Vestibular recruitment: new application for an old concept.

INTRODUCTION: Vestibular recruitment is a sign of hyperexcitability of central vestibular neurons and may be characteristic of peripheral vestibular damage. OBJECTIVE: To define the post-caloric recruitment index and its ability to predict the stage of vestibular compensation and peripheral lesion. METHODS: First of all, we demonstrated that larger values in the cold post-caloric stimulation compared to warm stimulation were equivalent to vestibular recruitment observed during the sinusoidal harmonic acceleration test. In the next step, patients with vestibular complaints and asymptomatic controls were submitted to the caloric test. We calculated post-caloric recruitment index for the control group. Among the study group, we analyzed the relation between post-caloric recruitment and unilateral weakness as well as the types of vestibular diagnoses. RESULTS: Mean post-caloric recruitment was 17.06% and 33.37% among the control and study group, respectively. The ratio between post-caloric recruitment and unilateral weakness was 1.3 in the study group. Among recruiting subjects, no significant difference of unilateral weakness from the lesioned or healthy side was observed. We found no differences in vestibular diagnoses between recruiting and non-recruiting subjects. CONCLUSION: Post-caloric recruitment index identified asymmetric vestibular tonus and central compensation. The normal value was established at 17.06%.

Video head impulse test relevance in the early postoperative period after cochlear implantation.

BACKGROUND: Cochlear implantation (CI) is the gold standard therapy for profound or severe sensorineural hearing loss. It is a safe surgical procedure but, because of the proximity of the cochlea and vestibule, postoperative vestibular disorder may occur. Our hypothesis is that the video head impulse test (vHIT) may be a good tool to achieve a topographic diagnosis of dizziness in the early postoperative period after CI. AIMS/OBJECTIVES: To evaluate patients with instability, imbalance and vertigo between 7 and 14 days after CI procedure. MATERIAL AND METHODS: A total of 31patients scheduled for unilateral CI were included in this study. vHIT for horizontal semicircular canal was performed before CI and between days 7 to 14 after the surgery. RESULTS: Six subjects had dizziness complaints after CI: instability (N = 2), imbalance (N = 2) and vertigo (N = 2). The postoperative vHIT test turned abnormal only in subjects with vertigo as compared to the preoperative vHIT test results. CONCLUSION AND SIGNIFICANCE: vHIT is a good vestibular function test during the first 2 weeks after CI surgery when vertigo is the main complaint.

Hearing performance as a predictor of postural recovery in cochlear implant users.

OBJECTIVE: This study aimed to evaluate if hearing performance is a predictor of postural control in cochlear implant (CI) users at least six months after surgery. METHODS: Cross-sectional study including (CI) recipients with post-lingual deafness and controls who were divided into the following groups: nine CI users with good hearing performance (G+), five CI users with poor hearing performance (G-), and seven controls (CG). For each patient, computerized dynamic posturography (CDP) tests, a sensory organization test (SOT), and an adaptation test (ADT) were applied as dual task performance, with first test (FT) and re-test (RT) on the same day, including a 40-60min interval between them to evaluate the short-term learning ability on postural recovery strategies. The results of the groups were compared. RESULTS: Comparing the dual task performance on CDP and the weighted average between all test conditions, the G+ group showed better performance on RT in SOT4, SOT5, SOT6, and CS, which was not observed for G- and CG. The G- group had significantly lower levels of short-term learning ability than the other two groups in SOT5 (p=0.021), SOT6 (p=0.025), and CS (p=0.031). CONCLUSION: The CI users with good hearing performance had a higher index of postural recovery when compared to CI users with poor hearing performance.

Sensitivity of caloric test and video head impulse as screening test for chronic vestibular complaints.

OBJECTIVE:: This study compared the results of the caloric test with those of the video head impulse test obtained during the same session and evaluated whether the former can be used to screen for non-acute vestibular dysfunction. METHODS:: A total of 157 participants complaining of dizziness with vestibular characteristics of varying durations and clinical courses completed the caloric test and video head impulse test. RESULTS:: Significantly more caloric test results than video head impulse test results were abnormal. CONCLUSIONS:: The results of the caloric test and video head impulse test are distinct but complement each other. Within our sample, the caloric test was more sensitive for vestibular dysfunction. Therefore, the video head impulse test is not a suitable screening tool of the vestibular system in patients with chronic complaints.

