Resumen ejecutivo del documento de consenso SEORL CCC-SEEN sobre hipoparatiroidismo postiroidectomía / Executive summary of the SEORL CCC-SEEN consensus statement on post-thyroidectomy hypoparathyroidism

El hipoparatiroidismo es la complicación más frecuente tras la tiroidectomía total. Se define por la presencia de hipocalcemia con unos niveles de hormona paratiroidea (PTH) bajos o inadecuadamente normales. La hipocalcemia aguda es una complicación potencialmente grave. Su tratamiento se basa, según la gravedad del cuadro, en la administración de calcio por vía oral o intravenosa, pudiendo requerir asimismo calcitriol oral. El riesgo de hipocalcemia sintomática tras una tiroidectomía es muy bajo si la PTH postoperatoria desciende menos del 80% respecto de la preoperatoria. Estos pacientes podrían ser dados de alta sin tratamiento, aunque los umbrales son variables entre laboratorios y recomendamos extremar la vigilancia en los casos de riesgo aumentado (enfermedad de Graves, grandes bocios, reintervenciones o constancia de la extirpación de alguna paratiroides). El tratamiento a largo plazo busca controlar los síntomas manteniendo la calcemia en el límite bajo de la normalidad, vigilando el producto calcio-fósforo y la aparición de hipercalciuria

Hypoparathyroidism is the most common complication after total or completion thyroidectomy. It is defined as the presence of hypocalcemia accompanied by low or inappropriately normal parathyroid hormone (PTH) levels. Acute hypocalcemia is a potential lethal complication. Hypocalcemia treatment is based on endovenous or oral calcium supplements as well as oral calcitriol, depending on the severity of the symptoms. The risk of clinical hypocalcemia after bilateral thyroidectomy is considered very low if postoperative intact PTH decrease less than 80% with respect to preoperative levels. These patients could be discharged home without treatment, although this threshold may vary between institutions, and we recommend close surveillance in cases with increased risk (Graves disease, large goiters, reinterventions or evidence of parathyroid gland removal). Long-term treatment objectives are to control the symptoms and to keep serum calcium levels at the lower limit of the normal range, while preserving the calcium phosphate product and avoiding hypercalciuria

Resumen ejecutivo del documento de consenso SEORL CCC-SEEN sobre hipoparatiroidismo postiroidectomía / Executive summary of the SEORL CCC-SEEN consensus statement on post-thyroidectomy hypoparathyroidism

El hipoparatiroidismo es la complicación más frecuente tras la tiroidectomía total. Se define por la presencia de hipocalcemia con unos niveles de hormona paratiroidea (PTH) bajos o inadecuadamente normales. La hipocalcemia aguda es una complicación potencialmente grave. Su tratamiento se basa, según la gravedad del cuadro, en la administración de calcio por vía oral o intravenosa, pudiendo requerir asimismo calcitriol oral. El riesgo de hipocalcemia sintomática tras una tiroidectomía es muy bajo si la PTH postoperatoria desciende menos del 80% respecto de la preoperatoria. Estos pacientes podrían ser dados de alta sin tratamiento, aunque los umbrales son variables entre laboratorios y recomendamos extremar la vigilancia en los casos de riesgo aumentado (enfermedad de Graves, grandes bocios, reintervenciones o constancia de la extirpación de alguna paratiroides). El tratamiento a largo plazo busca controlar los síntomas manteniendo la calcemia en el límite bajo de la normalidad, vigilando el producto calcio-fósforo y la aparición de hipercalciuria

