Otoacoustic Emission Response Research Articles

The outcomes of an audiological management programme for neonates with hyperbilirubinaemia.

Hyperbilirubinaemia is a contributing condition to the prevalence of neonatal hearing loss. Because of its pathophysiology, the use of Otoacoustic Emissions (OAE) and Automated Auditory Brainstem Response (AABR) testing is essential in diagnosing hearing loss. Two-tier screening models are typically used in developing world contexts; however, a combined approach to testing (using both tests) should be used for early detection. Blood serum levels should also be monitored to determine how they impact audiological test results. To determine the outcomes of using a combined testing approach of both OAE and Auditory Brainstem Response (ABR) for both screening and diagnostic testing of neonates with hyperbilirubinaemia and studying the relationship between the test results and the serum bilirubin levels. A cross-sectional, comparative design was utilised. Forty neonates were tested (80 ears). Neonates underwent hearing screening and diagnostic testing (ABR and/or AABR and DPOAE tests). The study was conducted at a hospital in South Africa. One-third (32.5%) of the neonates had comorbidities. Screening results indicated that the AABR test could identify more cases of abnormalities than DPOAEs (p= 0.001). Participants with a serum level greater than 10 mg/dL presented with abnormal diagnostic ABR test results while passing the DPOAE test (p 0.001). Combined use of ABR and DPOAE testing yielded a greater identification of auditory pathology than using either test alone. Serum bilirubin levels can be used as an indicator for combination testing.Contribution:Combined use of ABR and DPOAE testing leads to greater identification of auditory pathology.

Objective audiometric evaluation of individuals with type 2 diabetes mellitus: A cross-sectional survey in South West Nigeria

Aims: Diabetes mellitus affects more than 450 million people around the world. The relationship between diabetes and sensorineural hearing loss has been an area of interest. The aim of this study is to evaluate hearing loss, among type 2 diabetes diagnosed in the endocrinology unit of a private tertiary health facility in South West Nigeria. Methods: This was a hospital-based cross-sectional study carried out among type 2 diabetic patients and normal healthy non-diabetic individuals as control. A total of 120 participants were recruited for the test and control. Otoacoustic emission and auditory steady-state response audiometry were carried out on all the participants. Result: The total number of study participants was 120 (60 for test and control) with an age range of 30–79 years for the test and 20–80 years for the control. Otoacoustic emission showed passes for both ears, 61.7% pass in both ears for the test group and 76.7% pass in both ears for the control group. 21.7% of the test and control were referred for both ears. 16.6% of the test group was referred in one ear compared to 1.7% in the control group. Auditory steady-state response (ASSR) audiometry showed mild to profound hearing loss in all test groups while in the control group 20% had normal hearing. Moderate to moderately severe hearing loss in at least one ear was 38.4% in the test ear compared to 16.7% in the control group. Conclusion: Hearing loss is an established complication of type 2 diabetes. Therefore, it is necessary to incorporate regular hearing screening for patients with diabetes for early detection, counseling, and rehabilitation for those with disabling hearing loss.

ELEKTROFIZJOLOGICZNE POMIARY UPOŚLEDZENIA SŁUCHU U NARAŻONYCH NA HAŁAS ŻOŁNIERZY ZE SŁUCHEM W NORMIE

IntroductionSome electrophysiological changes can occur in the auditory system in response to noise exposure with or without any permanent auditory threshold shift. The purpose of this study was to identify and measure cochlear function after noise exposure in individuals with normal hearing according to standard audiometric thresholds.Material and methodsPure tone audiometry (PTA) over the standard 0.250–8 kHz range and at 12 kHz, as well as distortion product otoacoustic emission (DPOAE) and auditory brainstem response (ABR) testing, were performed on 42 soldiers who had participated in combat. A control group of 40 participants underwent the same tests.ResultsIn the noise-exposed group, significantly poorer PTA thresholds were recorded at 12 kHz. DPOAE levels were significantly low only at 4 kHz. On ABR testing, both wave I and wave V demonstrated a significant decrease in amplitude and a significant increase in latency for the noise-exposed group.ConclusionsOur findings reveal that high levels of noise can not only damage outer hair cells but also cause changes at the level of the synapses (synaptopathy) which are not evident using standard PTA tests. However, electrophysiological methods can detect some changes in cochlear function.

