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CONCLUSION: Responses with greater amplitude were recorded when carrier frequencies were modulated at 37, 40, and 43 Hz. These responses can be recorded even in patients with significant sensorineural hearing loss, from the sternocleidomastoid (SCM) muscle for a 500 Hz tone, 100% modulated at 40 Hz. OBJECTIVE: To determine the best carrier and modulating frequencies to evoke steady-state myogenic responses. METHODS: The present study investigated 156 ears of 78 normal-hearing young adults, with carrier frequencies of 250, 500, and 1000 Hz, modulated at 20, 37, 40, 43, 70, 77, and 80 Hz, with an intensity of 95 dBA. Furthermore, we observed responses evoked by stimulus carrier frequency of 500 Hz, modulated at 40 Hz, with an intensity of 95 dBA in a group of five subjects with severe sensorineural loss. RESULTS: Responses were found for all stimuli studied (p < 0.01). Modulated stimuli at frequencies of 37, 40, and 43 Hz evoked better steady-state vestibular evoked myogenic potential (S-VEMP) (p < 0.05). No statistically significant differences were found between the group of normal hearers and the group of subjects with hearing loss (p = 0.431), for the stimulus used.

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INTRODUÇÃO: O Potencial Evocado Miogênico Vestibular (VEMP) é um teste promissor para a avaliação do sistema vestíbulo-cólico descendente. Este reflexo depende da integridade da mácula sacular, do nervo vestibular inferior, dos núcleos vestibulares, das vias vestíbulo-espinhais e do músculo efetor. OBJETIVO: Realizar revisão sistemática de literatura pertinente por meio de bases de dados (COCHRANE, MEDLINE, LILACS, CAPES). CONCLUSÃO: A aplicação clínica do VEMP expandiu-se nos últimos anos, com o objetivo de que este exame seja utilizado como complementar na avaliação otoneurológica atualmente utilizada. Porém, questões metodológicas devem ser esclarecidas. Dessa forma, este método, quando combinado com o protocolo padrão, poderá fornecer uma avaliação mais abrangente do sistema vestibular. A padronização da metodologia é fundamental critério para a replicabilidade e sensibilidade do exame.

INTRODUCTION: The Vestibular Evoked Myogenic Potential (VEMP) is a promising test for the evaluation of the cholic descending vestibular system. This reflex depends of the integrity from the saccular macula, from the inferior vestibular nerve, the vestibular nuclei, the vestibule-spinal tract and effectors muscles. OBJECTIVE: Perform a systematic review of the pertinent literature by means of database (COCHRANE, MEDLINE, LILACS, CAPES). CONCLUSION: The clinical application of the VEMP has expanded in the last years, as goal that this exam is used as complementary in the otoneurological evaluation currently used. But, methodological issues must be clarified. This way, this method when combined with the standard protocol, can provide a more widely evaluation from the vestibular system. The standardization of the methodology is fundamental criterion for the replicability and sensibility of the exam.

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Verificar se os potenciais evocados miogênicos vestibulares podem apresentar anormalidades na orelha comprometida e na orelha assintomática em pacientes com hipótese diagnóstica de doenca de Ménière definida unilateral. FORMA DE ESTUDO: Transversal coorte. MATERIAL E MÉTODO: Foram avaliados os potenciais evocados miogênicos vestibulares de 20 pacientes com doenca de Ménière definida unilateral. A selecão dos indivíduos baseou-se na história e na avaliacão clínica sugestivas de doenca de Ménière definida unilateral, e eletrococleografia com anormalidades na orelha comprometida. Os potenciais evocados miogênicos vestibulares foram avaliados em ambas as orelhas de cada paciente por meio da latência absoluta de p13 e n23, diferenca interaural da latência dos picos p13 e n23 e índice de assimetria da amplitude de p13-n23. RESULTADO: Os potenciais evocados miogênicos vestibulares estavam alterados em 35,0 por cento das orelhas comprometidas e em 25,0 por cento das orelhas assintomáticas. As alteracões foram: ausência de resposta em sete casos, aumento da latência absoluta de p13 em três casos, e aumento do índice de assimetria da amplitude em um caso. CONCLUSAO: Os potenciais evocados miogênicos vestibulares podem apresentar anormalidades nas orelhas comprometida e assintomática de pacientes com hipótese diagnóstica de doenca de Ménière definida unilateral.

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AIM: To verify whether vestibular evoked myogenic potentials can present abnormalities in the affected ear and in the asymptomatic ear in patients with diagnosis of unilateral Ménière's disease. STUDY DESIGN: Transversal cohort. MATERIAL AND METHOD: The vestibular evoked myogenic potentials of 20 patients with unilateral Ménière's disease were analyzed. The selection of individuals was based on the history and in clinical evaluation suggestive of unilaterally defined Ménière's disease, and with electrocochleography abnormalities in the affected ear. Vestibular evoked myogenic potentials were evaluated in both ears of each patient through absolute latencies of p13 and n23, interaural difference of latency of peaks p13 and n23 and amplitude p13-n23 asymmetry rate. RESULTS: Vestibular evoked myogenic potentials were altered in 35.0% of the affected ears and in 25.0% of the asymptomatic ears. The alterations were: absence of responses in seven cases, prolongation of p13 latency in three cases, and increase in interaural amplitude difference ratio in one case. CONCLUSION: The vestibular evoked myogenic potentials can present abnormalities in the affected and asymptomatic ears in patients with diagnosis of unilaterally defined Ménière's disease.

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