HYPOPLASIA, STENOSIS AND OTHER ALTERATIONS OF THE VERTEBRAL ARTERY - DOES IMPAIRED BLOOD RHEOLOGY MANIFEST A HIDDEN DISEASE

Objectives - The clinical relevance of abnormal vessel findings in the posterior circulation is still a matter of controversy. Patients and methods We compared 48 patients displaying sonographic abnormalities o f one vertebral artery, i.e., vertebral artery hypoplasia in 24 cases, stenosis in 13 cases, plaques in 11 cases, with 25 healthy subjects i n terms of whole blood viscoelasticity and plasma viscosity. Results - All patients with stenosis and plaques suffered from clinical signs a nd symptoms of ischemic cerebrovascular disease, predominantly in the posterior circulation. Free of acute clinical symptoms were 5 of the 2 4 patients with hypoplasia. Highly statistically significant differenc es in blood viscoelasticity were found between the patients and the he althy subjects. As regards differences between the groups, whole blood viscoelasticity was most impaired in stenosis, shear resistance was s ignificantly higher in stenosis compared to hypoplasia. Symptom-free p atients with one-sided vertebral artery hypoplasia had a significantly better, nearly normal blood rheology at a low shear rate (10/s), comp ared to clinically symptomatic patients with hypoplasia. Conclusion - The results of the present study offer some evidence that altered hemo rheology may be associated with symptomatic vertebrobasilar occlusive disease. (C) Munksgaard 1998.