Novel standardized indexes of brainstem auditory evoked potentials for predicting hearing preservation in vestibular schwannomas.

Hearing preservation (HP) during vestibular schwannomas (VSs) surgery poses a significant challenge. Although brainstem auditory evoked potentials (BAEPs) on the affected side are commonly employed to monitor cochlear nerve function, their low signal-to-noise ratio (SNR) renders them susceptible to interferences, compromising their reliability. We retrospectively analyzed the data of patients who underwent tumor resection, while binaural brainstem auditory evoked potentials (BAEPs) were simultaneously recorded during surgery. To standardize BAEPs on the affected side, we incorporated the synchronous healthy side as a reference (interval between affected and healthy side ≤ 3 min). A total of 127 patients were enrolled. Comparison of the raw BAEPs data pre- and post-tumor resection revealed that neither V-wave amplitude (Am-V) nor latency (La-V) could serve as reliable predictors of HP simultaneously. However, following standardization, V-wave latency (STIAS-La-V) and amplitude (STIAS-Am-V) emerged as stable predictors of HP. Furthermore, the intraoperative difference in V-wave amplitude (D-Am-V) predicted postoperative HP in patients with preoperative HP and remained predictive after standardization. The utilization of intraoperative synchronous healthy side BAEPs as a reference to eliminate interferences proves to be an effective approach in enhancing the reliability of BAEPs for predicting HP in VSs patients.

Intraoperative Brainstem Auditory Evoked Potentials and Postoperative Nausea and Vomiting After Microvascular Decompression.

BACKGROUND: We performed this study to investigate the effect of intraoperative brainstem auditory evoked potential (IBAEP) changes on the development of postoperative nausea and vomiting (PONV) after microvascular decompression (MVD) for neurovascular cross compression. METHODS: A total of 373 consecutive cases were treated with MVD. The use of rescue antiemetics after surgery was used as an objective indicator of PONV. IBAEP monitoring was routinely performed in all. RESULTS: The use of rescue antiemetics was significantly associated with female sex (OR = 3.427; 95% CI, 2.077-5.654; P < 0.001), PCA use (OR = 3.333; 95% CI, 1.861-5.104; P < 0.001), and operation time (OR = 1.017; 95% CI, 1.008-1.026; P < 0.001). A Wave V peak delay of more than 1.0 milliseconds showed a significant relation with the use of rescue antiemetics (OR = 1.787; 95% CI, 1.114-2.867; P = 0.016) and a strong significant relation with the use of rescue antiemetics more than 5 times (OR = 2.426; 95% CI, 1.372-4.290; P = 0.002). CONCLUSIONS: A wave V peak delay of more than 1.0 milliseconds might have value as a predictor of PONV after MVD. More detailed neurophysiological studies will identify the exact pathophysiology underlying PONV after MVD.

From periphery to center, untold story of pure neuritic leprosy: an electrophysiological study.

BACKGROUND: Pure neuritic leprosy (PNL) is uncommon form of leprosy involving peripheral nerves. Some isolated case reports have shown imaging changes in the central nervous system (CNS) and also impairment in visual evoked potential (VEP), somatosensory evoked potential (SSEP) and brain stem auditory-evoked potentials (BAEPs) parameters in PNL, but there is lack of large study. This prospective observational study evaluates impairment in these central conduction studies among PNL patients. METHODS: We screened patients with leprosy presenting with features of neuropathy and/or thickened nerves. Patients with bacilli-positive nerve biopsies were included in the study and subjected to routine tests along with nerve conduction study (NCS), VEP, tibial SSEP and BAEPs. Parameters of these studies were analyzed based on data from previous studies. RESULTS: Of 76 patients screened for PNL 49 had positive findings in biopsy. Most of patients were male and mean age group was 46.35 ± 15.35 years. Mononeuritis multiplex was most common NCS pattern in 46.93% (23/49) patients. We found abnormal VEP in 13 out of 35 patients (37.14%). Similarly abnormal SSEP and BAEPs among 42.85% and 40% patients respectively. DISCUSSION: This study shows that in PNL significant number of patients have subclinical CNS involvement. Exact pathophysiology of CNS involvement is not known till now but study of VEP, SSEP and BAEPs parameter may help in early diagnosis of PNL.

Intraoperative EABR Testing Predicts Strength of Cochlear Implant Stimulation Optimized After Long-Term Use in Pediatric Malformation Ears.

