Cases of Pediatric Hearing Impairment with Bilateral Stenosis of the Bony Cochlear Nerve Canal: Bilateral Stenosis of Bony Cochlear Nerve Canal

Abstract

Cochlear nerve deficiency (CND) is diagnosed with magnetic resonance imaging (MRI) by an absent or small cochlear nerve. A small or absent bony cochlear nerve canal (BCNC) detected with computed tomography (CT) has been also considered as CND. We reviewed five bilateral hearing impaired children with BCNC. All patients were born maturely at full term birth. Two of them had undergone newborn hearing screening (NHS), one passed and the other was referred in only one ear. Among five children, only one had a small internal auditory canal (IAC) diagnosed with CT. Two children with intracranial abnormalities also had cochlear anomalies without a small IAC. Hearing aids showed some effectiveness in two patients with normal-sized IACs, and they could communicate with normal speech using hearing aids. One with a small-sized IAC was unable to communicate with speech using hearing aids. The efficacy of hearing aids in the other 2 patients has not been evaluated yet. We concluded that patients with small or absent BCNCs showed various audiometorical findings and clinical courses.