Normative data for TM electrocochleography measures.

OBJECTIVE: Establish normative data for tympanic electrocochleography (TM ECochG) parameters in normal hearing adults without Ménière's disease's (MD) symptoms. Describe TM ECochG variables that help to distinguish normal from MD ears. MATERIAL AND METHODS: We enrolled 100 subjects (N = 200 ears), 59 females, aged between 19 and 71 years from 09/2010 to 04/2014. Inclusion criteria: normal otomicroscopy, hearing thresholds ≤25 dB nHL from 250 to 4000 Hz, normal tympanogram, no symptoms of MD according to the AAO-HNS 1995 criteria and Gibson's score <7. We excluded subjects with dizziness, aural fullness or other symptoms of endolymphatic hydrops. The following parameters were analyzed: SP/AP amplitude ratio, SP/AP area ratio and the difference between AP latency with rarefaction and condensation stimuli. RESULTS: There was no significant difference between right and left ears (Intraclass correlation coefficient < 0.6). SP/AP amplitude ratio varied between 0.084 and 0.356 and SP/AP area ratio between 0.837 and 1.671 (percentiles 5 and 95). The AP latency difference to rarefaction and condensation clicks was between 0.0 and 0.333 ms. CONCLUSION: Normative data for TM ECochG parameters were established in 100 normal hearing subjects without MD. These data can be used to distinguish normal from pathological findings and in follow-up of MD patients.

Vestibular recruitment: new application for an old concept / Recrutamento vestibular: nova aplicação para um conceito antigo

Abstract Introduction Vestibular recruitment is a sign of hyperexcitability of central vestibular neurons and may be characteristic of peripheral vestibular damage. Objective To define the post-caloric recruitment index and its ability to predict the stage of vestibular compensation and peripheral lesion. Methods First of all, we demonstrated that larger values in the cold post-caloric stimulation compared to warm stimulation were equivalent to vestibular recruitment observed during the sinusoidal harmonic acceleration test. In the next step, patients with vestibular complaints and asymptomatic controls were submitted to the caloric test. We calculated post-caloric recruitment index for the control group. Among the study group, we analyzed the relation between post-caloric recruitment and unilateral weakness as well as the types of vestibular diagnoses. Results Mean post-caloric recruitment was 17.06% and 33.37% among the control and study group, respectively. The ratio between post-caloric recruitment and unilateral weakness was 1.3 in the study group. Among recruiting subjects, no significant difference of unilateral weakness from the lesioned or healthy side was observed. We found no differences in vestibular diagnoses between recruiting and non-recruiting subjects. Conclusion Post-caloric recruitment index identified asymmetric vestibular tonus and central compensation. The normal value was established at 17.06%.

Resumo Introdução O recrutamento vestibular é um sinal de hiperexcitabilidade dos neurônios vestibulares centrais e pode ser característico de lesão vestibular periférica. Objetivo Definir o índice de recrutamento pós‐calórico e sua capacidade de predizer o estágio de compensação vestibular e lesão periférica. Método Em primeiro lugar, demonstramos que valores maiores na estimulação pós‐calórica fria em relação à estimulação quente foram equivalentes ao recrutamento vestibular observado durante o teste de aceleração harmônica sinusoidal. Na etapa seguinte, os pacientes com queixas vestibulares e controles assintomáticos foram submetidos à prova calórica. Calculamos o índice de recrutamento pós calórico para o grupo controle. No grupo de estudo, analisamos a relação entre o recrutamento pós‐calórico e predomínio labiríntico, bem como os tipos de diagnósticos vestibulares. Resultados O recrutamento pós‐calórico médio foi de 17,06% e 33,37% nos grupos controle e estudo, respectivamente. A razão entre o recrutamento pós‐calórico e o predominício labiríntico foi de 1,3 no grupo de estudo. Nos sujeitos com recrutamento, não foi observada diferença significativa de predominício labiríntico do lado lesionado ou saudável. Não encontramos diferenças de diagnóstico vestibular entre sujeitos com recrutamento e sem recrutamento. Conclusão O índice de recrutamento pós‐calórico identificou tônus vestibular assimétrico e compensação central. O valor normal foi estabelecido em 17,06%.

Are auditory steady-state responses a good tool prior to pediatric cochlear implantation?

