Prevalence Of Auditory Neuropathy Research Articles

The association between consanguineous marriage and offspring with congenital hearing loss.

ABSTRACTBACKGROUND: Consanguinity is a commonly recognized practice among marriages in the Middle East and may lead to an increase in the prevalence of inherited disorders. Autosomal recessive deafness is the most common form of inherited congenital hearing loss (CHL).OBJECTIVES: Determine the association of consanguineous marriages with congenital sensorineural hearing loss (SNHL) and auditory neuropathy.DESIGN: Descriptive and analytical cross-sectional study.SETTING: Ear specialist hospital.PATIENTS AND METHODS: Children with severe-to-profound congenital SNHL, who had been referred to the specialist hospital for cochlear implant were analyzed. Patients were divided into subgroups based on degree of consanguinity.MAIN OUTCOME MEASURE: The relative risk of having more than one child with SNHL in offspring of a consanguineous marriage.SAMPLE SIZE: 189 parents and children with CHL.RESULTS: The parents of 157 children (83.1%) were blood-related. Of those, 48 had more than one child with CHL (31.4%), while only two parents who were not blood-related had more than one child with CHL (6.25%; P=.005). Among the 189 children, 131 (69.3%) parents were direct cousins. Only 39 (20.6%) and 43 (22.8%) children had family histories of CHL on the paternal and maternal sides, respectively. There was no statistically significant difference in the prevalence of auditory neuropathy between the offspring of consanguineous and non-consanguineous marriages (P=.648).CONCLUSION: The risk of having more than one child with SNHL in the offspring from a consanguineous marriage is 3.5 times higher than that of a non-consanguineous mating.LIMITATION: The association of hearing loss degree with consanguinity was not studied.CONFLICT OF INTEREST: None.

Early Phototherapy at Lower Total Serum Bilirubin Can Decrease Auditory Neuropathy Disorder

Background: Neurologic dysfunctions, specifically hearing impairments due to hyperbilirubinemia are ranked among the main concerns in medicine. Objectives: This study evaluates the prevalence of acute auditory neuropathy (AN) disorders in term neonates with mild to moderate hyperbilirubinemia and low bilirubin-induced neurological dysfunction (BIND) score and the roll of early treatment on reducing their incidence. Methods: Fifty one term jaundice neonates with normal newborn exam and total serum bilirubin (TSB) ≥ 15 mg/dL after the third day of birth with normal otoacoustic emission (OAE) test were enrolled. The BIND score assessment for severity of neurologic dysfunction was done. Neonates with low BIND score were divided into two groups based on their TSB levels at the time of admission (15 - 18 mg/dL: Mild-moderate hyperbilirubinemia and ≥ 19 mg/dL: Severe hyperbilirubinemia). ABR was performed within the first 12 hours of their admission and the second ABR was performed before discharge. Results: The 30.60% of neonates with TSB < 19 mg/dl had abnormal ABR. Latency of V, III waves and interpeak interval latency of I-III, I-V waves were detected. Mean latency of wave V and I-V interpeak latency after phototherapy were significantly decreased compared to pre-treatment (P < 0.001). Conclusions: With the prevalence of auditory neuropathy (AN) at lower TSB concentrations (that have traditionally been considered safe) it can be concluded that more attention should be given to this group despite the absence of neurologic signs, and it also shows the sensitivity of early phototherapy to lower bilirubin level.

Critical appraisal of appropriate method for early detection of hearing impairment in newborns in a tertiary care centre

Background: Hearing plays a vital role in developmental of a child. Hearing loss not only affects the speech and language development of a child but also affects the social, emotional and intellectual development. Hearing is important in the first 2 years of life as this is the critical period for language acquisition. Thereby early detection and intervention for hearing loss is recommended. However, there are no standard protocols for newborn hearing screening. Hence, this study is undertaken to evaluate the appropriate protocol for early detection of hearing impairment in newborns and to ascertain the sensitivity and specificity of Distortion Product Oto-acoustic Emission (DPOAE) and Auditory Brainstem Response (ABR).Methods: A prospective study was conducted in the Department of Paediatrics and Department of Audiology and Speech Pathology in SRM Medical College Hospital and Research Centre. A total of 122 neonates were screened for hearing loss using both DPOAE and ABR before discharge from the hospital. A rescreening with ABR after 1 month was done for those infants who had hearing loss at the initial screening.Results: The study revealed that 16.4% of infants had hearing loss. The referral rate of DPOAE was 54.1% and ABR was 16.4%. ABR had higher passing rates when compared to DPOAE. In a combined screening with both DPOAE and ABR, 17 (13.9%) babies had failed DPOAE with abnormal hearing in ABR (True positives), 49 (40.2%) babies failed DPOAE but had normal hearing in ABR (False positives), 3 (2.5%) babies passed DPOAE but had hearing loss in ABR (False negatives) and 53 (43.4%) babies passed DPOAE and had normal hearing in ABR (True negatives). The association between the results of DPOAE and ABR was statistically significant (0.002). Auditory neuropathy was detected in 3 out of 122 neonates. All these 3 babies belonged to high-risk population. The prevalence of auditory neuropathy is 2.5% which is much lower when compared to other studies. The sensitivity and specificity of DPOAE is 85% and 51.9% respectively. The sensitivity and specificity of ABR was 100%.Conclusions: Present study concludes that the use of combination protocol using both DPOAE and ABR identifies babies with auditory neuropathy spectrum disorder and also ensures high sensitivity and acceptable specificity. Thus, helps in early identification and intervention of congenital hearing loss.

