OSTEOGENESIS IMPERFECTA - CLINICAL SYMPTOMS AND UPDATE FINDINGS IN COMPUTED-TOMOGRAPHY AND TYMPANO-COCHLEAR SCINTIGRAPHY

Osteogenesis imperfecta (OI) is an autosomal-dominantly inherited conn ective tissue disorder characterized by abnormal bone fragility combin ed with blue sclerae. The association of OI with hearing impairment is commonly known as Van der Hoeve-de Kleyn syndrome. Besides typical sy mptoms we here report on findings by high resolution CT and by high re solving scintigraphy of the labyrinthine capsule in 3 families (9 pati ents) with OI, which resemble those in otosclerosis (OS): In 4 of 6 ca ses with OI and mixed hearing loss, severely decreased pericochlear bo ne density was established by CT. In these cases, increased bone metab olism could be revealed by high resolving tympano-cochlear scintigraph y (TCS) in the cochlear region. In 2 patients with mixed hearing loss and 3 cases without hearing impairment or with slight conductive heari ng loss, bone alteration was not detectable by CT and TCS. These resul ts raise the question whether OI and OS lead to similar labyrinthine b one alterations, based on different aetiologies or whether these disea ses may co-exist, OS being part of OI.