COMPUTED TOMOGRAPHIC DIAGNOSIS OF X-LINKED CONGENITAL MIXED DEAFNESS,FIXATION OF THE STAPEDIAL FOOTPLATE, AND PERILYMPHATIC GUSHER

Stapes surgery for fixed foot plate associated with X-linked congenita l mixed hearing loss usually results in a ''gusher'' and severe worsen ing of hearing. Four patients with X-linked deafness were diagnosed by the characteristic temporal bone computed tomography (CT) findings of enlarged internal auditory canal, hypoplasia of the cochlear base, ab sent bony modiolus, abnormal vestibular aqueduct, and enlarged labyrin thine facial nerve canal. Three patients were scanned after stapes sur gery resulted in a gusher and, in two patients, severe worsening of th eir hearing loss. Stapes fenestration in the other patient was avoided by CT recognition of the dysplasia. The authors believe that young ma les presenting with congenital mixed hearing loss should be studied wi th temporal bone CT prior to middle ear exploration.