The large vestibular aqueduct syndrome

Area of Science:

• Otolaryngology
• Pediatric Audiology
• Medical Imaging

Background:

• Abnormally large vestibular aqueducts (LVA) are associated with congenital inner ear malformations.
• Enlargement of the vestibular aqueducts as an isolated finding represents a distinct congenital anomaly.
• The pathogenesis is linked to early embryogenesis derangements of the endolymphatic duct.

Purpose of the Study:

• To characterize the clinical presentation and audiometric features of large vestibular aqueduct syndrome.
• To assess the progression of hearing loss in affected children.
• To evaluate the efficacy of endolymphatic sac surgery for this condition.

Main Methods:

• Retrospective review of 17 patients (33 ears) with radiographically identified large vestibular aqueducts.
• Analysis of audiometric data including hearing levels and speech discrimination scores at presentation and during follow-up.
• Evaluation of outcomes for seven ears that underwent endolymphatic to subarachnoid shunt surgery.

Main Results:

• Hearing loss in large vestibular aqueduct syndrome is typically bilateral, progressive, and stepwise, often triggered by head trauma.
• Average hearing level at presentation was 57 dB with 66% speech discrimination; hearing loss progressed by an average of 25 dB over 7.3 years.
• Endolymphatic sac surgery resulted in immediate hearing loss in four of seven treated ears, indicating it is not recommended.

Conclusions:

• Large vestibular aqueduct syndrome is a significant, likely underdiagnosed, cause of sensorineural hearing loss in children.
• Hearing loss characteristically worsens over time, impacting speech discrimination.
• Endolymphatic sac surgery is contraindicated for patients with large vestibular aqueduct syndrome due to poor outcomes.