Assessment of hemodynamics in vertebral arteries in patients with atlantoaxial instability using functional tests

Abstract

Background. Hemodynamic disturbances in the vertebral arteries often lead to neurological imbalances. Assessing blood flow parameters in different parts of the vertebral arteries can help predict the development of serious neurological diseases and promptly carry out appropriate treatment and preventive measures. Purpose. To determine quantitative parameters of blood flow in the vertebral arteries in young people with atlantoaxial instability using functional tests in triplex mode. Materials and methods. In triplex mode, blood flow was recorded in the V2 and V3 segments of the vertebral arteries (VA) in 41 young patients. Maximum systolic velocity (Vs), end-diastolic velocity (Vd), resistive index (RI), pulsatility index (PI), and minute volume of blood flow (Vvol) were assessed. These hemodynamic parameters were measured in a straight head position during functional tests. Result. The RI value in the left VA was the highest in contralateral turning (CLT) of the head: 0.71±0.03, which is statistically (p<0.01) significantly higher than the corresponding parameter in healthy individuals. In CLT, Vs in the right VA was 57.3±5.2 cm/s; in ipsilateral turning (ILT) of the head – 37.4±3.6 cm/s (p<0.01), and in healthy individuals – 47.8±4.3 cm/s. RI in the right VA was 0.70±0.03 in CLT and 0.69±0.03 in ILT, which was significantly (p<0.05) higher than in healthy individuals. RI had the highest value in the left VA in CLT: 1.05±0.07, which was statistically significantly (p <0.05) higher than in healthy individuals. At the same time, Vvol in CLT was 92±10 mL/min – significantly (p <0.05) lower than in healthy individuals. Conclusions. Sharp turns of the head in young people with instability of the atlantoaxial joint are accompanied by an increase in the indices of resistance and pulsatility in the V3 segment of the vertebral arteries and a decrease in the minute volume of blood flow in them. In persons with instability of the atlantoaxial joint, contralateral turning of the head is accompanied by an increase in the systolic velocity of blood flow in the corresponding vertebral artery, and ipsilateral turning leads to its decrease. At the same time, hemodynamic parameters in patients with atlantoaxial instability are statistically significantly different from the corresponding data of healthy individuals.