Hypoparathyroidism is the most common complication after total or completion thyroidectomy. It is defined as the presence of hypocalcemia accompanied by low or inappropriately normal parathyroid hormone (PTH) levels. Acute hypocalcemia is a potential lethal complication. Hypocalcemia treatment is based on endovenous or oral calcium supplements as well as oral calcitriol, depending on the severity of the symptoms. The risk of clinical hypocalcemia after bilateral thyroidectomy is considered very low if postoperative intact PTH decrease less than 80% with respect to preoperative levels. These patients could be discharged home without treatment, although this threshold may vary between institutions, and we recommend close surveillance in cases with increased risk (Graves disease, large goiters, reinterventions or evidence of parathyroid gland removal). Long-term treatment objectives are to control the symptoms and to keep serum calcium levels at the lower limit of the normal range, while preserving the calcium phosphate product and avoiding hypercalciuria

Executive summary of the SEORL CCC-SEEN consensus statement on post-thyroidectomy hypoparathyroidism. / Resumen ejecutivo del documento de consenso SEORL CCC-SEEN sobre hipoparatiroidismo postiroidectomía.

Hypoparathyroidism is the most common complication after total or completion thyroidectomy. It is defined as the presence of hypocalcemia accompanied by low or inappropriately normal parathyroid hormone (PTH) levels. Acute hypocalcemia is a potential lethal complication. Hypocalcemia treatment is based on endovenous or oral calcium supplements as well as oral calcitriol, depending on the severity of the symptoms. The risk of clinical hypocalcemia after bilateral thyroidectomy is considered very low if postoperative intact PTH decrease less than 80% with respect to preoperative levels. These patients could be discharged home without treatment, although this threshold may vary between institutions, and we recommend close surveillance in cases with increased risk (Graves disease, large goiters, reinterventions or evidence of parathyroid gland removal). Long-term treatment objectives are to control the symptoms and to keep serum calcium levels at the lower limit of the normal range, while preserving the calcium phosphate product and avoiding hypercalciuria.

Executive summary of the SEORL CCC-SEEN consensus statement on post-thyroidectomy hypoparathyroidism. / Resumen ejecutivo del documento de consenso SEORL CCC-SEEN sobre hipoparatiroidismo postiroidectomía.

Hypoparathyroidism is the most common complication after total or completion thyroidectomy. It is defined as the presence of hypocalcemia accompanied by low or inappropriately normal parathyroid hormone (PTH) levels. Acute hypocalcemia is a potential lethal complication. Hypocalcemia treatment is based on endovenous or oral calcium supplements as well as oral calcitriol, depending on the severity of the symptoms. The risk of clinical hypocalcemia after bilateral thyroidectomy is considered very low if postoperative intact PTH decrease less than 80% with respect to preoperative levels. These patients could be discharged home without treatment, although this threshold may vary between institutions, and we recommend close surveillance in cases with increased risk (Graves disease, large goiters, reinterventions or evidence of parathyroid gland removal). Long-term treatment objectives are to control the symptoms and to keep serum calcium levels at the lower limit of the normal range, while preserving the calcium phosphate product and avoiding hypercalciuria.

Implantes activos de oído medio / Active middle ear implants

Los implantes activos de oído medio son prótesis implantadas quirúrgicamente, que estimulan la cadena osicular o los fluidos del oído interno a través de la ventana oval o redonda. Estos implantes pueden ser útiles para el tratamiento de determinados pacientes con pérdida auditiva neurosensorial, así como para pérdida auditiva conductiva o mixta. Esta guía clínica pretende resumir los conocimientos actuales sobre las características básicas y las indicaciones de los implantes de oído medio más utilizados, como Vibrant Soundbrige (Med-el, Innsbruck), Carina (Cochlear, Australia) y CodacsTM. (Cochlear, Australia)

Active middle ear implants are surgically implanted prosthesis, which intend to stimulate the ossicular chain or the inner ear fluids through the oval or round windows. These implants may be useful for the treatment of certain patients with sensorineural hearing loss as well as for conductive or mixed hearing loss. This clinical guide attempts to summarize the current knowledge concerning the basic characteristics and indications of the most commonly used middle ear implants, including Vibrant Soundbrige (Med-el, Innsbruck), Carina (Cochlear, Australia), and CodacsTM. (Cochlear, Australia)

