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%.

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%.

Contribution of audiovestibular tests to the topographic diagnosis of sudden deafness

Sudden hearing loss (SHL) is an ENT emergency defined as sensorineural hearing loss (SNHL) > 30 dB HL affecting at least 3 consecutive tonal frequencies, showing a sudden onset, and occurring within 3 days. In cases of SHL, a detailed investigation should be performed in order to determine the etiology and provide the best treatment. Otoacoustic emission (OAE) analysis, electronystagmography (ENG), bithermal caloric test (BCT), and vestibular evoked myogenic potential (VEMP) assessments may be used in addition to a number of auxiliary methods to determine the topographic diagnosis. OBJECTIVE: To evaluate the contribution of OAE analysis, BCT, VEMP assessment, and magnetic resonance imaging (MRI) to the topographic diagnosis of SHL. METHOD: Cross-sectional and retrospective studies of 21 patients with SHL, as defined above, were performed. The patients underwent the following exams: audiometry, tympanometry, OAE analysis, BCT, VEMP assessment, and MRI. Sex, affected side, degree of hearing loss, and cochleovestibular test results were described and correlated with MRI findings. Student's t-test was used for analysis of qualitative variables (p < 0.05). RESULTS: The mean age of the 21 patients assessed was 52.5 ± 15.3 years; 13 (61.9%) were women and 8 (38.1%) were men. Most (55%) had severe hearing loss. MRI changes were found in 20% of the cases. When the audiovestibular test results were added to the MRI findings, the topographic SHL diagnosis rate increased from 20% to 45%. CONCLUSION: Only combined analysis via several examinations provides a precise topographic diagnosis. Isolated data do not provide sufficient evidence to establish the extent of involvement and, hence, a possible etiology...

Contribution of audiovestibular tests to the topographic diagnosis of sudden deafness.

INTRODUCTION: Sudden hearing loss (SHL) is an ENT emergency defined as sensorineural hearing loss (SNHL) ≥ 30 dB HL affecting at least 3 consecutive tonal frequencies, showing a sudden onset, and occurring within 3 days. In cases of SHL, a detailed investigation should be performed in order to determine the etiology and provide the best treatment. Otoacoustic emission (OAE) analysis, electronystagmography (ENG), bithermal caloric test (BCT), and vestibular evoked myogenic potential (VEMP) assessments may be used in addition to a number of auxiliary methods to determine the topographic diagnosis. Objective To evaluate the contribution of OAE analysis, BCT, VEMP assessment, and magnetic resonance imaging (MRI) to the topographic diagnosis of SHL. Method Cross-sectional and retrospective studies of 21 patients with SHL, as defined above, were performed. The patients underwent the following exams: audiometry, tympanometry, OAE analysis, BCT, VEMP assessment, and MRI. Sex, affected side, degree of hearing loss, and cochleovestibular test results were described and correlated with MRI findings. Student's t-test was used for analysis of qualitative variables (p < 0.05). Results The mean age of the 21 patients assessed was 52.5 ± 15.3 years; 13 (61.9%) were women and 8 (38.1%) were men. Most (55%) had severe hearing loss. MRI changes were found in 20% of the cases. When the audiovestibular test results were added to the MRI findings, the topographic SHL diagnosis rate increased from 20% to 45%. Conclusion Only combined analysis via several examinations provides a precise topographic diagnosis. Isolated data do not provide sufficient evidence to establish the extent of involvement and, hence, a possible etiology.

Evaluation of the organic and functional results of tympanoplasties through a retro-auricular approach at a medical residency unit.

UNLABELLED: Tympanoplasty aims at rebuilding the tympanic membrane with or without middle ear functional recovery. AIM: To evaluate the surgical results of tympanoplasties with a retro-auricular surgical approach at a medical residency unit. MATERIALS AND METHODS: Thirty-nine patients with diagnosis of simple chronic otitis media were evaluated; these patients underwent tymplanoplasty by a retro-auricular approach (underlay technique) at a medical residency unit. Patients were included in a prospective medical and audiologic investigation protocol that consisted of a clinical, otomicroscopic and audiometric evaluation. All procedures were supervised by training specialists otorrinolaringology. RESULTS: The rate of surgical success - full integration of the graft - was 95% of cases. Improvement of hearing, as demonstrated in audiometry, occurred in 72% of cases. Improvement in tinnitus was demonstrated subjectively on a visual analog scale in 69% of cases. CONCLUSION: Tympanoplasty through a retro-auricular approach is easy to perform. Full graft integration occurred in 95% of cases and was independent of factors deemed by many authors as relevant. The results - improvement of the quality of hearing and tinnitus - were significant.

Evaluation of the organic and functional results of tympanoplasties through a retro-auricular approach at a medical residency unit / Avaliação dos resultados organofuncionais de timpanoplastias por via retroauricular em serviço de residência médica

Tympanoplasty aims at rebuilding the tympanic membrane with or without middle ear functional recovery. AIM: To evaluate the surgical results of tympanoplasties with a retro-auricular surgical approach at a medical residency unit. MATERIALS AND METHODS: Thirty-nine patients with diagnosis of simple chronic otitis media were evaluated; these patients underwent tymplanoplasty by a retro-auricular approach (underlay technique) at a medical residency unit. Patients were included in a prospective medical and audiologic investigation protocol that consisted of a clinical, otomicroscopic and audiometric evaluation. All procedures were supervised by training specialists otorrinolaringology. RESULTS: The rate of surgical success - full integration of the graft - was 95 percent of cases. Improvement of hearing, as demonstrated in audiometry, occurred in 72 percent of cases. Improvement in tinnitus was demonstrated subjectively on a visual analog scale in 69 percent of cases. CONCLUSION: Tympanoplasty through a retro-auricular approach is easy to perform. Full graft integration occurred in 95 percent of cases and was independent of factors deemed by many authors as relevant. The results - improvement of the quality of hearing and tinnitus - were significant.

Atimpanoplastia tem por objetivo a reconstrução da membrana timpânica com ou sem reconstrução funcional da orelha média. OBJETIVO: Avaliar os resultados cirúrgicos das timpanoplastias com o acesso cirúrgico retroauricular realizadas em serviço de residência médica. MATERIAL E MÉTODO: Foram avaliados 39 pacientes com diagnóstico de otite média crônica simples submetidos à timpanoplastia por via retroauricular (técnica "underlay") em um serviço de residência médica. Os pacientes foram incluídos em um protocolo de investigação médica e audiológica prospectivo que consistiu em avaliação clínica, otomicroscópica e audiométrica. Todos os procedimentos foram supervisionados por preceptores especialistas em otorrinolaringologia. RESULTADOS: A taxa de sucesso cirúrgico representado pela integração total do enxerto ocorreu em 95 por cento dos casos. A melhora da qualidade auditiva, comprovada pela audiometria, ocorreu em 72 por cento dos casos. Foi demonstrada a melhora subjetiva do zumbido, com a utilização da escala visual analógica, em 69 por cento dos casos. CONCLUSÃO: A timpanoplastia por via retroauricular é de fácil realização. A integração total do enxerto ocorreu em 95 por cento dos casos e foi independente de fatores considerados por muitos autores como relevantes. Os resultados quanto à melhora da qualidade auditiva e do zumbido foram significativos.