Eletroneurografia do nervo facial métodos de estimulação e registro

Medeiros, Jovany Luis Alves de; Nóbrega, J.A.M.; Novo, Neil Ferreira

doi:10.1590/s0004-282x1992000200006

Cited by 2 publications

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References 9 publications

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“…The ground electrode was fixed to the hand. The facial nerve was stimulated with the cathode just over the tragus, according to a method previously described 14 .…”

Section: Methodsmentioning

confidence: 99%

Facial electroneurography in Bell's palsy: variability in the early stage and comparison between interpretation methods

Medeiros

Nóbrega

Andrade

et al. 1996

Arq. Neuro-Psiquiatr.

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-To determine the variability of the abnormalities found in the electroneurography (ENG) of the facial nerve in cases of Bell's palsy during the initial two week period was one of the objectives of the authors. A second one was to investigate the value of ENG as a tool to determine an early prognosis of recovery utilizing two different methods. In the first one the amplitude of the compound muscular action potential (CMAP) obtained on the paralyzed side was compared to this potential on the opposite (normal) side. The second method compared the CMAP on the paralyzed side to normal standardized data from normal individuals. A group of 33 patients with Bell's palsy was followed until total recovery or for at least 4 months, if the recovery was not achieved earlier. It was observed that amplitude of the CMAP become stable towards the sixth day of palsy and this is a good time to establish the prognosis. Another conclusion is that both methods were equivalent to determine the prognosis in Bell's palsy.KEY WORDS: electroneurography, Bell's palsy, facial nerve.Eletroneurografia do nervo facial na paralisia de Bell: variabilidade na fase aguda e comparação entre técnicas RESUMO -O objetivo deste trabalho é determinar a variabilidade da eletroneurografia (ENG) do nervo facial na paralisia de Bell durante as primeiras duas semanas e investigar o valor da ENG na determinação de um prognóstico precoce utilizando-se dois métodos diferentes. O primeiro método compara a amplitude do potencial de ação muscular composto obtido no lado paralisado com o lado normal e o segundo método compara o potencial de ação muscular composto obtido no lado paralisado com valores normativos. Um grupo de 33 pacientes com paralisia de Bell foi seguido até a recuperação total ou pelo menos por quatro meses nos casos em que não houve recuperação. Observou-se que a amplitude do potencial de ação muscular composto estabiliza-¬ se em torno do sexto dia e que este é um bom momento para se realizar o exame e se estabelecer um prognóstico. Outra conclusão é que ambos os métodos são equivalentes para determinação prognóstica. PALAVRAS-CHAVE: eletroneurografia, paralisia de Bell, nervo facial.The pathologic process in idiopathic peripheral facial palsy stabilizes two weeks after the beginning of the illness 58 . The usual method of electroneurography (ENG) used to determine the prognosis in Bell's palsy consists of comparing the amplitude of the compound muscular action potential (CMAP) registered on the affected side with the CMAP amplitude obtained on the normal hemiface. A large difference implies a great number of nerve fibers affected and a worse prognosis.

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“…The ground electrode was fixed to the hand. The facial nerve was stimulated with the cathode just over the tragus, according to a method previously described 14 .…”

Section: Methodsmentioning

confidence: 99%

Facial electroneurography in Bell's palsy: variability in the early stage and comparison between interpretation methods

Medeiros

Nóbrega

Andrade

et al. 1996

Arq. Neuro-Psiquiatr.

Self Cite

View full text Add to dashboard Cite

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Facial nerve electroneurography: variability in normal subjects

Medeiros

Nóbrega

Andrade

et al. 1996

Arq. Neuro-Psiquiatr.

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SUMMARY -Twenty normal individuals were submitted to facial nerve electroneurography using different techniques in order to determine the most accurate to obtain the latencies and amplitudes of the compound muscle action potentials (CMAP) of the facial muscles. First of all it was determined in which muscle or muscle group highest amplitude CMAP could be recorded with the lowest variability between sides and in test-retest. Different techniques were studied in order to determine which could give the best results. This was shown to be an arrangement of bipolar surface electrodes fixed to a plastic bar. The records with higher amplitude where obtained from the nasolabial fold muscles. Therefore 65 normal volunteers were examined using this technique and recording the potentials obtained over the nasolabial fold muscles. Normal values were determined (latency lower than 4.5 ms and amplitude larger than 2 mV -95% confidence limits).KEY WORDS: facial nerve, eletroneurography. Eletroneurografia do nervo facial: variabilidade em indivíduos normaisRESUMO -Vinte voluntários normais foram submetidos a eletroneurografia do nervo facial utilizando-se diferentes técnicas para a determinação da mais acurada para a obtenção das latências e amplitudes do potencial de ação muscular composto (CMAP) dos músculos faciais. Inicialmente determinou-se em qual músculo ou grupo muscular registra-se CMAP com maior amplitude e menor variabilidade entre lados e entre testes, assim como determinou-se qual técnica proporcionou melhores resultados. A que mostrou melhores resultados foi realizada com eletrodos de superfície bipolares de discos fixos em barra de plástico e os melhores registros foram obtidos nos músculos do sulco nasolabial. A seguir 65 voluntários normais foram estudados com esta técnica registrando-se os potenciais nos músculos do sulco nasolabial e foram determinados os valores normais para a latência (menor que 4,5 ms) e amplitude (acima de 2 mV). PALAVRAS-CHAVE: nervo facial, eletroneurografia.Since Desmedt's 4 description of compound muscle action potential (CMAP) in facial muscles, many electrophysiological techniques have been described aiming to establish an early prognosis for facial nerve palsy. Most of these techniques are based on comparative analysis between the CMAP obtained by the stimulation of the normal and damaged facial nerves. Another method is to compare the amplitude of the CMAP obtained by the stimulation of the damaged facial nerve with values obtained from a normal group of subjects, which is particulary helpful in patients with bilateral facial palsy. Fisch* and Esslen 7 considered that the percentage of reduction of the CMAP obtained on the paralyzed side is proportional to the number of affected nerve fibers. Many techniques have been described analyzing CMAPs of different facial muscles obtained with different stimuli and recording conditions 10,12 " 1416 "' 20 . To validate these techniques it must be assumed that normal subjects have small variability in CMAP amplitude between sides and in succ...

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Eletroneurografia do nervo facial métodos de estimulação e registro

Cited by 2 publications

References 9 publications

Facial electroneurography in Bell's palsy: variability in the early stage and comparison between interpretation methods

Facial electroneurography in Bell's palsy: variability in the early stage and comparison between interpretation methods

Facial nerve electroneurography: variability in normal subjects

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