Guía clínica sobre implantes cocleares / Guideline on cochlear implants

Introducción: En la última década son numerosos los hospitales que han iniciado su actividad en pacientes candidatos a un implante coclear (IC), y se han producido numerosos y relevantes avances para el tratamiento de la hipoacusia neurosensorial que han desembocado en una ampliación de las indicaciones de los IC. Objetivos: Ofrecer a los especialistas de otorrinolaringología, de otras especialidades médicas, autoridades sanitarias y a la sociedad en general una guía clínica sobre implantes cocleares. Métodos: Las comisiones científicas de otología, otoneurología y audiología de la Sociedad Española de Otorrinolaringología y Cirugía de Cabeza y Cuello (SEORL-CCC), de manera coordinada y consensuada, han llevado a cabo una revisión del estado actual de los IC basándose en las reglamentaciones existentes y en las publicaciones científicas que se referencian en la bibliografía del documento elaborado. Resultados: La guía clínica sobre implantes cocleares aporta información sobre: a) definición y descripción sobre IC; b) indicaciones de los IC; y c) requisitos organizativos para un programa de IC. Conclusiones: Se ha elaborado por un comité de expertos de la SEORL-CCC una Guía clínica sobre implantes cocleares que aporta coordenadas de actuación para todos aquellos agentes de la sanidad en la toma de decisiones en el ámbito de los IC como forma de tratamiento de la discapacidad auditiva

Introduction: In the last decade numerous hospitals have started to work with patients who are candidates for a cochlear implant (CI) and there have been numerous and relevant advances in the treatment of sensorineural hearing loss that extended the indications for cochlear implants. Objectives: To provide a guideline on cochlear implants to specialists in otorhinolaryngology, other medical specialities, health authorities and society in general. Methods: The Scientific Committees of Otology, Otoneurology and Audiology from the Spanish Society of Otolaryngology and Head and Neck Surgery (SEORL-CCC), in a coordinated and agreed way, performed a review of the current state of CI based on the existing regulations and in the scientific publications referenced in the bibliography of the document drafted. Results: The clinical guideline on cochlear implants provides information on: a) Definition and description of Cochlear Implant; b) Indications for cochlear implants; c) Organizational requirements for a cochlear implant programme. Conclusions: A clinical guideline on cochlear implants has been developed by a Committee of Experts of the SEORL-CCC, to help and guide all the health professionals involved in this field of CI in decision-making to treathearing impairment

Active middle ear implants. / Implantes activos de oído medio.

Active middle ear implants are surgically implanted prosthesis, which intend to stimulate the ossicular chain or the inner ear fluids through the oval or round windows. These implants may be useful for the treatment of certain patients with sensorineural hearing loss as well as for conductive or mixed hearing loss. This clinical guide attempts to summarize the current knowledge concerning the basic characteristics and indications of the most commonly used middle ear implants, including Vibrant Soundbrige (Med-el, Innsbruck), Carina (Cochlear, Australia), and CodacsTM. (Cochlear, Australia).

Guideline on cochlear implants. / Guía clínica sobre implantes cocleares.

INTRODUCTION: In the last decade numerous hospitals have started to work with patients who are candidates for a cochlear implant (CI) and there have been numerous and relevant advances in the treatment of sensorineural hearing loss that extended the indications for cochlear implants. OBJECTIVES: To provide a guideline on cochlear implants to specialists in otorhinolaryngology, other medical specialities, health authorities and society in general. METHODS: The Scientific Committees of Otology, Otoneurology and Audiology from the Spanish Society of Otolaryngology and Head and Neck Surgery (SEORL-CCC), in a coordinated and agreed way, performed a review of the current state of CI based on the existing regulations and in the scientific publications referenced in the bibliography of the document drafted. RESULTS: The clinical guideline on cochlear implants provides information on: a) Definition and description of Cochlear Implant; b) Indications for cochlear implants; c) Organizational requirements for a cochlear implant programme. CONCLUSIONS: A clinical guideline on cochlear implants has been developed by a Committee of Experts of the SEORL-CCC, to help and guide all the health professionals involved in this field of CI in decision-making to treathearing impairment.