Re-evaluating the scoring criteria of the Interacoustics Sera Neonatal Hearing Screener

Abstract Introduction: Newborn hearing screeners via otoacoustic emissions (OAEs) have become the standard in audiological clinical practice. Despite the application of OAE protocols for more than 3 decades, there has been no consensus on the standardization of the recorded responses. Usually, manufacturers based the scoring criteria of the OAE responses on small scale samples and in many cases on data published in the literature. Since there are no standards in the OAE probe construction, the resulted OAE responses are quite different between OAE screeners. The project evaluated the scoring criteria used in the Interacoustics Sera OAE screener. Methods: Eight hundred and eleven infants were initially screened by the Accuscreen OAE screener for a Pass or a Fail outcome. Seven hundred and ninety-two infants resulted as Pass were re-evaluated with the Sera transient-evoked OAE (TEOAE) and distortion-product OAE (DPOAE) protocols. Results: In terms of screening efficiency, the DPOAE protocol performed better, showing results very similar to the Accuscreen performance (Fail %: 2.4 vs. 2.3). The data showed that the recordings of the TEOAE responses were more prone to noise corruption. Using 10th percentile normative distribution values, DPOAE-optimized scoring criteria were estimated as 3.1, 7.9, 9.9, and 8.9 dB for the tested frequencies of 2.0, 3.0, 4.0, and 5.0 kHz. Unfortunately, the TEOAE signal-to-noise (S/N) data resulted as too noisy (despite relatively large TEOAE responses); therefore, the TEOAE responses were considered as scoring criteria candidates. The latter were estimated as 4.61, 6.35, 7, 1 and 3, 35 dB at 1.4, 2.0, 2.8, 4.0 kHz. Conclusion: It is possible to improve the screening efficiency of the DPOAE Sera protocol using optimized scoring criteria, aiming the correct identification of at least 90% of all normal hearing subjects. The Sera TEOAE protocol needs further investigation to identify the source of the noise, which lowers significantly the reported S/N ratios. The collected OAE data confirm that there are differences among the responses obtained by various screeners; therefore, an OAE probe standardization is necessary.

Hearing Loss Among Families with 2 and More Affected Members in Golestan Province, Iran: A Cross-Sectional Study of 320 Families.

Our study centers on various aspects of families who have 2 or more members with hearing loss (HL) and are living in Golestan province in Iran. We aimed to identify those families with the highest probability of hereditary HL and also to examine the impact of consanguinity among them. The families included in the study underwent a comprehensive screening process that involved their prenatal and postnatal histories as well as family medical histories. Additionally, each patient received a thorough clinical ear examination. The evaluation also took into account factors such as patterns of inheritance, consanguinity, a 3-generation pedigree, and physical examination. Following this initial assessment, patients were referred for a complete hearing evaluation, which included pure-tone audiometry, speech recognition threshold, otoacoustic emission, and auditory brainstem response tests. We identified a total of 8553 individuals living in Golestan province who are hearing impaired. Among those, our records indicate that 320 families had at least 2 affected members. The rate of consanguinity marriage in non-syndromic families was 64.43%. Also, a significant number (88.12%, or n=282) of the families exhibited hereditary HL, among which a substantial proportion (89.72%, or n=253) presented with nonsyndromic forms of HL. Furthermore, bilateral, stable, and prelingual HL were the most frequently observed types, and a majority of the patients were diagnosed with sensorineural and profound HL. This study revealed a correlation between consanguinity and the incidence of familial HL, with more probability of bilateral, prelingual, sensorineural, and profound forms.

