Ossicular abnormalities in Down's syndrome.

Down's syndrome has been associated with hearing loss and otitis media. Because of difficulty in examination, however, there have been few detailed otologic studies on this population. An understanding of the nature and frequency of ear disease in Down's syndrome is important, since it is common and occurs in more than one in every 600 live births. To define the aural manifestation of Down's syndrome, complete otologic and audiometric examination was performed on 107 consecutive patients. This included micropneumatic otoscopy, pure-tone and speech audiometry, impedance tympanometry, and, in some cases, electronystagmography. Deficient hearing was found in 64% of these patients, and of these hearing losses, 83% were conductive. Surprisingly, middle ear effusion or tympanic membrane perforation accounted for only 60% of the conductive hearing losses. This finding prompted us to examine five temporal bones of children with Down's syndrome. These histologic sections revealed middle ear abnormalities including fixation and superstructure deformity of the stapes and dehiscence of the fallopian canal. Operative findings in 16 procedures on patients with Down's syndrome and conductive hearing loss suport those findings.