The Photon-Counting CT Enters the Field of Cochlear Implantation: Comparison to Angiography DynaCT and Conventional Multislice CT.

INTRODUCTION: Cochlear duct length (CDL) measurement plays a role in the context of individualized cochlear implant (CI) surgery regarding an individualized selection and implantation of the CI electrode carrier and an efficient postoperative anatomy-based fitting process. The level of detail of the preoperative temporal bone CT scan depends on the imaging modality with major impact on CDL measurements and CI electrode contact position determination. The aim of this study was to evaluate the accuracy of perioperative CDL measurements and electrode contact determination in photon-counting CT (PCCT). METHODS: Ten human fresh-frozen petrous bone specimens were examined with a first-generation PCCT. A clinically applicable radiation dose of 27.1 mGy was used. Scans were acquired before and after CI insertion. Postoperative measurement of the CDL was conducted using an otological planning software and 3D-curved multiplanar reconstruction. Investigation of electrode contact position was performed by two respective observers. Measurements were compared with a conventional multislice CT and to a high-resolution flat-panel volume CT with secondary reconstructions. RESULTS: Pre- and postoperative CDL measurements in PCCT images showed no significant difference to high-resolution flat-panel volume CT. Postoperative CI electrode contact determination was also as precise as the flat-panel CT-based assessment. PCCT and flat-panel volume CT were equivalent concerning interobserver variability. CONCLUSION: CDL measurement with PCCT was equivalent to flat-panel volume CT with secondary reconstructions. PCCT enabled highly precise postoperative CI electrode contact determination with substantial advantages over conventional multislice CT scanners.

Dependence of Cochlear Duct Length Measurement on the Resolution of the Imaging Dataset.

HYPOTHESIS: Measurements of the cochlear duct length (CDL) are dependent on the resolution of the imaging dataset. BACKGROUND: Previous research has shown highly precise cochlear measurements using 3D-curved multiplanar reconstruction (MPR) and flat-panel volume computed tomography (fpVCT). Thus far, however, there has been no systematic evaluation of the imaging dataset resolution required for optimal CDL measurement. Therefore, the aim of this study was to evaluate the dependence of CDL measurement on the resolution of the imaging dataset to establish a benchmark for future CDL measurements. METHODS: fpVCT scans of 10 human petrous bone specimens were performed. CDL was measured using 3D-curved MPR with secondary reconstruction of the fpVCT scans (fpVCT SECO ) and increasing resolution from 466 to 99 µm. In addition, intraobserver variability was evaluated. A best-fit function for calculation of the CDL was developed to provide a valid tool when there are no measurements done with high-resolution imaging datasets. RESULTS: Comparison of different imaging resolution settings showed significant differences for CDL measurement in most of the tested groups ( p < 0.05), except for the two groups with the highest resolution. Imaging datasets with a resolution lower than 200 µm showed lower intraobserver variability than the other resolution settings, although there were no clinically unacceptable errors with respect to the Bland-Altman plots. The developed best-fit function showed high accuracy for CDL calculation using resolution imaging datasets of 300 µm or lower. CONCLUSION: 3D-curved MPR in fpVCT with a resolution of the imaging dataset of 200 µm or higher revealed the most precise CDL measurement. There was no benefit of using a resolution higher than 200 µm with regard to the accuracy of the CDL measurement.

Desórdenes en el espectro de la neuropatía auditiva (DENA) / Auditory neuropathy spectrum disorder (ANSD)

Desórdenes en el espectro de la neuropatía auditiva (DENA) es el término más aceptado en la actualidad para definir la antes llamada neuropatía auditiva o desincronía auditiva. Su prevalencia es difícil de estimar debido a sus múltiples etiologías (hiperbilirrubinemia, enfermedades infecciosas, neuropatías sensoriomotoras, hereditarias y/o isquémico-hipóxicas). Clínicamente se manifiesta con alteraciones auditivas y comunicativas variables, desde una discapacidad leve o sin ella, hasta la sordera funcional profunda, que puede ser fluctuante o permanente. En los métodos diagnósticos no se evidencian los potenciales auditivos del tallo cerebral o se notan marcadamente anormales, y hay presencia de emisiones otoacústicas o de microfónicos cocleares. Para el tratamiento inicial de los desórdenes en el espectro de la neuropatía auditiva se sugiere hacer amplificación con audífonos en los casos leves, reservando el implante coclear para los estados más severos. El objetivo del artículo es hacer una revisión de la literatura acerca de los desórdenes en el espectro de la neuropatía auditiva.