OBJECTIVE: This study focused on the intensities of cochlear implant (CI) stimulation in pediatric CI users with inner ear malformation or cochlear nerve deficiency (CND). In this population, CI programming is difficult because a large intensity of CI stimulation is required to achieve sufficient hearing, but the excess CI stimuli often induce facial nerve stimulation. We aimed to assess whether the results of intraoperative electrically evoked auditory brainstem responses (EABRs) testing predict maximum current levels of CI stimuli (cC levels) optimized by a behavioral-based method after long-term CI use. STUDY DESIGN: A retrospective case review. SETTING: A tertiary referral CI center. PATIENTS: A total of 116 ears with malformations (malformation group) and 63 control ears (control group) from patients younger than 18 years who received CI. The malformation group comprised 23 ears with a common cavity (CC), 26 with incomplete partition type 1 (IP-1), 26 with incomplete partition type 2 (IP-2), and 41 with CND. INTERVENTIONS: Diagnostic. MAIN OUTCOME MEASURES: Correlation between intraoperative EABR results and cC levels determined by the behavioral-based CI programming after long-term CI use. RESULTS: The CC, IP-1, and CND ears required significantly larger cC levels than the IP-2 ears and control groups. However, the cC levels increased to reach the plateau 1 year after surgery in all groups. Among the malformation group, 79 ears underwent intraoperative EABR testing. Greater than 80% of the CC, IP-1, and IP-2 ears and 54.8% of the CND ears exhibited evoked wave V (eV) and were included in the eV-positive category. Myogenic responses but no eV were observed in 18.2, 15.0, and 35.5% of the CC, IP-1, and CND ears, defined as the myogenic category. No eV or myogenic response was elicited in 9.7% of the CND ears. We focused on minimum current levels that elicited eV (eV levels) in the eV-positive category and maximum current levels that did not elicit any myogenic responses (myogenic levels) in the myogenic category. A significant relationship was detected between the eV levels and the cC levels. When analyzed in each malformation type, the eV levels significantly correlate with the cC levels in the CC and CND ears but not in the IP-1 and IP-2 ears, probably because of slight variation within the IP-1 group and the small number of the IP-2 group. The myogenic category did not show a significant relationship between the myogenic levels and cC levels, but the cC levels were similar to or smaller than the myogenic levels in most ears. CONCLUSIONS: This study confirmed that intraoperative EABR testing helps predict the optimal cC levels in malformation ears. EABR-based CI programming immediately after cochlear implantation, followed by behavioral-based CI programming, may allow us to achieve early postoperative optimization of CI maps even in young children with severe malformations.

[Study on gene therapy for DPOAE and ABR threshold changes in adult Otof-/- mice].

Objective:This study aims to analyze the threshold changes in distortion product otoacoustic emissions（DPOAE） and auditory brainstem response（ABR） in adult Otof-/- mice before and after gene therapy, evaluating its effectiveness and exploring methods for assessing hearing recovery post-treatment. Methods:At the age of 4 weeks, adult Otof-/- mice received an inner ear injection of a therapeutic agent containing intein-mediated recombination of the OTOF gene, delivered via dual AAV vectors through the round window membrane（RWM）. Immunofluorescence staining assessed the proportion of inner ear hair cells with restored otoferlin expression and the number of synapses.Statistical analysis was performed to compare the DPOAE and ABR thresholds before and after the treatment. Results:AAV-PHP. eB demonstrates high transduction efficiency in inner ear hair cells. The therapeutic regimen corrected hearing loss in adult Otof-/- mice without impacting auditory function in wild-type mice. The changes in DPOAE and ABR thresholds after gene therapy are significantly correlated at 16 kHz. Post-treatment,a slight increase in DPOAE was observeds,followed by a recovery trend at 2 months post-treatment. Conclusion:Gene therapy significantly restored hearing in adult Otof-/- mice, though the surgical delivery may cause transient hearing damage. Precise and gentle surgical techniques are essential to maximize gene therapy's efficacy.

Analysis of predictive factors related to long-term hearing and temporal bone development in congenital microtia.

OBJECTIVE: To investigate the predictive factors of long-term hearing threshold and temporal bone development in children with congenital microtia (CM). METHODS: 74 patients (92 ears) with CM enrolled, which all had auditory brainstem response (ABR) results during infancy or toddlerhood, pure tone audiometry (PTA) and high-resolution computed tomography (HRCT) results during childhood or adolescence, and had not undergone any surgery. We compared the relationship between ABR, auditory steady-state response (ASSR), the affected side, auricular morphology, presence of external auditory canal stenosis or atresia, PTA average, mastoid pneumatization, Jarhsdoerfer scores, and wether cholesteatoma exists. RESULTS: The average age of ABR in 92 ears was 2.72 ± 3.52 years old, PTA was 7.26 ± 2.51 and HRCT was 6.91 ± 2.76 years old. ABR-AC was related to PTA average, mastoid pneumatization, Jarhsdoerfer scores, and wether cholesteatoma exists in CM. While ABR-ABG was related to all of these factors except Jarhsdoerfer score, and ABR-BC had no relationship with any of them. ASSR only showed correlation with frequencies of 1, 2 kHz and was related to Jarhsdoerfer score, with no other correlations observed. The impaired ear side showed no relevance. However, auricular morphology was related to all of these factors except wether cholesteatoma exist. External auditory canal stenosis or atresia was related to PTA average, but unrelated to mastoid pneumatization. CONCLUSION: The ABR examination in the infant stage plays a crucial role in predicting the long-term hearing and temporal bone development in patients with CM.

Preoperative EABR evaluation of auditory pathway integrity in patients with different etiology and postoperative effect estimation.

