Enlarged vestibular aqueduct as a cause of postneonatal deafness.

INTRODUCTION: The enlarged vestibular aqueduct (EVA) is the most frequent malformation of the inner ear associated with sensorineural hearing loss (5-15%). It exists when the diameter in imaging tests is greater than 1.5 mm at its midpoint. The association between hearing loss and EVA has been described in a syndromic and non-syndromic manner. It can appear as a familial or isolated form and the audiological profile is highly variable. The gene responsible for sensorineural hearing loss associated with EVA is located in the same region described for Pendred syndrome, where the SCL26A4 gene is located. OBJECTIVE: To describe a series of children diagnosed with EVA in order to study their clinical and audiological characteristics, as well as the associated genetic and vestibular alterations. METHOD: Retrospective study of data collection of children diagnosed with EVA, from April 2014 to February 2023. RESULTS: Of the 17 cases, 12 were male and 5 were female. 5 of them were unilateral and 12 bilateral. In 5 cases, a cranial traumatism triggered the hearing loss. Genetic alterations were detected in 3 cases: 2 mutations in the SCL26A4 gene and 1 mutation in the MCT1 gene. 13 patients (76.5%) were rehabilitated with hearing aids and 9 of them required cochlear implantation. DISCUSSION: The clinical importance of AVD lies in the fact that it is a frequent finding in the context of postneonatal hearing loss. It is convenient to have a high suspicion to diagnose it with imaging tests, to monitor its evolution, and to rehabilitate early.

Universal neonatal hearing screening and delayed hearing loss or late-developmental hearing loss.

OBJECTIVE: To determine the percentage of children with permanent bilateral postnatal hearing loss in order to study its incidence, related risk factors, diagnosis and treatment. METHODS: Retrospective study to collect data on children diagnosed with hearing loss outside the neonatal period in the Hearing Loss Unit of the Hospital Universitario Central de Asturias, from April 2014 to April 2021. RESULTS: 52 cases met the inclusion criteria. The detection rate of congenital hearing loss in the neonatal screening programme in the same study period was 1.5 children per thousand newborns per year, adding postnatal hearing loss results in a rate of infant bilateral hearing loss of 2.7 children per thousand (55.5% and 44.4% respectively). Thirty-five children presented risk factors for hearing loss, of which 23 were at retrocochlear risk. The mean age at referral was 91.9 (18-185) months. Hearing aid fitting was indicated in 44 cases (84.6%). Cochlear implantation was indicated in eight cases (15.4%). DISCUSSION: Although congenital hearing loss accounts for the majority of childhood deafness, postnatal hearing loss has a significant incidence. This may be mainly due to: (1) that hearing impairment may arise in the first years of life, (2) that mild hearing loss as well as hearing loss in severe frequencies are undetectable by neonatal screening in some cases, (3) that some children may have false negative results. CONCLUSION: postnatal hearing loss requires identification of risk factors and long-term follow-up of children with hearing loss, as it needs to be detected and treated early.

Vowel production in hearing impaired children: A comparison between normal-hearing, hearing-aided and cochlear-implanted children. / Comparación de la producción vocal en niños con hipoacusia prelocutiva con adaptación audioprotésica e implante coclear con normooyentes.

INTRODUCTION AND OBJECTIVES: Inadequate auditory feedback in prelingually deaf children alters the articulation of consonants and vowels. The purpose of this investigation was to compare vowel production in Spanish-speaking deaf children with cochlear implantation, and with hearing-aids with normal-hearing children by means of acoustic analysis of formant frequencies and vowel space. METHODS: A total of 56 prelingually deaf children (25 with cochlear implants and 31 wearing hearing-aids) and 47 normal-hearing children participated. The first 2 formants (F1 and F2) of the five Spanish vowels were measured using Praat software. One-way analysis of variance (ANOVA) and post hoc Scheffé test were applied to analyze the differences between the 3 groups. The surface area of the vowel space was also calculated. RESULTS: The mean value of F1 in all vowels was not significantly different between the 3 groups. For vowels /i/, /o/ and /u/, the mean value of F2 was significantly different between the 2 groups of deaf children and their normal-hearing peers. CONCLUSION: Both prelingually hearing-impaired groups tended toward subtle deviations in the articulation of vowels that could be analyzed using an objective acoustic analysis programme.

Auditory-steady-state response reliability in the audiological diagnosis after neonatal hearing screening. / Fiabilidad de los potenciales evocados auditivos de estado estable en la fase diagnóstica del cribado neonatal universal de la hipoacusia.

INTRODUCTION AND OBJECTIVES: Conventional audiometry is the gold standard for quantifying and describing hearing loss. Alternative methods become necessary to assess subjects who are too young to respond reliably. Auditory evoked potentials constitute the most widely used method for determining hearing thresholds objectively; however, this stimulus is not frequency specific. The advent of the auditory steady-state response (ASSR) leads to more specific threshold determination. The current study describes and compares ASSR, auditory brainstem response (ABR) and conventional behavioural tone audiometry thresholds in a group of infants with various degrees of hearing loss. METHODS: A comparison was made between ASSR, ABR and behavioural hearing thresholds in 35 infants detected in the neonatal hearing screening program. RESULTS: Mean difference scores (±SD) between ABR and high frequency ABR thresholds were 11.2 dB (±13) and 10.2 dB (±11). Pearson correlations between the ASSR and audiometry thresholds were 0.80 and 0.91 (500Hz); 0.84 and 0.82 (1000Hz); 0.85 and 0.84 (2000Hz); and 0.83 and 0.82 (4000Hz). CONCLUSION: The ASSR technique is a valuable extension of the clinical test battery for hearing-impaired children.