Auditory Neuropathy Spectrum Disorders (ANSD) is the most currently accepted term to define the previously called auditory neuropathy or auditory dyssynchrony. Its prevalence is difficult to estimate due to multiple etiologies (hyperbilirubinemia, infectious diseases and sensory-motor, hereditary and/or ischemic-hypoxic neuropathies). Some individuals with AN have little or no communication difficulties while others are functionally deaf. Within the diagnostic criteria abnormal auditory nerve response in ABR are observed absent or markedly abnormal while otoacoustic emissions (OAEs) or the cochlear microphonic (CM) remain present and normal. Within the management of DENA is suggested that some children with ANSD appear to benefit from amplification and auditory based intervention while others require CI or other implants for the most severe cases. The objective of this article is to review the literature on disorders of the auditory neuropathy spectrum.

Complicaciones y causas de fallo en cirugía de implante coclear en pacientes del servicio de otorrinolaringología del Hospital Universitario Clínica San Rafael / Complications and causes of failure in cochlear implant surgery patients in the “Hospital Universitario Clínica San Rafael” service

Este estudio corresponde a un análisis descriptivo de los pacientes del Hospital Universitario Clínica San Rafael llevados a cirugía de implante coclear entre enero/2000 a diciembre/2010 y describe la ocurrencia de complicaciones menores y mayores en la cirugía de implante coclear con un mínimo de seguimiento de 12 meses. Las complicaciones de la cirugía de implante coclear se dividen en dos categorías; complicaciones menores y mayores. Las complicaciones menores son aquellas que pueden, o no, producir una disminución en el funcionamiento del implante, pero que se resuelven de manera espontánea o con tratamiento conservador, sin necesidad de realizar una nueva intervención quirúrgica, e incluyen: dolor local, tinnitus, vértigo, alteraciones del gusto, infección, fístula de líquido cefalorraquídeo y parálisis facial. Las complicaciones mayores son aquellas que requieren reintervención quirúrgica o explante. Se logró recopilar la información de 172 pacientes, 88 (51,16%) de sexo masculino y 84 (48,83%) de sexo femenino, con unas edades entre los 3 y los 71 años promedio de 22,1 años. El porcentaje global de complicaciones fue del 22,67% incluyendo las complicaciones menores y mayores, que corresponde a 39 implantes. El porcentaje de fallos es de 3,4%, que representa un total de 6 implantes. El porcentaje de reimplantes es de 5,2% del total, que corresponden a 09 implantes, siendo la causa más común falla técnica del dispositivo (06), seguido por falla por impacto (03). En cuanto a las complicaciones, se presentaron 12 complicaciones mayores que corresponden al 6,97%. El porcentaje de complicaciones menores en nuestro estudio fue de 15,6% (27)...

The following study corresponds to a descriptive analysis in patients from the Hospital Universitario Clínica San Rafael, which received cochlear implant surgery between january/2000 and december/2010. It describes the incidence of minor and major complications in the cochlear implant surgery, with a minimum follow up of 12 months. The complications of the cochlear implant surgery are divided in to two main categories: minor and major ones. The minor complications are those that can, or cannot, produce a decrease in the performance of the implant; but resolves spontaneously or with medical treatment, without making any surgery. Its clue symptoms involve: local pain, tinnitus, vertigo, taste alterations, infections, CSF fistula and facial paralysis. The major complications require a second surgery intervention or explants. The clinical histories of 172 patients were obtained, in which 88 (51,16%) were men and 84 (48,83%) were women, all with ages that comes from 3 to 71 years giving an average of 22.1 years old. The percentage of global complications was of 22,67% included the minor and major complications, that correspond to 39 implants. The fail percentage is of 3,4%, representing a total of 6 implants. The re-implants percentage corresponds to 5,2% from 9 implants that were in total, leading to the main cause of technical device fail (06), following by a fail for an impact cause (03). There were 12 major complications presented that correspond to 6.97%. The percentage of minor complications on the following study was of 15,6% (27)...

El impacto del implante coclear en la integración auditiva: resultados y factores predictores en un grupo de 116 niñas y niños sordos españoles / Impact of cochlear implants on auditory integration: Results and predictive factors in a group of 116 deaf Spanish children

El implante coclear ha revolucionado el tratamiento de las pérdidas graves de audición. Las funciones auditivas son las primeras que se despliegan después de la conexión de este dispositivo, y en ellas se apoyará el desarrollo del habla, del lenguaje y de la comunicación oral. Nuestros objetivos fueron, en primer lugar, evaluar las funciones auditivas (percepción, comunicación e integración auditiva) en un grupo de 116 niños sordos españoles mediante la Escala de Integración Auditiva para Niños, y en segundo lugar, analizar los factores implicados en este proceso. Según los datos obtenidos, no todos estos niños habían conseguido que sus funciones auditivas fuesen las esperadas por el uso continuado y suficiente del implante. Quienes recibieron su implante a edades más tempranas presentaban una integración auditiva conforme a lo esperado. Otras variables, como la marca del implante y la adaptación previa de audífonos, han resultado asimismo señaladas como factores predictores para la percepción auditiva. No obstante, se plantea la necesidad de evaluar muestras más extensas por la gran cantidad de factores implicados. A tenor de los resultados, planteamos la necesidad de reflexionar acerca del riesgo que supone asimilar, en cualquier caso, el implante coclear en población infantil con un adecuado desarrollo auditivo (AU)

