Influence of obstructive sleep apnea on auditory event-related potentials.

PURPOSE: To evaluate the influence of obstructive sleep apnea (OSA) on the P300 response of auditory event-related potentials (ERPs) and to correlate the electrophysiological findings with OSA severity. METHODS: Patients with no OSA and mild, moderate, and severe OSA according to polysomnography (PSG) with normal hearing and no comorbidities were studied. Individuals with a body mass index (BMI) ≥ 40 kg/m2, hypertension, diabetes, dyslipidemia, the use of chronic medications, and a risk of hearing loss were excluded. All patients underwent full PSG and auditory ERP measurement using the oddball paradigm with tone burst and speech stimuli. For P300 analysis (latencies and amplitudes), normal multiple linear regression models were adjusted with the groups (No OSA, Mild OSA, Moderate OSA, Severe OSA), age, BMI, and Epworth score as explanatory variables. RESULTS: We studied 54 individuals (47 males) aged 35 ± 8 years with a BMI of 28.4 ± 4.3 kg/m2. Patients were divided according to the apnea-hypopnea index (AHI) derived from PSG into no OSA (n = 14), mild (n = 16), moderate (n = 12), and severe OSA (n = 12) groups. Patients with severe OSA presented prolonged P300 latencies with tone burst stimuli compared to patients with no OSA and those with mild and moderate OSA. CONCLUSION: Severe OSA is associated with impairment of the P300 response of auditory ERPs, suggesting a decrease in the processing speed of acoustic information that may be mediated by the level of somnolence.

Brainstem Auditory Evoked Potential in HIV-Positive Adults.

BACKGROUND: To characterize the findings of brainstem auditory evoked potential in HIV-positive individuals exposed and not exposed to antiretroviral treatment. MATERIAL AND METHODS: This research was a cross-sectional, observational, and descriptive study. Forty-five HIV-positive individuals (18 not exposed and 27 exposed to the antiretroviral treatment - research groups I and II, respectively - and 30 control group individuals) were assessed through brainstem auditory evoked potential. RESULTS: There were no significant between-group differences regarding wave latencies. A higher percentage of altered brainstem auditory evoked potential was observed in the HIV-positive groups when compared to the control group. The most common alteration was in the low brainstem. CONCLUSIONS: HIV-positive individuals have a higher percentage of altered brainstem auditory evoked potential that suggests central auditory pathway impairment when compared to HIV-negative individuals. There was no significant difference between individuals exposed and not exposed to antiretroviral treatment.

Brainstem auditory evoked potentials in children with autism spectrum disorder.

OBJECTIVES: This study aimed to analyze the neural encoding of verbal and nonverbal stimuli in individuals with autism spectrum disorder using brainstem auditory evoked potentials. METHODOLOGY: Thirty individuals between 7 and 12 years of age and of both genders participated in this study. Fifteen were diagnosed with autism spectrum disorder, and 15 had typical development. All subjects had normal hearing and no other impairments. An electrophysiological hearing assessment was performed using brainstem auditory evoked potentials with click and speech stimuli. RESULTS: In the brainstem auditory evoked potentials with click stimuli, the mean wave I latency was longer for the right ear in both groups, and interpeak intervals III-V were greater for the individuals with autism spectrum disorder. For brainstem auditory evoked potentials with speech stimuli, wave V latency was shorter in individuals with autism spectrum disorder. CONCLUSION: These data suggest that individuals with autism spectrum disorder may have a dysfunction of the central auditory nervous system for nonverbal stimuli and faster neural encoding of the initial part of the verbal stimulus, suggesting hypersensitivity to complex sounds such as speech.

Audiologic and electrophysiologic evaluation in children with psychiatric disorders.

UNLABELLED: Individuals with psychiatric disorders can present perception, attention and memory deficits, raising doubts about peripheral and/or central hearing loss. Thus, the aim of this study is to describe the audiological and electrophysiological results of individuals with psychiatric disorders, looking for peripheral and/or central auditory disorders. METHODS: 20 individuals with autism and Asperger syndrome and 20 individuals without psychiatric disorders from eight to 19 years of age, were submitted to audiological and electrophysiological evaluation. RESULTS: No alterations were observed on the audiological evaluation in all the individuals. In ABR, 50% of individuals with autism and 30% with Asperger syndrome presented alterations. Significant statistical differences were observed between the groups in the quantitative analysis. All groups presented alterations in AMLR and P300. In AMLR, no significant statistical differences were observed between the groups in the qualitative and quantitative analyses. In the P300, we noticed significant statistical differences between Asperger and control groups in the quantitative analysis. CONCLUSIONS: A high occurrence of alterations in auditory evoked potentials was seen in children with psychiatric disorders, although in some analysis it was observed a non-statistically significant difference when comparing study and control groups. We stress the need for a more careful investigation of the auditory function in this population.