OBJECTIVES: To evaluate the effect of electrical auditory brainstem response (EABR) on the integrity evaluation of auditory pathway and the prediction of postoperative effect of cochlear implantation in patients with different etiology of hearing loss. METHODS: A total of 580 patients with neuropathic deafness who underwent cochlear implantation surgery from August 2011 to December 2020 were selected for EABR test. The preoperative EABR waveform was analyzed, and parameters such as V wave amplitude, threshold, latency and interval of each wave, and slope of V wave I/O curve were measured. Neural response telemetry (NRT) test was performed during MAP 1 month after operation, and C and T values of the machine were recorded. RESULTS: The total EABR extraction rate was 98.45% among 580 patients, including 100% for the normal structure group and enlarged vestibular aqueduct group (LVAS), 92.44% for other malformed group. The average threshold of V wave in patients with normal cochlear structure was significantly better than the malformation groups (p < 0.05). The total extraction rate of NRT was 78.62%, including 99.72% in the group with normal structure, 95.65% in the LVAS group, 1.85-88.24% in the group with other malformations, and 0% in the cochlear ossification group. The correlation analysis showed a statistically significant correlation between the average preoperative EABR threshold and the C value of NRT. CONCLUSIONS: Preoperative EABR could evaluate the integrity of auditory conduction pathway of patients with cochlear implantation and predict the postoperative hearing rehabilitation effect.

Preserved Auditory Steady State Response and Envelope-Following Response in Severe Brainstem Dysfunction Highlight the Need for Cross-Checking.

OBJECTIVES: Commercially available auditory steady state response (ASSR) systems are widely used to obtain hearing thresholds in the pediatric population objectively. Children are often examined during natural or induced sleep so that the recorded ASSRs are of subcortical origin, the inferior colliculus being often designated as the main ASSR contributor in these conditions. This report presents data from a battery of auditory neurophysiological objective tests obtained in 3 cases of severe brainstem dysfunction in sleeping children. In addition to ASSRs, envelope-following response (EFR) recordings designed to distinguish peripheral (cochlear nerve) from central (brainstem) were recorded to document the effect of brainstem dysfunction on the two types of phase-locked responses. DESIGN: Results obtained in the 3 children with severe brainstem dysfunctions were compared with those of age-matched controls. The cases were identified as posterior fossa tumor, undiagnosed (UD), and Pelizaeus-Merzbacher-Like Disease. The standard audiological objective tests comprised tympanograms, distortion product otoacoustic emissions, click-evoked auditory brainstem responses (ABRs), and ASSRs. EFRs were recorded using horizontal (EFR-H) and vertical (EFR-V) channels and a stimulus phase rotation technique allowing isolation of the EFR waveforms in the time domain to obtain direct latency measurements. RESULTS: The brainstem dysfunctions of the 3 children were revealed as abnormal (weak, absent, or delayed) ABRs central waves with a normal wave I. In addition, they all presented a summating and cochlear microphonic potential in their ABRs, coupled with a normal wave I, which implies normal cochlear and cochlear nerve function. EFR-H and EFR-V waveforms were identified in the two cases in whom they were recorded. The EFR-Hs onset latencies, response durations, and phase-locking values did not differ from their respective age-matched control values, indicating normal cochlear nerve EFRs. In contrast, the EFR-V phase-locking value and onset latency varied from their control values. Both patients had abnormal but identifiable and significantly phase-locked brainstem EFRs, even in a case with severely distorted ABR central waves. ASSR objective audiograms were recorded in two cases. They showed normal or slightly elevated (explained by a slight transmission loss) thresholds that do not yield any clue about their brainstem dysfunction, revealing the method's lack of sensitivity to severe brainstem dysfunction. CONCLUSIONS: The present study, performed on 3 sleeping children with severe brainstem dysfunction but normal cochlear responses (cochlear microphonic potential, summating potential, and ABR wave I), revealed the differential sensitivity of three auditory electrophysiological techniques. Estimated thresholds obtained by standard ASSR recordings (cases UD and Pelizaeus-Merzbacher-Like Disease) provided no clue to the brainstem dysfunction clearly revealed by the click-evoked ABR. EFR recordings (cases posterior fossa tumor and UD) showed preserved central responses with abnormal latencies and low phase-locking values, whereas the peripheral EFR attributed to the cochlear nerve was normal. The one case (UD) for which the three techniques could be performed confirms this sensitivity gradient, emphasizing the need for applying the Cross-Check Principle by avoiding resorting to ASSR recording alone. The entirely normal EFR-H recordings observed in two cases further strengthen the hypothesis of its cochlear nerve origin in sleeping children.

Neonatal hearing screening - does failure in TEOAE screening matter when the AABR test is passed?

