High-Frequency Cochlear Amplifier Dysfunction: A Dominating Contribution to the Cognitive-Ear Link

Objective: The objective of this study was to investigate the role of the high-frequency cochlear dysfunction in the cognitive-ear link.Methods: Seventy-four presbycusis patients (PC group) and seventy-one age-, sex-, and education-level matched normal hearing controls (NH group) were recruited in this study. Participants underwent a battery of cognitive tests estimated by Montreal Cognitive Assessment (MoCA), Stroop Color-Word Interference Test (Stroop), Symbol Digit Modalities Test (SDMT), Auditory Verbal Learning Test (AVLT), and Trail-Making Test (TMT-A and B), as well as auditory tests including distortion product otoacoustic emission (DPOAE), pure tone (PT) thresholds, and speech reception thresholds (SRT). Data were analyzed using the factor analysis, partial correlation analysis, multiple linear regression models, and mediation models.Results: Distortion product otoacoustic emission detection amplitudes and PT thresholds performed worse gradually from low to high frequencies in both the NH and PC groups. High-frequency DPOAE (H-DPOAE) was significantly correlated with cognitive domains in the PC group (AVLT: r = 0.30, p = 0.04; SDMT: r = 0.36, p = 0.01; Stroop: r = –0.32, p = 0.03; TMT-A: r = –0.40, p = 0.005; TMT-B: r = –0.34, p = 0.02). Multiple linear regression models showed that H-DPOAE predicted cognitive impairment effectively for aspects of memory (R2 = 0.27, 95% CI, 0.03 to 1.55), attention (R2 = 0.32, 95% CI, –6.18 to –0.40), processing speed (R2 = 0.37, 95% CI, 0.20 to 1.64), and executive function (TMT-A: R2 = 0.34, 95% CI, –5.52 to 1.03; TMT-B: R2 = 0.29, 95% CI, –11.30 to –1.12). H-DPOAE directly affected cognition and fully mediated the relationship between pure tone average (PTA)/SRT and cognitive test scores, excluding MoCA.Conclusion: This study has demonstrated that the high-frequency cochlear amplifier dysfunction has a direct predictive effect on the cognitive decline and makes a large contribution to the cognitive-ear link.

A single-centre study of genetic mutations, audiology, echocardiogram and pulmonary function in Saudi children with osteogenesis imperfecta

Objectives Osteogenesis imperfecta (OI) is a heterogeneous group of inherited connective tissue disorders, characterised by skeletal fragility. Patients with OI may also exhibit extra-skeletal features like blue or grey scleral colour, fragile skin, easy bruising, joint laxity, short stature, deafness, cardiac valve abnormalities and abnormal pulmonary function. The objective of this study is to describe genetic mutations, prevalence of hearing issues, cardiac complications and impaired pulmonary function in children with OI. Methods This is a cross-sectional study of 23 Saudi children aged 6 months to 18 years who were diagnosed with OI. The revised Sillence classification (2,105) was used to classify the OI type. Whole exome sequencing was performed for genetic mutations. The hearing was assessed by either pure-tone audiometry and/or otoacoustic emission testing. Cardiac defects were screened by echocardiograms. Spirometry was performed to assess pulmonary function. Data were analysed with descriptive statistics. Results Based on the Sillence classification, 16 patients had OI type III, 6 had type IV and 1 had type I. Of the18 patients who had genetic sequencing, 66.6% had autosomal dominant and 33.3% had autosomal recessive mutations. Among children who had screening, hearing loss was diagnosed in 53% (9/17), congenital cardiac malformations in 26% (5/19) and restrictive lung disease in 70% (7/10). Conclusions We found significant extra-skeletal features and a high yield of genetic mutations associated with OI. We suggest further studies to develop a screening protocol for extra-skeletal features in children with OI.

Audiological Involvement in Patients with Systemic Sclerosis

Objective The aim of the present study was to evaluate hearing loss in patients diagnosed with SSc (systemic sclerosis) and to investigate the relation between hearing loss, subtypes of the disease, its duration and clinical findings, and antibody positivity. Methods The study included 47 patients with SSc and 44 healthy controls. Audiometric, tympanometric and otoacoustic emission measurements were applied to both groups. Results The evaluation of the participants medical history showed that among the patients with SSc, 19.1% experienced ear fullness, 27.7% experienced vertigo and 36.2% experienced tinnitus. Hearing loss was detected in 23.4% of the patients with SSc. The corresponding result was 4.3% in the control group with a statistically significant difference (p = 0.001). Transient evoked otoacoustic emission (TEOAE) amplitude values were significantly lower in the patients both ears with SSc than the control group (p < 0.005). Duration of disease was significantly longer and DLCO (diffusing capacity of the lungs for carbon monoxide) values were significantly higher in the patients with SSc and sensorineural hearing loss. Conclusions The present study found that the incidence of hearing loss was significantly higher in the study group than healthy control group. In addition to other organ involvements, cochlear involvement occurs in these patients, and further studies are required.

