Auditory-pupillary responses in patients with vestibular neuritis

Area of Science:

• Neuroscience
• Otolaryngology
• Autonomic Neuroscience

Background:

• Auditory-pupillary responses (APRs) are linked to the startle reflex and involve cochlear and otolith pathways.
• Previous research indicates APRs persist even with bilateral deafness, suggesting a role for otolith organs, specifically the saccule.

Purpose of the Study:

• To investigate vestibulo-autonomic responses in vestibular neuritis (VN) patients by assessing APRs.
• To clarify the relationship between APRs and vestibular function, particularly otolith function, in VN patients.

Main Methods:

• Evaluated 12 healthy volunteers and 10 VN patients.
• Performed caloric and vestibular-evoked myogenic response (VEMR) testing on VN patients.
• Assessed APRs using sound stimuli delivered binaurally, to the affected side, and to the unaffected side in VN patients.

Main Results:

• VN patients showed significantly different pupillary indices (PIs) compared to normal subjects during binaural stimulation.
• In VN patients, PIs were significantly larger on the affected side than on the unaffected side.
• APRs varied based on the side of vestibular stimulation in VN patients.

Conclusions:

• Examining APRs may serve as a valuable tool for assessing vestibulo-autonomic reflexes.
• APRs show promise for evaluating otolith-autonomic reflexes, especially in conditions like vestibular neuritis.