INTRODUCTION: ASSR allow frequency-specific evaluation in intensities up to 120dB HL and detection of residual hearing in patients with severe-to-profound hearing loss. AIM: to compare ASSR thresholds and behavioral test results in children with suspected severe-to-profound hearing loss. METHODS: Cross sectional study to compare ASSR and behavioral responses (VRA or audiometry) in 63 pediatric cochlear implant candidates (126 ears) aged between 6 and 72 months. We included children with normal otomicroscopy, absent responses to click-ABR and otoaccoustic emissions. We excluded children with inner ear malformations, auditory neuropathy spectrum disorder or who did not complete VRA or achieve EEG noise<30nV during the ASSR test. Air-conduction ASSR stimuli were continuous sinusoidal tones presented at 0.5, 1, 2 and 4kHz starting at 110dB HL. Behavioral thresholds were acquired with warble tones presented at 0.5, 1, 2 and 4kHz in each ear through insert or head phones at maximum presentation level of 120dB HL. RESULTS: Behavioral thresholds were obtained in 36.7% (185/504) of all frequencies in all subjects, 9% in intensities >110dB HL. Among 504 ASSR measurements, 53 thresholds were obtained (10.5%). Overall 89.5% of the tested frequencies did not show any response at 110dB HL. Most responses were at 500Hz. Mean differences between behavioral and ASSR thresholds varied from 0.09 to 8.94dB. Twenty-seven comparisons of behavioral and ASSR thresholds were obtained: 12 at 0.5kHz, 9 at 1kHz, 5 at 2kHz and 1 at 4kHz. Absent responses were observed in both tests in 38.1% at 0.5kHz, 52.4% at 1kHz, 74.6% at 2kHz and 81.0% at 4kHz. Specificity was>90% at 1, 2 and 4kHz. In ears with no behavioral response at 120dB HL all ASSR thresholds were in the profound hearing loss range, 90% of them were ≥110dB HL. CONCLUSION: Among 63 pediatric CI candidates, absent responses to high-intensity ASSR was the major finding (specificity>90%) predicting behavioral thresholds in the profound hearing loss range. These findings can be helpful to confirm the decision for cochlear implantation.

Evaluation of residual hearing in cochlear implants candidates using auditory steady-state response.

CONCLUSION: The correlations between behavioral and auditory steady-state response (ASSR) thresholds were significant at 500, 1000, 2000, and 4000 Hz. ASSR presented high sensitivity and specificity in the detection of residual hearing in cochlear implant candidates when compared with warble-tone audiometry. OBJECTIVES: To assess residual hearing in cochlear implant candidates by comparing the electrophysiological thresholds obtained in dichotic single-frequency ASSR with behavioral thresholds at 500, 1000, 2000, and 4000 Hz. METHODS: This was a comparative study between ASSR and warble-tone audiometry thresholds in 40 cochlear implant candidates (80 ears) before cochlear implantation with bilateral severe-to-profound sensorineural hearing loss. RESULTS: Thresholds were obtained in 62.5% of all frequencies evaluated in warble-tone audiometry and in 63.1% in the ASSR. ASSR sensitivity was 96% and specificity was 91.6%. Mean differences between behavioral and ASSR thresholds did not reach significance at any frequencies. Strong correlations between behavioral and ASSR thresholds were observed in 500, 1000, and 2000 Hz and moderate in 4000 Hz, with correlation coefficients varying from 0.65 to 0.81. On 90% of occasions, ASSR thresholds were acquired within 10 dB of behavioral thresholds.

Are Auditory Steady-State Responses Useful to Evaluate Severe-to-Profound Hearing Loss in Children?

OBJECTIVE: To evaluate Auditory Steady-State Responses (ASSR) at high intensities in pediatric cochlear implant candidates and to compare the results to behavioral tests responses. METHODS: This prospective study evaluated 42 children with suspected severe-to-profound hearing loss, aged from 3 to 72 months. All had absent ABR and OAE responses. ASSR were evoked using binaural single frequency stimuli at 110 dB HL with a 10 dB down-seeking procedure. ASSR and behavioral test results were compared. RESULTS: Forty-two subjects completed both ASSR and behavioral evaluation. Eleven children (26.2%) had bilateral responses. Four (9.5%) showed unilateral responses in at least two frequencies, all confirmed by behavioral results. Overall 61 ASSR responses were obtained, most (37.7%) in 500 Hz. Mean thresholds were between 101.3 and 104.2 dB HL. Among 27 subjects with absent ASSR, fifteen had no behavioral responses. Seven subjects showed behavioral responses with absent ASSR responses. No spurious ASSR responses were observed at 100 or 110 dB HL. CONCLUSION: ASSR is a valuable tool to detect residual hearing. No false-positive ASSR results were observed among 42 children, but in seven cases with absent ASSR, the test underestimated residual hearing as compared to the behavioral responses.

