The P300 Auditory Evoked Potential in Cochlear Implant Users: A Scoping Review

Abstract Introduction The P300 auditory evoked potential is a long-latency cortical potential evoked with auditory stimulation, which provides information on neural mechanisms underlying the central auditory processing. Objectives To identify and gather scientific evidence regarding the P300 in adult cochlear implant (CI) users. Data Synthesis A total of 87 articles, 20 of which were selected for this study, were identified and exported to the Rayyan search software. Those 20 articles did not propose a homogeneous methodology, which made comparison more difficult. Most articles (60%) in this review compare CI users with typical hearing people, showing prolonged P300 latency in CI users. Among the studies, 35% show that CI users present a smaller P300 amplitude. Another variable is the influence of the kind of stimulus used to elicit P300, which was prolonged in 30% of the studies that used pure tone stimuli, 10% of the studies that used pure tone and speech stimuli, and 60% of the studies that used speech stimuli. Conclusion This review has contributed with evidence that shows the importance of applying a controlled P300 protocol to diagnose and monitor CI users. Regardless of the stimuli used to elicit P300, we noticed a pattern in the increase in latency and decrease in amplitude in CI users. The user's experience with the CI speech processor over time and the speech test results seem to be related to the P300 latency and amplitude measurements.

Is there a change in P300 evoked potential after 6 months in cochlear implant users?

Abstract Objective: There are few studies on long-latency auditory evoked potential (P300) in people with hearing loss who use a cochlear implant. Central auditory system evaluation with behavioral and electrophysiological tests is believed to help understand the neuroplasticity mechanisms involved in auditory functioning after cochlear implant surgery. This study investigated the electrophysiological processing of cortical level acoustic signals in a group of 21 adult individuals with postlingual bilateral severe-to-profound hearing loss who were submitted to cochlear implant surgery. Methods: Data were collected in three phases: pre-cochlear implant surgery, at cochlear implant activation, and 6 months after surgery. P300 measures were also registered during all phases. Tone-burst and speech stimuli were used to elicit P300 and were presented in free field. Results: Mean P3 component latency with tone-burst and speech stimuli were 352.9 and 321.9 ms in the pre-cochlear implant phase, 364.9 and 368.7 ms in the activation phase, 336.2 and 343.6 ms 6 months after the surgery. The P3 component mean latency values using tone-burst at activation were significantly different from those 6 months after cochlear implant. They were also significantly different using speech, between pre-cochlear implant and activation phases. Lower P3 component latency occurred 6 months after cochlear implant activation with tone-burst and pre-cochlear implant with speech stimulus. There was a weak correlation between mean P3 component latency with speech stimulus and time of hearing loss. There was no difference in amplitude between phases or in the comparison with the other variables. Conclusion: There were changes in P3 component latency during the period assessed, for both speech and pure-tone stimuli, with increased latency in the activation phase and similar lower results in the two other phases, Pre-CI and 6 months after CI use. Mean amplitude measures did not vary in the three phases.

Surgical and audiological results of bone-anchored hearing aids: comparison of two surgical techniques / Resultados cirúrgicos e audiológicos de próteses ancoradas no osso: comparação de duas técnicas cirúrgicas

