Electrococleografía en implante coclear / Electrocochleography in cochlear implant

La electrococleografía es una técnica electrofisiológica desarrollada en modelos animales hace más de 90 años. En la actualidad se utiliza en la práctica clínica en audiolo-gía y otoneurología, ya que permite evaluar la función coclear, a través del registro del potencial microfónico coclear, y la funcionalidad del nervio auditivo por medio del registro del potencial de acción compuesto. Debido al avance de la tecnología de los implantes cocleares, actualmente existe la posibilidad de realizar mediciones clínicas a tiempo real con electrococleografía intraoperatoria, por lo que se puede monitorizar la función auditiva residual durante la inserción de los electrodos del implante coclear. En este artículo se presenta una revisión narrativa del uso y aplicación clínica de la electrococleografía en la evaluación de pacientes con implante coclear para predecir el desempeño auditivo y la percepción del habla. La literatura muestra que la electroco-cleografía es una técnica que se encuentra, plenamente, vigente para evaluar la función auditiva en pacientes usuarios de implantes cocleares. Si bien las respuestas cocleares han demostrado ser un buen predictor de los umbrales perceptuales auditivos y del habla en silencio en adultos, aún es una técnica que requiere más desarrollo para ser una herramienta clínica que permita predecir el habla en ruido y la función auditiva en niños y adultos mayores.

Electrocochleography is an electrophysiological technique developed in animal models more than 90 years ago. It is currently used in clinical practice in audiology and otoneurology, since it allows the evaluation of cochlear function, through the recording of the cochlear microphonic potentials, and the functionality of the auditory nerve by means of compound action potential recordings. Due to the advancement of cochlear implant technology, there is currently the possibility of real-time clinical measurements with intraoperative electrocochleography, so that residual hearing function can be monitored during the insertion of the cochlear implant electrodes. This article presents a narrative review of the use and clinical application of electrocochleography in the evaluation of patients with cochlear implants to predict auditory performance and speech perception. The literature shows that electrocochleography is a technique that is fully in force to assess hearing function in patients who use cochlear implants. Although cochlear responses have been shown to be a good predictor of auditory perceptual thresholds and speech in quiet in adults, it is still a technique that requires further development to become a clinical tool for predicting speech in noise and auditory function in children and older adults.

Effect of Cochlear Implant Electrode Array Design on Electrophysiological and Psychophysical Measures: Lateral Wall versus Perimodiolar Types

BACKGROUND AND OBJECTIVES: The present study aims to investigate whether the cochlear implant electrode array design affects the electrophysiological and psychophysical measures. SUBJECTS AND METHODS: Eighty five ears were used as data in this retrospective study. They were divided into two groups by the electrode array design: lateral wall type (LW) and perimodiolar type (PM). The electrode site was divided into three regions (basal, medial, apical). The evoked compound action potential (ECAP) threshold, T level, C level, dynamic range (DR), and aided air conduction threshold were measured. RESULTS: The ECAP threshold was lower for the PM than for the LW, and decreased as the electrode site was closer to the apical region. The T level was lower for the PM than for the LW, and was lower on the apical region than on the other regions. The C level on the basal region was lower for the PM than for the LW whereas the C level was lower on the apical region than on the other regions. The DRs on the apical region was greater for the PM than for the LW whereas the DR was narrower on the apical region than on the other regions. The aided air conduction threshold was not different for the electrode design and frequency. CONCLUSIONS: The current study would support the advantages of the PM over the LW in that the PM had the lower current level and greater DR, which could result in more localized neural stimulation and reduced power consumption.

Analysis of Auditory Rehabilitation Outcomes of the Cochlear Neural Canal Stenosis Patients after Cochlea Implantation / 听力学及言语疾病杂志