Comparative study between pure tone audiometry and auditory steady-state responses in normal hearing subjects.

INTRODUCTION: Auditory steady-state responses (ASSR) are an important tool to detect objectively frequency-specific hearing thresholds. Pure-tone audiometry is the gold-standard for hearing evaluation, although sometimes it may be inconclusive, especially in children and uncooperative adults. AIM: Compare pure tone thresholds (PT) with ASSR thresholds in normal hearing subjects. MATERIALS AND METHODS: In this prospective cross-sectional study we included 26 adults (n = 52 ears) of both genders, without any hearing complaints or otologic diseases and normal puretone thresholds. All subjects had clinical history, otomicroscopy, audiometry and immitance measurements. This evaluation was followed by the ASSR test. The mean pure-tone and ASSR thresholds for each frequency were calculated. RESULTS: The mean difference between PTand ASSR thresholdswas 7,12 for 500 Hz, 7,6 for 1000 Hz, 8,27 for 2000 Hz and 9,71 dB for 4000 Hz. There were no difference between PT and ASSR means at either frequency. CONCLUSION: ASSR thresholds were comparable to pure-tone thresholds in normal hearing adults. Nevertheless it should not be used as the only method of hearing evaluation.

Sensitivity of caloric test and video head impulse as screening test for chronic vestibular complaints

OBJECTIVE: This study compared the results of the caloric test with those of the video head impulse test obtained during the same session and evaluated whether the former can be used to screen for non-acute vestibular dysfunction. METHODS: A total of 157 participants complaining of dizziness with vestibular characteristics of varying durations and clinical courses completed the caloric test and video head impulse test. RESULTS: Significantly more caloric test results than video head impulse test results were abnormal. CONCLUSIONS: The results of the caloric test and video head impulse test are distinct but complement each other. Within our sample, the caloric test was more sensitive for vestibular dysfunction. Therefore, the video head impulse test is not a suitable screening tool of the vestibular system in patients with chronic complaints.

Hearing performance as a predictor of postural recovery in cochlear implant users / Desempenho auditivo como preditor de recuperação postural em usuários de implante coclear

Abstract Objective This study aimed to evaluate if hearing performance is a predictor of postural control in cochlear implant (CI) users at least six months after surgery. Methods Cross-sectional study including (CI) recipients with post-lingual deafness and controls who were divided into the following groups: nine CI users with good hearing performance (G+), five CI users with poor hearing performance (G−), and seven controls (CG). For each patient, computerized dynamic posturography (CDP) tests, a sensory organization test (SOT), and an adaptation test (ADT) were applied as dual task performance, with first test (FT) and re-test (RT) on the same day, including a 40–60 min interval between them to evaluate the short-term learning ability on postural recovery strategies. The results of the groups were compared. Results Comparing the dual task performance on CDP and the weighted average between all test conditions, the G+ group showed better performance on RT in SOT4, SOT5, SOT6, and CS, which was not observed for G− and CG. The G− group had significantly lower levels of short-term learning ability than the other two groups in SOT5 (p = 0.021), SOT6 (p = 0.025), and CS (p = 0.031). Conclusion The CI users with good hearing performance had a higher index of postural recovery when compared to CI users with poor hearing performance.

