Osteogenesis imperfecta: clinical symptoms and update findings in computed tomography and tympano-cochlear scintigraphy.

Osteogenesis imperfecta (OI) is an autosomal-dominantly inherited connective tissue disorder characterized by abnormal bone fragility combined with blue sclerae. The association of OI with hearing impairment is commonly known as Van der Hoeve-de Kleyn syndrome. Besides typical symptoms we here report on findings by high resolution CT and by high resolving scintigraphy of the labyrinthine capsule in 3 families (9 patients) with OI, which resemble those in otosclerosis (OS): In 4 of 6 cases with OI and mixed hearing loss, severely decreased peri-cochlear bone density was established by CT. In these cases, increased bone metabolism could be revealed by high resolving tympano-cochlear scintigraphy (TCS) in the cochlear region. In 2 patients with mixed hearing loss and 3 cases without hearing impairment or with slight conductive hearing loss, bone alteration was not detectable by CT and TCS. These results raise the question whether OI and OS lead to similar labyrinthine bone alterations, based on different aetiologies or whether these diseases may co-exist, OS being part of OI.