PURPOSE: Newborns who fail the transient evoked otoacoustic emissions (TEOAE) but pass the automatic auditory brainstem response (AABR) in universal newborn hearing screening (UNHS), frequently have no further diagnostic test or follow-up. The present study aimed to investigate whether hearing loss might be missed by ignoring neonatal TEOAE failure in the presence of normal AABR. METHODS: A retrospective analysis was conducted in newborns presenting between 2017 and 2021 to a tertiary referral centre due to failure in the initial UNHS. The main focus was on infants who failed TEOAE tests, but passed AABR screening. The clinical characteristics and audiometric outcomes were analysed and compared with those of other neonates. RESULTS: Among 1,095 referred newborns, 253 (23%) failed TEOAE despite passing AABR screening. Of the 253 affected infants, 154 returned for follow-up. At 1-year follow-up, 46 (28%) achieved normal audiometric results. 32 (21%) infants had permanent hearing loss (HL) confirmed by diagnostic ABR, 58 (38%) infants had HL solely due to middle ear effusion (MEE), and for 18 (12%) infants HL was suspected without further differentiation. The majority of permanent HL was mild (78% mild vs. 13% moderate vs. 9% profound). The rate of spontaneous MEE clearance was rather low (29%) leading to early surgical intervention in 36 children. The profile of the risk factors for hearing impairment was similar to that of newborns with failure in both, TEOAE and AABR; however, there was a stronger association between the presence of risk factors and the incidence of HL (relative risk 1.55 vs. 1.06; odds ratio 3.61 vs. 1.80). CONCLUSION: In newborns, the discordance between a "refer" in TEOAE and a "pass" in AABR screening is associated with a substantial prevalence of hearing impairment at follow-up, especially in the presence of risk factors.

Relationships between bilateral auditory brainstem activity and inter-implant interval in children with cochlear implants.

PURPOSE: To investigate the effect of the interval between bilateral cochlear implantation on the development of bilateral peripheral auditory pathways as revealed by the electrically evoked auditory brainstem response (EABR). METHODS: Fifty-eight children with profound bilateral sensorineural hearing loss were recruited. Among them, 33 children received sequential bilateral cochlear implants (CIs), and 25 children received simultaneous bilateral CIs. The bilateral EABRs evoked by electrical stimulation from the CI electrode were recorded on the day of second-side CI activation. RESULTS: The latencies of wave III (eIII) and wave V (eV) were significantly shorter on the first CI side than on the second CI side in children with sequential bilateral CIs but were similar between the two sides in children with simultaneous bilateral CIs. Furthermore, the latencies were prolonged from apical to basal channels along the cochlea in the two groups. In children with sequential CIs, the inter-implant interval was negatively correlated with the eV latency on the first CI side and was positively correlated with bilateral differences in the eIII and eV latencies. CONCLUSIONS: Unilateral CI use promotes the maturation of ipsilateral auditory conduction function. However, a longer inter-implant interval results in more unbalanced development of bilateral auditory brainstem pathways. Bilateral cochlear implantation with no or a short interval is recommended.

Efficacy and safety of chloral hydrate in auditory brainstem response test: A systematic review and single-arm meta-analysis.

OBJECTIVES: To evaluate the safety and efficacy of chloral hydrate in auditory brainstem response (ABR) tests. SETTING AND DESIGN: In this study, the authors systematically searched both English (Embase, PubMed, and Web of Science) and Chinese (Chinese National Knowledge Infrastructure, Wanfang Data, and VIP Chinese Science) databases. Two authors independently performed data extraction and quality assessment. The pooled sedation failure rate and the pooled incidence of adverse events were calculated via a random-effects model. Sensitivity and subgroup analyses were performed to explore the sources of heterogeneity, and the PRISMA guideline was followed. PARTICIPANTS: Patients with ABR tests receiving chloral hydrate sedation. MAIN OUTCOME MEASURES: The pooled sedation failure rate and the pooled incidence of adverse events. RESULTS: A total of 23 clinical studies were included in the final analysis. The pooled sedation failure rate of patients who received chloral hydrate sedation before ABR examination was 10.0% [95% confidence interval (CI) (6.7%, 15.0%), I2 = 95%, p < .01]. There were significant differences in the prevalence of sedation failure between sample sizes greater than 200 and those less than or equal to 200 (5.6% vs. 19.6%, p < .01) and between the studies that reported sleep deprivation and those that did not report sleep deprivation (7.1% vs. 18.9%, p < .01). The pooled incidence of adverse events was 10.32% [95% CI (5.83%, 14.82%), I2 = 98.1%, p < .01]. CONCLUSIONS: Chloral hydrate has a high rate of sedation failure, adverse events, and potential carcinogenicity. Therefore, replacing its use in ABR tests with safer and more effective sedatives is warranted.

Potenciales evocados auditivos de tronco en neonatos nacidos a gran altitud / Brainstem auditory evoked potentials in newborn infants born in a high-altitude area

Introducción. Una forma no invasiva y segura de evaluar los parámetros neurofisiológicos en recién nacidos es la evaluación de los potenciales evocados auditivos del tronco encefálico (PEAT). Objetivo. Evaluar las latencias e intervalos de ondas de los PEAT en neonatos sanos nacidos a gran altitud (Cusco, 3399 msnm). Población y métodos. Estudio transversal y prospectivo. Se incluyeron neonatos menores a 14 días de vida, dados de alta a menos de 7 días de nacidos, evaluados para determinar los valores de los PEAT a intensidades sonoras de 70 dB, 80 dB y 90 dB. Se incluyeron las variables edad gestacional, peso al nacer, tipo de parto. Se calcularon las diferencias de las medianas de las latencias e intervalos de las ondas según edad gestacional y peso al nacer. Resultados. Se evaluaron 96 neonatos (17 pretérminos). Las medianas de las latencias de las ondas I a V a 90 dB fueron las siguientes: onda I 1,56 ms; onda II 2,74 ms; onda III 4,37 ms; onda IV 5,62 ms, onda V 6,63 ms. La latencia de la onda I para 80 dB fue de 1,71 ms y para 70 dB de 1,88 ms. Los intervalos para las ondas (I-III), (III-V) y (I-V) fueron de 2,8 ms, 2,2 ms y 5,0 ms respectivamente, sin diferencias entre intensidades (p >0,05). La prematuridad y el bajo peso estuvieron asociados a latencias de la onda I más prolongadas (p <0,05). Conclusiones. Se presentan valores ajustados de latencias e intervalos de los PEAT en neonatos nacidos a gran altitud. Se identificó que, a distintas intensidades sonoras, se ven diferencias en las latencias de las ondas, pero no en los intervalos entre ondas.