Análisis experimental mediante vibrometría láser doppler en huesos temporales de cadáver fresco de una nueva prótesis de maleovestibulopexia / A new malleostapedotomy prosthesis. Experimental analysis by laser doppler vibrometer in fresh cadaver temporal bones

Introducción y objetivos. Confirmar en temporales frescos de cadáver el comportamiento óptimo teórico (previamente determinado en un modelo computadorizado del oído medio humano) de una nueva prótesis de sustitución osicular total así como objetivar la facilidad de colocación de la misma. Finalmente comprobamos su estabilidad tras ser colocada puesto que el diseño de esta nueva prótesis evita, teóricamente, su movilización o extrusión al anclarse directamente en el mango del martillo. Material y métodos. En el estudio analizamos, mediante vibrometría láser doppler, el comportamiento mecanoacústico de una nueva prótesis de recambio osicular total en el oído medio humano utilizando 10 huesos temporales de cadáver fresco. Resultados. El diseño de la prótesis impide su desplazamiento o extensión y facilita su colocación en el oído medio. La función de transferencia de los temporales a quienes se implantó la nueva prótesis se superpone con la del oído medio intacto antes de la colocación de la prótesis lo que sugiere un comportamiento mecanoacústico óptimo de la misma. Conclusiones. La prótesis de titanio evaluada en este estudio presenta un comportamiento mecanoacústico superponible al del oído medio intacto, lo que se suma a la facilidad de colocación y estabilidad posquirúrgica conviertiéndola en un diseño de prótesis a tener en cuenta ante una reconstrucción osicular total (AU)

Introduction and objectives. One of the problems with total ossicular replacement prostheses is their stability. Prosthesis dislocations and extrusions are common in middle ear surgery. This is due to variations in endo-tympanic pressure as well as design defects. The design of this new prosthesis reduces this problem by being joined directly to the malleus handle. The aim of this study is to confirm adequate acoustic-mechanical behaviour in fresh cadaver middle ear of a new total ossicular replacement prosthesis, designed using the finite elements method. Methods. Using the doppler vibrometer laser, we analysed the acoustic-mechanical behaviour of a new total ossicular replacement prosthesis in the human middle ear using 10 temporal bones from fresh cadavers. Results. The transfer function of the ears in which we implanted the new prosthesis was superimposed over the non-manipulated ear. This suggests optimum acoustic-mechanical behaviour. Conclusions. The titanium prosthesis analysed in this study demonstrated optimum acoustic-mechanical behaviour. Together with its ease of implantation and post-surgical stability, these factors make it a prosthesis to be kept in mind in ossicular reconstruction (AU)

A new malleostapedotomy prosthesis. Experimental analysis by laser doppler vibrometer in fresh cadaver temporal bones. / Análisis experimental mediante vibrometría láser doppler en huesos temporales de cadáver fresco de una nueva prótesis de maleovestibulopexia.

INTRODUCTION AND OBJECTIVES: One of the problems with total ossicular replacement prostheses is their stability. Prosthesis dislocations and extrusions are common in middle ear surgery. This is due to variations in endo-tympanic pressure as well as design defects. The design of this new prosthesis reduces this problem by being joined directly to the malleus handle. The aim of this study is to confirm adequate acoustic-mechanical behaviour in fresh cadaver middle ear of a new total ossicular replacement prosthesis, designed using the finite elements method. METHODS: Using the doppler vibrometer laser, we analysed the acoustic-mechanical behaviour of a new total ossicular replacement prosthesis in the human middle ear using 10 temporal bones from fresh cadavers. RESULTS: The transfer function of the ears in which we implanted the new prosthesis was superimposed over the non-manipulated ear. This suggests optimum acoustic-mechanical behaviour. CONCLUSIONS: The titanium prosthesis analysed in this study demonstrated optimum acoustic-mechanical behaviour. Together with its ease of implantation and post-surgical stability, these factors make it a prosthesis to be kept in mind in ossicular reconstruction.

