Acoustic Reflex Screening of Conductive Hearing Loss for Third Window Disorders

Area of Science:

• Otolaryngology
• Audiology
• Neurotology

Background:

• Conductive hearing loss can stem from various causes, including third window disorders like superior semicircular canal dehiscence.
• Accurate pre-operative screening is crucial to identify specific etiologies and plan appropriate interventions.

Purpose of the Study:

• To evaluate the efficacy of acoustic reflexes in screening for third window disorders in patients with conductive hearing loss.
• To determine the diagnostic value of acoustic reflexes, third window symptoms, and their combination in identifying the cause of hearing loss.

Main Methods:

• A retrospective chart review of 212 ears evaluated for conductive hearing loss without chronic otitis media.
• Analysis of acoustic reflex testing results and correlation with intraoperative findings and CT imaging to determine hearing loss etiology.

Main Results:

• Absence of acoustic reflexes was associated with ossicular etiologies (88%).
• Presence of at least one acoustic reflex suggested non-ossicular causes (52%).
• Combined acoustic reflexes and third window symptoms yielded the highest positive predictive value (94%) for ossicular etiology.

Conclusions:

• Acoustic reflex testing is a valuable screening tool for third window disorders in conductive hearing loss.
• Complementary screening with third window symptom assessment enhances diagnostic precision.
• Any detected acoustic reflex or third window symptom warrants further investigation before middle ear exploration.