Abstract Introduction: The bone-anchored hearing system has become the most viable treatment option for subjects with conductive or mixed hearing loss, who are unable to benefit from conventional hearing aids or middle ear surgery. Objective: To compare the surgical and audiological outcomes between the minimally-invasive Ponto surgery and a linear incision with soft tissue preservation techniques in bone-anchored hearing system recipients. Methods: A retrospective study was carried out from January 2017 to June 2018. Forty-two adult patients eligible for unilateral bone-anchored hearing system surgery with the Ponto system were included in the study. The implant and abutment lengths used varied from 3 to 4 mm and from 6 to 14 mm, according to the bone and skin thickness of the participants, respectively. Results: Twenty-two surgeries were performed using the minimally invasive Ponto surgery technique (52.4%) and 20 (47.6%) using the linear incision. The mean age of the subjects implanted with minimally invasive Ponto surgery and linear incision techniques were 42.0 and 33.3 years old, respectively. Ten male (45,5%) and 14 (70%) female patients were implanted using minimally invasive Ponto surgery and the linear incision techniques, respectively. There were no differences between pure tone audiometric thresholds and monosyllabic word recognition scores of the subjects, when comparing both surgical techniques. The minimally invasive Ponto surgery technique significantly reduced the surgical time compared to the linear incision technique. There were no differences between both surgical techniques for skin-related complications; (Holgers 3 and 4) which occurred in 18.8% for MIPS and in 25% for linear incision. Subjects included in the minimally invasive Ponto surgery technique group showed a superior cosmetic outcome, with no surgical scar or additional sutures. Conclusion: The surgical and audiological outcomes were satisfactory and were not correlated to the surgical technique selected in all subjects. When compared to the linear incision, the minimally invasive Ponto surgery technique showed reduced surgical time and superior esthetic outcomes in the postoperative follow-up.

Resumo Introdução: As próteses auditivas ancoradas ao osso têm se tornado a opção de tratamento mais viável para indivíduos com perda auditiva condutiva ou mista, incapazes de se beneficiar de aparelhos auditivos convencionais ou cirurgia da orelha média. Objetivo: Comparar os resultados cirúrgicos e audiológicos entre as técnicas minimally invasive Ponto surgery e incisão linear com preservação de tecidos moles em usuários de próteses auditivas ancoradas ao osso. Método: Foi feito um estudo retrospectivo de janeiro de 2017 a junho de 2018. Foram incluídos no estudo 42 pacientes adultos candidatos para cirurgia de prótese auditiva ancorada ao osso unilateral com o sistema Ponto. Os comprimentos de implante e pilar usados variaram de 3-4 milímetros e de 6-14 milímetros, de acordo com a espessura óssea e subcutânea dos participantes, respectivamente. Resultados: Foram feitas 22 cirurgias com uso da técnica minimally invasive Ponto surgery (52,4%) e 20 (47,6%) com incisão linear. A idade média dos indivíduos implantados com técnicas minimally invasive Ponto surgery e incisão linear foi de 42 e 33,3 anos, respectivamente. Dez homens (45,5%) e 14 (70%) mulheres foram implantadas com técnicas minimally invasive Ponto surgery e incisão linear, respectivamente. Não houve diferenças entre os limiares audiométricos em campo livre e as pontuações de reconhecimento de palavras monossilábicas dos sujeitos, quando comparadas as duas técnicas cirúrgicas. A técnica minimally invasive Ponto surgery reduziu significantemente o tempo cirúrgico em comparação com a técnica de incisão linear. Não houve diferenças entre as duas tecnicas cirúrgicas para complicações cutâneas maiores (Holgers 3 e 4), que ocorreram em 18,18% para MIPS e em 25% para incisão linear. Os indivíduos incluídos no grupo da técnica minimally invasive Ponto surgery apresentaram aspecto cosmético superior, sem cicatriz cirúrgica ou sutura adicional. Conclusão: Os resultados cirúrgicos e audiológicos foram satisfatórios e não se correlacionaram com a técnica cirúrgica empregada em todos os indivíduos. Quando comparada à incisão linear, a técnica minimally invasive Ponto surgery apresentou tempo cirúrgico reduzido e resultados estéticos superiores no seguimento pós-operatório.

Clinical implications of intraoperative eABRs to the Evo®-CI electrode array recipients / Implicações clínicas do eABR intraoperatório para usuários do feixe de eletrodos Evo

