Brazilian Society of Otology task force - Vestibular Schwannoma ‒ evaluation and treatment.

OBJECTIVE: To review the literature on the diagnosis and treatment of vestibular schwannoma. METHODS: Task force members were educated on knowledge synthesis methods, including electronic database search, review and selection of relevant citations, and critical appraisal of selected studies. Articles written in English or Portuguese on vestibular schwannoma were eligible for inclusion. The American College of Physicians' guideline grading system and the American Thyroid Association's guideline criteria were used for critical appraisal of evidence and recommendations for therapeutic interventions. RESULTS: The topics were divided into 2 parts: (1) Diagnosis - audiologic, electrophysiologic tests, and imaging; (2) Treatment - wait and scan protocols, surgery, radiosurgery/radiotherapy, and systemic therapy. CONCLUSIONS: Decision making in VS treatment has become more challenging. MRI can diagnose increasingly smaller tumors, which has disastrous consequences for the patients and their families. It is important to develop an individualized approach for each case, which highly depends on the experience of each surgical team.

Brazilian Society of Otology task force - Otosclerosis: evaluation and treatment.

OBJECTIVES: To review and provide evidence-based recommendations for the diagnosis and treatment of otosclerosis. METHODS: Task force members were educated on knowledge synthesis methods, including electronic database search, review and selection of relevant citations, and critical appraisal of selected studies. Articles written in English or Portuguese on otosclerosis were eligible for inclusion. The American College of Physicians' guideline grading system and the American Thyroid Association's guideline criteria were used for critical appraisal of evidence and recommendations for therapeutic interventions. RESULTS: The topics were divided into 2 parts: 1) Diagnosis - audiologic and radiologic; 2) Treatment - hearing AIDS, pharmacological therapy, stapes surgery, and implantable devices - bone-anchored devices, active middle ear implants, and Cochlear Implants (CI). CONCLUSIONS: The pathophysiology of otosclerosis has not yet been fully elucidated, but environmental factors and unidentified genes are likely to play a significant role in it. Women with otosclerosis are not at increased risk of worsening clinical condition due to the use of contraceptives or during pregnancy. Drug treatment has shown little benefit. If the patient does not want to undergo stapedotomy, the use of hearing aids is well indicated. Implantable systems should be indicated only in rare cases, and the CI should be indicated in cases of profound deafness.

Brazilian Society of Otology task force - Vestibular Schwannoma - evaluation and treatment

Abstract Objective: To review the literature on the diagnosis and treatment of vestibular schwannoma. Methods: Task force members were educated on knowledge synthesis methods, including electronic database search, review and selection of relevant citations, and critical appraisal of selected studies. Articles written in English or Portuguese on vestibular schwannoma were eligible for inclusion. The American College of Physicians' guideline grading system and the American Thyroid Association's guideline criteria were used for critical appraisal of evidence and recommendations for therapeutic interventions. Results: The topics were divided into 2 parts: (1) Diagnosis - audiologic, electrophysiologic tests, and imaging; (2) Treatment - wait and scan protocols, surgery, radiosurgery/radiotherapy, and systemic therapy. Conclusions: Decision making in VS treatment has become more challenging. MRI can diagnose increasingly smaller tumors, which has disastrous consequences for the patients and their families. It is important to develop an individualized approach for each case, which highly depends on the experience of each surgical team.

Degree of satisfaction of patients fitted with hearing aids at a high complexity service.

UNLABELLED: Some individuals with hearing loss choose to be fitted with hearing aids. Compliance is significantly affected by how satisfied patients are with their hearing aids. Patient satisfaction can be assessed through questionnaires and scales. OBJECTIVE: To assess the degree of satisfaction of patients fitted with hearing aids. METHOD: Scale "Satisfaction With Amplification in Daily Life" (SADL) was applied to 180 patients fitted with hearing aids; results were categorized based on the mean values observed for global satisfaction scores and scores attained on each subscale. Patients were interviewed for additional information. RESULTS: Mean global score was 5.6; 48.9% of the subjects were very satisfied, 47.2% were satisfied, and 3.9% were dissatisfied. The mean score on subscale Positive Effects was 5.6; the mean score for Service and Cost was 6.2; for Negative Factors the mean score was 4.9; and the mean score on subscale Personal Image was 5.8. Of the patients fitted with in-the-ear hearing aids, 83.3% were very satisfied. Fifteen percent of the individuals were dissatisfied with their Personal Image. Sensorineural and profound hearing loss patients were less satisfied, with 5.4% and 50.0% of the subjects revealing dissatisfaction with their hearing aids. CONCLUSION: Patients were generally very satisfied with their hearing aids. Satisfaction rates were higher among patients fitted with in-the-ear hearing aids. Dissatisfaction was higher in subscale Personal Image. Lesser degrees of satisfaction were seen in patients with sensorineural and profound hearing loss.

