Hemorheological disturbances and characteristic parameters in patients with cerebrovascular disease.

Whole blood and plasma viscosity were measured of 90 patients with chronic cerebrovascular disease (CVD) and 56 healthy individuals by Couette rotational viscometer Contraves Low Shear 30 at a steady flow. Plasma viscosity was measured with capillary viscometer of Ubbelohde type. Two subgroups of patients were investigated: 23 patients with transient ischemic attacks (TIAs) and 67 patients with chronic cerebral infarctions (CCI). They were compared with two control groups: 56 healthy individuals without risk factors for stroke and 37 randomly selected subjects with risk factors for stroke. It is established significant elevation of plasma viscosity in the patients with cerebral ischemia. The elevation of blood viscosity was most pronounced at shear rate of 94.5 s(-1). This comparison is confirmed by the criterion, using blood rigidity number h defined by the formula of Whittington and Harkness. Conclusion is drawn from our study that chronic ischemic cerebrovascular disorders are characterized with chronic hyperviscosity.