intracranial arteries and whole-brain perfusion in undetermined isolated vertigo

“…The risk of stroke is greater for vertigo patients with ≥ 3 risk factors than for patients with 1 to 2 risk factors or general population without any risk factors [1]. A regional hypoperfusion is a hidden sign for the risk of stroke in vertebrobasilar disease [15]. However, whether this state may be reversible or be on behalf of potential subsequent signals for posterior ischemic stroke is still not clear.…”

“…Details on VRFs including age ≥ 60 years, hypertension (HT), diabetes mellitus (DM), hyperlipidemia, coronary artery disease (CHD), smoking have been previously published [1], [15].…”

Perfusion weighted imaging in the assessment of the pathology and outcomes of lateral medullary infarction

“…These findings raise the intriguing question as to whether VAH combined with multiple conventional vascular risk factors may be associated with LMI occurrence. Regional hypoperfusion is considered an important potential contributor to stroke risk in vertebrobasilar disease;7 however, the evaluation of hemodynamic status has traditionally been limited to the assessment of tissue perfusion in anterior circulation disease, with imaging techniques that poorly translate into the assessment of the more compact posterior circulation territory 7. In a recent study,6 VAH was associated with relative hypoperfusion in the dependent PICA territory in approximately ≤42% of patients without PCI.…”