Introduction. A non-invasive and safe way to assess neurophysiological parameters in newborn infants is the evaluation of brainstem auditory evoked potentials (BAEPs). Objective. To assess the latencies and wave intervals of BAEPs in healthy newborn infants born in a high-altitude area (Cusco, 3399 MASL). Population and methods. Cross-sectional and prospective study. Newborn infants younger than 14 days of age, discharged less than 7 days after birth, were assessed to determine BAEP values at intensities of 70 dB, 80 dB, and 90 dB. The study variables were gestational age, birth weight, and type of delivery. The median differences in wave latencies and intervals were estimated according to gestational age and birth weight. Results. A total of 96 newborn infants (17 preterm infants) were assessed. The median latencies of waves I­V at 90 dB were for wave I: 1.56 ms, wave II: 2,74 ms, wave III: 4.37 ms, wave IV: 5.62 ms, and wave V: 6.63 ms. The latency of wave I for 80 dB was 1.71 ms and for 70 dB, 1.88 ms. Wave intervals (I­III, III­V, I­V) were 2.8 ms, 2.2 ms, and 5.0 ms, respectively, without differences among intensities (p > 0.05). Prematurity and low birth weight were associated with a longer wave I latency (p < 0.05). Conclusions. Here we describe adjusted BAEP latency and interval values for newborn infants born at high altitude. At different sound intensities, we identified differences in wave latencies, but not in interwave intervals.

Utilização do Potencial Auditivo de Estado Estável em lactentes com baixo risco para perda auditiva / Use of Auditory Steady State Response in infants at low risk for hearing loss / Uso del potencial auditivo de estado estacionario en bebés con bajo riesgo de pérdida auditiva

Introdução: Com base na necessidade do diagnóstico audiológico e da intervenção precoce na vida de uma criança com perda auditiva, faz-se necessário a elaboração de protocolos de avaliação auditiva que forneçam o maior número de informações. Objetivo: Analisar um programa de saúde auditiva infantil com relação à adesão à triagem auditiva e procedimentos de diagnóstico. Metodologia: Pesquisa de caráter transversal com análise quantitativa. Realizado em três etapas: 1ª etapa: triagem auditiva de neonatos de alojamento conjunto; 2ª etapa: reteste das falhas; 3ª etapa: diagnóstico audiológico dos lactentes que falharam nas etapas anteriores com a utilização do Potencial Evocado Auditivo de Estado Estável (PEAEE) em conjunto com o Potencial Evocado Auditivo de Tronco Encefálico (PEATE). Resultados: Em 2019, 1.898 neonatos foram triados e destes, 287 (15.2%) falharam na primeira testagem em pelo menos uma orelha. Um total de 197 (10.3%) foram retestados e 14 (0,73%) falharam em pelo menos uma orelha. Dez (0,52%) neonatos retornaram para diagnóstico compondo uma amostra homogênea de neonatos nascidos a termo. Um neonato apresentou perda auditiva unilateral. O tempo necessário para coleta de dados no PEAEE foi de 20 minutos. Conclusão: O PEAEE pode ser considerado uma alternativa a ser utilizado na bateria de testes na avaliação audiológica infantil, juntamente com outros procedimentos, utilizando-se do princípio de verificação cruzada e adicionando uma informação valiosa, especialmente com relação às baixas frequências. (AU)

Introduction: Based on the need for audiological diagnosis and intervention as soon as possible in the life of a child with hearing loss, it is necessary to elaborate of hearing evaluation protocols with high efficiency, which provide the greatest amount of information. Aim: To analyze a pediatric hearing health program regarding their adherence to hearing screening, failure rates, and diagnostic procedures. Method: This is a cross-sectional, descriptive, quantitative study, and consisted of tree stages: Performed in three steps: 1st step: hearing screening of rooming-in neonates; 2nd stage: retest of failures; 3rd stage: audiological diagnosis of infants who failed in the previous stages using the Steady State Response (ASSR) together with the Brainstem Evoked Response Audiometry (BERA). Results: In 2019, 1,898 infants were submitted to the program, of whom 287 (15.2%) failed the screening in at least one of the ears. A total of 197 (10.3%) infants attended the retest and 14 (0.73%) failed the TOAE in at least one of the ears. Ten (0.52%) infants returned for diagnosis. The sample was homogeneously full-term children. One child showed unilateral HL. The average amount of time required to collect information in the ASSR was 20 minutes. Conclusion: For diagnosis, ASSR can be an alternative to be used in the battery of examinations in pediatric hearing assessment along with the other procedures, using the cross-check principle and adding valuable information, especially regarding the low frequencies. (AU)