Auditory Neuropathy Spectrum Disorder in Individuals with Sickle Cell Anemia: Case Study.

The present study attempted to understand the association between Auditory neuropathy spectrum disorder (ANSD) and Sickle cell anemia (SCA) and to recognize possible causative factors for the presence of ANSD in SCA individuals. Two cases, 24 years male and 17years female with a laboratory-confirmed diagnosis of Sickle cell anemia underwent detailed audiological evaluation i.e., pure tone audiometry, speech audiometry, immittance audiometry, otoacoustic emission, and auditory brainstem responses. Audiological evaluation revealed a bilateral moderate low-frequency sensorineural hearing loss in male and bilateral moderately severe sensorineural Hearing loss in female case with elevated Speech Recognition Threshold and poor Speech Identification Scores. 'A' type tympanogram with the absence of Acoustic reflexes and the presence of Otoacoustic emission with no distinct and reproducible peak V in Auditory Brainstem Response (ABR) at 90 dBnHL with the presence of ringing cochlear microphonics on polarity reversal collectively indicating bilateral ANSD in both cases. ANSD and SCA are reported to have a genetic basis of etiology. There might be possibilities that one genetic condition may be common in manifesting both conditions or one genetic condition can cause the presence of another genetic condition or can exaggerate the evolution of another genetic condition. Also, abnormal ABR findings indicate the possibility of neuropathological involvement in isolation or in combination with genetic abnormalities that need detailed investigation to understand non-genetic causative factors. Thus, paved the path for further research in this line and might provide better rehabilitative options.

Evaluation of Neurological and Auditory Development in Children with Congenital Heart Disease using Essence Q Questionnaire and Auditory Brainstem Response (ABR) Test.

The progress of cardiac surgery in children and the increase in the survival of children with Congenital Heart Disease (CHD) has led to consider another issue called a neurodevelopmental disorder. In this study, 53 children with CHD were evaluated in terms of development with the Essence Q questionnaire, Otoacoustic Emission (OAE), and Auditory Brainstem Response (ABR) regarding these patients' hearing and risk factors. The Essence Q scores were also examined. In this prospective, cross-sectional study, the researchers included 53 children diagnosed with CHD. Initially, each child underwent ABR and OAE tests. Subsequently, data on potential risk factors associated with neurodevelopmental delay were collected. A trained project associate administered the Essence Q questionnaire, using parents' information as a guide. Following data collection, this study proceeded with an in-depth analysis of the information. Thirty-six boys (67.92%) and 17 girls (32.08%) with CHD were included in the study. The mean age of children was 26.9810.64 months. The mean Essence Q score for boys was 7.482.57. Moreover, the average score for girls was 2.23 8.11. According to this questionnaire, 39 patients (73.58%) had hyperactivity disorder, 46 patients (86.79%) had behavioral disorders, and ten patients (16.98%) had a motor delay. Unlike previous studies, all patients had normal OAE and ABR hearing. This study demonstrated that factors such as developmental delay in the first year, a known genetic disease, and a history of seizures significantly impacted the Essence Q score. However, elements like prematurity, the use of ventilation, abnormalities on the dorsum, and the number of days post-surgery did not significantly affect the Essence Q score. Essence Q can be a reliable tool in screening for neurodevelopment in children with CHD.

Cochlear implantation compliance among minorities at high risk for hearing impairment following universal newborn hearing screening.