Abstract Introduction Electrically evoked auditory brainstem responses provide reliable clinical information to assist professionals in the auditory rehabilitation of cochlear implant users. Objective This study aimed to investigate intraoperative evoked auditory brainstem response recordings in Evo®-cochlear implant electrode array recipients and its correlation with their behavioral levels and auditory performance. Methods This is a retrospectivey study. Intraoperative evoked auditory brainstem responses were recorded in adult Evo®-cochlear implant electrode array recipients. Wave V latencies, amplitudes and interpeak III-V intervals were recorded in three different electrode locations and compared to the sentence recognition scores obtained from subjects after six months of device use. Evoked auditory brainstem responses thresholds were also recorded and compared to the behaviorally determined levels of the subjects in the sound processor activation. Results Evoked auditory brainstem responses thresholds were significantly correlated with both, behavioral T- and C-levels and they were recorded at audible electrical stimulation levels in all subjects. There was a significant correlation between interpeak III-V interval recorded in the apical electrode and sentence recognition scores of the subjects. Conclusions Intraoperative evoked auditory brainstem responses can be used to establish audible levels for fitting the sound processor in Evo®-cochlear implant recipients and it could help professionals to plan further actions aiming to improve their auditory performance.

Resumo Introdução Os potenciais auditivos de tronco encefálico evocados eletricamente fornecem informações clínicas confiáveis que auxiliam no processo de reabilitação auditiva de usuários de implante coclear. Objetivo Investigar o registro intraoperatório dos potenciais auditivos de tronco encefálico evocados eletricamente em usuários do feixe de eletrodos Evo® e sua correlação com os níveis comportamentais e desempenho auditivo dos indivíduos. Método Estudo retrospectivo. Os potenciais auditivos de tronco encefálico intraoperatórios foram registrados em usuários adultos de implante coclear com feixe de eletrodos Evo®. As latências e amplitudes da onda V e os intervalos interpico III-V foram registrados em três diferentes eletrodos e comparados às pontuações de reconhecimento de sentenças após 6 meses de uso do implante coclear. Os limiares dos eABRs foram comparados aos níveis comportamentais dos indivíduos na ativação do processador de som. Resultados Os limiares do eABR foram significativamente correlacionados aos níveis comportamentais T e C e registrados em níveis de estimulação elétrica audíveis em todos os indivíduos. Houve uma correlação significativa entre o intervalo interpico III-V no eletrodo apical e a pontuação de reconhecimento de sentenças dos indivíduos. Conclusões O eABR intraoperatório pode ser usado para estabelecer níveis audíveis de estimulação elétrica na ativação do processador sonoro em usuários de implante coclear‐Evo® e pode auxiliar os profissionais no planejamento de ações visando melhorar o desempenho auditivo nesses pacientes.

Cochlear implant revision surgeries in children / Cirurgias revisionais de implante coclear em crianças

Abstract Introduction: The surgery during which the cochlear implant internal device is implanted is not entirely free of risks and may produce problems that will require revision surgeries. Objective: To verify the indications for cochlear implantation revision surgery for the cochlear implant internal device, its effectiveness and its correlation with certain variables related to language and hearing. Methods: A retrospective study of patients under 18 years submitted to cochlear implant surgery from 2004 to 2015 in a public hospital in Brazil. Data collected were: age at the time of implantation, gender, etiology of the hearing loss, audiological and oral language characteristics of each patient before and after cochlear implant surgery and any need for surgical revision and the reason for it. Results: Two hundred and sixty-five surgeries were performed in 236 patients. Eight patients received a bilateral cochlear implant and 10 patients required revision surgery. Thirty-two surgeries were necessary for these 10 children (1 bilateral cochlear implant), of which 21 were revision surgeries. In 2 children, cochlear implant removal was necessary, without reimplantation, one with cochlear malformation due to incomplete partition type I and another due to trauma. With respect to the cause for revision surgery, of the 8 children who were successfully reimplanted, four had cochlear calcification following meningitis, one followed trauma, one exhibited a facial nerve malformation, one experienced a failure of the cochlear implant internal device and one revision surgery was necessary because the electrode was twisted. Conclusion: The incidence of the cochlear implant revision surgery was 4.23%. The period following the revision surgeries revealed an improvement in the subject's hearing and language performance, indicating that these surgeries are valid in most cases.

