Evaluation of peripheral auditory pathways and brainstem in obstructive sleep apnea

Area of Science:

• Neurology
• Otolaryngology
• Sleep Medicine

Background:

• Obstructive sleep apnea (OSA) causes chronic intermittent hypoxia, disrupting sleep architecture and potentially impacting auditory pathways.
• The link between OSA-related respiratory events and impaired auditory nerve impulse transmission remains unclear.
• Auditory pathways are oxygen-dependent, making them vulnerable to hypoxic conditions during sleep.

Purpose of the Study:

• To compare auditory pathway and brainstem function in individuals with and without obstructive sleep apnea.
• To investigate the relationship between OSA severity and auditory pathway function.

Main Methods:

• 38 adult males were divided into control, mild, moderate, and severe OSA groups based on polysomnography.
• Participants underwent audiometry, tympanometry, acoustic reflex testing, and Brainstem Auditory Evoked Response (BAER).
• Statistical analyses included ANOVA and chi-square tests to compare groups.

Main Results:

• No significant differences were found in hearing thresholds, tympanometry, or most BAER parameters between groups.
• A significant association was observed between the presence of OSA and changes in the absolute latency of wave V in BAER.
• Moderate OSA was specifically associated with changes in wave V latency.

Conclusions:

• Obstructive sleep apnea is associated with altered nerve conduction of acoustic stimuli in the brainstem auditory pathway.
• Increased OSA severity did not correlate with worsening auditory responses as assessed by standard audiological tests and BAER.