The universal newborn hearing screening (UNHS) allows for early detection of hearing impairment (HI). The goal of this current study was to evaluate the impact of cultural background involving consanguineous marriage on newborn HI diagnosed using UNHS, and compliance with hearing rehabilitation. This is a retrospective cohort study that included all children born at a single tertiary medical center between 2011 and 2017 who did not pass the UNHS (oto-acoustic emission and auditory brainstem response), and were diagnosed with HI. The study group included children from consanguineous marriage cultural background which were compared to a control group-all other children. Data were retrieved from the computerized medical charts and included epidemiological, audiological, and pregnancy/delivery-related data, and known risk factors for congenital HI. A total of 238 (196 study and 42 control) neonates were diagnosed with HI. Family history of HI was significantly more prevalent in the study group in mild-severe and profound HI subgroups (p = 0.03 and 0.01, respectively). Study group demonstrated lower rates of cochlear implantation (CI) compliance (p = 0.079), performed at a significantly older age (23 months (IQR 17-36.5) vs. 16 (IQR 12-26) months, p = 0.021). When recommended, bilateral CI compliance was significantly lower in the study group (94.1 vs.48.9%, p < 0.001). UNHS allows for early HI detection among minority populations at higher risk for CI, yet compliance rates remain lower compared with control. Familiarity of families with the importance of early detection and HI risk may result in higher compliance rates for cochlear implantation. Health providers should aim to improve education and communication with this unique group of patients and consider health promotion programs.

Can Ganciclovir and Quercetin-P188 Ameliorate Cytomegalovirus Induced Hearing Loss?

Determine whether combination therapy with ganciclovir (GCV) and a Quercetin-P188 solution improves hearing outcomes in a murine cytomegalovirus (CMV) model. BALB/c mice were infected with murine CMV on postnatal day 3 (p3). Quercetin was solubilized in saline using P188 (QP188). Treatment groups received either GCV, QP188, GCV and QP188, or P188 delivery vehicle BID at 12-hour intervals via intraperitoneal injection. All treatment groups were treated for 14 days starting at p3. Uninfected controls were treated with the combined regimen, saline or P188 delivery vehicle. Auditory thresholds were assessed using distortion product otoacoustic emission (DPOAE) and auditory brainstem response (ABR) testing at 4, 6, and 8 weeks of age. Temporal bones from separate CMV-infected groups were harvested at p10, and viral load was determined by quantitative polymerase chain reaction. CMV-infected mice receiving combination therapy GCV+QP188 demonstrated statistically significant lower ABR (p < 0.001) and DPOAE thresholds (p < 0.001) compared with mice treated with GCV monotherapy, QP188 monotherapy, and P188 delivery vehicle at 4, 6, and 8 weeks of age. GCV+QP188 combination therapy, GCV monotherapy, and QP188 monotherapy resulted in a nonsignificant reduction in mean viral titers compared to P188 monotherapy (p = 0.08). Combining GCV with the excipients quercetin and P188 effectively ameliorated CMV-induced sensorineural hearing loss in a murine model. This result may be partially explained by a reduction in viral titers in mouse temporal bones that correlate with in vitro studies demonstrating additive antiviral effect in cell culture. NA Laryngoscope, 134:1457-1463, 2024.

Wideband tympanometry and otoacoustic emissions in children with risk factors for hearing loss

Introduction: Wideband tympanometry and evoked otoacoustic emissions can help audiologically monitor children birth to 3 years old, with or without risk factors for hearing loss. Objective: To study wideband tympanometry results in acoustic absorbance measures and transient evoked and distortion-product otoacoustic emission records during audiological monitoring. Method: This prospective observational study encompassed 58 children with and without risk indicators for hearing loss, with a mean age of 16.7 months. Data were obtained from the databases of four public maternity hospitals in São Paulo. Subjects were characterized as normal hearing or conductive hearing loss in the groups with and without risk factors for hearing loss. Results: Wideband absorbance at 1000 to 8000 Hz was verified to correlate the absorbance level with the transient evoked and distortion-product otoacoustic emission response levels at 1000 to 8000 Hz and wideband tympanometry. Normal hearing individuals’ absorbance at 1500 Hz to 6000 Hz ranged from 0.92 to 0.98, in which the best results may be found. Conclusion: Absorbance values are higher in male and normal hearing children. Evoked otoacoustic emission levels agreed with absorbance measures – the greater the absorbance, the higher the transient evoked and distortion-product otoacoustic emission levels.

Hearing Following Prolonged and Delayed Ganciclovir Treatment in a Murine Cytomegalovirus Model.

