Neural Recovery Function of the Auditory Nerve in Cochlear Implant Surgery: Comparison between Prelingual and Postlingual Patients

Abstract Introduction Cochlear implants (CIs) enable objective measures of the neural function in implanted patients through the measurements of the neural response telemetry (NRT) and of the Auditory nerve Recovery Function (REC). These measurements help in programming the speech processor and understanding the auditory system. Objective To compare the NRT and the REC in prelingual and postlingual implanted patients. Methods An observational, descriptive and prospective study was carried out. The NRT and the REC (through the T0, A, and tau parameters) were evaluated in individuals submitted to CI surgery, who were divided into two groups: prelingual and postlingual patients. Results In total, 46 patients were evaluated. Data analysis showed no statistically significant difference between the NRT measurements and the T0, A, and Tau of the REC in the comparison between the two groups, except for the NRT in the basal cochlear region. Conclusion There was no statistically significant difference in the REC in pre- and postlingual patients.

Facial Nerve Intraoperative Monitoring in Otologic Surgeries under Sedation and Local Anesthesia - A Case Series and Literature Review

Abstract Introduction Local anesthesia with sedation has been employed for an increasingly number of otolaryngology procedures, and might be associated with lower surgical morbidity and costs. Facial nerve monitoring is often advisable in otology to minimize the risks of injuries to this cranial nerve, but the principles, techniques and parameters involved have only been studied for procedures under general anesthesia. Objective To report the preliminary outcomes of intraoperative facial nerve moni- toring during otologic procedures under sedation and local anesthesia. Methods A total of five procedures and their respective intraoperative electrophysi- ological main findings were described. Facial neuromonitoring was performed using the same device by an electrophysiologist. The monitor sensitivity was set at 100 mV, and a stimulating probe was used whenever needed. Results Progressively decreasing low-amplitude baseline values were usually obtained as the level of anesthesia increased, with isolated oscillations possibly related to some degree of voluntary muscular activity. These oscillations could be easily distinguished from those of the surgical manipulation or electrical stimulation of the nerve, which tended to be of much greater amplitude and shorter latency, occurring during specific surgical steps. Conclusion With a surgical team with proper procedural knowledge and broad expertise regarding the technique, intraoperative facial nerve monitoring under local anesthesia with sedation seemed both feasible and reliable. Thus, the need for intraoperative neuromonitoring should not be an obstacle for otologic procedures under less aggressive anesthetic management.

Use of remote control in the intraoperative telemetry of cochlear implant: multicentric study / Uso do controle remoto na telemetria intraoperatória do implante coclear: estudo multicêntrico

Abstract Introduction: The conventional evaluation of neural telemetry and impedance requires the use of the computer coupled to an interface, with software that provides visualization of the stimulus and response. Recently, a remote control (CR220®) was launched in the market, that allows the performance of intraoperative tests with minimal instrumentation. Objective: To evaluate the agreement of the impedance values and neural telemetry thresholds, and the time of performance in the conventional procedure and by the remote control. Methods: Multicentric prospective cross-sectional study. Intraoperative evaluations of cochlear implants compatible with the use of CR220® were included. The tests were carried out in the 22 electrodes to compare the time of performance in the two situations. The agreement of the neural telemetry threshold values obtained from five electrodes was analyzed, and the agreement of impedance was evaluated by the number of electrodes with altered values in each procedure. Results: There were no significant difference between the impedance values. There was a moderate to strong correlation between the electrically-evoked compound action potential thresholds. The mean time to perform the procedures using the CR220 was significantly lower than that with the conventional procedure. Conclusion: The use of the CR220 provided successful records for impedance telemetry and automatic neural response telemetry.

Resumo Introdução: A avaliação convencional da telemetria neural e de impedâncias implica o uso do computador acoplado a uma interface, o software fornece o estímulo e a visualização das respostas. Recentemente, foi lançado um controle remoto (CR220®), que possibilita testes intraoperatórios com instrumental mínimo. Objetivo: Avaliar a concordância dos valores das impedâncias e dos limiares da telemetria neural e o tempo de execução no procedimento convencional e pelo controle remoto. Método: Estudo prospectivo transversal multicêntrico. Foram incluídas as avaliações intraoperatórias de implante coclear compatível com o uso do CR220®. Os testes foram realizados nos 22 eletrodos para comparar os tempos de execução nas duas situações. Foi analisada a concordância dos valores do limiar da telemetria neural obtidos em cinco eletrodos e a concordância das impedâncias foi avaliada pelo número de eletrodos com valores alterados em cada procedimento. Resultados: Não houve diferença significante entre as impedâncias. Obteve-se moderada a forte correlação entre os limiares do potencial de ação composto eletricamente evocado. O tempo médio para os procedimentos com o CR220 foi significativamente menor do que com o procedimento convencional. Conclusão: O uso do CR220 proporcionou registros bem-sucedidos para a telemetria de impedância e a telemetria automática de respostas neurais.