Grau de satisfacao em usuarios de proteses auditivas em um servico de alta complexidade / Degree of satisfaction of patients fitted with hearing aids at a high complexity service

A prótese auditiva é utilizada por alguns portadores de perda auditiva. A satisfação com a prótese é importante para a adesão ao uso e pode ser avaliada por meio de questionários. OBJETIVO: Avaliar o grau de satisfação dos usuários de próteses auditivas. MÉTODO: Aplicou-se o questionário Satisfaction With Amplification in Daily Life (SADL) a 180 usuários de próteses auditivas, classificando-os de acordo com a média obtida no Escore Global de satisfação e subescalas. Os demais dados individuais foram obtidos na mesma entrevista. RESULTADOS: A média do escore global de satisfação foi 5,6, revelando 48,9% muito satisfeitos, 47,2% satisfeitos e 3,9% insatisfeitos. A média para Efeitos Positivos foi 5,6, para Serviços e Custos 6,2, para Fatores Negativos 4,9 e para Imagem Pessoal 5,8. Para as próteses auditivas intra-auriculares, 83,3% estavam muito satisfeitos. A subescala Imagem Pessoal apresentou 15,0% de insatisfação. Perda auditiva neurossensorial e perda auditiva profunda apresentaram menores graus de satisfação, com 5,4% de insatisfação na primeira e 50,0% na segunda. CONCLUSÃO: Os pacientes avaliados apresentaram satisfação elevada com as próteses auditivas. Destacaram-se as próteses intra-auriculares com maiores satisfações. A subescala Imagem Pessoal revelou mais insatisfação. Menores graus de satisfação foram encontrados para perda auditiva neurossensorial e perda auditiva profunda. .

Some individuals with hearing loss choose to be fitted with hearing aids. Compliance is significantly affected by how satisfied patients are with their hearing aids. Patient satisfaction can be assessed through questionnaires and scales. OBJECTIVE: To assess the degree of satisfaction of patients fitted with hearing aids. METHOD: Scale "Satisfaction With Amplification in Daily Life" (SADL) was applied to 180 patients fitted with hearing aids; results were categorized based on the mean values observed for global satisfaction scores and scores attained on each subscale. Patients were interviewed for additional information. RESULTS: Mean global score was 5.6; 48.9% of the subjects were very satisfied, 47.2% were satisfied, and 3.9% were dissatisfied. The mean score on subscale Positive Effects was 5.6; the mean score for Service and Cost was 6.2; for Negative Factors the mean score was 4.9; and the mean score on subscale Personal Image was 5.8. Of the patients fitted with in-the-ear hearing aids, 83.3% were very satisfied. Fifteen percent of the individuals were dissatisfied with their Personal Image. Sensorineural and profound hearing loss patients were less satisfied, with 5.4% and 50.0% of the subjects revealing dissatisfaction with their hearing aids. CONCLUSION: Patients were generally very satisfied with their hearing aids. Satisfaction rates were higher among patients fitted with in-the-ear hearing aids. Dissatisfaction was higher in subscale Personal Image. Lesser degrees of satisfaction were seen in patients with sensorineural and profound hearing loss. .

Laryngeal involvement in rheumatoid arthritis.

UNLABELLED: The prevalence of laryngeal involvement in Rheumatoid Arthritis (RA) ranges from 13 to 75%. The specific RA manifestations include the cricoarytenoid arthritis and the presence of rheumatoid nodules in the vocal folds. OBJECTIVE: The objective of this study is to evaluate the prevalence of dysphonia and laryngeal alterations on videolaryngoscopy in RA patients and their association with disease activity. METHOD: This is a clinical cross-sectional study that evaluated patients with rheumatoid arthritis as to their disease activity score in 28 joints (DAS-28), laryngeal symptoms, application of a Portuguese version of the Voice Handicap Index and videolaryngoscopy findings, comparing them with a control group. RESULTS: We evaluated 47 (54%) patients with rheumatoid arthritis and 40 (46%) controls. The prevalence of dysphonia and videolaryngoscopy changes was respectively 12.8% and 72.4% in patients with RA. The mean of DAS-28 was 3.3 ± 1.2; 26 (74.3%) of 35 patients presenting active disease had laryngeal changes (p = 0.713). Posterior laryngitis was the most common diagnosis (44.7%). CONCLUSION: The prevalence of laryngeal disorders in RA patients was 72.4% and the prevalence of dysphonia was 12.8%. There was no significant relationship between laryngeal disorders and disease activity.