Compare hearing outcomes utilizing standard, prolonged and delayed ganciclovir (GCV) therapy in a murine model of cytomegalovirus (CMV). BALB/c mice were inoculated with mouse cytomegalovirus (mCMV) or saline via intracerebral injection on postnatal day 3 (p3). Intraperitoneal GCV or saline was administered at 12 h intervals for the duration of the standard (p3-p17), delayed (p30-p44), or prolonged treatment windows (p3-p31). Auditory thresholds were assessed using distortion product otoacoustic emission (DPOAE) and auditory brainstem response (ABR) testing at 4, 6, and 8 weeks of age. Blood and tissue samples were harvested from mice on p17 and p37 one hour after GCV administration, and their concentrations were assessed via liquid chromatography-mass spectrometry. A delayed course of GCV improved ABR but not DPOAE thresholds in mCMV-infected mice. A prolonged course of GCV did not provide better hearing thresholds than those administered standard treatment. The average GCV concentration in all 17-day-old mice tissue was significantly higher than those in older 37-day-old mice. Delayed GCV treatment provided a hearing benefit on ABR over untreated mCMV infected mice. Prolonged CGV administration showed no benefit compared to a shorter duration GCV treatment. GCV drug concentrations both systemically and in the cochlea are much lower in older mice. These results have potential implications for the clinical management of cCMV infected children. NA Laryngoscope, 134:433-438, 2024.

Short-term outcomes of infants with hyperbilirubinemia-associated auditory neuropathy spectrum disorder in neonatal intensive care unit

Hyperbilirubinemia is a high-risk factor for auditory neuropathy spectrum disorder (ANSD) as well as hearing loss in general. This study described the outcomes of hyperbilirubinemia-associated ANSD infants diagnosed in hearing screening in the neonatal intensive care unit (NICU).A total of 578 children with hyperbilirubinemia admitted to the NICU between October 2020 and October 2021 were included in this study. The distortion product otoacoustic emission (DPOAE) and automatic auditory brainstem response (AABR) were combined for hearing screening, and those who failed the DPOAE or/and AABR underwent an auditory brainstem response (ABR) test. Infants with ANSD were followed up for 12 months.Forty infants (40/578, 6.9%) failed the DPOAE or/and AABR tests, of which, 13 (13/578, 2.2%) were diagnosed as ANSD, and 27 (27/578, 4.7%) were diagnosed as having sensorineural hearing loss (SNHL). Of the 13 ANSD infants followed up for 12 months, 7 recovered, 3 improved, 3 did not recover, and 1 was lost, equating to improved or recovered hearing in 75% (9/12) of ANSD infants at 12 months of age. Moreover, the maximum bilirubin in recovered or improved ANSD infants was 408.6 ± 129.0 μmol/L, while the maximum bilirubin in unrecovered ANSD infants was 749.3 ± 323.0 μmol/L. Furthermore, poorly differentiated and absent ABR waveforms were observed in 6 and 14 ears at 1 month, 2 ears were lost, 6 (6/6, 100.0%) and 6 (6/12, 50.0%) ears were recovered or improved at 12 months of age.s: The incidence of hyperbilirubinemia associated-ANSD was 2.2% of infants screened in the NICU. ANSD caused by hyperbilirubinemia may be transient, with most infants improving or recovering hearing by 12 months of age. Infants with poorly differentiated ABR waveforms and low bilirubin concentration are more likely to recover and hearing aids are not recommended in hyperbilirubinemia-associated ANSD below 12 months of age.

Auditory neuropathy in mice and humans with Friedreich ataxia.