Introducción: En base a la necesidad de diagnóstico audiológico e intervención lo antes posibles en la vida de un niño con pérdida auditiva, es necesario elaborar protocolos de evaluación auditiva de alta eficiencia, que proporcionan la mayor cantidad de información. Objetivo: Analizar un programa de salud auditiva infantil en cuanto a la adherencia al tamizaje auditivo, tasa de fracaso y procedimientos diagnósticos. Metodología: Investigación transversal con análisis cuantitativo, Realizado en tres pasos: 1er paso: tamizaje auditivo de los neonatos en alojamiento conjunto; 2ª etapa: retest de fallas; 3ª etapa: diagnóstico audiológico de los lactantes que fracasaron en las etapas anteriores utilizando el Potencial Evocado Auditivo de Estado Estacionario junto con el Potencial Evocado Auditivo de Tallo Cerebral. Resultados: Em 2019, se cribaron 1,898 neonatos y de estos, 287 (15,2%) no pasaron la primera prueba en al menos un oído. Un total de 197 (10,3) fueron reevaluados y 14 (0,73%) fallaron en al menos un oído. Diez (0,52%) neonatos regresaron para diagnóstico, conformando una muestra homogénea de neonatos a término, con una edad gestacional media de 39 semanas y dos días. Un neonato tuvo pérdida auditiva unilateral. El tiempo de recogida de los resultados en el ASSR fue de 20 min. Conclusión: Para el diagnóstico, la ASSR puede considerarse una alternativa para ser utilizada en la batería de pruebas en la evaluación audiológica infantil, junto con otros procedimientos, utilizando el principio de verificación cruzada y agregando información valiosa, especialmente en lo que se refiere a las bajas frecuencia. (AU)

Occurrence of changes in the auditory evoked potentials of smokers: systematic review of the literature. / Ocorrência de alterações nos potenciais evocados auditivos de fumantes: revisão sistemática da literatura.

PURPOSE: To verify the occurrence of abnormal auditory evoked potentials (AEP) tests in adult smokers. RESEARCH STRATEGIES: Systematic review of the literature according to the PRISMA guidelines, to answer the question: "Are there any changes in the AEP results in adult smokers?", PECOS strategy. Research carried out on PubMed, Embase, CINAHL, LIVIVO, Scopus, Web of Science, LILACS and Scielo databases. Additional search of gray literature: Google Scholar and ProQuest hand searching of reference lists of the included studies. SELECTION CRITERIA: Cross-sectional studies were selected, without restriction on the year of publication and language. DATA ANALYSIS: First, the titles and abstracts of all the studies were analyzed, followed by the full reading of the eligible studies. RESULTS: 898 articles were collected, after the duplicate studies were removed and after blind analysis by three researchers, 8 studies of the observational type were selected. Most studies have found an association between active smoking and changes in electrophysiological tests. CONCLUSION: Normal hearing adult smokers present alterations in short and long AEP. In the auditory brainstem response, the main altered components were the increase in waves latencies of I and III and in the interpeaks I - III and III - V, as well as a decrease in the amplitude of the waves. In Mismatch Negativity, there was a significant increase in wave amplitude and latency. In the long latency potential, P300, there was an increase in latencies and decreased amplitudes in the components N1 (in Fz) and P3.

OBJETIVO: Verificar a ocorrência de alterações nos exames de potencial evocado (PEA) auditivo em adultos fumantes normo-ouvintes. ESTRATÉGIA DE PESQUISA: Revisão sistemática da literatura de acordo com recomendações do PRISMA, buscando responder à pergunta: "Há alterações nos resultados do exame de PEA em adultos fumantes?", estratégia PECOS. Pesquisa realizada nas bases de dados PubMed, Embase, CINAHL, LIVIVO, Scopus, Web of Science, LILACS e Scielo. Busca adicional da literatura cinzenta: Google Scholar e ProQuest e busca manual das referências dos estudos incluídos. CRITÉRIOS DE SELEçÃO: Foram selecionados estudos com delineamento transversal, sem restrição do ano de publicação e idioma. ANÁLISE DOS DADOS: Primeiramente foram analisados os títulos e resumos de todos os estudos encontrados, seguido da leitura na íntegra dos estudos elegíveis. RESULTADOS: Foram obtidos 898 artigos, que após remoção dos duplicados e análise cega por três pesquisadores, foram selecionados oito trabalhos. Grande parte dos estudos encontrou uma associação entre tabagismo ativo e alterações nos testes eletrofisiológicos. CONCLUSÃO: Adultos fumantes normo-ouvintes apresentam alterações nos exames de PEA de curta e longa latência. No potencial evocado auditivo de tronco encefálico, os principais componentes alterados foram o aumento das latências das ondas I e III e nos interpicos I - III e III - V, bem como diminuição da amplitude das ondas. No Mismatch Negativity, houve aumento significativo da amplitude da onda e da latência. No potencial de longa latência, P300, houve aumento das latências e redução das amplitudes nos componentes N1 (em Fz) e P3.

A longitudinal study of the peripheral and central auditory pathways in individuals with acute lymphoid leukemia.

