To evaluate the incidence and type of intracranial and inner ear abnormalities in children with sensorineural hearing loss (SNHL) identified with magnetic resonance imaging (MRI) and stratified by the degree and type of SNHL.
Retrospective review of medical records and MRIs.
Tertiary care children's hospital.
A total of 227 children aged 1 month to 17 years (mean age, 5.3 years; male to female ratio, 1:1) with a diagnosis of SNHL underwent MRI from June 1,1996, to June 1, 2002. Of these children, 170 had clinical information available and technically adequate MRIs and were included in the study.
Magnetic resonance imaging.
Main Outcome Measure
Identification of an abnormality of the intracranial contents, inner ear, and cochlear nerve.
Of the 170 children, 101 (59%) had bilateral SNHL and 69 (41%) had unilateral SNHL, comprising 271 ears with SNHL. Abnormalities of the inner ear were found in 108 ears (40%) with 87 (32%) having abnormalities of the cochlea, which were considered mild in 63 (23%) and moderate to severe in 24 (9%). Forty-nine of 271 ears (18%) with SNHL demonstrated an either absent (26/49 [53%]) or deficient (23/49 [47%]) cochlear nerve. Ears with severe and profound SNHL had more abnormalities than ears with mild and moderate SNHL (66/138 [48%] vs 23/80 [29%]; P = .006), and children having ears with unilateral moderate, severe, or profound SNHL had more inner ear abnormalities than children with bilateral moderate, severe, or profound SNHL (28/45 [62%] vs 54/144 [38%]; P = .004).
The overall incidence of inner ear abnormalities in ears of children with SNHL evaluated by MRI is 40%. The most common abnormalities seen were an abnormal cochlea and abnormal cochlear nerve. Children with severe and profound SNHL have a greater percentage of inner ear anomalies than children with mild or moderate SNHL. Children with unilateral hearing loss have a greater percentage of inner ear anomalies than children with bilateral SNHL.