Audiological and electrophysiological alterations in HIV-infected individuals subjected or not to antiretroviral therapy.

INTRODUCTION: The Human Immunodeficiency Virus (HIV) and infections related to it can affect multiple sites in the hearing system. The use of High Activity Anti-Retroviral Therapy (HAART) can cause side effects such as ototoxicity. Thus, no consistent patterns of hearing impairment in adults with Human Immunodeficiency Virus / Acquired Immune Deficiency Syndrome have been established, and the problems that affect the hearing system of this population warrant further research. OBJECTIVES: This study aimed to compare the audiological and electrophysiological data of Human Immunodeficiency Virus-positive patients with and without Acquired Immune Deficiency Syndrome, who were receiving High Activity Anti-Retroviral Therapy, to healthy individuals. METHODS: It was a cross-sectional study conducted with 71 subjects (30-48 years old), divided into groups: Research Group I: 16 Human Immunodeficiency Virus-positive individuals without Acquired Immunodeficiency Syndrome (not receiving antiretroviral treatment); Research Group II: 25 Human Immunodeficiency Virus-positive individuals with Acquired Immunodeficiency Syndrome (receiving antiretroviral treatment); Control Group: 30 healthy subjects. All individuals were tested by pure-tone air conduction thresholds at 0.25-8kHz, extended high frequencies at 9-20kHz, electrophysiological tests (Auditory Brainstem Response, Middle Latency Responses, Cognitive Potential). RESULTS: Research Group I and Research Group II had higher hearing thresholds in both conventional and high frequency audiometry when compared to the control group, prolonged latency of waves I, III, V and interpeak I-V in Auditory Brainstem Response and prolonged latency of P300 Cognitive Potential. Regarding Middle Latency Responses, there was a decrease in the amplitude of the Pa wave of Research Group II compared to the Research Group I. CONCLUSIONS: Both groups with Human Immunodeficiency Virus had higher hearing thresholds when compared to healthy individuals (group exposed to antiretroviral treatment showed the worst hearing threshold) and seemed to have lower neuroelectric transmission speed along the auditory pathway in the brainstem, subcortical and cortical regions.

Monitoring auditory cortical plasticity in hearing aid users with long latency auditory evoked potentials: a longitudinal study.

OBJECTIVE: The objective of this study was to compare long-latency auditory evoked potentials before and after hearing aid fittings in children with sensorineural hearing loss compared with age-matched children with normal hearing. METHODS: Thirty-two subjects of both genders aged 7 to 12 years participated in this study and were divided into two groups as follows: 14 children with normal hearing were assigned to the control group (mean age 9 years and 8 months), and 18 children with mild to moderate symmetrical bilateral sensorineural hearing loss were assigned to the study group (mean age 9 years and 2 months). The children underwent tympanometry, pure tone and speech audiometry and long-latency auditory evoked potential testing with speech and tone burst stimuli. The groups were assessed at three time points. RESULTS: The study group had a lower percentage of positive responses, lower P1-N1 and P2-N2 amplitudes (speech and tone burst), and increased latencies for the P1 and P300 components following the tone burst stimuli. They also showed improvements in long-latency auditory evoked potentials (with regard to both the amplitude and presence of responses) after hearing aid use. CONCLUSIONS: Alterations in the central auditory pathways can be identified using P1-N1 and P2-N2 amplitude components, and the presence of these components increases after a short period of auditory stimulation (hearing aid use). These findings emphasize the importance of using these amplitude components to monitor the neuroplasticity of the central auditory nervous system in hearing aid users.

Middle latency response study of auditory evoked potentials amplitudes and lantencies audiologically normal individuals.

