Potencial evocado miogênico vestibular: novas perspectivas diagnósticas em esclerose múltipla

Abstract

Aim:To evaluate vestibular evoked myogenic potentials in patients with multiple sclerosis as method of diagnostic support. Study design: Case-control. Material and Method: We studied a group of normal individuals (n=15) and a Studied group (n=15) that comprised patients with diagnosis of multiple sclerosis. Both groups were submitted to vestibular evoked myogenic potential exam. In each ear it was applied 200 stimuli by clicks and repeated for 2 consecutive cycles with the purpose of evaluating reproducibility. The active electrode of surface was put on the superior S ‡of sternocleidomastoid muscle and the reference electrode on the anterior border of the clavicle. The individuals were instructed to rotate theirs head to the opposite side to the stimulated ear. Results: Vestibular evoked myogenic potential responses were prompt, reproducible and biphasic. The latency of wave P1 and N2 and P1-N2 amplitude showed a higher value in the studied group when compared with the normal group. There was no significant difference when the ears were compared in P1 and N2 amplitude. We noticed that individuals with multiple sclerosis showed no response in 30% of the cases. In evaluating the individuals of the Studied group with otoneurology symptoms and compared with individuals without symptoms, it was observed that P1 and N2 latencies and P1-N2 amplitude were higher in symptomatic cases. Conclusion: Vestibular evoked myogenic potential was considered a good method of diagnostic support of vestibulospinal tract in cases of multiple sclerosis.

Potencial evocado miogênico vestibular (VEMP)

“…8 Com relação aos parâmetros para realização do VEMP, alguns estudos utilizaram cliques para estimulação da mácula. 7,9 Dentre todos os órgãos vestibulares, o sáculo, situado exatamente abaixo da base do estribo, é o mais sensível ao som. 1 O reflexo se origina no sáculo, é transmitido para os neurônios do Gânglio de Scarpa, caminha pelo nervo vestibular inferior, núcleo vestibular e trato vestibuloespinhal e chega aos neurônios motores do músculo.…”

“…Estudos realizados verificaram o valor do VEMP no diagnóstico e monitoramento de diversas doenças de origem central e periférica: doença de Meniere, [16][17][18][19][20][21] trauma acústico, 22 fenômeno de Tullio, 7 degeneração espinocerebelar, 23 deiscência do canal vestibular superior, 24 neurinoma do acústico, 11 esclerose múltipla, 9,10,[25][26] vertigem posicional paroxística benigna, 27 neuronite vestibular, 28 entre outras.…”

Esclerose Múltipla: imunopatologia, diagnóstico e tratamento – Artigo de revisão

“…Existe ainda o potencial evocado miogênico vestibular (VEMP), que é um teste que avalia as lesões no tronco encefálico ou as que venham a comprometer a via vestíbulo-espinal, ele é realizado a partir de estímulos acústicos em forma de cliques a partir de fones de ouvido (AIDAR, 2005).…”

“…São as características genéticas que definem a maior ou menor frequência de EM entre os indivíduos e não o local onde residem (TILBERY, 2005 (ZIEGELBOIM, 2010). Existe, também, um método de diagnóstico da EM realizado pelo Potencial Evocado Miogênico Vestibular (VEMP), que avalia a via vestíbulo-espinal a partir de mácula de sáculo (AIDAR, 2005).…”

Vestibular evoked myogenic potentials (VEMP) captured in the forearm flexor muscles: a study of its feasibility and reference ranges

“…VEMP has positive and negative components, which vary according to the capture location. The values corresponding to the contractile neck muscles - named cervical VEMP and the extraocular muscles-ocular VEMP - have been described previously in the literature, as well as their respective recording techniques ( 13 , 14 ).…”