Recent studies have found that human Friedreich ataxia patients have dysfunction of transmission in the auditory neural pathways. Here, we characterize hearing deficits in a mouse model of Friedreich ataxia and compare these to a clinical population. Sixteen mice with a C57BL/6 background were evaluated. Eight were YG8Pook/J animals (Friedreich ataxia phenotype) and eight wild-type mice served as controls. Auditory function was assessed between ages 6 and 12 months using otoacoustic emissions and auditory steady-state responses. At study end, motor deficit was assessed using Rotorod testing and inner ear tissue was examined. Thirty-seven individuals with Friedreich ataxia underwent auditory steady-state evoked potential assessment and response amplitudes were compared with functional hearing ability (speech perception-in-noise) and disease status was measured by the Friedreich Ataxia Rating Scale. The YG8Pook/J mice showed anatomic and functional abnormality. While otoacoustic emission responses from the cochlear hair cells were mildly affected, auditory steady-state responses showed exaggerated amplitude reductions as the animals aged with Friedreich ataxia mice showing a 50-60% decrease compared to controls who showed only a 20-25% reduction (F(2,94) = 17.90, p < 0.00). Furthermore, the YG8Pook/J mice had fewer surviving spiral ganglion neurons, indicating greater degeneration of the auditory nerve. Neuronal density was 20-25% lower depending on cochlear region (F(1, 30) = 45.02, p < 0.001). In human participants, auditory steady-state response amplitudes were correlated with both Consonant-Nucleus-Consonant word scores and Friedreich Ataxia Rating Scale score. This study found degenerative changes in auditory structure and function in YG8Pook/J mice, indicating that auditory measures in these animals may provide a model for testing Friedreich ataxia treatments. In addition, auditory steady-state response findings in a clinical population suggested that these scalp-recorded potentials may serve as an objective biomarker for disease progress in affected individuals.

The Effect of Gestational Diabetes Mellitus on Hearing of Neonates in a Tertiary Healthcare Centre.

Congenital hearing loss is hearing loss present in a child at birth or soon after birth. It is a debilitating condition with the potential for lifelong disability. It is thought to be multifactorial in aetiology with both genetic (autosomal and X-linked) and acquired causes (such as maternal infections, drug intake, trauma). Gestational Diabetes Mellitus (GDM) is a relatively common condition found in pregnant females but is a rather understudied risk factor in terms of congenital hearing loss. GDM is easily treatable which makes the hearing loss due to it easily preventable. (1) Determine correlation between Gestational Diabetes Mellitus and congenital hearing loss in neonates. (2) Calculate the prevalence of Gestational Diabetes Mellitus related congenital hearing loss. A two-step screening process was used for hearing evaluation of neonates with normal mothers (non-exposed) and neonates with mothers suffering from GDM (exposed) through Otoacoustic emission (OAE) and Brainstem Evoked Response Audiometry (BERA). (1) The difference of neonates diagnosed with hearing impairment in exposed and non-exposed group was statistically significant with a p-value of 0.024. OR 2.1538 95% CI 0.6120-7.5796, p < 0.05. (2) Prevalence of hearing loss in neonates of GDM mothers: 13.3%. Through rigorous exclusion of the already known risk factors for congenital hearing loss, Gestational Diabetes Mellitus has been isolated as an independent risk factor for neonatal hearing impairment. We hope to identify additional cases of congenital hearing loss early leading to a decrease in disease burden.

Effects of sex and gestational age on the auditory brainstem responses among two ears in moderate preterm infants

Objectives Auditory cortex in each hemisphere mostly receives the sounds from the opposite ear. The present study aimed at the contralateral dominance of auditory brainstem response (ABR) among the ears in preterm neonates by comparing sex and gestational age. Methods Transient Evoked Otoacoustic Emission (TEOAE) and Auditory Brainstem Response (ABR) were recorded at 3 months postconceptional age (PCA). The performance of two ears in ABR was compared. In addition, performance of each ear was analysed in females and males. A comparison of moderate gestational age also was performed. Twenty preterm neonates from 32 to 36 weeks gestational age admitted to the neonatal intensive care unit at Shafizadeh Children’s Hospital were participated. Results No significant asymmetry in ABR absolute latency and inter-peak intervals of right and left ears in preterm infants was noticed. Females and males did not demonstrate statistically significant values in ABR latencies. Moreover, the results of four gestational ages were not statistically different from each other. Conclusion The maturation of the auditory brainstem pathways most likely take places in both hemispheres simultaneously, independent of sex in preterm infants. Changes of gestational age in each month do not impact on the maturation of the auditory brain pathways.