Alterações laríngeas em pacientes com artrite reumatoide / Laryngeal involvement in rheumatoid arthritis

Aprevalência do envolvimento laríngeo em pacientes com artrite reumatoide (AR) varia de 13% a 75%. As manifestações específicas compreendem a artrite cricoaritenóidea e os nódulos reumatoides em pregas vocais. OBJETIVO: O objetivo da pesquisa é avaliar a prevalência da disfonia e das alterações laríngeas à videolaringoscopia em pacientes com AR e a associação com o grau de atividade da doença. MÉTODO: Trata-se de estudo clínico transversal que avaliou pacientes com AR quanto ao escore de atividade de doença em 28 articulações (DAS-28), sintomas laríngeos, incluindo a aplicação da versão traduzida do Voice Handicap Index, e realizou videolaringoscopia, comparando com um grupo controle. RESULTADOS: Foram avaliados 47 pacientes com artrite reumatoide e 40 controles. As prevalências de disfonia e de alterações videolaringoscópicas foram, respectivamente, de 12,8% e 72,3% em pacientes com AR. A média do DAS-28 foi de 3,3 ± 1,2; 26 (74,3%) dos 35 pacientes com doença ativa apresentaram alterações laríngeas (p = 0,713). A laringite posterior (44,7%) foi o diagnóstico mais comum em pacientes com AR. CONCLUSÃO: A prevalência de alterações laríngeas em pacientes com AR foi 72,4% e a prevalência de disfonia foi 12,8%. Não houve relação significativa entre alterações laríngeas e grau de atividade da doença.

The prevalence of laryngeal involvement in Rheumatoid Arthritis (RA) ranges from 13 to 75%. The specific RA manifestations include the cricoarytenoid arthritis and the presence of rheumatoid nodules in the vocal folds. OBJECTIVE: The objective of this study is to evaluate the prevalence of dysphonia and laryngeal alterations on videolaryngoscopy in RA patients and their association with disease activity. METHOD: This is a clinical cross-sectional study that evaluated patients with rheumatoid arthritis as to their disease activity score in 28 joints (DAS-28), laryngeal symptoms, application of a Portuguese version of the Voice Handicap Index and videolaryngoscopy findings, comparing them with a control group. RESULTS: We evaluated 47 (54%) patients with rheumatoid arthritis and 40 (46%) controls. The prevalence of dysphonia and videolaryngoscopy changes was respectively 12.8% and 72.4% in patients with RA. The mean of DAS-28 was 3.3 ± 1.2; 26 (74.3%) of 35 patients presenting active disease had laryngeal changes (p = 0.713). Posterior laryngitis was the most common diagnosis (44.7%). CONCLUSION: The prevalence of laryngeal disorders in RA patients was 72.4% and the prevalence of dysphonia was 12.8%. There was no significant relationship between laryngeal disorders and disease activity.

Avaliação do efeito do tratamento de distúrbios temporomandibulares sobre o zumbido / Evaluating the effect of the temporomandibular disorder treatment over tinnitus

INTRODUÇÃO: A interação entre o zumbido e os distúrbios temporomandibulares é um tema que possui abordagem antiga e complexa, pois os fatores etiológicos, bem como a patogênese desta inter-relação ainda não são bem definidos. Ademais, sabe-se que o zumbido possui maior prevalência nos portadores de distúrbios temporomandibulares quando comparados com a população geral, o que sugere haver esta correlação. OBJETIVO: Avaliar o efeito do tratamento dos distúrbios temporomandibulares na percepção do zumbido. MÉTODO: Trata-se de um estudo de coorte, prospectivo, em que se estudaram pacientes portadores de distúrbios temporomandibulares (DTM) que apresentavam zumbido antes e após o tratamento odontológico do DTM. Os pacientes foram avaliados quanto à idade, sexo, caracterização do zumbido - local do sintoma e tempo de duração e avaliação auditiva através de audiometria. A intensidade do zumbido foi avaliada através de escala analógico-digital antes e após o tratamento dos DTM. RESULTADOS: Avaliamos 15 pacientes com DTM e zumbido, com idade média de 37,7±17,1 anos, sendo 86,7 por cento do sexo feminino. Em 60 por cento dos casos o zumbido era unilateral e a mediana do tempo de duração foi de 24 meses. Em 5 (33,3 por cento) pacientes identificou-se perda auditiva neurossensorial a audiometria. Comparando-se os escores da escala analógico-visual antes e após o tratamento odontológico, verificou-se que houve redução significativa (p<0,001) da intensidade do zumbido. Em 4 (26,6 por cento) pacientes houve desaparecimento do zumbido. CONCLUSÃO: Houve redução significativa na percepção do zumbido nos pacientes submetidos a tratamento das desordens temporomandibulares.