UNLABELLED: Contemporary cohort cross-sectional study. INTRODUCTION: The auditory middle latency response (AMLR) is generated between 10 and 80 ms and has multiple generators, with a greater contribution from the thalamus-cortical pathways. The establishment of normality criteria for latency and amplitude values is necessary for clinical use. AIM: to analyze the latency and amplitude of the AMLR in individuals without audiological disorders, and verify the reliability of Pa-Nb amplitude. MATERIALS AND METHODS: The AMLR of 25 individuals was collected during 2005 and the Na, Pa, Nb components were analyzed for each tested ear (A1 and A2), and electrode positioning (C3 and C4). RESULTS: A statistically significant difference was noticed among middle latency values for C3A1 and C4A1 regarding components Na and Pa, and no difference for component Nb and mean values for amplitudes Na-Pa and Pa-Nb. CONCLUSIONS: We established average and standard deviation values for latency and amplitude parameters for components Na, Pa, Nb and Na-Pa and Pa-Nb, under conditions C3A1, C4A1, C3A2, C4A2, providing a parameter for the analysis and interpretation of this potential.

Cortical maturation of long latency auditory evoked potentials in hearing children: the complex P1-N1-P2-N2. / Maturação dos potenciais evocados auditivos de longa latência em crianças ouvintes: análise do complexo P1-N1-P2-N2.

PURPOSE: The purpose of this study was to monitor the emergence and changes to the components of the Long Latency Auditory Evoked Potentials (LLAEP) in normal hearing children. METHODS: This longitudinal study included children of both genders: seven aged between 10 and 35 months, and eight children between 37 and 63 months. The electrophysiological hearing evaluation consisted of analysis of LLAEP obtained in a sound field generated with loudspeakers positioned at an azimuth of 90°, through which the syllable /ba/ was played at an intensity of 70 dB HL. Each child underwent an initial evaluation followed by two re-evaluations three and nine months later. RESULTS: The emergence of LLAEP components across the nine-month follow-up period was observed. P1 and N2 were the most common components in children of this age range. There was no statistically significant difference regarding the occurrence of P1, N1, P2, and N2 components amongst younger and older children. Regarding latency values, the greatest changes overtime were observed in the P1 component for younger children and in the N2 component for older children. Only the P1 component significantly differed between the groups, with the highest latency values observed in younger children. CONCLUSION: LLAEP maturation occurs gradually and the emergence of complex components appears to be related more to the maturation of the central auditory nervous system than to chronological age.

Maturation of long latency auditory evoked potentials in hearing children: systematic review. / Maturação dos potenciais evocados auditivos de longa latência em crianças ouvintes: revisão sistemática.

PURPOSE: To analyze how Auditory Long Latency Evoked Potentials (LLAEP) change according to age in children population through a systematic literature review. RESEARCH STRATEGIES: After formulation of the research question, a bibliographic survey was done in five data bases with the following descriptors: Electrophysiology (Eletrofisiologia), Auditory Evoked Potentials (Potenciais Evocados Auditivos), Child (Criança), Neuronal Plasticity (Plasticidade Neuronal) and Audiology (Audiologia). SELECTION CRITERIA: Level 1 evidence articles, published between 1995 and 2015 in Brazilian Portuguese or English language. DATA ANALYSIS: Aspects related to emergence, morphology and latency of P1, N1, P2 and N2 components were analyzed. RESULTS: A total of 388 studies were found; however, only 21 studies contemplated the established criteria. P1 component is characterized as the most frequent component in young children, being observed around 100-150 ms, which tends to decrease as chronological age increases. The N2 component was shown to be the second most commonly observed component in children, being observed around 200-250 ms.. The other N1 and P2 components are less frequent and begin to be seen and recorded throughout the maturational process. CONCLUSION: The maturation of LLAEP occurs gradually, and the emergence of P1, N1, P2 and N2 components as well as their latency values are variable in childhood. P1 and N2 components are the most observed and described in pediatric population. The diversity of protocols makes the comparison between studies difficult.

Audiological and electrophysiological evaluation of children with acquired immunodeficiency syndrome (AIDS).

We examined the peripheral auditory system and the auditory brainstem pathway of children with Acquired Immunodeficiency Syndrome (AIDS). One hundred and one children, 51 with AIDS diagnosis and 50 normal children were evaluated. Audiological assessment included immittance measures, pure tone and speech audiometry and auditory brainstem response (ABR). The children with AIDS more frequently had abnormal results than did their matched controls, presenting either peripheral or auditory brainstem impairment. We suggest that AIDS be considered a risk factor for peripheral and/or auditory brainstem disorders. Further research should be carried out to investigate the auditory effects of HIV infection along the auditory pathway.

Auditory training program in subjects with tinnitus.