Vestibular Schwannoma Surgery with Endoscope-Assisted Retrolabyrinthine Approach under Modified Reinforced Continuous Intraoperative Monitoring for Hearing Preservation: Experience of 33 Cases in a Single Center.

Surgery for vestibular schwannoma includes various techniques such as the middle cranial fossa, suboccipital, translabyrinthine, and retrolabyrinthine approaches. The retrolabyrinthine approach does not impair the labyrinth and allows postoperative hearing preservation. Previously, we reported an endoscope-assisted retrolabyrinthine approach under reinforced continuous intraoperative monitoring for preservation of hearing and facial nerve function. However, the hearing preservation rate was relatively low in patients with long-wave V latency in the auditory brainstem response or poor otoacoustic emission response under this approach. Thus, the hearing preservation rate in such patients remains to be improved. To overcome this limitation, we modified the previous approach. In 26 of the 33 consecutive cases (79%) over the last three years, preservation of hearing equivalent to that before surgery or improved hearing was achieved. Postoperative deafness was observed in only two of the 33 cases (6%). According to previous reports, the rate of hearing preservation using the retrolabyrinthine approach is approximately 30-50%. Therefore, we have achieved a higher hearing preservation rate than that previously reported using the endoscopy-assisted retrolabyrinthine approach under reinforced continuous intraoperative monitoring. These improvements in our department are considered to be helpful for hearing preservation.

Tetramethylpyrazine Attenuates Radiation-Induced Ototoxicity in a Rat Model

Introduction: Tetramethylpyrazine (TMP) is a chemical compound, which has been shown to possess numerous biological features such as anticoagulation, inhibition of platelet aggregation, anti-inflammation, capillary dilatation, improvement in microcirculation, and protection against reactive oxygen radicals. The aim of the present study was to investigate the protective effect of TMP against radiation-induced ototoxicity. Materials and Methods: 40 rats were divided into four groups. The first group was irradiated for 5 days. The second group received a single dose of 140 mg/kg/day intraperitoneal TMP given to the rats 30 min before radiotherapy (RT) for 5 days. The third group received a single dose of 140 mg/kg/day i.p. TMP for 5 days, whereas the fourth group was administered saline. All rats underwent distortion product otoacoustic emission (DPOAE) and auditory brainstem response measurements before and after the application. The temporal bulla of animals was removed for immunohistopathological examination. Results: Signal-noise ratio values were significantly decreased in the RT group for the frequencies of 2–32 kHz after RT (p < 0.05), whereas the difference was not significant in terms of pre- and posttreatment values for the other groups. Also in the RT group, the ABR thresholds were significantly increased after treatment. In H&E staining, the mean scores for outer hair cells (OHCs), stria vascularis (SV), and spiral ganglion (SG) injuries were significantly higher in RT and RT + TMP groups than in the other groups. The mean OHCs and SV injury scores were also significantly higher in the RT group than in the RT + TMP group (p < 0.05). The number of cochleas that showed cytoplasmic caspase-3 immunoreactivity in the OHC, SV, and SG was significantly higher in RT and RT + TMP groups than in the other groups. Conclusion: The findings of the present study suggest that TMP may have a therapeutic potential for preventing sensorineural hearing loss (SNHL) related to RT.

Evaluation of auditory system in obstructive sleep apnea patients.