Cochlear implantation in children has revolutionized the treatment of prelingual, profound and sensorineural deafness. Auditory functions are the first to develop after connecting the device and are those that support the development of speech, language and oral communication. The aims of this study were firstly to evaluate auditory functions (perception, communication and auditory integration) in a group of 116 deaf Spanish children through the Meaningful Auditory Integration Scale (MAIS), and secondly to analyze the factors involved in this process. According to the results, not all children in the sample achieved the expected development of auditory functions, despite using the device daily and for a minimum of 12 months. The children who achieved the expected auditory development were those who received their cochlear implant at a younger age. Other variables, such as the make of the implant and prior adaptation of the headphones, were also predictive factors for auditory perception. Nevertheless, due to the large number of factors involved, further studies should be performed with larger samples. The results of this study suggest that the use of cochlear implant alone may not be sufficient for the development of auditory functions (AU)

Prueba repetición de oraciones para niños de 24 a 48 meses (PRO-24). Estudio piloto con niños típicos y niños sordos con implante coclear / A sentence repetition test for children aged 24-48 months (PRO-24). Pilot study in children with normal hearing and deaf children with a cochlear implant

Se presenta la prueba de repetición de oraciones PRO-24 para niños típicos de entre 24 y 48 meses de edad. Dos estudios analizan el interés de la prueba. El primer estudio explora el rendimiento de un grupo de 18 niños típicos de entre 26 y 40 meses. Los resultados muestran que hay una correlación muy alta con la edad y que las dificultades aumentan especialmente en función de la carga fonológica y semántica. El análisis cualitativo muestra que aparecen errores gramaticales propios de esa franja de edad como son los protoartículos en los más pequeños o las generalizaciones morfológicas. El segundo estudio analiza los resultados de un grupo de 10 niños sordos profundos que han recibido un implante coclear entre los 12 y los 24 meses. La edad auditiva oscila entre los 30 y los 42 meses. Se obtiene además una muestra de lenguaje espontáneo. La puntuación directa en repetición es muy baja y 5 niños no tienen ningún acierto. Sin embargo, se observa que la longitud media de enunciados en repetición se correlaciona de manera significativa con la misma medida en el lenguaje espontáneo. Otros datos confirman el paralelismo entre ambas pruebas. La repetición de oraciones y la prueba PRO-24 en particular tienen gran interés como instrumento de evaluación y de investigación sobre el desarrollo lingüístico en este periodo inicial (AU)

This article describes a sentence repetition task, the PRO-24, designed for use in children with normal development, aged between 24 and 48 months. The potential usefulness of the PRO-24 was analyzed in two distinct studies. The first study was carried out in 18 typically developing children whose chronological ages ranged between 26 and 40 months. A strong correlation was found between chronological age and the PRO-24 score. Multiple regression analysis revealed that the main predictors of success in repeating each sentence were the number of syllables in a sentence, followed by the number of content words. Qualitative analysis revealed that the children made errors typical for their age, commonly observed in spontaneous language (e.g., protoarticles, morphological generalizations, omissions of unstressed words, etc.). The second analysis evaluated the results of a group of 10 deaf children with a cochlear implant (CI). Age at CI implantation was between 12 and 24 months. The time of implant use ranged between 30 and 42 months. A sample of spontaneous language was obtained from each child. Most CI users scored very poorly in the PRO-24. Five children scored zero. However, the mean length of utterance in the PRO-24 was significantly correlated with that in spontaneous language. Other data confirmed the close parallelism between the data sets. We conclude that the PRO-24 score is a true reflection of a child's command of productive language. Consequently, this task is potentially useful in evaluation of early language development and research in this field (AU)

Evolución de la otosclerosis hacia la implantación coclear / Evolution of otosclerosis to cochlear implantation

