CT screening for temporal bone abnormalities in idiopathic bilateral sensorineural hearing loss.

Bilateral sensorineural hearing loss can be caused by a variety of temporal bone abnormalities including primary cochlear otosclerosis, local and systemic bony diseases and some metabolic conditions. These may be identified using computerized tomography (CT), with attenuation recordings taken across the cochlear capsule (CT densitometry). Eighty patients with bilateral sensorineural hearing loss were screened over a period of six and a half years using this technique, and only three cases (3.8 per cent) of treatable disease were detected. Positive yields may be increased by screening selected cases with other clinical or biochemical stigmata of temporal bone disease.