Changes in resting-state brain function of pilots after hypoxic exposure based on methods for fALFF and ReHo analysis / 解放军医学杂志

ABSTRACT

Objective The objective of this study was to evaluate the basic changes in brain activity of pilots after hypoxic exposure with the use of resting-state functional magnetic resonance imaging (rs-f MRI) and regional homogeneity (ReHo) method. Methods Thirty healthy male pilots were successively subjected to normal and hypoxic exposure (with an oxygen concentration of 14.5%). Both the fALFF and ReHo methods were adopted to analyze the resting-state functional MRI data before and after hypoxic exposure of the subjects, the areas of the brain with fALFF and ReHo changes after hypoxic exposure were observed. Results After hypoxic exposure, the pulse was 64.0±10.6 beats/min, and the oxygen saturation was 92.4%±3.9% in these 30 pilots, and it was lower than those before exposure (71.4±10.9 beats/min, 96.3%±1.3%, P<0.05). Compared with the condition before hypoxic exposure, the fALFF value was decreased in superior temporal gyri on both sides and the right superior frontal gyrus, and increase in the left precuneus, while the value of ReHo was decreased in the right superior frontal gyrus (P<0.05). No brain area with an increase in ReHo value was found. Conclusions Hypoxic exposure could significantly affect the brain functions of pilots, which may contribute to change in their cognitive ability.