UNLABELLED: Tinnitus may be defined as the conscious perception of sound or noise, without the presence of external acoustic stimulation. Given the damage caused by tinnitus and the lack of effective treatment, alternatives are necessary to rehabilitate subjects with tinnitus. There is an assumption that auditory training (AT) could lead to a plastic reorganization of this system, thus promoting an improvement of the symptom. OBJECTIVE: To verify the effect of an AT program in subjects with tinnitus in the perception of this symptom. METHODS: Twelve subjects with tinnitus were included in the study and divided into two groups: Study Group (SG) and Control Group (CG). All of them underwent audiometric and electrophysiological assessments; acuphenometry; Tinnitus Handicap Inventory and auditory processing assessment (GIN - Gaps in Noise, Frequency Pattern Test and Speech-in-Noise). Afterward, trainings began and the SG was submitted to the formal AT, and the CG to the visual training. RESULTS: In the characterization of the groups, no statistically significant difference was found for the variables such as age, pitch, and loudness of tinnitus, or for hearing thresholds in conventional audiometry and high frequencies. Comparisons were performed between the groups, before and after the trainings, regarding electrophysiological, behavioral, and Tinnitus Handicap Inventory tests, and no statistically significant differences were found between them for any of the evaluations. CONCLUSION: Findings showed no statistically significant differences between groups in the comparison between the moments pre- and post-trainings (auditory or visual), nor for the electrophysiological findings or behavioral assessment of the auditory processing and for the Tinnitus Handicap Inventory, although some specific differences in the individual analysis have occurred.

Effect of hearing aids use on speech stimulus decoding through speech-evoked ABR.

INTRODUCTION: The electrophysiological responses obtained with the complex auditory brainstem response (cABR) provide objective measures of subcortical processing of speech and other complex stimuli. The cABR has also been used to verify the plasticity in the auditory pathway in the subcortical regions. OBJECTIVE: To compare the results of cABR obtained in children using hearing aids before and after 9 months of adaptation, as well as to compare the results of these children with those obtained in children with normal hearing. METHODS: Fourteen children with normal hearing (Control Group - CG) and 18 children with mild to moderate bilateral sensorineural hearing loss (Study Group - SG), aged 7-12 years, were evaluated. The children were submitted to pure tone and vocal audiometry, acoustic immittance measurements and ABR with speech stimulus, being submitted to the evaluations at three different moments: initial evaluation (M0), 3 months after the initial evaluation (M3) and 9 months after the evaluation (M9); at M0, the children assessed in the study group did not use hearing aids yet. RESULTS: When comparing the CG and the SG, it was observed that the SG had a lower median for the V-A amplitude at M0 and M3, lower median for the latency of the component V at M9 and a higher median for the latency of component O at M3 and M9. A reduction in the latency of component A at M9 was observed in the SG. CONCLUSION: Children with mild to moderate hearing loss showed speech stimulus processing deficits and the main impairment is related to the decoding of the transient portion of this stimulus spectrum. It was demonstrated that the use of hearing aids promoted neuronal plasticity of the Central Auditory Nervous System after an extended time of sensory stimulation.

Evaluation of peripheral auditory pathways and brainstem in obstructive sleep apnea.

INTRODUCTION: Obstructive sleep apnea causes changes in normal sleep architecture, fragmenting it chronically with intermittent hypoxia, leading to serious health consequences in the long term. It is believed that the occurrence of respiratory events during sleep, such as apnea and hypopnea, can impair the transmission of nerve impulses along the auditory pathway that are highly dependent on the supply of oxygen. However, this association is not well established in the literature. OBJECTIVE: To compare the evaluation of peripheral auditory pathway and brainstem among individuals with and without obstructive sleep apnea. METHODS: The sample consisted of 38 adult males, mean age of 35.8 (±7.2), divided into four groups matched for age and Body Mass Index. The groups were classified based on polysomnography in: control (n=10), mild obstructive sleep apnea (n=11) moderate obstructive sleep apnea (n=8) and severe obstructive sleep apnea (n=9). All study subjects denied a history of risk for hearing loss and underwent audiometry, tympanometry, acoustic reflex and Brainstem Auditory Evoked Response. Statistical analyses were performed using three-factor ANOVA, 2-factor ANOVA, chi-square test, and Fisher's exact test. The significance level for all tests was 5%. RESULTS: There was no difference between the groups for hearing thresholds, tympanometry and evaluated Brainstem Auditory Evoked Response parameters. An association was observed between the presence of obstructive sleep apnea and changes in absolute latency of wave V (p=0.03). There was an association between moderate obstructive sleep apnea and change of the latency of wave V (p=0.01). CONCLUSION: The presence of obstructive sleep apnea is associated with changes in nerve conduction of acoustic stimuli in the auditory pathway in the brainstem. The increase in obstructive sleep apnea severity does not promote worsening of responses assessed by audiometry, tympanometry and Brainstem Auditory Evoked Response.