Estenosis congénita de la apertura piriforme: forma inusual de obstrucción nasal / Congenital nasal pyriform aperture stenosis: unusual form of nasal airway obstruction

La estenosis congénita de la apertura piriforme con megaincisivo central (ECAP) es una causa poco frecuente de obstrucción de la vía aérea en neonatos. Dada su baja frecuencia y por la similitud de la clínica se confunde inicialmente con la atresia coanal, trastorno más prevalente (1:5.000 nacidos vivos). Puede tratarse de una forma menor de holoprosencefalia, por lo que el diagnóstico incluye el screening de malformaciones cardíacas y cerebrales asociadas. Presentamos un caso de una recién nacida con ECAP (AU)

Congenital nasal pyriform aperture stenosis (CNPAE) with a single mega-incisor is an uncommon form of nasal airway obstruction in the neonate. Its low frequency and its similar clinical presentation may lead us to a wrong initial diagnosis of choanal atresia, which is more frequent (1:5000 live births). CNPAE may be a minor form of holoprosencephaly, so diagnosis should include screening for heart and central nervous system abnormalities. A case of a newborn with CNPAE is reported (AU)

Carcinoma neuroendocrino primario de la piel, carcinoma de células de Merkel. Casuística 1991-2012 / Primary cutaneous neuroendocrine carcinoma, Merkel cell carcinoma. Case series 1991-2012

Introducción y objetivos: El llamado clásicamente carcinoma de células de Merkel fue descrito por Toker en 1972, se trata de un carcinoma neuroendocrino primario de la piel. Aparece en la unión dermoepidérmica, es poco frecuente, de crecimiento rápido, agresivo y de mal pronóstico. El objetivo de este trabajo es dar a conocer este carcinoma que se implanta preferentemente en la piel de la cabeza y del cuello, y que aumenta su prevalencia en los últimos años. Material y método: Recogemos 16 pacientes afectados por el carcinoma neuroendocrino primario de la piel, tratados en nuestro centro entre 12/09/91 y 13/07/12. Se precisa la edad y el sexo. Se describe la zona de implantación del tumor. Su tamaño lo expresamos en milímetros según el eje mayor de la lesión. Resultados: Nuestros pacientes son mayores de 70 años, excepto la última incluida que contaba 55, la mayor frecuencia es en mayores de 80. Los casos recogidos, cuando asientan en la piel de cabeza y cuello (10/16) tienen localización: nasal-lateronasal, mejilla-malar, párpado superior, frontal, mandibular. El eje mayor de la lesión oscila entre 7 y 35 mm. A diferencia de lo que ocurre en los carcinomas espinocelulares o basocelulares son frecuentes las recurrencias y las metástasis. Para el diagnóstico es imprescindible la inmunohistoquímica con citoqueratina 20. El tratamiento es quirúrgico, ocasionalmente seguido de radioterapia y quimioterapia. Conclusión: Se trata de un carcinoma poco frecuente de la piel, aparece en la edad avanzada, asienta en cabeza y cuello en más del 50% de los casos y conduce con frecuencia al exitus (AU)

