Vestibular function and hearing ability in 5 children with semicircular canal aplasia

<p>Objectives: We investigated vestibular function and gross motor development as well as the presence of cochlear malformation and auditory function in five children with aplasia of the semicircular canals.</p><p>Subjects: The subjects comprised five children with congenital hearing-impairment, in whom temporal bone imaging revealed aplasia of the bilateral semicircular canals. CHARGE syndrome was diagnosed in four of the five patients.</p><p>Methods: 1. Evaluation of vestibular semicircular canal function: Damped rotational chair test. 2. Evaluation of gross motor development: The ages at acquisition of head control and independent walking were used as indicators of motor development. 3. Evaluation of middle ear and inner ear morphology by temporal bone CT. 4. Auditory evaluation. </p><p>Results: 1. The results of damped rotational chair test revealed that all five subjects had no response, and decreased function of the vestibular semicircular canals was diagnosed. 2. The mean age of acquisition of head control was 10.2±7.9 months, and the mean age of acquisition of independent walking was 30.5±13.4 months. 3. Temporal bone CT findings showed that normal cochlear morphology in two ears, cochlear hypoplasia type I (CH-type I) in two ears, CH-type III in four ears, and CH-type IV in two ears. 4. Regarding hearing ability, three subjects had moderate bilateral hearing loss, and two had severe bilateral hearing deafness. All five subjects wore hearing aids. Cochlear implant surgery was not performed in any subject.</p><p>Conclusion: 1. All five subjects with aplasia of the semicircular canals showed severe deterioration of vestibular semicircular canal function, and acquisition of head control and independent walking was significantly delayed. 2. Auditory evaluation of five subjects revealed moderate to severe hearing impairment. Temporal bone CT findings revealed that there were cases with cochlea malformations ranged from normal to CH-type I-IV.</p>