Electrophysiological characterization of hearing in individuals with Down syndrome. / Caracterização eletrofisiológica da audição em indivíduos com Síndrome de Down.

INTRODUCTION: Few studies have performed Brainstem (BAEP) and P300 Auditory Evoked Potentials simultaneously to assess central auditory pathways in normal hearing individuals with Down syndrome (DS), mainly because of the difficulty in applying these procedures to this population. Previous studies have suggested that individuals with DS might present different patterns of response compared with those of individuals with typical development; nevertheless, the identification of these potentials would be crucial for the establishment of an accurate audiological diagnosis. PURPOSE: To characterize BAEP and P300 in normal-hearing individuals with DS. METHODS: BAEP and P300 were analyzed in 17 individuals with DS and in 21 individuals with typical development aged 7 to 15 years. The results were quantitatively and qualitatively analyzed using descriptive measures and hypothesis tests. RESULTS: In the quantitative analysis, latency values were lower in the BAEP for the DS group, with statistically significant difference for wave V and interpeaks III-V and I-V; there were no significant differences in the P300 latency values. In the qualitative analysis, there were a larger number of individuals with early values for BAEP latencies and late latencies for P300 in the DS group; both comparisons showed statistically significant differences. CONCLUSION: Children and adolescents with DS can present early responses to the components of BAEP, suggesting that their auditory pathway requires less time for the neural transmission of acoustic stimuli to the brainstem. Concerning P300, individuals with DS may present increased latencies, suggesting impairment in the central auditory pathway for the cortical processing of auditory information.

Auditory evoked potentials: predicting speech therapy outcomes in children with phonological disorders.

OBJECTIVES: This study investigated whether neurophysiologic responses (auditory evoked potentials) differ between typically developed children and children with phonological disorders and whether these responses are modified in children with phonological disorders after speech therapy. METHODS: The participants included 24 typically developing children (Control Group, mean age: eight years and ten months) and 23 children clinically diagnosed with phonological disorders (Study Group, mean age: eight years and eleven months). Additionally, 12 study group children were enrolled in speech therapy (Study Group 1), and 11 were not enrolled in speech therapy (Study Group 2). The subjects were submitted to the following procedures: conventional audiological, auditory brainstem response, auditory middle-latency response, and P300 assessments. All participants presented with normal hearing thresholds. The study group 1 subjects were reassessed after 12 speech therapy sessions, and the study group 2 subjects were reassessed 3 months after the initial assessment. Electrophysiological results were compared between the groups. RESULTS: Latency differences were observed between the groups (the control and study groups) regarding the auditory brainstem response and the P300 tests. Additionally, the P300 responses improved in the study group 1 children after speech therapy. CONCLUSION: The findings suggest that children with phonological disorders have impaired auditory brainstem and cortical region pathways that may benefit from speech therapy.

Audiological manifestations in HIV-positive adults.

OBJECTIVE: To characterize the findings of behavioral hearing assessment in HIV-positive individuals who received and did not receive antiretroviral treatment. METHODS: This research was a cross-sectional study. The participants were 45 HIV-positive individuals (18 not exposed and 27 exposed to antiretroviral treatment) and 30 control-group individuals. All subjects completed an audiological evaluation through pure-tone audiometry, speech audiometry, and high-frequency audiometry. RESULTS: The hearing thresholds obtained by pure-tone audiometry were different between groups. The group that had received antiretroviral treatment had higher thresholds for the frequencies ranging from 250 to 3000 Hz compared with the control group and the group not exposed to treatment. In the range of frequencies from 4000 through 8000 Hz, the HIV-positive groups presented with higher thresholds than did the control group. The hearing thresholds determined by high-frequency audiometry were different between groups, with higher thresholds in the HIV-positive groups. CONCLUSION: HIV-positive individuals presented poorer results in pure-tone and high-frequency audiometry, suggesting impairment of the peripheral auditory pathway. Individuals who received antiretroviral treatment presented poorer results on both tests compared with individuals not exposed to antiretroviral treatment.