Resumo Objetivo O presente estudo teve por objetivo avaliar se o desempenho auditivo é preditor de controle postural em usuários de IC pelo menos seis meses após a cirurgia. Método Estudo transversal que consistiu em recipientes de implante coclear (IC) com surdez pós-lingual e controles, que foram divididos nos seguintes grupos: nove usuários de IC com bom desempenho auditivo (G+), cinco usuários de usuários de IC com desempenho auditivo insatisfatório (G-) e sete controles (GC). Aplicamos os testes de posturografia dinâmica computadorizada (PDC), de organização sensitiva (TOS) e de adaptação (TAd) como desempenho de dupla tarefa, primeiro teste (PT) e reteste (RT) no mesmo dia, com intervalo de 40-60 minutos entre testes, com o objetivo de avaliar a capacidade de aprendizado em curto prazo nas estratégias de recuperação postural. Comparamos os resultados dos testes. Resultados Na comparação do desempenho de dupla tarefa no teste PDC e a média ponderal entre todas as condições de teste, o grupo G+ demonstrou melhor desempenho no RT nos TOS4, TOS5, TOS6 e EC, o que não foi observado para os grupos G- e GC. O grupo G- obteve níveis significantemente mais baixos de capacidade de aprendizado em curto prazo vs. outros dois grupos no TOS5 (p = 0,021), TOS6 (p = 0,025) e EC (p = 0,031). Conclusão Usuários de IC com bom desempenho auditivo tiveram índice melhor de recuperação postural, quando comparados com usuários de IC com desempenho auditivo insatisfatório.

Dizziness profile and clinical features: a population based survey in São Paulo City, Brazil / Perfil e características clínicas de tontura: um estudo baseado na população da cidade de São Paulo

OBJECTIVE: This is a cross-sectional epidemiological survey designed to estimate the prevalence of dizziness among the adult population of the city of São Paulo, Brazil, and to describe the clinical features and level of discomfort. METHOD: This population based study was conductedin the city of São Paulo, Brazil, between April and October 2012. A total of 1,960 household interviews were completed. The following variables were assessed: gender, age, clinical characteristics of dizziness, and dizziness disability index. Chi-square test, Student's t-test,Tukey test and logistic regression were used for statistical analysis. RESULTS: The dizziness prevalence in São Paulo was 42%. Peaks of dizziness were observed in two age groups: 49% among the 46 to 55 year-old, and 44% among the elderly subjects(> 65 years-old). Vestibular vertigo was detected in 8.3% of patients, with a strong female preponderance (p < 0.001). Symptoms caused disability in 27% of the affected respondents and were more frequent among women (p < 0.001). These sought medical care more frequently (p < 0.001). The dizziness disability index was significantly higher (p = 0.0165) among subjects with a lower educational level. There was no correlation between dizziness discomfort and the type of job. CONCLUSION: The prevalence of dizziness in São Paulo, Brazil, was established at 42%. Among the symptomatic subjects, 67% reported interruption of daily activities, but only 46% of them sought medical attention.

RESUMO OBJETIVO: Estudo epidemiológico transversal, desenvolvido para avaliar a prevalência de tontura entre a população adulta da cidade de São Paulo, Brasil, e descrever as características clínicas e nível de desconforto. MÉTODO: Estudo de base populacional na cidade de São Paulo, Brasil, entre abril e outubro de 2012. Um total de 1.960 entrevistas domiciliares foram concluídas. As seguintes variáveis foram analisadas: sexo, idade, características clínicas de tonturas e vertigens, índice de incapacidade. Os testes qui-quadrado, "t" de Student, Tukey e regressão logística foram utilizados para análise estatística. RESULTADOS: Aprevalência de tontura em São Paulo foi de 42%. Em dois grupos etários, foram observados picos de tontura: 49% entre os 46 e 55 anos de idade e 44% entre os idosos (> 65 anos de idade). Vertigem vestibular foi detectada em 8,3%, com uma forte preponderância para o sexo feminino (p <0,001). Os sintomas causaram deficiência em 27% dos entrevistados, com predominância entre as mulheres (p <0,001), que procuraram atendimento médico commais freqüência (p <0,001). O índice de incapacidade por tontura foi significativamente maior (p = 0,0165) entre os indivíduos com menor escolaridade. Não houve correlação entre desconforto por tontura e o tipo de emprego. CONCLUSÃO: Aprevalência de tontura em São Paulo, Brasil, foi estabelecida em 42%. Entre os pacientes sintomáticos, 67% relataram a interrupção das atividades diárias, mas apenas 46% deles procuraram atendimento médico.

Sensory organization test in elderly patients with and without vestibular dysfunction.

