СОСТОЯНИЕ ОБОЛОЧЕК ЗРИТЕЛЬНЫХ НЕРВОВ И ПУТИ ОТТОКА КРОВИ ИЗ ПОЛОСТИ ЧЕРЕПА В 21-СУТОЧНОЙ «СУХОЙ» ИММЕРСИИ ПО ДАННЫМ УЛЬТРАЗВУКОВЫХ МЕТОДОВ ИССЛЕДОВАНИЯ

Abstract

Venous blood circulation and liquid dynamics in the brain, and collateral venous blood circulation were investigated in participants of 21-day dry immersion study. The ultrasonic technique was used to measure the optic nerve sheaths, register hemodynamics in the internal jugular vein, inferior vena cava and superficial femoral vein. We observed a significant acceleration of blood flow through the jugular veins by day 7 with a decrease in the lumen of the jugular veins and a gradual expansion of the liquor space around the optic nerves. Hemodynamics in the vena cava inferior as a potential collateral of outflow from the cranial cavity indirectly suggests reorganization of the outflow pathway and venous blood distribution between the jugular and vertebral pathways in specific periods of exposure to immersion. After the immersion, all hemodynamic parameters returned to their initial levels; however, after two weeks of recovery the inverse trend in the state of optic nerve sheaths was observed only in some of the participants.