Audiological and electrophysiological alterations in HIV-infected individuals subjected or not to antiretroviral therapy / Alterações audiológicas e eletrofisiológicas em indivíduos infectados pelo HIV submetidos ou não à terapia antirretroviral

Abstract Introduction: The Human Immunodeficiency Virus (HIV) and infections related to it can affect multiple sites in the hearing system. The use of High Activity Anti-Retroviral Therapy (HAART) can cause side effects such as ototoxicity. Thus, no consistent patterns of hearing impairment in adults with Human Immunodeficiency Virus / Acquired Immune Deficiency Syndrome have been established, and the problems that affect the hearing system of this population warrant further research. Objectives: This study aimed to compare the audiological and electrophysiological data of Human Immunodeficiency Virus-positive patients with and without Acquired Immune Deficiency Syndrome, who were receiving High Activity Anti-Retroviral Therapy, to healthy individuals. Methods: It was a cross-sectional study conducted with 71 subjects (30-48 years old), divided into groups: Research Group I: 16 Human Immunodeficiency Virus-positive individuals without Acquired Immunodeficiency Syndrome (not receiving antiretroviral treatment); Research Group II: 25 Human Immunodeficiency Virus-positive individuals with Acquired Immunodeficiency Syndrome (receiving antiretroviral treatment); Control Group: 30 healthy subjects. All individuals were tested by pure-tone air conduction thresholds at 0.25-8 kHz, extended high frequencies at 9-20 kHz, electrophysiological tests (Auditory Brainstem Response, Middle Latency Responses, Cognitive Potential). Results: Research Group I and Research Group II had higher hearing thresholds in both conventional and high frequency audiometry when compared to the control group, prolonged latency of waves I, III, V and interpeak I-V in Auditory Brainstem Response and prolonged latency of P300 Cognitive Potential. Regarding Middle Latency Responses, there was a decrease in the amplitude of the Pa wave of Research Group II compared to the Research Group I. Conclusions: Both groups with Human Immunodeficiency Virus had higher hearing thresholds when compared to healthy individuals (group exposed to antiretroviral treatment showed the worst hearing threshold) and seemed to have lower neuroelectric transmission speed along the auditory pathway in the brainstem, subcortical and cortical regions.

Resumo Introdução: O HIV e as infecções relacionadas a ele podem afetar vários locais do sistema auditivo. O uso de terapia antirretroviral altamente ativa pode causar efeitos colaterais, como ototoxicidade. Assim, não foram estabelecidos padrões consistentes de deficiência auditiva em adultos com HIV/Aids e os problemas que afetam o sistema auditivo dessa população justificam pesquisas futuras. Objetivos: Este estudo teve como objetivo comparar os dados audiológicos e eletrofisiológicos de pacientes HIV positivos com e sem Aids que recebiam terapia antirretroviral altamente ativa com os de indivíduos saudáveis. Método: Estudo transversal com 71 indivíduos (30-48 anos), divididos em grupos: Grupo de Pesquisa I: 16 indivíduos HIV-positivos sem Aids (não recebiam tratamento antirretroviral); Grupo de Pesquisa II: 25 indivíduos HIV-positivos com Aids (recebiam tratamento antirretroviral); Grupo Controle: 30 indivíduos saudáveis. Todos os indivíduos foram testados para limiares de condução aérea de tons puros a 0,25-8 kHz, altas frequências de 9-20 kHz, testes eletrofisiológicos (potencial evocado auditivo de tronco encefálico, potencial evocado auditivo de média latência, potencial cognitivo). Resultados: Os grupos de pesquisa I e II apresentaram limiares auditivos mais elevados em audiometria convencional e nas frequências altas quando comparados com o grupo controle, latência prolongada das ondas I, III, V e interpico I-V em resposta auditiva de tronco encefálico e latência prolongada de P300. Em relação às respostas de latência média, houve uma diminuição na amplitude da onda Pa do Grupo de pesquisa II em comparação com o grupo de pesquisa I. Conclusões: Ambos os grupos com HIV apresentaram limiares auditivos mais elevados quando comparados aos indivíduos saudáveis (o grupo exposto ao tratamento antirretroviral apresentou o pior limiar auditivo) e parecem ter menor velocidade de transmissão neuroelétrica ao longo da via auditiva nas regiões do tronco encefálico, subcortical e cortical.

