Asymmetrically severe internal auditory canal hypoplasia: A case report

Area of Science:

• Otolaryngology
• Pediatric Radiology
• Neuroscience

Background:

• Congenital sensorineural hearing loss (CSNHL) is a common birth defect, necessitating early diagnosis and intervention.
• Understanding the underlying anatomical causes of CSNHL is crucial for effective management.
• Internal auditory canal (IAC) abnormalities are a known, though less common, cause of CSNHL.

Observation:

• A case study of a 20-month-old child with otherwise normal health presenting with CSNHL.
• Computed tomography (CT) and magnetic resonance (MR) imaging revealed bilateral, asymmetrically severe hypoplasia of the IACs and vestibulocochlear nerves.
• Further inner ear anomalies included unilateral semicircular canal hypoplasia and suspected bilateral cochlear hypoplasia.

Findings:

• The imaging findings strongly correlate the observed hypoplasia of the IACs and vestibulocochlear nerves with the patient's severe CSNHL.
• The presence of additional inner ear malformations suggests a complex developmental etiology.
• Notably, the facial nerve function remained normal, indicating selective developmental impact.

Implications:

• This case underscores the importance of advanced imaging in diagnosing the anatomical basis of CSNHL.
• It contributes to the understanding of congenital IAC abnormalities and their association with hearing loss.
• Further research into the genetic and developmental pathways of IAC formation is warranted to explore potential therapeutic targets.