Auditory and temporal bone abnormalities in CHARGE association.

CHARGE association is a recently described cluster of congenital defects including ocular coloboma, heart disease, choanal atresia, retarded development and/or CNS abnormalities, genital hypoplasia, and ear anomalies. Although congenital hearing loss has been reported in CHARGE association, no information regarding the underlying temporal bone disease is available in the literature to date. The authors evaluated four patients with multiple anomalies consistent with CHARGE syndrome. Two surviving patients have bilateral severe hearing loss on auditory brain stem response testing. Two patients did not survive, and their temporal bones were obtained at autopsy for histologic examination. All four temporal bones showed severe middle ear defects including ossicular deformities, absence of the stapedius muscle, absence of the oval window, aberrant course of the facial nerve, and dehiscence of the facial nerve canal. In the more severely affected case, a Mondini-type malformation of the cochlea was present, together with multiple anomalies of the vestibular apparatus. Vestibular defects also occurred in the other case; however, the cochleae were found to be normally developed.