CONCLUSIONS: Elderly subjects without vestibular dysfunction had an overall worse performance as compared with the group of normal adults, confirming that age has a negative impact on balance. The group of elderly subjects with vestibular dysfunction had more important balance alterations than those without, confirming that vestibular dysfunction has a major impact on balance control in the elderly. The visual and vestibular systems presented more important functional changes with ageing than the somatosensory system. OBJECTIVE: The main sensory input comes from the visual, vestibular and somatosensory systems; all of them may present changes due to ageing. This study aimed to investigate the performance of vestibular, visual and somatosensory systems in aged subjects with or without vestibular dysfunction, as compared to normal adults. SUBJECTS AND METHODS: Dynamic posturography was used in 60 elderly subjects without vestibular dysfunction (Gaa), 60 with vestibular dysfunction (Gas) and 58 normal adults (Gn). RESULTS: For condition 1 and 2 Gn performed significantly better than Gaa and Gas, with no difference between the latter. In conditions 4, 5 and 6 the performance of Gn was statistically superior to that of Gaa, which in turn, was better than that of Gas. The somatosensory responses showed no significant differences between the three groups. The performance of visual and vestibular systems showed progressive dysfunction: Gn did better than than Gaa, and Gaa did better than Gas.

Estudo comparativo entre audiometria tonal limiar e resposta auditiva de estado estavel em normouvintes / Comparative study between pure tone audiometry and auditory steady-state responses in normal hearing subjects

Introdução: As respostas auditivas de estado estável permitem avaliar de forma objetiva limiares auditivos frequência-específica. A audiometria tonal é o exame padrão-ouro; no entanto, nem sempre pode ser conclusiva, principalmente em crianças e adultos não colaborativos. Objetivo: Comparar os limiares auditivos da RAEE aos da audiometria tonal em indivíduos com audição normal. Materiais e métodos: Foram incluídos neste estudo prospectivo de corte transversal 26 adultos (52 orelhas), de ambos os gêneros, com audiometria normal e sem queixas otológicas. Os pacientes foram submetidos a anamnese, otomicroscopia, audiometria e imitanciometria. A seguir, realizou-se avaliação de respostas auditivas de estado estável. Os resultados obtidos foram analisados estatisticamente e comparados entre si. Resultados: A diferença entre os limiares (em dB NA) obtidos em ambos os exames para cada frequência testada foi de 7,12 dB para 500 Hz; 7,6 dB para 1000 Hz; 8,27 dB para 2000 Hz e 9,71 dB para 4000 Hz, com limiares mais elevados na RAEE, em todas as frequências. Não houve diferença estatística entre as médias para cada frequência testada. Conclusão: Os limiares obtidos na RAEE foram comparáveis aos da audiometria tonal em indivíduos normouvintes; entretanto, não deve ser usado como único método de avaliação auditiva. .

Introduction: Auditory steady-state responses (ASSR) are an important tool to detect objectively frequency-specific hearing thresholds. Pure-tone audiometry is the gold-standard for hearing evaluation, although sometimes it may be inconclusive, especially in children and uncooperative adults. Aim: Compare pure tone thresholds (PT) with ASSR thresholds in normal hearing subjects. Materials and methods: In this prospective cross-sectional study we included 26 adults (n = 52 ears) of both genders, without any hearing complaints or otologic diseases and normal puretone thresholds. All subjects had clinical history, otomicroscopy, audiometry and immitance measurements. This evaluation was followed by the ASSR test. The mean pure-tone and ASSR thresholds for each frequency were calculated. Results: The mean difference between PTand ASSR thresholdswas 7,12 for 500 Hz, 7,6 for 1000 Hz, 8,27 for 2000 Hz and 9,71 dB for 4000 Hz. There were no difference between PT and ASSR means at either frequency. Conclusion: ASSR thresholds were comparable to pure-tone thresholds in normal hearing adults. Nevertheless it should not be used as the only method of hearing evaluation. .

Formas incomuns de apresentaçäo clínica da hiperplasia do tecido linfóide da rinofaringe / Uncommon forms of clinical presentation of nasopharyngeal hyperplastic lymphoid tissue

Os autores apresentam 2 casos de hiperplasia do tecido linfóide da rinofaringe, com aspectos clínicos e radiológicos incomuns. Säo discutidos os principais aspectos clínicos e radiológicos no diagnóstico diferencial entre hiperplasia linfóide e neoplasias

Diagnostico precoce da deficiencia auditiva no primeiro ano de vida de criancas com alto risco atraves de audiometria de tronco cerebral / Early diagnosis of hearing loss in high-risk infants using auditory brainstem respons

O ouvido e um orgao fundamental na comunicacao humana. Uma deficiencia auditiva nao corrigida precocemente gera alteracoes irreversiveis, comprometendo de maneira global o processo de aprendizado...