Audio-Vestibular Evaluation of Pediatric Pseudo-Conductive Hearing Loss: Third Window Syndromes.

Conductive hearing loss caused by external or middle ear problems prevents the transmission of sound waves from the external auditory canal to the cochlea, and it is a common condition, especially in pediatric patients aged 1-5 years. The most common etiological factors are otitis media and cerumen during childhood. In some patients, external and middle ear functions and structures may be normal bilaterally despite the air-bone gap on the audiogram. This condition, which is often a missed diagnosis in children, is defined as a pseudo-conductive hearing loss (PCHL) caused by third window syndromes (TWSs) such as semicircular canal dehiscence, inner ear malformations with third window effect, and perilymphatic fistula. In this review of the literature, the authors emphasize the pitfalls of pediatric audio-vestibular evaluation on TWSs as well as the key aspects of this evaluation for the differential diagnosis of PCHL brought on by TWSs. This literature review will provide audiologists and otologists with early diagnostic guidance for TWSs in pediatric patients.