Age and gender effects on submental motor-evoked potentials

Area of Science:

• Neuroscience
• Physiology
• Gerontology

Background:

• Investigating age- and gender-related differences in submental muscle motor-evoked potentials (MEPs) is crucial for understanding swallowing neurophysiology.
• Submental muscle function is vital for effective swallowing, and its neurophysiological underpinnings may change with age.

Purpose of the Study:

• To determine if age and gender influence the magnitude of submental muscle MEPs and surface electromyography (sEMG) during swallowing.
• To explore potential compensatory mechanisms in cortical activity related to age-associated changes in swallowing function.

Main Methods:

• Recruited 40 healthy participants (20 males, 20 females; 20 young, 20 old).
• Measured MEPs via single-pulse transcranial magnetic stimulation (TMS) over the motor cortex.
• Recorded sEMG from the submental muscle group during non-stimulated saliva swallows.

Main Results:

• Older participants exhibited larger MEPs during saliva swallowing compared to younger participants (p=0.04).
• Older adults showed lower amplitude submental sEMG during non-stimulated swallows (p=0.045).
• No significant effects of gender on MEP magnitude or submental activity were observed; age and gender did not affect MEP latencies.

Conclusions:

• Findings suggest age-related muscle function deterioration in healthy adults, potentially compensated by increased cortical activity to maintain swallowing.
• Increased submental MEPs in older adults may represent a compensatory cortical effort to preserve swallowing function.
• The study highlights the necessity for age-specific reference values when evaluating submental MEPs.