RESUMEN
Williams syndrome is a neurodevelopmental disorder associated with cardiovascular problems, facial abnormalities and several behavioural and neurological disabilities. It is also characterized by some typical audiological features including abnormal sensitivity to sounds, cochlear impairment related to the outer hair cells of the basal turn of the cochlea, and sensorineural or mixed hearing loss, predominantly in the high frequency range. The aim of this report is to describe a follow-up study of auditory function in a cohort of children affected by this syndrome. 24 patients, aged 5-14 years, were tested by means of air/bone conduction pure-tone audiometry, immittance test and transient evoked otoacoustic emissions. They were evaluated again 5 years after the first assessment, and 10 of them underwent a second follow-up examination after a further 5 years. The audiometric results showed hearing loss, defined by a pure tone average >15 dB HL, in 12.5% of the participants. The incidence of hearing loss did not change over the 5-year period and increased to 30% in the patients who underwent the 10-year follow-up. Progressive sensorineural hearing loss was detected in 20% of the patients. A remarkable finding of our study regarded sensorineural hearing impairment in the high frequency range, which increased significantly from 25% to 50% of the participants over the 5-year period. The increase became even more significant in the group of patients who underwent the 10-year follow-up, by which time the majority of them (80%) had developed sensorineural hearing loss. Otoacoustic emissions were found to be absent in a high percentage of patients, thus confirming the cochlear fragility of individuals with Williams syndrome. Our study verified that most of the young Williams syndrome patients had normal hearing sensitivity within the low-middle frequency range, but showed a weakness regarding the high frequencies, the threshold of which worsened significantly over time in most patients.
Asunto(s)
Pérdida Auditiva/fisiopatología , Sonido , Síndrome de Williams/fisiopatología , Adolescente , Audiología , Niño , Preescolar , Femenino , Estudios de Seguimiento , Pérdida Auditiva/diagnóstico , Humanos , Masculino , Umbral Sensorial , Síndrome de Williams/diagnósticoRESUMEN
The aim of this study was to investigate, in a clinical setting, the auditory function of a group of individuals affected by Williams syndrome (WS). Sixty-nine patients with WS, aged 2-30, underwent comprehensive audiological testing including air/bone conduction behavioral audiometry, speech audiometry, tympanometry and measurement of the acoustic reflex, transient evoked otoacoustic emissions and brainstem auditory evoked responses. Hearing loss, defined by a pure-tone average above 15 dB HL, affected 22.6% of the patients studied with traditional audiometry and was mostly slight in severity. Hearing loss was conductive in 9.4% of patients, mainly children with otitis media with effusion, and sensorineural in 13.2% of patients. However, 30% of the ears studied had a hearing impairment in the high frequency range (high-frequency pure-tone audiometry above 15 dB HL), higher in participants above 15 years (46.15%) than in the younger ones (23.45%). Contralateral stapedial reflexes were present in all patients with A-type tympanograms. Transient otoacoustic emissions were absent in 44% of the ears of patients with normal hearing. Brainstem auditory evoked responses fell within normal ranges thus confirming the absence of retrocochlear dysfunction. Although hearing loss does not seem to be frequent, a cochlear fragility, especially in the high frequency range, related to outer hair cells is characteristic of WS. Therefore we strongly recommend monitoring patients affected by WS using annual audiometric tests and performing otoacoustic emissions in order to identify a subclinical cochlear dysfunction which might benefit from an audiological follow up before the possible onset of hearing loss.
Asunto(s)
Pérdida Auditiva Conductiva , Pérdida Auditiva de Alta Frecuencia , Pérdida Auditiva Sensorineural , Síndrome de Williams/patología , Síndrome de Williams/fisiopatología , Pruebas de Impedancia Acústica , Adolescente , Adulto , Audiometría , Audiometría de Tonos Puros , Niño , Preescolar , Cóclea/patología , Potenciales Evocados Auditivos del Tronco Encefálico/fisiología , Femenino , Audición/fisiología , Humanos , Masculino , Emisiones Otoacústicas Espontáneas/fisiología , Reflejo Acústico/fisiología , Adulto JovenRESUMEN
The aim of this study was to investigate the functionality of cochlear active mechanisms in normal-hearing subjects affected by Williams syndrome (WS). Transient evoked otoacoustic emissions (TEOAEs) were recorded in a group of young WS subjects and a group of typically developing control subjects, all having normal-hearing thresholds and normal middle-ear functionality. We also analysed the narrow-band frequency components of TEOAEs, extracted from the broad-band TEOAE recordings by using a time-frequency analysis algorithm based on the Wavelet transform. We observed that TEOAEs and the frequency components extracted from TEOAEs measured in WS subjects had significantly lower energy compared to the controls. Also, the narrow-band frequency components of TEOAEs measured in WS subjects had slightly increased latency compared to the controls. Overall, results would suggest a subtle (i.e., sub-clinical) dysfunction of the cochlear active mechanisms in WS subjects with otherwise normal hearing. Also, results point out the relevance of using otoacoustic emissions in the audiological evaluation and monitoring of WS subjects to early identify possible subtle auditory dysfunctions, before the onset of mild or moderate hearing loss that could exacerbate language or cognitive impairments associated with WS.