Temporal bone imaging findings in Waardenburg's syndrome.

OBJECTIVE: (a) To report computed tomography findings of eight new cases with Waardenburg's syndrome (WS) type I and review reported temporal bone radiographic and histopathological findings in WS with hearing loss; (b) To determine the frequency of inner ear pathologies that may contraindicate cochlear implantation. METHODS: A review of 1166 pediatric patients with sensorineural hearing loss revealed 12 cases (1%) with WS, whose family screenings disclosed additional 12 subjects with the same disorder. Among these 24 cases, eight had WS type I and were subjected to computed tomography scanning of temporal bone. Imaging findings of 28 cases reported previously in English literature were evaluated together with our eight patients. RESULTS: Malformation of the inner ear was found in none of the nine WS type I cases evaluated here, while the frequency of internal acoustic canal malformation was 11%. Regardless of the subtypes of the syndrome, 6 of 36 cases (17%) had radiological abnormality of the inner ear. Malformation and/or absence of the semicircular canals were the most common congenital abnormality of the inner ear. Hypoplasia of the cochlea was present in 3 of 36 cases (8%). CONCLUSIONS: Abnormality of bony labyrinth in WS with congenital deafness is not a frequent finding, particularly in WS type I. Therefore, the otologist and audiologist must keep in mind that most of these cases are suitable for cochlear implantation regarding inner ear anatomy.

Audiometric manifestations of Waardenburg's syndrome.

We studied 23 patients (from 11 families) who had Waardenburg's syndrome. Patients were evaluated by conventional audiometric methods and by distortion-product otoacoustic emissions to determine the penetrance and the degree and type of hearing loss. Twelve of the patients had the type I form of the syndrome and 11 had type II. Overall, we found hearing loss in 19 of the 23 patients (83%); hearing loss affected nine type I patients (75%) and 10 type II patients (91%). Five type I patients (42%) and eight type II patients (73%) had a hearing loss of > 100 dB. Bilateral symmetrical hearing loss was the most common type of loss, as it was seen in six of the type I patients (50%) and eight of the type II patients (73%). At lower frequencies, distortion-product otoacoustic emission amplitudes were found to be significantly above the noise floor in five of the 11 patients whose hearing thresholds were 60 dB HL or worse by click auditory brainstem response testing. These findings led us to conclude that it is necessary to use otoacoustic emissions in patients with Waardenburg's syndrome in order to provide optimum fitting of hearing aids, especially in children.