The Effects of Clinical Factors and Neonatal Morbidities on Hearing Screening Among Neonatal Admissions

Background: Hearing loss is an important disorder affecting newborns admitted to NICU. A national hearing screening program using otoacoustic emission testing is an essential tool to identify hearing loss early in neonates enabling early intervention to avoid further challenges of pediatric deafness. On the other hand, a delay of the auditory pathway maturation in preterm babies compared to term newborns has already been suggested in the literature. Taking this information into account, in this paper, we aim to identify the best time to perform NICU infant hearing screening tests. Objectives: We aim to study the clinical factors and neonatal morbidities that may affect neonatal hearing screening results using otoacoustic emission test, in order to decrease the false positive test results that increase parental anxiety and increase the need for subsequent investigations. Methods: This is a prospective cross-sectional study that included 204 infants who were admitted to a tertiary referral hospital NICU unit between September 2017 and May 2018. Both transient evoked otoacoustic emissions (TEOAE) and distortion product otoacoustic emission (DPOAE) screening tests were performed in order to screen hearing loss. Results: Our study included 204 infants, 52.9% of which were males and 47.1% females. There were correlations between both hyperbilirubinemia and ventilation ≥5 days and the failure rate of the first OAE test results among NICU infants where the P-values were (p=0.0133) and (p=0.0456) respectively. Moreover, 165 babies (80.9%) passed the first OAE with a mean birth weight of 2759 gram and mean maternal age of 30.6 years, while 39 babies (19.1%) failed the test with a mean birth weight of 2436 gram and mean maternal age of 32 years. There was no statistically significant relation between both maternal age and birth weight with failure of the first screening test. Conclusion: Our study suggests a higher failure rate of the first OAE in NICU infants who had hyperbilirubinemia or ventilation ≥5 days. Therefore, our recommendation is to postpone the first phase of hearing screening for those infants until the first scheduled vaccine appointment to achieve high compliance to attendance and decrease distress to the family that can be associated with false-negative results of the test.

Deletion of Oncomodulin Gives Rise to Early Progressive Cochlear Dysfunction in C57 and CBA Mice

Ca2+ signaling is a major contributor to sensory hair cell function in the cochlea. Oncomodulin (OCM) is a Ca2+ binding protein (CaBP) preferentially expressed in outer hair cells (OHCs) of the cochlea and few other specialized cell types. Here, we expand on our previous reports and show that OCM delays hearing loss in mice of two different genetic backgrounds: CBA/CaJ and C57Bl/6J. In both backgrounds, genetic disruption of Ocm leads to early progressive hearing loss as measured by auditory brainstem response (ABR) and distortion product otoacoustic emission (DPOAE). In both strains, loss of Ocm reduced hearing across lifetime (hearing span) by more than 50% relative to wild type (WT). Even though the two WT strains have very different hearing spans, OCM plays a considerable and similar role within their genetic environment to regulate hearing function. The accelerated age-related hearing loss (ARHL) of the Ocm KO illustrates the importance of Ca2+ signaling in maintaining hearing health. Manipulation of OCM and Ca2+ signaling may reveal important clues to the systems of function/dysfunction that lead to ARHL.

Oto acoustic emissions in early detection of sensorineural hearing loss in high-risk neonates

<p><strong>Background: </strong>Early identification of congenital hearing loss and early intervention ameliorated many adverse consequences. This study was performed to observe effectiveness of otoacoustic emission in screening of hearing loss in high-risk babies.</p><p><strong>Methods: </strong>Prospective study on 45 high-risk newborns delivered during period of 2013-2014. Selective newborn hearing performed with oto acoustic emissions (OAE) and auditory brain stem responses (ABR), in high-risk infants aged below 7 days, 15 days, after 45 days and after 90 days.</p><p><strong>Results: </strong>Study population comprised of 45 high-risk newborns. In 1^st level screening, 28 (62%) babies showed recordable OAE, 17 (38%) babies failed. In 2^nd level screening 31 (81%) passed and 7 (19%) failed and death occurred in 7 infants. In 3^rd level screening both OAE and brain stem evoked response audiometry (BERA), was performed in 38 cases and positivity was reported in 37 cases. 4^th level screening was similar to 3^rd level screening where 3 babies failed ABR test. In our study incidence of sensorineural hearing loss found to be 78.91% (3/38×1000) per 1000 high-risk babies. Auditory neuropathy was observed in 2 (4.4%) patients. Sensitivity and specificity of OAE was 100% and 33.3% respectively. In high-risk low birth weight neonates’ sensitivity and specificity was 66.7% and 50.0%.</p><p><strong>Conclusions: </strong>In high-risk babies, appropriate time for screening with OAE is around 60 days of age. OAE are useful diagnostic tool in evaluation of high-risk neonates for early detection of sensorineural hearing loss.</p>

Effect of Radiofrequency Waves of Mobile Phones on Distortion Product Otoacoustic Emissions

Objective The prolonged exposure to electromagnetic fields of mobile phones can damage the cochlear hair cells, which can be detected by otoacoustic emission (OAE). To know the effect of mobile phones on hearing, the young volunteers were subjected to prolonged mobile phone usage and changes in OAE were recorded. Materials and Methods Twenty-eight volunteers with normal hearing were made to talk one full hour continuously on the mobile phone. Distortion product otoacoustic emission (DPOAE) was measured prior to the usage of mobile phones and immediately after the use (post-exposure 1) and 24 hours after the use (post-exposure 2). The values were compared. Results Out of the 28 volunteers, 20 were females and 8 were males. Twenty-one volunteers preferred the right ear while using mobile phones, 7 preferred the left ear. There was no statistically significant difference between the baseline DPOAE values and values of post-exposure 1 and 2 when only the preferred ear was taken into consideration. When the preferred ear was compared with nonpreferred ear, a statistically significant difference was found only in the low frequencies between the pre-exposure and post-exposure 1 values. Conclusion This study shows there was no significant correlation between OAE and prolonged mobile phone exposure when the preferred ear was not considered.