Obstructive sleep apnea (OSA) has been associated with auditory dysfunction both to the cochlear and higher auditory pathways. However, available literatures presented conflicting results. We aimed to study the impact of OSA severity and their polysomnography parameters on hearing function. A total of 44 patients were included after evaluation for sleep disorders and were divided into four groups in accordance with apnea-hypopnea index (AHI). Pure tone audiometry (PTA), distortion product otoacoustic emission (DPOAE) and auditory brainstem response (ABR) were compared in commensurate with the severity of AHI. Polysomnography oximetry parameters of oxygen desaturation index, mean SPO2, minimum SPO2 and percent SPO2 < 90% were correlated with their respective PTA, DPOAE and ABR results. There was no significant change in the PTA, DPOAE and ABR results in connection with AHI severity. However, we found significant correlations between mean SPO2 and percent SPO2 < 90% with ABR wave I, III and V absolute latencies. Minimum SPO2 was also significantly correlated with wave III peak latency changes. Mean SPO2, percent SPO2 < 90% and minimum SPO2 could be key prognostic indicators of central auditory dysfunction in OSA patients. These parameters should be explored further as indicators of OSA severity rather than utilizing AHI alone. The hypoxic burden derived could be a better predictor of auditory function abnormalities rather than one derived from AHI.

Audiological results in newborn babies undergoing neonatal hearing screening at zonal hospital in western Maharashtra: A cross sectional study

To analyze the variation in audiological results with oto-acoustic emission (OAE) and auditory brainstem response (ABR) of term newborns with those at risk (preterm and newborns with hyperbilirubinemia). Auditory screening was conducted in 746 infants born in zonal hospital in western Maharashtra from May 2019 to May 2020. The cases included 633 healthy term, 71 preterm infants managed in the neonatal intensive care unit (NICU) and 42 newborns with hyperbilirubinemia. Hearing impairment was confirmed through a primary screening by OAE response followed by ABR. Based on these findings, we divided infants into pass and refer. 16 patients in ‘refer’ group were identified through our protocol out of 746 newborns. The incidence of the refer group was 11 out of 633 in term newborns, 3 out of 71 in preterm and 2 out of 42 in newborns with hyperbilirubinemia after OAE. Refer groups were subjected to further evaluation by ABR which was able to remove false positives and a final tally of 8 out of 11 term newborns, 2 out of 3 preterm were found to have hearing loss. Hence, we conclude that incidence of hearing loss detected by OAE in preterm and hyperbilirubinemia newborns was more as compared to term newborns and is significant. OAE followed by ABR is a good modality of audiological assessment in ruling out false positive cases.

Assessment of Hearing Loss in Two-Year Follow-up Study of Neonates with Congenital Cytomegalovirus Infection

ObjectivesCongenital Cytomegalovirus (cCMV) infection constitutes the main cause of sensory neural hearing loss (SNHL) worldwide. The rate of Cytomegalovirus (CMV)-induced SNHL is not well documented in developing countries, such as Iran. Therefore, this prospective follow-up study aimed to evaluate this rate among neonates with cCMV infection in Iran.Materials & MethodsNeonates with cCMV infection admitted to neonatal intensive care units and neonates with CMV infection identified in two other prospective screening studies in Tehran, Iran, were enrolled in this study. Audiological assessments, including otoacoustic emission and auditory brainstem response tests, were performed for all the cases. Antiviral therapy was administered for the newborns in case of having severe symptoms.ResultsA total of 22 neonates with cCMV infection were entered into the study, of whom 8 and 14 subjects had symptomatic and asymptomatic cCMV infection, respectively. In total, 3 of 22 newborns had SNHL (13.6%; 95% CI: 2.8-39.8), 2 of 8 cases with symptomatic cCMV infection (25.0%; 95% CI: 3-90) and 1 of 14 cases with asymptomatic cCMV infection (7.1%; 95% CI: 0.1-39). No association was observed between SNHL and CMV-related risk factors in newborns.ConclusionThe findings of this study revealed that the rate of cCMV-induced SNHL is high among neonates born in Tehran. The severe sequelae of cCMV infection indicate the need for screening for CMV infection at birth to reduce the risk of CMV complications and the financial load of treatment imposed on healthcare and treatment systems in Iran.