Control the Functional State of the Brain Based on the Dynamics of Integral Parameters of Multichannel EEG in Human under Acute Hypoxia

• Published in: Human physiology Vol. 47; no. 1; pp. 1 - 13
• Main Authors: Rozhkov, V. P., Trifonov, M. I., Soroko, S. I.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 2021; Springer Nature B.V
• Subjects: Biomedical and Life Sciences; Biomedicine; EEG; Hemoglobin; Human Physiology; Hypoxia; Lability; Life Sciences; Neural networks; Oscillations; Oxygen; Physiology; Structure-function relationships; acute normobaric hypoxia; individual hypoxic resistance; brain; structure function of multichannel EEG
• ISSN: 0362-1197; 1608-3164
• DOI: 10.1134/S0362119721010114

Development of methods for monitoring the functional state (FS) of people under extreme conditions is of great applied significance. The aim of this study was to investigate the dynamics of integral EEG parameters in individuals with different levels of hypoxia sensitivity and tolerance during their exposure to oxygen deficiency. Acute hypoxia was induced by a mixture of 8% oxygen in nitrogen for breathing. The study cohort was composed of 41 male participants aged from 19 to 45 years. We recorded a complex of physiological indices, as well as multichannel EEGs, based on which the structure function and the integral normalized parameters were calculated. These parameters were used as a measure of temporal (
Pt
) and spatial (
Ps
) connectivity between oscillations of brain potentials. The extreme values of parameters, 0 and 1, corresponded to the completely deterministic and “random” temporal and spatial organization of the EEG. A decrease in
Pt
, as hypoxia deepened, indicated a growth in the temporal connectivity and inertness in the EEG, which characterized a decrease in the physiological lability and the FS of the brain. Significant changes in
Ps
, which indicated an increase in the degree of EEG spatial connectivity, were recorded only in individuals with low hypoxia tolerance in a precollaptoid state. The use of the normalized
Pt
and
Ps
parameters allowed us to classify the subjects by the degree of their sensitivity to hypoxia and identify individuals with high sensitivity, under a relatively small fall in hemoglobin oxygen saturation (SaO
2
), and persons resistant to hypoxia even at low levels of SaO
2
, which is important for the selection of persons exposed to hypoxia by occupation.