[Clinical significance of changes in blood viscosity in cerebrovascular insufficiency (author's transl)].

In 50 patients with encephalomalacia and 50 patients with a transient cerebral ischemic attack (TIA) the risk factors and viscosity of the whole blood as well as the hematocrit were determined before the start of treatment. Compared to a control group, the blood viscosity in patients with encephalomalacia was significantly increased (p less than 0.001) in all ranges of shearing velocity tested, in patients with TIA only at that shearing velocity which may be assumed for the area of microcirculation. This increase was related to the presence of arterial hypertension, hyperlipemia, heart failure, diabetes mellitus, hyperfibrinogenemia and increased tendency of thrombocytes and erythrocytes to aggregate. From the results obtained it was concluded that increased blood viscosity in the cerebral area of microcirculation with insufficient cerebral collateral circulation may decisively favor the development of encephalomalacia.