Congenital cochlear aplasia presenting as recurrent meningitis and cerebrospinal fluid rhinorrhea: a diagnostic challenge

Abstract

Cerebrospinal fluid (CSF) otorrhea presenting as "pseudo-rhinorrhea" via the Eustachian tube is a rare and deceptive diagnostic entity. In pediatric patients, congenital inner ear malformations can cause this phenomenon, often leading to misdiagnosis, treatment delays, and life-threatening recurrent meningitis. This case highlights the importance of distinguishing otogenic sources in patients presenting with apparent rhinorrhea. A 3-year-old boy presented with persistent clear watery nasal discharge and a history of recurrent bacterial meningitis. Initial brain MRI failed to identify an anatomical defect or leak source. However, a focused history revealed prior ear pain, prompting targeted imaging. High-resolution CT (HRCT) and CT cisternography identified a complex right-sided congenital malformation, including cochlear aplasia, a cystic vestibule, and an absent stapes footplate (Type I leak). The diagnosis of CSF otorrhea manifesting as rhinorrhea was confirmed as contrast tracked from the inner ear through the middle ear and down the Eustachian tube. The patient underwent definitive surgical repair via a post-auricular approach, involving a canal wall down mastoidectomy, oval window plugging, Eustachian tube obliteration, and blind sac closure of the external auditory canal. The patient remained symptom-free with no recurrence of meningitis at the 6-month follow-up. Clinicians must consider otogenic sources for apparent CSF rhinorrhea in children with recurrent meningitis. Standard brain MRI may overlook subtle otic capsule defects; therefore, HRCT of the temporal bone and a high index of suspicion for inner ear malformations are essential for accurate diagnosis.