Introduction and objectives: Merkel cell carcinoma was first described by Toker in 1972. It is an uncommon, primary neuroendocrine skin carcinoma which appears in the dermoepidermic area, grows fast, is very aggressive and has a poor prognosis. The aim of this work is to highlight the importance of this tumour, which develops mainly in the skin of the head and neck area, and whose prevalence has increased in recent years. Material and method: We gathered data on 16 patients suffering cutaneous neuroendocrine carcinoma treated at our hospital between September 12, 1991 and July 13, 2012. We indicated the age and gender of patients. We described the area where the tumour was located, indicating the size in millimetres, according to the major axis of the lesion. Results: Most of the patients studied were over 70 years old, except for one who was 55. The highest frequency of cases appeared among patients aged over 80 years. In the cases studied, when the tumour appeared in the head and neck region (10/16), its location could be nasal-lateronasal, cheek-malar, upper eyelid, frontal or mandibular. The major axis of the lesion ranged between 7 and 35 mm. Unlike with epidermoid or basocellular carcinomas, recurrence and ganglionar metastases were common. Immunohistochemical (CK20) tests are essential for a correct diagnosis. Treatment is usually surgical and occasionally followed by radiotherapy and chemotherapy. Conclusion: This carcinoma is not a very common skin tumour. It appears in old age, in the head and neck region in 50% of cases and often leads to exitus (AU)

Primary cutaneous neuroendocrine carcinoma, Merkel cell carcinoma. Case series 1991-2012.

INTRODUCTION AND OBJECTIVES: Merkel cell carcinoma was first described by Toker in 1972. It is an uncommon, primary neuroendocrine skin carcinoma which appears in the dermoepidermic area, grows fast, is very aggressive and has a poor prognosis. The aim of this work is to highlight the importance of this tumour, which develops mainly in the skin of the head and neck area, and whose prevalence has increased in recent years. MATERIAL AND METHOD: We gathered data on 16 patients suffering cutaneous neuroendocrine carcinoma treated at our hospital between September 12, 1991 and July 13, 2012. We indicated the age and gender of patients. We described the area where the tumour was located, indicating the size in millimetres, according to the major axis of the lesion. RESULTS: Most of the patients studied were over 70 years old, except for one who was 55. The highest frequency of cases appeared among patients aged over 80 years. In the cases studied, when the tumour appeared in the head and neck region (10/16), its location could be nasal-lateronasal, cheek-malar, upper eyelid, frontal or mandibular. The major axis of the lesion ranged between 7 and 35 mm. Unlike with epidermoid or basocellular carcinomas, recurrence and ganglionar metastases were common. Immunohistochemical (CK20) tests are essential for a correct diagnosis. Treatment is usually surgical and occasionally followed by radiotherapy and chemotherapy. CONCLUSION: This carcinoma is not a very common skin tumour. It appears in old age, in the head and neck region in 50% of cases and often leads to exitus.

The Zuckerkandl tubercle: problematic or helpful in thyroid surgery?

The Zuckerkandl tubercle is a residue from the embryological development of the thyroid gland. Although it is undeniably well known in surgery, this is not so among otolaryngologists. Our objective is to highlight the importance of the Zuckerkandl tubercle, as it has proven to be a reliable point of reference to locate the upper parathyroid, the lower thyroid artery and the recurrent nerve. In order to study the Zuckerkandl tubercle, we made a prospective analysis of the posterolateral border of the thyroid lobes in 107 thyroidectomies (88 total thyroidectomies and 19 hemithyroidectomies) carried out by the same surgeon; in total, 195 thyroid lobes were analysed. The Zuckerkandl tubercle was certainly detected in 155 thyroid lobes (79.48%). The Zuckerkandl tubercle was most frequent in the right thyroid lobe (P = 0.06). When the Zuckerkandl tubercle was present, we localised the upper parathyroid due to its relationship with the tubercle in 80 right thyroid lobes (95.23%) and in 65 left (91.54%). On 147 occasions (94.83%), the recurrent nerve was directed towards the cricothyroid membrane beneath the Zuckerkandl tubercle, laterally to the tracheal surface in relation with the Berry ligament. The lower thyroid artery and some of the distal branches, such as the recurrent nerve, also ran under the Zuckerkandl tubercle. The areolar tissue underlying the Zuckerkandl tubercle is difficult to dissect, and so this protuberance constitutes a surgical difficulty but it is fundamentally helpful to find those important structures that must be preserved in thyroid surgery.