Objective To study the analysis of auditory rehabilitation outcomes of patients with cochlear nerve canal stenosis after cochlear implantation(CI).Methods A cohort of 30 patients with bilateral profound senso-rineural hearing loss who were diagnosed with cochlear neural canal stenosis by high-resolution CT were tested with evoked compound action potential (ECAP)and evoked auditory brainstem response (EABR)during and 3 ,6 , 9 months after CI.Audiometry in sound field was also assessed before and 3 ,6 ,9 months after CI.Among the co-hort,1 7 patients over 3 years old underwent postoperative speech recognition rate test.All the auditory rehabilita-tion outcomes were analyzed.Results ① For all 30 patients,there were no obvious differences of ECAP and EABR waveforms tested in 3,6 and 9 months after CI.②The thresholds in sound field in 3,6,9 months after CI were 65 ±8 dB HL,62 ±4 dB HL and 61 ±7 dB HL,respectively.The thresholds in sound field were significantly im-proved after than before CI (100 ±5 dB HL).③ The single vowel recognition rates of 17 patients in 3 ,6 and 9 months after CI were 55%±7%,56%±8% and 80%±4%,respectively.The single vowel recognition rate was significantly improved in 9 months after than before CI(52%±8%).The single consonant recognition rates of 17 pa-tients in 3 ,6 and 9 months after CI were 9%±3%,8%±4% and 9%±2%,respectively.The single consonant recognition rates were not significantly improved after than before CI (8%±2%).Conclusion ① For patients with bi-lateral cochlear neural canal stenosis,neither ECAP nor EABR waves were produced during or after CI.The language com-munication of patients is limited as a result of their poor subjective thresholds in sound field and speech recognition rates.

Microestructura y propiedades mecánicas del Acero AISI 1016 calibrado procesado por ECAP / Microstructure and mechanical properties of cold drawn AISI 1016 steel processed by ECAP / Microestrutura e propriedades mecânicas do aço AISI 1016 calibrado processado por ECAP

Se utilizó el proceso de presión en canal angular de sección constante para deformar un acero de bajo carbono calibrado, con el fin de evaluar microestructura y propiedades mecánicas. A su vez, se identificó la posibilidad de mejorar propiedades más allá del proceso de calibrado. El material utilizado fue un acero de bajo carbono calibrado de composición 0.16 % C, 0.8 % Mn, 0.2 % Si, 0.02 % P, 0.012 % S y balance Fe. El proceso se realizó a temperatura ambiente con cuatro pasadas usando la ruta Bc, con una deformación equivalente de ∼0.6 en cada pasada. Se estudió la evolución de la estructura antes y después de la deformación usando microscopía electrónica de barrido y difracción de rayos X y se evaluaron las propiedades mecánicas de microdureza y resistencia a la tensión. Se encontró un aumento leve de las propiedades mecánicas al aumentar el número de pasadas en el proceso. Los análisis mostraron cambios en la estructura ferrítica-perlítica original a través del refinamiento de los granos de ferrita y la deformación de la perlita.

Low carbon cold drawn steel was deformed using equal channel angular pressing to evaluate its mechanical properties and microstructure, while assessing the possibility of improving properties beyond the cold drawn process. We used low carbon cold drawn steel with a composition of 0.16% C, 0.8% Mn, 0.2% Si, 0.02% P, 0.012% S and Fe balance. The process was carried out at room temperature and four passes at route Bc with a deformation of ∼0.6 in each pass. Using scanning electron microscopy and x-ray diffraction, we evaluated the evolution of the structure before and after deformation as well as the mechanical properties of microhardness and tensile strength. A slight increase in the mechanical properties occurred when the number of passes was increased. There were changes in the original ferritic-pearlitic structure with the refinement of ferrite grains and pearlite deformation.

Utilizou-se o processo de pressão em canal angular de secção constante para deformar um aço de baixo carbono calibrado, com a finalidade de avaliar microestruturas e propriedades mecânicas. Assim, identificou-se a possibilidade de melhorar propriedades para além do processo de calibração. O material utilizado foi um aço de baixo carbono calibrado com a seguinte composição 0.16% C, 0.8% Mn, 0.2% Si, 0.02% P, 0.012% S e balance Fe. O processo realizou-se à temperatura ambiente com quatro passos utilizando a rota Bc, com uma deformação equivalente de ∼0.6 em cada passo. Estudou-se a evolução da estrutura antes e depois da formação utilizando microscopia electrónica de varrimento e difracção de rayos X e avaliaram-se as propriedades mecânicas de microdureza e resistência à tensão. Encontrou-se um aumento ligeiro das propriedades mecânicas ao aumentar o número de passos no processo. As análises mostraram alterações nas estruturas ferrítica-perlítica original a através do refinamento dos grãos de ferrita e a deformação da perlita.

