Air and Bone-Conduction Masseteric Vestibular Evoked Myogenic Potentials: A Simulated Conductive Hearing Loss Study

Area of Science:

• Vestibular evoked myogenic potentials
• Audiology
• Neurophysiology

Background:

• Masseteric vestibular evoked myogenic potentials (mVEMPs) evaluate the saccular-masseteric pathway.
• Stimulation can be delivered via air or bone conduction.
• Understanding mVEMP response to hearing loss is crucial for clinical application.

Purpose of the Study:

• To investigate the effect of simulated bilateral conductive hearing loss on mVEMP characteristics.
• To compare air-conducted versus bone-conducted mVEMP responses under these conditions.
• To assess the diagnostic utility of bone-conducted mVEMPs.

Main Methods:

• Fifty healthy young adults participated.
• Bilateral conductive hearing loss was simulated using silicone ear tips in 25 participants.
• Masseteric vestibular evoked myogenic potentials were elicited using 500 Hz tone bursts (air and bone conduction) and recorded via zygomatic electrodes.

Main Results:

• Simulated conductive hearing loss reduced response rate, delayed latency, and decreased amplitude for air-conducted mVEMPs.
• Bone-conducted mVEMPs showed higher amplitudes and earlier latencies compared to air-conducted responses in the simulated hearing loss group.
• Spectral analysis revealed a consistent peak around 100 Hz for bone-conducted, but not air-conducted, stimuli in the simulated hearing loss group.

Conclusions:

• Simulated conductive hearing loss significantly impairs air-conducted mVEMP responses.
• Bone-conducted mVEMPs remain robust and reliable, even with simulated conductive hearing loss.
• Bone-conducted mVEMPs offer diagnostic value when air-conducted pathways are compromised by conductive pathologies.