Introducción: La otosclerosis es una osteodistrofia de la cápsula laberíntica que produce hipoacusia de conducción. Si el proceso invade la cóclea, aparece una hipoacusia neurosensorial, siendo el implante coclear una buena alternativa en estos pacientes. Objetivo: Conocer el comportamiento de la otosclerosis en la implantación coclear. Material y métodos: Se revisó una base de datos de 250 pacientes intervenidos de implante coclear realizando un estudio retrospectivo sobre 13 pacientes con criterios clínicos, audiológicos y/o de imagen de otosclerosis bilateral. Se estudian los 26 oídos analizando la historia natural, cirugías previas, evolución hacia hipoacusia profunda, hallazgos en imagen mediante tomografía computarizada, complicaciones y resultados funcionales. Resultados: El 46% fueron mujeres y el 54% hombres con una edad media de 26 años al inicio de la hipoacusia conductiva. La cirugía del estribo fue llevada a cabo en 19 oídos (73%) a una edad media de 29 años y de estos en el 53% se realizó posteriormente un implante coclear. Los resultados de la tomografía computarizada muestran que en el 54% de los oídos existen signos de afectación radiológica en diferente grado. Se registraron un total de 3 complicaciones (23%): un fallo de implante coclear, una estimulación del nervio facial y un acúfeno bilateral. Al año de la implantación obtenemos un porcentaje promedio de aciertos en bisílabos del 80% y del 85% en frases en contexto abierto. Conclusiones: Pacientes que presentan una hipoacusia neurosensorial profunda bilateral secundaria a una otosclerosis se benefician extraordinariamente de la implantación coclear(AU)

Introduction: Otosclerosis is an osteodystrophy of the labyrinthine capsule producing conductive hearing loss. If the process invades the cochlea, a sensorineural hearing loss usually takes place. The cochlear implant is a good alternative in these patients. Objective: To ascertain the behaviour of cochlear implantation in otosclerosis. Material and methods: We reviewed a database of 250 patients that underwent cochlear implantation, performing a retrospective study of 13 patients with clinical, audiological and/or imaging findings of bilateral otosclerosis. The 26 ears were studied as to their natural history, previous surgeries, evolution to profound hearing loss, computed tomography images, complications and functional results. Results: Of the cases studied, 46% were female and 54% were men, with a mean age of 26 years at the onset of conductive hearing loss. Stapes surgery was performed in 19 ears (73%), with a mean patient age of 29 years, and 53% of them underwent cochlear implantation. Computed tomography results showed that there were signs of different degrees of radiological affectation in 54% of the ears. A total of 3 complications took place (23%): implant failure, overstimulation of the facial nerve and bilateral tinnitus were found. One year after implantation, the average percentages of correct 2-syllable words were 80% and 85% in open sentences. Conclusions: Patients having profound bilateral sensorineural hearing loss secondary to otosclerosis obtain great benefit from cochlear implantation(AU)

Desarrollo lingüístico de un caso de sordera prelocutiva más trastorno por déficit atencional (TDAH) / Linguistic development in a case of prelocutive deafness and attention deficithyperactivity disorder

En este informe se describe de manera restrospectiva el desarrollo lingüístico de una niña con sordera profunda prelocutiva, que fue admitida para un estudio longitudinal de larga duración. El objetivo principal era evaluar el efecto del uso simultáneo del implante coclear (IC) temprano y la palabra complementada (LPC). Desde los 15 meses hasta los 6 años de edad, fue rehabilitada en el modelo oral complementado (MOC). Durante este periodo se grabaron 159 muestras de habla de 30 min cada una, que forman el CORPUS-MOC, disponible en CHILDES. Fueron objeto de estudio el desarrollo prelingüístico -balbuceo canónico, inventario fonético y primeras palabras- y el lingüístico -fonología, léxico, gramática y pragmática-. Como el desarrollo lingüístico no era el esperado para un caso de sordera con IC+LPC, se indagaron otras hipótesis. A los 4 años de uso del IC se confirmó el TDAH, que fue tratado con metilfenidato, y se reanalizaron los datos desde la perspectiva de sordera+TDAH, en la presunción de que ambas discapacidades estaban presentes desde el principio. Se contraponen los rasgos diferenciales del desarrollo lingüístico entre sordera típica y sordera+TDAH (AU)

This article retrospectively describes language development in a prelocutive deaf girl who was enrolled in a long-term longitudinal study. The main aim was to study the effect of the simultaneous use of an early cochlear implant (CI) and cued speech (CS). From 15 months to 6 years old the child underwent rehabilitation in the complemented oral model [COM, Modelo Oral Complementado (MOC) in Spanish]. During this period, 159 sessions of 30-minutes each were videotaped, forming the MOC-CORPUS, available in the CHILDES database. Prelinguistic acquisitions (canonical babbling, phonetic inventory, and first words), and linguistic development (phonology, lexicon, grammar and pragmatics) were explored. As the child's linguistic development did not follow the expected course for a case of deafness with CI+CS, other hypotheses were investigated. After 4 years of CI use, attention-deficit hyperactivity disorder (ADHD) was confirmed and was treated with methylphenidate. The data were reanalyzed from the perspective of deafness plus ADHD, assuming that both disorders were present from the beginning. The differential features in linguistic development in cases of typical deafness versus deafness plus ADHD are contrasted (AU)