Conductive hearing loss: investigation of possible inner ear origin in three cases studies.

This is a report of three cases of mixed hearing loss that resulted from inner ear disorders. Two cases were unilateral and the third was bilateral. The diagnosis was based on the findings of normal middle and external ears in association with the absence of round window reflexes. The contralateral stapedial reflex was present in the two unilateral cases. This is the first documentation of conductive deafness due to inner ear abnormality. This diagnosis should be considered in cases of conductive hearing loss if the middle and external ears are normal. More studies are needed to establish the pathophysiology of this entity.