INTRODUCTION: The interaction between tinnitus and temporomandibular disorders is a very complex issue that has been long approached, because neither the etiologic factors nor the pathogenesis of such a two-way association has been clearly defined yet. Additionally, tinnitus is known to be more prevalent in temporomandibular dysfunction individuals in comparison with the general population, hence, suggesting the existence of this two-way association. OBJECTIVE: Evaluate the effect of the temporomandibular disorder treatment when tinnitus is noticed. METHODS: It is about a prospective cohort study, in which temporomandibular dysfunction (TMD) individuals showing a tinnitus before and after the dental TMD treatment were studied. Patients' age, sex, and tinnitus features - place of symptom and time length were examined, and an audiometric evaluation was performed. Intensity of tinnitus was evaluated by a digital analogue scale before and after the TMD treatment. RESULTS: We evaluated 15 TMD and tinnitus patients aged between 37. 7±17. 1, 86. 7 percent of whom were female. In 60 percent of the cases, tinnitus was unilateral and the average time length was 24 months. In 5 (33. 3 percent) patients, a neurosensorial hearing loss was seen at audiometry. When comparing the visual analogue scale scores before and after the dental treatment, a significant decrease (p<0,001) in the intensity of tinnitus was evident. In 4 (26. 6 percent) patients, tinnitus disappeared. CONCLUSION: A significant decrease in the recognition of tinnitus by patients submitted to a temporomandibular dysfunction treatment was evident.

Perfil dos pacientes do Programa de Saúde Auditiva do Estado de Santa Catarina atendidos no HU-UFSC / Profile of patients of the Auditory Health of the State of Santa Catarina served at HU-UFSC

Introdução: A audição é uma das funções essenciais para o desenvolvimento da linguagem e sua deficiência pode levar a diversas consequências. Objetivo: Descrever o perfil dos pacientes do Programa de Saúde Auditiva do Estado de Santa Catarina atendidos no Hospital Universitário da Universidade Federal de Santa Catarina. Método: Realizou-se um estudo retrospectivo com os pacientes com indicação de protetização auditiva atendidos nos anos de 2007 e 2008. Dividiram-se os pacientes em 2 grupos: pediátrico (< 18 anos) e adulto (> 18 anos). Avaliou-se: idade, sexo, tipo e grau de perda, duração, comorbidades e etiologia provável. Resultados: Analisaram-se 304 prontuários, sendo 10,2% do grupo pediátrico e 89,8% do grupo adulto. No grupo pediátrico, a idade média foi de 7,7±5,4 anos, com 58,06% meninos e 41,94% meninas, e no grupo adulto a idade média foi de 61±16 anos, com 52,38% mulheres e 47,62% homens. Perda auditiva neurossensorial foi a mais encontrada nos 2 grupos. No grupo pediátrico, perda de grau profundo foi o mais frequente e no grupo adulto, graus moderado e moderado-severo. As principais etiologias foram causas genéticas/desconhecidas no grupo pediátrico e presbiacusia no grupo adulto. Conclusão: No grupo pediátrico, a maioria é de meninos, com perda neurossensorial, de graus leve e profundo, duração > 1 ano e sem comorbidades. No grupo adulto, a maioria é de mulheres, com perda neurossensorial, de graus moderado e moderado-severo, duração > 5 anos e comorbidades.

