Influence of hyperbaric environment on physiological tremor.

Area of Science:

• Physiology
• Environmental Medicine
• Neuroscience

Background:

• Physiological tremor is a normal bodily function.
• Understanding tremor under pressure is crucial for diving and space exploration.
• Previous research has not fully elucidated tremor responses to extreme atmospheric pressures.

Purpose of the Study:

• To investigate the impact of hyperbaric environments on the total power spectrum (TP) of human physiological tremor.
• To differentiate the effects of nitrogen and heliox gas mixtures at varying pressures.
• To explore the role of autonomic nervous system inhibitors in modulating tremor response to pressure.

Main Methods:

• Subjects were exposed to pressures ranging from 1 to 24 ATA (Atmosphere Absolute).
• Total power spectrum (TP) of physiological tremor was measured (0.5-50 Hz).
• Autonomic nervous system inhibitors (atropine, propanol) were administered at 3 ATA.

Main Results:

• At 3 ATA, TP initially remained stable then increased; at 4 ATA (3.6 ATA nitrogen), TP decreased, correlating with nitrogen narcosis.
• Using heliox, TP decreased at 16-19 ATA but increased at 24 ATA, potentially linked to high pressure nervous syndrome.
• Atropine (parasympathetic inhibitor) increased TP at 3 ATA, while propanol (sympathetic inhibitor) decreased TP.

Conclusions:

• Physiological tremor is significantly altered by hyperbaric conditions, with pressure effects varying by gas composition and partial pressures.
• Nitrogen narcosis and high pressure nervous syndrome demonstrably influence tremor dynamics.
• Autonomic nervous system activity plays a key role in regulating tremor responses under pressure.