Hearing Loss After Vestibular Implantation in Sand Rats With Normal Hearing.

Area of Science:

• Otolaryngology
• Neuroscience
• Biomedical Engineering

Background:

• Bilateral vestibular failure significantly impacts quality of life.
• Vestibular implants are being explored to restore vestibular function.
• Ensuring implants do not compromise hearing is crucial.

Purpose of the Study:

• To assess the impact of vestibular implant insertion on hearing in a normal-hearing sand rat model.
• To evaluate hearing threshold shifts following electrode implantation in the semicircular canals.

Main Methods:

• Adult fat sand rats (Psammomys obesus) underwent unilateral or bilateral vestibular implant electrode insertion into the semicircular canals.
• Auditory nerve brainstem evoked responses were measured pre- and post-surgery to assess air and bone conduction thresholds.

Main Results:

• Unilateral implantation led to head tilt; bilateral implantation caused severe disorientation and mobility issues.
• Significant air conduction threshold shifts were observed post-implantation, especially for the superior and posterior canals.
• Bone conduction thresholds remained largely unaffected by electrode insertion.

Conclusions:

• Vestibular device implantation in sand rats is linked to conductive hearing loss, more pronounced with posterior and superior canal placement.
• Bilateral implantation leads to significant vestibular pathology.
• Further research is required to confirm the safety of vestibular implants in animals with existing cochlear or vestibular deficits.