Introduction: Hearing is one of the essential functions for the development of language and its deficiency may lead to several consequences. Objective: To describe the profile of patients of the Hearing Health Program of the State of Santa Catarina attended at the College Hospital of the Federal University of Santa Catarina. Method: We performed a retrospective study with the patients with hearing aid indication attended in the years 2007 and 2008. They were divided into 2 groups: children (< 18 years) and adult (> 18 years). We assessed the following: age, sex, loss type and degree, duration, co-morbidity and probable etiology. Results: 304 reports were reviewed, 10.2% of the children group and 80.8% of the adult group. In the children group, the mean age was of 7.7±5,4 years, with 58.06% boys and 41.94% girls, and in the adult group the mean age was of 61±16 years, with 52.38% women and 47.62% men. The neurosensorial hearing loss was found more frequently in both groups. In the children group, the severe degree loss was more frequent, and in the adult group, the moderate and moderate to severe degrees were more frequent. The main etiologies were genetic/unknown causes in the children group and presbycusis in the adults group. Conclusion: In the children group, most was formed by boys with neurosensorial loss of light and severe degrees, duration > 1 year and without co-morbidities. In the adult group, most was formed by women with neurosensorial loss of moderate and moderate-severe degrees, duration > 5 year and with co-morbidities.

Effects of a nitric oxide synthase Type II inhibitor on compound action potential thresholds in experimental endolymphatic hydrops.

HYPOTHESIS: Nitric oxide (NO) is likely to be synthesized by nitric oxide synthase Type II (NOS II) action and may partake in the origin of changes of compound action potential (CAP) threshold observed in guinea pigs with induced endolymphatic hydrops. This study aimed to assess the action of a NOS II inhibitor on CAP thresholds in these experimental samples. BACKGROUND: In guinea pigs with experimental endolymphatic hydrops, there are lesions on the cochlea and progressive increase of CAP threshold. NOS II was found in the cochlea of this animal model, and it was inferred that NO can contribute by such alterations. METHODS: The animals were divided into two groups, in which eight received an intake of a NOS II inhibitor, aminoguanidine, and another eight served as a control group. During 16 weeks, CAP thresholds at 1,000, 2,000, 4,000 and 6,000 on electrocochleography were compared between the groups. RESULTS: The group that had an intake of aminoguanidine showed a lower increase on CAP thresholds at 2,000 (p < 0.05) and 6,000 Hz (p < 0.05) at the 12th postoperative week, and at 1,000 (p < 0.05), 2,000 (p < 0.001), 4,000 (p < 0.001), > and 6,000 Hz (p < 0.001) at the 16th week. CONCLUSION: We conclude that NOS II inhibitor reduced the elevation of CAP thresholds in experimentally induced endolymphatic hydrops.

Summating potential-action potential waveform amplitude and width in the diagnosis of Menière's disease.

OBJECTIVES: It has been suggested that analyzing the width and amplitude of the summating potential-action potential (SP-AP) waveforms can increase the sensitivity of electrocochleography. The objective of this study was to evaluate the ratio of SP to AP amplitude (SP/AP) and SP-AP waveform width, as well as the AP latency difference to condensation and rarefaction clicks, for the diagnosis of Menière's disease. STUDY DESIGN: This was a prospective, controlled study. METHODS: We used transtympanic electrocochleography to evaluate 21 patients with definite Menière's disease and 19 normal-hearing patients with other cochleovestibular disorders, comparing SP/AP, AP latency difference, and SP-AP waveform widths as well as calculating the diagnostic sensitivity of these parameters. RESULTS: Mean SP-AP waveform width was 1.89 ms in the study group and 1.58 ms in the control group. Mean SP/AP was 0.37 in the study group and 0.22 in the control group. The mean product of SP-AP waveform width and SP/AP was 75.26 ms% in the study group and 34.60 ms% in the control group. Mean AP latency difference was 0.13 ms in the study group and 0.07 ms in the control group. For the parameters evaluated, the differences between the groups were statistically significant. In the study group, the sensitivities for the width of the SP-AP waveform, the SP/AP, and the AP latency difference were 33.3%, 52.4%, and 23.8%, respectively. CONCLUSIONS: The use of the parameters evaluated did not increase the sensitivity of the electrocochleography, whether used in isolation or in conjunction with the SP/AP. Determining SP/AP presented the greatest sensitivity.

Experimental endolymphatic hydrops under action of a type II nitric oxide synthase inhibitor: otoacoustic emissions evaluation and electrocochleography.