Prevalence of Hearing Loss among Preterm Very‐Low‐Birth‐Weight Babies

Objectives: Determine the prevalence of hearing impairment and auditory neuropathy among preterm very-low-birth-weight (VLBW) babies at 1 year corrected age. Methods: Twenty babies were recruited. The subjects underwent transient evoked otoacoustic emission (TEOAE) and automated auditory brainstem response (AABR) at 34 to 36 weeks while they were still in the neonatal intensive care unit. The subjects were followed up with brainstem evoked response (BSER) at 3 months and 1 year of corrected age. A patient was considered to have hearing impairment if either 1 or both ears failed the test. The risk factors for hearing impairment are noted. Results: Thirty-five percent (14 out of 40 ears) failed TEOAE and 12.5% (5 out of 40 ears) failed AABR screen. Two babies defaulted BSER appointment. BSER at 3 months corrected age showed 5.5% (1 out of 18) with bilateral profound sensorineural hearing loss, 16.7% (3 out of 18) bilateral mild conductive hearing loss, and 77.8% (14 out of 18) with normal hearing. At 1 year of corrected age 5.5% (1 out of 18) had profound sensorineural hearing loss, 5.5% (1 out of 18) mild conductive hearing loss, and 89% (16 out of 18) had normal hearing. There was no prevalence of auditory neuropathy or progressive hearing loss in this study. Conclusions: Those VLBW babies achieved maturity of hearing at 3 months corrected age, therefore no repeat BSER is required at 1 year.

Auditory neuropathy in late preterm infants treated with phototherapy for hyperbilirubinemia

Objective: To evaluate the prevalence of auditory neuropathy (AN) in late preterms treated with phototherapy for hyperbilirubinemia. Design: Prospective observational study comprising late preterms treated with phototherapy for hyperbilirubinemia. Newborns were screened with combined transient-evoked otoacoustic emissions (TEOAEs) / automated auditory brainstem responses (AABR). Infants who failed screening underwent diagnostic (ABR). Infants were all re-evaluated with AABR at one year. Study sample: Eighty-five infants with a mean serum total bilirubin concentration of 22.3 ± 1.76 mg/dl; severe-hyperbilirubinemia (SH), and 102 infants with a mean serum total bilirubin concentration of 18.6 ± 1.26 mg/dl; non-severe hyperbilirubinemia (NSH) were included. Results: From 85 late preterms with SH, six (7.1%) failed screening and underwent diagnostic ABR for six weeks. AN was diagnosed in two (2%) infants with SH. Four (3.9%) of the 102 controls with NSH demonstrated failure at TEOAE/AABR. No AN was diagnosed in the control group at the diagnostic ABR. No statistically significant difference was found between infants treated with phototherapy for SH and NSH with regard to AN/AD either in the postnatal period or at one year. No correlation was found between serum bilirubin levels and ABR latencies or thresholds. Conclusions: AN (2%) in late preterms treated with phototherapy for severe-hyperbilirubinemia was not higher than in those with non-severe hyperbilirubinemia.

Prevalence of auditory neuropathy (AN) among infants and young children with severe to profound hearing loss

Auditory neuropathy is a challenging disorder and needs special habilitative/rehabilitative approach. This study aimed to detect its prevalence among infants and young children with severe to profound hearing loss. 112 infants and young children with age ranged 6–32 months were examined and diagnosed as having severe to profound hearing loss and were referred for hearing aid fitting. Those infants were reassessed in our centers for detecting cases with auditory neuropathy. The study group was subjected to immittancemetry, behavioral observation audiometry, ABR and cochlear microphonics. Results 15 patients were found to have auditory neuropathy according to our criteria for diagnosis. Conclusions The prevalence of AN in the study group was 13.4%. CM were recommended to be tested routinely during ABR assessment whenever abnormal results are obtained.

The prevalence of auditory neuropathy in students with hearing impairment in Tehran, Iran.

Auditory neuropathy is defined as a sensorineural hearing loss characterized by normal cochlear hair cell function and absent or abnormal auditory brainstem evoked potentials. These people can hear the sound but can not understand it. They have neural hearing loss and the auditory rehabilitation approach for these people may be different from those who have sensorineural hearing loss. Therefore, screening of auditory neuropathy among hearing impaired students is essential. The prevalence of auditory neuropathy among the students with hearing impairment in specific schools for them was the objective of the current research. From 2002 through 2003, 841 hearing impaired students, aged 2 - 20 years, underwent a complete history taking, clinical examination, and audiometry. We found 13 students with auditory neuropathy who comprised 1.55% (CI 95%: 0.71 - 2.38%) of the students with hearing impairment. We suggest that a complete panel of audiological tests for detection of auditory neuropathy be performed before admission of students with hearing impairment to schools.