Comparação da telemetria de resposta neural via cocleostomia ou via janela redonda no implante coclear / A comparison between neural response telemetry via cochleostomy or the round window approach in cochlear implantation

Existem duas técnicas para inserção dos eletrodos do implante coclear (IC): Via cocleostomia ou via janela redonda (JR). OBJETIVO: Comparar a telemetria de resposta neural (NRT) no pós-operatório imediato, verificando se há diferenças na estimulação do nervo auditivo entre estas duas técnicas. MÉTODOS: Prospectivo e transversal. Foram avaliados 23 pacientes. Seis submetidos à cirurgia via cocleostomia e 17 via JR. RESULTADOS: Comparação das unidades de corrente médias (UCM) para sons agudos: via JR com média de 190,4 (± 29,2) e via cocleostomia 187,8 (± 32,7), p = 0,71. Comparação das UCM para sons intermediários: via JR, média de 192,5 (± 22) e via cocleostomia 178,5 (± 18.5), p = 0,23. Comparação das UCM para sons graves: via JR, média de 183,3 (± 25) e via cocleostomia 163,8 (± 19,3), p = 0,19. CONCLUSÃO: Este estudo não mostrou diferença na captação do potencial de ação da porção distal do nervo auditivo em pacientes usuários do implante coclear multicanal submetidos à cirurgia via cocleostomia ou via JR, utilizando o próprio implante para eliciar o estímulo e gravar as respostas. Portanto, ambas as técnicas estimulam de maneira igual o nervo coclear, e baseado nisto conclui-se, também, que realizar o implante coclear via cocleostomia ou RW é uma escolha que depende da experiência cirúrgica e opção do cirurgião.

There are two techniques for cochlear implant (CI) electrode placement: cochleostomy and the round window (RW) approach. OBJECTIVE: This study aims to compare neural response telemetry (NRT) results immediately after surgery to check for possible differences on auditory nerve stimulation between these two techniques. MATERIALS AND METHODS: This is a prospective cross-sectional study. Twenty-three patients were enrolled. Six patients underwent surgery by cochleostomy and 17 had it through the RW approach. RESULTS: Mean charge units (MCU) for high frequency sounds: patients submitted to the RW approach had a mean value of 190.4 (± 29.2) while cochleostomy patients averaged 187.8 (± 32.7); p = 0.71. MCU for mid frequency sounds: patients submitted to the RW approach had a mean value of 192.5 (± 22) while cochleostomy patients averaged 178.5 (± 18.5); p = 0.23. MCU for low frequency sounds: patients submitted to the RW approach had a mean value of 183.3 (± 25) while cochleostomy patients averaged 163.8 (± 19.3); p = 0.19. CONCLUSION: This study showed no differences in the action potential of the distal portion of the auditory nerve in patients with multichannel cochlear implants submitted to surgery by cochleostomy or through the RW approach, using the implant itself to generate stimuli and record responses. Both techniques equally stimulate the cochlear nerve. Therefore, the choice of approach can be made based on the surgeon's own preference and experience.

Potencial evocado cognitivo e desordem de processamento auditivo em crianças com distúrbios de leitura e escrita / Cognitive evoked potentials and central auditory processing in children with reading and writing disorders

As dificuldades na aprendizagem escolar muitas vezes podem ser causadas por uma alteração do Processamento Auditivo - PA. OBJETIVO: Identificar se acima da média dos valores de latência do P300, num grupo de indivíduos com Distúrbio de Leitura e Escrita, também seriam encontradas alterações no teste Staggered Spondaic Word - SSW e no teste de Fala no Ruído que sugerissem Desordem do Processamento Auditivo - DPA. MATERIAL E MÉTODOS: Estudo de coorte transversal. Foram avaliados 21 indivíduos com distúrbio de leitura e escrita, idade entre 7 e 14 anos. RESULTADOS: Todos apresentaram resultados normais no exame otorrinolaringológico, na avaliação audiológica e Potencial Evocado Auditivo de Tronco Encefálico. Fazendo-se a média aritmética de todos os valores de latência do P300 obtidos, chegou-se à média de 334,25 ms, sendo divididos em dois grupos: grupo "A", com média da latência acima de 335 ms, e "B", com latência abaixo de 335 ms. Nos indivíduos do grupo "A", foram realizados os testes SSW e Fala no Ruído. CONCLUSÃO:O presente estudo pode concluir que foram encontradas alterações nos testes de fala dicótica (SSW) e de Fala no Ruído no grupo de indivíduos com Distúrbio da Escrita e Leitura com valores de latência do P300 acima de 335 ms, sugerindo DPA.