UNLABELLED: In experimental endolymphatic hydrops distortion-products otoacoustic emission (dpoae) amplitudes decrease and there is elevation on electrocochleographic thresholds. Some authors found type ii nitric oxide synthase (nos ii) expression in hydropic cochleas and they suggest nitric oxide (no) may be involved in endolymphatic hydrops pathogenesis. The aim of this study was to evaluate the action of a nos ii inhibitor on dpoae and electrocochleography in experimental endolymphatic hydrops. MATERIAL AND METHODS: endolymphatic hydrops was induced in 16 guinea pigs by obliterating the endolymphatic duct and sac in the right ear. They were divided in two groups: eigth guinea pigs under the action of aminoguanidine, a nos ii inhibitor and eigth control guinea pigs. We compared dpoae amplitudes at geometric means of frequencies 1062, 2187, 4375 and 7000 hz, compound action potential threshold at 1000, 2000, 4000 and 6000 hz and summating potential to action potential (sp/ap) ratio between the groups during the postoperative observation period of 16 weeks. RESULTS: there were no significant changes in the dpoae amplitudes and in the sp/ap ratio. The group that received aminoguanidine had a lower degree of threshold increase at 2000 (p<0.05) And 6000 hz (p<0.05) In 12th postoperative week and at 1000 (p<0.05), 2000 (P<0.001), 4000 (P<0.001) And 6000 hz (p<0.001) At 16th postoperative week. CONCLUSIONS: nos ii inhibitor decreased the electrocochleography threshold elevation on experimental endolymphatic hydrops.

Hidropsia endolinfática experimental sob ação de inibidor da óxido nítrico sintase tipo II: avaliação com emissões otoacústicas e eletrococleografia / Experimental endolymphatic hydrops under action of a type II nitric oxide synthase inhibitor: otoacoustic emissions evaluation and electrocochleography

No modelo experimental de hidropsia endolinfática há redução na amplitude das emissões otoacústicas produtos de distorção (EOAPD) e elevação nos limiares eletrofisiológicos na eletrococleografia. Estudos mostraram que há expressão da óxido nítrico sintase tipo II (ONS II) na cóclea com hidropsia, sugerindo a participação do óxido nítrico (ON) na patogênese desta doença. O objetivo deste trabalho foi avaliar a ação de um inibidor da ONS II nas EOAPD e eletrococleografia em cobaias com hidropisia endolinfática experimental. MATERIAL E MÉTODOS: Foram estudadas 16 cobaias nas quais se induziu hidropsia endolinfática experimental por obliteração do ducto e saco endolinfático na orelha direita durante 16 semanas, divididas em dois grupos: oito cobaias recebendo um inibidor da ONS II, a aminoguanidina, por via oral e um grupo de oito cobaias como controle. Comparamos as amplitudes das EOAPD nas médias geométricas de freqüências de 1062, 2187, 4375 e 7000Hz, os limiares eletrofisiológicos nas freqüências de 1000, 2000, 4000 e 6000Hz e a relação entre os potenciais de somação e de ação (PS/PA) entre os grupos. RESULTADOS: Não houve diferença significante nas EOAPD e na relação PS/PA entre os grupos. O grupo que recebeu a aminoguanidina apresentou menor elevação nos limiares eletrofisiológicos nas freqüências de 2000 (p<0,05) e 6000 Hz (p<0,05) na 12ª semana e nas freqüências de 1000 (p<0,05), 2000 (p<0,001), 4000 (p<0,001) e 6000Hz (p<0,001) na 16ª semana. CONCLUSÕES: O inibidor da ONS II reduziu a elevação dos limiares eletrofisiológicos na eletrococleografia na hidropsia endolinfática experimental.

Hidropsia endolinfática experimental sob ação de inibidor da óxido nítrico sintase tipo II: avaliação com emissões otoacústicas produtos de distorção e eletrococleografia / Experimental endolymphatic hydrops under action of a type II nitric oxide synthase inhibitor: distortion product otoacustic emissions and electrocochleography evaluation

O objetivo deste trabalho foi avaliar a ação de um inibidor da óxido nítrico sintase tipo II (ONS II) nas emissões otoacústicas produtos de distorção (EOAPD) e na eletrococleografia em 16 cobaias com hidropsia endolinfática experimental induzida por obliteração do ducto e saco endolinfático da orelha direita. Oito cobaias receberam o inibidor da ONS II, a aminoguanidina e oito cobaias formaram o grupo controle. Comparamos as amplitudes das EOAPD nas médias geométricas de freqüências de 1062, 2187, 4375 e 7000 Hz, os limiares eletrofisiológicos nas freqüências de 1000, 2000, 4000 e 6000 Hz e a relação entre os potenciais de somação e de ação entre os grupos durante 16 semanas./The aim of this study was to evaluate the action of a type II nitric oxide synthase (NOS II) inhibitor on distortion product otoacoustic emissions (DPOAE) and electrocochleography in 16 guinea pigs with experimental endolymphatic hydrops induced by obliterating the endolymphatic duct and sac in the right ear. Eight guinea pigs received NOS II inhibitor, aminoguanidine and eigth guinea pigs were control group...