I. Velcheva 1, N. Antonova 2, E. Titianova 3,4, P. Damianov 1
1 University Hospital of Neurology and Psychiatry, Medical University – Sofia,
2 Institute of Mechanics, Bulgarian Academy of Sciences – Sofia,
3 Military Medical Academy – Sofia,
4 Medical Faculty of Sofia University St. Kl. Ohridski – Sofia, Bulgaria

Objective: To assess the complex influence of blood viscosity and blood pressure on the neurosonographic parameters in the common carotid artery (CCA) in patients with chronic unilateral cerebral infarctions (CUCI).

Material and Methods: Thirty two patients with CUCI, 58 patients with risk factors (RF) for cerebrovascular disease (CVD) and 25 controls were included in the study. The blood flow velocities (BFV), the internal diameters (D) and the vessel wall intima-media thickness (IMT) in the CCA were recorded by color duplex sonography. Systolic (SBP) and diastolic (DBP) blood pressure were measured and mean blood pressure (MBP) was calculated by the formula of Wiggers. Additional division of the patients in subgroups with MBP < 100 and ≥ 100 was performed. The blood flow velocities (BFV), the internal diameters (D) and the vessel wall intima-media thickness (IMT) in the CCA were recorded. Whole blood viscosity (WBV) at the shear rate of 94,5 s^-1 was measured on the day of the Doppler ultrasound examination and the wall shear stress (WSS), the circumferential wall tension (T) and the tensile stress (τ) were calculated.