Resumo Introdução: A cirurgia para a implantação do dispositivo interno do implante coclear não é inteiramente livre de riscos e pode apresentar problemas que exigem cirurgias revisionais. Objetivo: Verificar a incidência das indicações de cirurgias revisionais para a implantação do dispositivo interno do implante coclear, sua efetividade e correlacionar às variáveis relacionadas às categorias de linguagem e audição. Método: Estudo retrospectivo de pacientes menores de 18 anos submetidos à cirurgia de implante coclear de 2004 a 2015 em um hospital público no Brasil. Os dados coletados foram: idade no momento da implantação, sexo, etiologia da surdez, características audiológicas e da linguagem oral de cada paciente no pré e pós-operatório, necessidade de revisão cirúrgica e razão para ela. Resultados: Foram feitas 265 cirurgias em 236 pacientes. Oito pacientes foram submetidos ao implante coclear bilateral e 10 necessitaram de cirurgia de revisão. Foram necessárias 32 cirurgias para essas 10 crianças (um implante coclear bilateral), das quais 21 foram cirurgias de revisão. Em duas crianças, a remoção do implante coclear foi necessária, sem realização de reimplante; uma delas apresentava malformação coclear, por partição incompleta tipo I; e a outra, devido a trauma. Quanto à causa da necessidade da cirurgia revisional, das oito crianças que permaneceram com implante coclear, quatro apresentaram calcificação coclear após meningite, seguida de trauma (1), malformação do nervo facial (1), falha do dispositivo interno da IC (1) e torção do feixe de eletrodos (1). Conclusão: A incidência de cirurgias revisionais foi de 4,23%. O pós-operatório das cirurgias revisionais permite uma melhoria no desempenho de audição e na linguagem dos pacientes, indicando que essas cirurgias são válidas na maioria dos casos.

Is there a best side for cochlear implants in post-lingual patients? / Existe um lado melhor para implantes cocleares em pacientes pós-linguais?

Abstract Introduction: Cochlear Implant is a sensory prosthesis capable of restoring hearing in patients with severe or profound bilateral sensorineural hearing loss. Objective: To evaluate if there is a better side to be implanted in post-lingual patients. Methods: Retrospective longitudinal study. Participants were 40 subjects, of both sex, mean age of 47 years, with post-lingual hearing loss, users of unilateral cochlear implant for more than 12 months and less than 24 months, with asymmetric auditor reserve between the ears (difference of 10 dBNA, In at least one of the frequencies with a response, between the ears), divided into two groups. Group A was composed of individuals with cochlear implant in the ear with better auditory reserve and Group B with auditory reserve lower in relation to the contralateral side. Results: There was no statistical difference for the tonal auditory threshold before and after cochlear implant. A better speech perception in pre-cochlear implant tests was present in B (20%), but the final results are similar in both groups. Conclusion: The cochlear implant in the ear with the worst auditory residue favors a bimodal hearing, which would allow the binaural summation, without compromising the improvement of the audiometric threshold and the speech perception.

Resumo Introdução: O implante coclear é uma prótese sensorial capaz de restaurar a audição em pacientes com perda auditiva neurossensorial bilateral severa ou profunda. Objetivo: Avaliar se há um melhor lado para o implante coclear em pacientes pós-linguais. Método: Estudo longitudinal retrospectivo; incluiu 40 indivíduos, de ambos os sexos, média de 47 anos, com perda auditiva pós-lingual, usuários de implante coclear unilateral por mais de 12 meses e menos de 24 meses, com perda auditiva assimétrica entre as orelhas (diferença de 10 dBNA, em pelo menos uma das frequências), divididos em dois grupos. O Grupo A foi composto por indivíduos com implante coclear na orelha com melhor audição residual e Grupo B com menor audição residual em relação ao lado contralateral. Resultados: Não houve diferença estatística entre o limiar auditivo tonal antes e depois do implante coclear. Uma melhor percepção da fala nos testes pré-implante coclear foi observada no grupo B (20%), mas os resultados finais foram semelhantes em ambos os grupos. Conclusão: O implante coclear na orelha com pior audição residual favorece uma audição bimodal, o que possibilitaria a somação binaural, sem comprometer a melhora do limiar audiométrico e a percepção da fala.