Effect of hearing aids use on speech stimulus decoding through speech-evoked ABR / Efeito do uso do AASI na decodificação do estímulo de fala por meio do Peate-fala

Abstract Introduction The electrophysiological responses obtained with the complex auditory brainstem response (cABR) provide objective measures of subcortical processing of speech and other complex stimuli. The cABR has also been used to verify the plasticity in the auditory pathway in the subcortical regions. Objective To compare the results of cABR obtained in children using hearing aids before and after 9 months of adaptation, as well as to compare the results of these children with those obtained in children with normal hearing. Methods Fourteen children with normal hearing (Control Group - CG) and 18 children with mild to moderate bilateral sensorineural hearing loss (Study Group - SG), aged 7-12 years, were evaluated. The children were submitted to pure tone and vocal audiometry, acoustic immittance measurements and ABR with speech stimulus, being submitted to the evaluations at three different moments: initial evaluation (M0), 3 months after the initial evaluation (M3) and 9 months after the evaluation (M9); at M0, the children assessed in the study group did not use hearing aids yet. Results When comparing the CG and the SG, it was observed that the SG had a lower median for the V-A amplitude at M0 and M3, lower median for the latency of the component V at M9 and a higher median for the latency of component O at M3 and M9. A reduction in the latency of component A at M9 was observed in the SG. Conclusion Children with mild to moderate hearing loss showed speech stimulus processing deficits and the main impairment is related to the decoding of the transient portion of this stimulus spectrum. It was demonstrated that the use of hearing aids promoted neuronal plasticity of the Central Auditory Nervous System after an extended time of sensory stimulation.

Resumo Introdução As respostas eletrofisiológicas obtidas com o Potencial Evocado Auditivo de Tronco Encefálico complexo (Peate-c) fornecem medidas objetivas do processamento subcortical dos estímulos de fala e outros estímulos complexos. O Peate-c também vem sendo utilizado para verificar a plasticidade na via auditiva nas regiões subcorticais. Objetivo Comparar os resultados do Peate-c obtidos em crianças usuárias de Aparelho de Amplificação Sonora Individual (AASI), antes e após 9 meses da adaptação, bem como comparar os resultados destas crianças com os obtidos em crianças com audição normal. Método Foram avaliadas 14 crianças com audição normal (Grupo Controle - GC) e 18 crianças com perda auditiva neurossensorial de grau leve a moderado bilateral (Grupo Estudo - GE), na faixa etária de 7 a 12 anos. As crianças foram submetidas às Audiometrias Tonal e Vocal, Medidas de Imitância Acústica e Peate com estímulo de fala, sendo submetidas às avalições em três momentos diferentes: avaliação inicial (M0), 3 meses após avaliação inicial (M3) e 9 meses após a avaliação inicial (M9), sendo que no M0 as crianças do grupo estudo ainda não faziam uso do AASI. Resultados Na comparação entre GC e GE, observou-se que o GE apresentou menor mediana para a amplitude V-A no M0 e no M3, menor mediana para a latência do componente V no M9 e, maior mediana para a latência do componente O no M3 e no M9. Observou-se no GE, redução na latência do componente A no M9. Conclusão Crianças com perda auditiva de grau leve a moderado apresentaram déficit no processamento do estímulo de fala sendo que o principal prejuízo está relacionado à decodificação da porção transitória do espectro deste estímulo. Evidenciou-se que o uso do AASI promoveu a plasticidade neuronal do Sistema Nervoso Auditivo Central após um tempo prolongado de estimulação sensorial.

Evaluation of peripheral auditory pathways and brainstem in obstructive sleep apnea / Avaliação da via auditiva periférica e do tronco encefálico na apneia obstrutiva do sono

Abstract Introduction Obstructive sleep apnea causes changes in normal sleep architecture, fragmenting it chronically with intermittent hypoxia, leading to serious health consequences in the long term. It is believed that the occurrence of respiratory events during sleep, such as apnea and hypopnea, can impair the transmission of nerve impulses along the auditory pathway that are highly dependent on the supply of oxygen. However, this association is not well established in the literature. Objective To compare the evaluation of peripheral auditory pathway and brainstem among individuals with and without obstructive sleep apnea. Methods The sample consisted of 38 adult males, mean age of 35.8 (±7.2), divided into four groups matched for age and Body Mass Index. The groups were classified based on polysomnography in: control (n = 10), mild obstructive sleep apnea (n = 11) moderate obstructive sleep apnea (n = 8) and severe obstructive sleep apnea (n = 9). All study subjects denied a history of risk for hearing loss and underwent audiometry, tympanometry, acoustic reflex and Brainstem Auditory Evoked Response. Statistical analyses were performed using three-factor ANOVA, 2-factor ANOVA, chi-square test, and Fisher's exact test. The significance level for all tests was 5%. Results There was no difference between the groups for hearing thresholds, tympanometry and evaluated Brainstem Auditory Evoked Response parameters. An association was observed between the presence of obstructive sleep apnea and changes in absolute latency of wave V (p = 0.03). There was an association between moderate obstructive sleep apnea and change of the latency of wave V (p = 0.01). Conclusion The presence of obstructive sleep apnea is associated with changes in nerve conduction of acoustic stimuli in the auditory pathway in the brainstem. The increase in obstructive sleep apnea severity does not promote worsening of responses assessed by audiometry, tympanometry and Brainstem Auditory Evoked Response.