OBJECTIVE: To characterize the peripheral and central auditory pathways in individuals with Acute Lymphoid Leukemia (ALL) and compare assessment results before and during chemotherapy. METHOD: The study included 17 subjects with ALL, divided into two age groups: 3 to 6 (11 individuals) and 7 to 16 years old (6 individuals). Each subject was evaluated twice (before and 3 to 6 months after chemotherapy treatment) with the following procedures: medical history survey, otoscopy, Pure-Tone Threshold (PTA) and speech audiometry, acoustic immittance measures, Brainstem Auditory Evoked Potentials (BAEP) and Long-Latency Auditory Evoked Potentials (LLAEP). RESULTS: PTA was normal. Tympanometry was abnormal in the second assessment in 2 individuals aged 3 to 6 years. One subject in each age group had absent ipsilateral acoustic reflexes. In high-frequency audiometry, 1 individual had abnormal results. BAEP was abnormal in 5 (first assessment) and 7 individuals (second assessment) aged 3 to 6 years and 2 (first assessment) and 1 individual (second assessment) aged 7 to 16 years. As for LLAEP, P1 latency was increased in 5 (first assessment) and 7 individuals (second assessment) aged 3 to 6 years. CONCLUSION: No hearing loss was identified in the behavioral audiological assessment. BAEP was more affected in the 3-to-6-year-old group, with greater impairment in the lower brainstem in the first and second assessments. In LLAEP, P1 was the most impaired component in children aged 3 to 6 years, and P2 and N2 were so for those 7 to 16 years old, especially in the second assessment.

[Preliminary application of combined auditory monitoring technique in resection of vestibular neurinoma].

Objective: To explore the value of electrically evoked auditory brainstem response (EABR) monitoring combined with brainstem auditory evoked potential (BAEP) and compound action potential (CAP) monitoring during vestibular schwannoma resection for the protection of the cochlear nerve. Methods: Clinical data from 12 patients with vestibular schwannomas who had useful hearing prior to surgery were analyzed at the PLA General Hospital from January to December 2021. Among them, there were 7 males and 5 females, ranging in age from 25 to 59 years. Before surgery, patients underwent audiology assessments (including pure tone audiometry, speech recognition rate, etc.), facial nerve function evaluation, and cranial MRI. They then underwent vestibular schwannoma resection via the retrosigmoid approach. EABR, BAEP, and CAP were simultaneously monitored during surgery, and patients' hearing preservation was observed and analyzed after surgery. Results: Prior to surgery, the average PTA threshold of the 12 patients ranged from11 to 49 dBHL, with a SDS of 80% to 100%. Six patients had grade A hearing, and six patients had grade B hearing. All 12 patients had House-Brackman grade I facial nerve function prior to surgery. The MRI indicated tumor diameters between 1.1 and 2.4 cm. Complete removal was achieved in 10/12 patients, while near-total removal was achieved in 2/12 patients. There were no serious complications at the one-month follow-up after surgery. At the three-month follow-up, all 12 patients had House-Brackman grade I or II facial nerve function. Under EABR with CAP and BAEP monitoring, successful preservation of the cochlear nerve was achieved in six of ten patients (2 with grade B hearing, 3 with grade C hearing, and 1 with grade D hearing). Successful preservation of the cochlear nerve was not achieved in another four patients (all with grade D hearing). In two patients, EABR monitoring was unsuccessful due to interference signals; however, Grade C or higher hearing was successfully preserved under BAEP and CAP monitoring. Conclusion: The application of EABR monitoring combined with BAEP and CAP monitoring during vestibular schwannoma resection can help improve postoperative preservation of the cochlear nerve and hearing.

[Auditory Brainstem Response: ABR].

Intraoperative auditory brainstem response(ABR)monitoring has been established as a reliable method to evaluate cochlear function. Intraoperative ABR is mandatory in microvascular decompression for hemifacial spasm, trigeminal neuralgia, and glossopharyngeal neuralgia. Cerebellopontine tumor with remaining effective hearing function also requires ABR monitoring during surgery to preserve hearing function. Prolonged latency and subsequent amplitude decrease in the ABR wave V predicts postoperative hearing impairment. Therefore, when alerted to an intraoperative ABR during surgery, the surgeon should release the cerebellar retraction stressing the cochlear nerve and wait for the abnormal ABR to recover.

Middle Ear Muscle Reflex in Normal-Hearing Individuals with Occupational Noise Exposure.

Objectives: Noise-induced cochlear synaptopathy is studied extensively in animal models. The diagnosis of synaptopathy in humans is challenging and the roles of many noninvasive measures in identifying synaptopathy are being explored. The acoustic middle ear muscle reflex (MEMR) can be considered as a vital tool since noise exposure affects the low-spontaneous rate fibers that play an important role in elicitation of MEMR. The present study aimed at measuring MEMR threshold and MEMR strength. Design: The study participants were divided into two groups. All the participants had normal-hearing thresholds. The control group consisted of 25 individuals with no occupational noise exposure whereas noise exposure group had 25 individuals who were exposed to occupational noise of 85 dBA for a minimum period of 1 year. MEMR threshold and strength was assessed for pure tones (500 Hz and 1000 Hz) and broadband noise. Results: The results showed that the MEMR threshold was similar in both the groups. MEMR strength was reduced in noise exposure group compared to control group. Conclusions: The results of the study suggest that MEMR strength could be used as a sensitive measure in identifying cochlear synaptopathy with careful consideration of the stimulus characteristics.

