Respiration triggered trans-spinal magnetic stimulation in healthy subjects

Area of Science:

• Neuroscience
• Respiratory Physiology
• Biomedical Engineering

Background:

• Respiratory muscle dysfunction is a common issue in neurological and pulmonary disorders.
• Enhancing diaphragm excitability is crucial for clinical applications.
• Non-invasive methods are needed to selectively activate spinal circuits.

Purpose of the Study:

• To establish a respiration-triggered trans-spinal magnetic stimulation protocol.
• To compare diaphragm motor evoked potentials during different respiratory phases.
• To assess the feasibility of this method for enhancing diaphragm activity.

Main Methods:

• Trans-spinal magnetic stimulation (TSMS) was triggered by respiratory signals.
• Bilateral diaphragm electromyograms were recorded in 11 males and 10 females.
• Stimulation was applied during expiration-inspiration and inspiration-expiration transitions.

Main Results:

• Diaphragmatic motor evoked potentials increased with stimulation intensity in both sexes.
• Males showed greater responses during the inspiration-expiration transition.
• This respiratory phase-dependent modulation was not observed in females.

Conclusions:

• Respiration-triggered TSMS is a feasible, non-invasive approach for spinal circuit activation.
• The protocol can selectively induce diaphragmatic motor evoked potentials.
• Potential sex-based differences in respiratory phase modulation warrant further investigation.