Vestibular function in children with the CHARGE association

Background: Histopathological examinations and computed tomographic scans o f the temporal bone in patients with the CHARGE association (a malformative syndrome that includes coloboma, heart disease, choanal atresia, retarded development, genital hypoplasia, and ear anomalies, including hypoplasia of the external ear and hearing loss) have shown an absence of semicircular c anals and a Mondini form of cochlear dysplasia. Until recently, no informat ion was available concerning a passible loss of vestibular function, which could be a factor in retarded posturomotor development. To our knowledge, t his is the first report of otolith tests done on patients with the CHARGE a ssociation. Objective: To test residual vestibular function in patients with the CHARGE association. Study Design: In 7 patients with the CHARGE association, we made electro-oc ulographic recordings of vestibule-ocular responses to earth-vertical and o ff-vertical axis rotations to evaluate the function of the canal and the ot ulith-vestibular systems. Results: None of the 7 patients had semicircular canals in the computed tom ographic scan, and none had canal vestibule-ocular responses to earth-verti cal axis rotation, but all had normal otolith vestibule-ocular responses to the off-vertical axis rotation test. Conclusions: These results support the hypothesis of a residual functional otolith organ in the hypoplastic posterior labyrinth of children with the C HARGE association. The severe delays in psychomotor development presented b y these children are more likely a consequence of multiple factors: canal v estibular deficit, visual impairment, and environmental conditions (long ho spital stays and breathing and feeding problems). The remaining sensitivity of the otolith system to gravity and linear acceleration forces in these c hildren could be exploited in early education programs to improve their pos turomotor development.