Resumo Introdução A Apneia Obstrutiva do Sono provoca modificações na arquitetura normal do sono, fragmentando-o de forma crônica com hipóxias intermitentes levando, a longo prazo, a sérias consequências na saúde. Acredita-se que a ocorrência de eventos respiratórios durante o sono como apneia e hipopneia pode prejudicar a transmissão de impulsos nervosos ao longo da via auditiva que são altamente dependentes do fornecimento do oxigênio. Contudo, essa associação não se encontra bem estabelecida na literatura. Objetivo Comparar os achados da avaliação da via auditiva periférica e no tronco encefálico entre indivíduos portadores e não portadores de apneia obstrutiva do sono. Método A casuística foi composta por 38 adultos do sexo masculino, média de idade de 35,8 (±7,2); divididos em quatro grupos experimentais pareados por idade e índice da massa corpórea. Os grupos foram classificados com base na polissonografia em: controle (n = 10), apneia obstrutiva do sono leve (n = 11), apneia obstrutiva do sono moderada (n = 8) e apneia obstrutiva do sono grave (n = 9). Todos os sujeitos do estudo negaram história pregressa de risco para perda auditiva e foram submetidos à audiometria, timpanometria, pesquisa dos reflexos acústicos e Potenciais Evocados Auditivos de Tronco Encefálico. As análises estatísticas foram realizadas por meio de ANOVA 3-fatores, ANOVA 2-fatores, teste de Qui-quadrado e teste exato de Fisher. O nível de significância adotado para todos os testes foi de 5%. Resultados Não houve diferença entre os grupos para os limiares auditivos, timpanometria e parâmetros avaliados do Peate. Observou-se associação entre a presença da apneia obstrutiva do sono e alteração da latência absoluta da onda V (p = 0,03). Observou-se associação entre apneia obstrutiva do sono de grau moderado e alteração da latência da onda V (p = 0,01). Conclusão A presença de apneia obstrutiva do sono está associada à presença de alteração na condução nervosa do estímulo acústico na via auditiva em tronco encefálico. O aumento do grau de severidade da apneia obstrutiva do sono não promove piora das respostas avaliadas pela audiometria, timpanometria e Potenciais Evocados Auditivos de Tronco Encefálico.

Monitoring auditory cortical plasticity in hearing aid users with long latency auditory evoked potentials: a longitudinal study

OBJECTIVE: The objective of this study was to compare long-latency auditory evoked potentials before and after hearing aid fittings in children with sensorineural hearing loss compared with age-matched children with normal hearing. METHODS: Thirty-two subjects of both genders aged 7 to 12 years participated in this study and were divided into two groups as follows: 14 children with normal hearing were assigned to the control group (mean age 9 years and 8 months), and 18 children with mild to moderate symmetrical bilateral sensorineural hearing loss were assigned to the study group (mean age 9 years and 2 months). The children underwent tympanometry, pure tone and speech audiometry and long-latency auditory evoked potential testing with speech and tone burst stimuli. The groups were assessed at three time points. RESULTS: The study group had a lower percentage of positive responses, lower P1-N1 and P2-N2 amplitudes (speech and tone burst), and increased latencies for the P1 and P300 components following the tone burst stimuli. They also showed improvements in long-latency auditory evoked potentials (with regard to both the amplitude and presence of responses) after hearing aid use. CONCLUSIONS: Alterations in the central auditory pathways can be identified using P1-N1 and P2-N2 amplitude components, and the presence of these components increases after a short period of auditory stimulation (hearing aid use). These findings emphasize the importance of using these amplitude components to monitor the neuroplasticity of the central auditory nervous system in hearing aid users.