Indicadores de compulsão alimentar periódica em pós-operatório de cirurgia bariátrica / Binge eating indicators after bariatric surgery / Indicadores atracón en post-quirúrgicos de la cirugía bariátrica

A obesidade mórbida se relaciona a altas taxas de morbidade e mortalidade. A cirurgia bariátrica (CB) tem se mostrado eficiente levando à perda rápida de peso e remissão de comorbidezes. Encontra-se maior incidência de psicopatologias nesta população. A Compulsão Alimentar Periódica (CAP) tem sido associada ao novo ganho de peso pós-cirúrgico. Este estudo investigou indicadores de CAP em 40 pacientes pós-cirúrgicos submetidos à CB há pelo menos 2 anos, divididos em Grupo 1 e 2, com perda de mais de 50% do peso inicial excedente e com perda menor de 50%, respectivamente. O método de Rorschach-SC e a Escala de Compulsão Alimentar Periódica foram os instrumentos utilizados. Os resultados indicaram diferenças significativas com elevações no Grupo 1 de CAP (p<0,01), presença de impulsividade (p<0,05) e dificuldade de integração perceptiva (p<0,05). Conclui-se que CAP no pós-cirúrgico pode ser considerado como um possível indicador de reganho de peso.

Morbid obesity is related to high rates of morbidity and mortality. Bariatric Surgery has been shown effective, leading to rapid weight loss and remission of comorbidities. Higher incidence of psychopathologies is in this population. Binge Eating has been linked to the new weight gain after surgery. This study investigated indicators on Binge Eating in 40 post-surgical patients undergoing Bariatric Surgery at least 2 years earlier, who were divided into Group 1 and 2,with a loss of more than 50% of the initial weight loss and less than 50%, respectively. The Rorschach method-SC and the Binge Eating Scale were the instruments used. The results indicated significant differences with elevations in Binge Eating Group 1 (p<0.01), presence of impulsivity (p<0.05) and difficulty in perceptual integration (p<0.05). It is concluded that Binge Eating after surgery is a precursor of weight regain and should be treated carefully.

La obesidad mórbida se relaciona con altas tasas de morbilidad y mortalidad. La cirugía bariátrica (CB) se ha mostrado eficaz que conduce a la pérdida de peso rápida y la remisión de las comorbilidades. Es mayor la incidencia de la psicopatología en esta población. El trastorno por atracón se ha relacionado con el nuevo aumento de peso después de la cirugía. Este estudio indicadores investigados en la tapa 40 pacientes post-quirúrgicos sometidos a CB durante al menos 2 años fueron divididos en Grupo 1 y 2, con una pérdida de más del 50% de la pérdida de peso inicial y más de 50% menos, respectivamente. El método de Rorschach-SC y la Escala de atracón fueron los instrumentos utilizados. Los resultados indicaron diferencias significativas en las elevaciones de Grupo Trastorno por Atracón 1 (p<0,01), la presencia de la impulsividad (p<0,05) y la dificultad en la integración perceptual (p<0,05). Llegamos a la conclusión de que la trastorno por atracón después de la cirugía es un precursor de la recuperación de peso y debe ser tratado con cuidado.

Influence of Changing the Parameters on the Wave of NRT / 听力学及言语疾病杂志

Objective To inevestigate the changes of the responses by changing the parameters in the neural response tetemety(NRT).Methods In this project,twenty patients who were implanted in Nucleus C124M were measured the electrically evoked compound action potential(ECAP)using the NRT system.It was expected to observe the changes of the responses by changing the parameters in the NRT 2.04 software.Results It was found that the parameters that made great influences to the responses were current level,stimulate pulse width,gain,delay and masker advance.Conclusion The parameters that made great influences to the record time were stimulate rate and number of sweeps.

The Study of EABR and ECAP in Cochlear Implantation / 听力学及言语疾病杂志

Objective To explore the threshold and latency of patients receiving cochlear implantation using electrically evoked auditory brainstem responses (EABR), and to evaluate the significance of EABR applied to those patients.Methods The EABR and ECAP were recorded in 14 subjects who were operated for Nucleus24 cochlear implant.They were assigned to Group A and Group B according to the results of ECAP. The threshholds of EABR, the wave latency of III and V and inter-wave latency of III-V of EABR were compared and analyzed between Group A and Group B.Results The threshholds of EABR were higher in Group B than in Group A on electrode No 22 when the pulse width was 25,50,75,100,125 ?s,respectively. There were significant differences between Group A and Group B(P0.05).Conclusion The threshholds of EABR were lower in patients whose ECAP findings were positive. The latencies of III and V,and inter-wave latency of III–V of EABR had no significant difference according to the positive findings of ECAP.