Using a Facial Nerve Stimulator to Record the Auditory Nerve Compound Action Potential to Locate the Auditory Nerve During Vestibular Schwannoma Resection.

BACKGROUND: Improved technology in vestibular neuroma resection and facial nerve protection has become more sophisticated, and the protection of hearing during vestibular schwannoma resection is crucial. Currently, brainstem auditory evoked potential (BAEP), cochlear electrography, and cochlear nerve compound action potential (CNAP) are frequently used. The CNAP waveform is stable; however, the recording electrode can easily affect the procedure and cannot map the auditory nerve. The purpose of the study was to explore a simple method to record the CNAP and map the auditory nerve. METHODS: In this study, CNAP was recorded using a facial nerve bipolar stimulator to localize and protect the auditory nerve. The BAEP click stimulation mode was used. A bipolar stimulator was used as the recording electrode to record CNAP and locate anatomical displacement of the auditory nerve. The CNAP of 40 patients was monitored. Pure tone audiometry, speech discrimination score, and auditory evoked potential (BAEP) evaluations were performed on all patients before and after surgery. RESULTS: Of the 40 patients, 30 patients obtained CNAP during surgery, and the rate of CNAP obtained was significantly higher than that of BAEP. The sensitivity and specificity of decrease in CNAP in predicting significant hearing loss were 88.9% and 66.7%, respectively. The sensitivity and specificity of the disappearance of CNAP in predicting significant hearing loss were 52.9% and 92.3%, respectively. CONCLUSIONS: The bipolar facial nerve stimulator can locate and protect the auditory nerve by recording a stable potential. The CNAP obtained rate was significantly higher than that of BAEP. The disappearance of BAEP during acoustic neuroma monitoring can be used as a standard alert for the surgeon, and decrease in CNAP is an alert for the operator.

Acoustically Evoked Compound Action Potentials Recorded From Cochlear Implant Users With Preserved Acoustic Hearing.

OBJECTIVES: Less traumatic intracochlear electrode design and the introduction of the soft surgery technique allow for the preservation of low-frequency acoustic hearing in many cochlear implant (CI) users. Recently, new electrophysiologic methods have also been developed that allow acoustically evoked peripheral responses to be measured in vivo from an intracochlear electrode. These recordings provide clues to the status of peripheral auditory structures. Unfortunately, responses generated from the auditory nerve (auditory nerve neurophonic [ANN]) are somewhat difficult to record because they are smaller than the hair cell responses (cochlear microphonic). Additionally, it is difficult to completely segregate the ANN from the cochlear microphonic, complicating the interpretation and limiting clinical applications. The compound action potential (CAP) is a synchronous response of multiple auditory nerve fibers and may provide an alternative to ANN where the status of the auditory nerve is of primary interest. This study is a within-subject comparison of CAPs recorded using traditional stimuli (clicks and 500 Hz tone bursts) and a new stimulus (CAP chirp). We hypothesized that the chirp stimulus might result in a more robust CAP than that recorded using traditional stimuli, allowing for a more accurate assessment of the status of the auditory nerve. DESIGN: Nineteen adult Nucleus L24 Hybrid CI users with residual low-frequency hearing participated in this study. CAP responses were recorded from the most apical intracochlear electrode using a 100 µs click, 500 Hz tone bursts, and chirp stimuli presented via the insert phone to the implanted ear. The chirp stimulus used in this study was CAP chirp generated using parameters from human-derived band CAPs ( Chertoff et al. 2010 ). Additionally, nine custom chirps were created by systematically varying the frequency sweep rate of the power function used to construct the standard CAP chirp stimulus. CAPs were recorded using all acoustic stimuli, allowing for within-subject comparisons of the CAP amplitude, threshold, percentage of measurable CAP responses, and waveform morphology. RESULTS: Considerable variation in response morphology was apparent across stimuli and stimulation levels. Clicks and CAP chirp significantly evoked identifiable CAP response more compared to 500 Hz tone bursts. At relatively high stimulation levels, the chirp-evoked CAPs were significantly larger in amplitude and less ambiguous in morphology than the click-evoked CAPs. The status of residual acoustic hearing at high frequencies influenced the likelihood that a CAP could be reliably recorded. Subjects with better preserved hearing at high frequencies had significantly larger CAP amplitudes when CAP chirp was used. Customizing the chirp stimulus by varying the frequency sweep rates significantly affected the CAP amplitudes; however, pairwise comparisons did not show significant differences between chirps. CONCLUSIONS: CAPs can be measured more effectively using broadband acoustic stimuli than 500 Hz tone bursts in CI users with residual low-frequency acoustic hearing. The advantage of using CAP chirp stimulus relative to standard clicks is dependent on the extent of preserved acoustic hearing at high frequencies and the stimulus level. The chirp stimulus may present an attractive alternative to standard clicks or tone bursts for this CI population when the goal is to record robust CAP responses.