Abstract
It is well known that the development of motor function is frequently retarded in children with congenital deafness, particularly in cases of inner ear anomaly. The relation between the results of vestibular function tests and the development of motor function in 4 children with inner ear anomaly is studied. CT scan obtained from these cases revealed the absence of lateral semicircular canals in both ears. There were no responses to caloric stimulation using 40 ml ice-water. However, damped rotation test elicited per-rotatory nystagmus in all cases. In contrast to this result, the same nystagmus was provoked only in 2 cases in Barany rotation test. Early development of motor functions, especially that of first walk, was more retarded in the 2 cases showing no per-rotatory nystagmus in Barany rotation test than in the other 2 positive cases.