Learning disorders are often magnified by auditory processing disorders (APD). OBJECTIVE: This paper aims to verify whether individuals with reading and writing disorders and P300 latencies above the average also present altered Staggered Spondaic Word (SSW) and speech-in-noise test results suggestive of APD. MATERIALS AND METHODS: This is a cross-sectional cohort study. Twenty-one individuals with reading and writing disorders aged between 7 and 14 years were enrolled. RESULTS: All subjects had normal findings on ENT examination, audiological tests, and brainstem auditory evoked potentials. The average P300 latency (334,25 ms) of all patients was picked as a cutoff point to divide the subjects into two groups: group A with latencies above 335 ms, and group B with latencies below 335 ms. Individuals in group A underwent SSW and speech-in-noise testing. CONCLUSION: Altered results in the SSW and speech-in-noise tests suggestive of APD were found in the group of individuals with reading and writing disorders with P300 latencies above 335 ms.

Anestesia local e sedação para cirurgia de implante coclear: uma alternativa possível / Local anesthesia for cochlear implant surgery: a possible alternative

Aanestesia geral sempre foi motivo de dúvida dos pacientes que vão ser submetidos a qualquer cirurgia, especialmente o implante coclear. Como já realizamos as cirurgias otológicas com anestesia local e sedação, julgamos perfeitamente possível a realização da cirurgia do implante coclear também com esse tipo de anestesia, diminuindo os riscos, a morbidade e os custos para o hospital. OBJETIVOS: Estudo prospectivo para demonstrar a técnica anestésica e cirúrgica utilizada em três casos de adultos submetidos ao implante coclear, avaliando a segurança e a eficácia de tal técnica. MATERIAL E MÉTODOS: Foram feitas três cirurgias de implante coclear, duas com implante Cochlear e uma com Med-EL, sem intercorrências transoperatórias, durante a telemetria e no pós-operatório imediato. RESULTADOS: Os três pacientes adultos tiveram alta hospitalar aproximadamente três horas após a cirurgia, deambulando, sem eventos nauseosos, relatando um pós-operatório mais fácil do que esperavam, mesmo no momento da telemetria intraoperatória. CONCLUSÃO: Anestesia local e sedação é uma alternativa para casos selecionados de pacientes para o implante coclear, principalmente naqueles de mais idade ou que apresentem contraindicação para a anestesia geral, os riscos e a morbidade são menores.

The aim of this paper is to illustrate the possibility of performing a cochlear implant surgery with local anesthesia and sedation, the anesthetic technique and the advantages of that in comparison to a general anesthesia. AIMS: prospective study demonstrating the possibility of doing cochlear implant surgery under local anesthesia and sedation. MATERIALS AND METHODS: we describe three successful cases operated under local anesthesia, including neural telemetry and the conditions the patient presented after the surgery, with a very good recovery and no complications during and after the procedure. RESULTS: these three surgeries show the possibility of doing the cochlear implant surgery with this kind of anesthesia, with a fast recovery, no symptoms of dizziness and vomiting after the surgery, and very few complaints from the patient. CONCLUSION: local anesthesia with sedation for cochlear implant surgery in adults is a very good alternative for lowering the morbidity for the patient. It bears fewer risks, low costs for the hospital, with a very good procedure control, being very useful for older patients or the ones that have contraindications for general anesthesia.

Event-related potentials (P300) and neuropsychological assessment in boys exhibiting Duchenne muscular dystrophy

OBJECTIVE: To examine auditory cognitive evoked potentials (P300 potentials) and neuropsychological dysfunction in patients with Duchenne muscular dystrophy (DMD). METHOD: P300 potentials and neuropsychological test results were obtained from 16 healthy control boys and 20 DMD patients. Full Intelligence Quotients (IQ) were estimated for patients and control group. Mean age was 9.5 years in the DMD patient group, and 10 years in the control group (p>0.05). RESULTS: The mean IQ values were 64.35 in the DMD patients and 82.68 in the control group (p=0.01). Mean P300 values were 347.6 in the DMD group and 337.4 in the control group (p=0.14). There was no significant correlation between parameters in each group. CONCLUSION: DMD patients showed a poor performance as evaluated by P300 potential compared to the control group, although the difference was not statistically significant. Systematic alterations in neuropsychological test results were found, the differences paralleling those detected in IQ.

OBJETIVO: Avaliar potenciais evocados cognitivos auditivos (P300) e disfunções neuropsicológicas em pacientes com distrofia muscular de Duchenne (DMD). MÉTODO: Potenciais auditivos P300 e testes neuropsicológicos foram obtidos de 16 controles e 20 pacientes com DMD. Valores de quociente de inteligência (QI) foram estimados para os dois grupos. A media de idade foi de 9.5 anos no grupo DMD e 10 anos no grupo controle (p>0.05). RESULTADOS: Os valores médios de QI foram 64.35 no grupo DMD e 82.68 no grupo controle (p=0.01). A média de valores de P300 foi 347.6 no grupo DMD e 337.4 no grupo controle (p=0.14). Não houve correlação significativa entre os parâmetros em cada grupo. CONCLUSÃO: Os pacientes com DMD mostraram um pior desempenho nas testagens de P300 quando comparados com o grupo controle, embora a diferença não tenha apresentado diferença significativa. Alterações sistemáticas foram encontradas nos testes neuropsicológicos, correspondendo às alterações significativas vistas nos valores de QI.