Arteria innominada aberrante alta en cirugía cervical / High-riding innominate artery in neck surgery

Presentamos 2 casos de posición cervical de la arteria innominada (AI). En el primer caso no se efectúa cirugía por no existir indicación, el segundo permite obtener imágenes quirúrgicas de la AI y sus ramas, situadas delante del eje laringotraqueal. Se alerta del grave riesgo de la cirugía cervical en estos casos (AU)

We present two cases of innominate artery (IA) in a cervical position. In the first case, surgery was not performed because there was no indication. In the second, it was possible to obtain surgical images of the AI and its branches located in front of the laryngotracheal axis. A warning about the serious risk involved in cervical surgery in these cases is indicated (AU)

High-riding innominate artery in neck surgery.

We present two cases of innominate artery (IA) in a cervical position. In the first case, surgery was not performed because there was no indication. In the second, it was possible to obtain surgical images of the AI and its branches located in front of the laryngotracheal axis. A warning about the serious risk involved in cervical surgery in these cases is indicated.

¿Es el oído medio el primer filtro de selección frecuencial? / Is the middle ear the first filter of frequency selectivity?

Introducción y objetivos: La cóclea es considerada el primer filtro de selección frecuencial en la vía auditiva debido a la acción contráctil de las células ciliadas externas. Sin embargo numerosas evidencias en animales de experimentación, algunas anatómicas (conexiones entre la vía auditiva y los núcleos motores de los músculos del oído medio) y otras fisiológicas, apuntan a que el oído medio pudiera ser el primer filtro gracias al cual comienza a discriminarse un determinado sonido de un entorno ruidoso. Métodos: En colaboración con el Departamento de Ingeniería Mecánica de la Escuela Técnica Superior (ETS) de Ingenieros Industriales de la Universidad de Valladolid (UVa) hemos desarrollado y puesto a punto un nuevo admitancímetro capaz de analizar los cambios de impedancia que ocurren en el oído medio humano en función de la frecuencia. Con él hemos cuantificado la variación de la impedancia del oído en 7 voluntarios otológicamente sanos sometidos a diferentes entornos sonoros. Resultados: Hemos hallado que la impedancia del oído no es constante sino que la atención que los sujetos explorados ofrecen para discriminar una conversación en un ambiente ruidoso hace que la impedancia del oído varíe en las frecuencias agudas. Conclusiones: A la vista de los resultados consideramos que el oído medio no es un mero actor pasivo durante la audición sino que la contracción de los músculos endotimpánicos hacen posible variaciones de la impedancia de forma que la frecuencia de resonancia del oído se desplace hacia frecuencias agudas mejorando la discriminación de la palabra en ambientes ruidosos (AU)

Introduction and objectives: The cochlea has traditionally been considered as the first frequency selection filter in the auditory pathway due to the contraction of its external ciliated cells. Yet, much evidence has emerged from work carried out during experiments with animals, some of which is anatomical (connections between the auditory pathway and motor nuclei of the middle ear muscles) and other physiological, which indicates that the middle ear might be the first filter through which specific sounds from noisy environments may initially be isolated. Methods: In cooperation with the Department of Mechanical Engineering of the Technical School of Industrial Engineering at the University of Valladolid (UVa) we have developed and refined a new admittance meter capable of evaluating changes in impedance that occur in the human middle ear depending on frequency. Using this device we have measured variation in impedance in 7 otologically healthy volunteers submitted to a varied range of sound environments. Results: We have found that hearing impedance is not constant but rather that the attention offered by the examined subjects when following a conversation in a noisy environment leads to variations in hearing impedance at high frequencies. Conclusions: In the light of these findings we feel that the middle ear does not play a merely passive role in hearing but rather that the contraction of the endotympanic muscles makes possible variations in impedance such that the resonance frequency of the ear shifts towards higher frequencies, thus enhancing sound discrimination in noisy environments (AU)

[Is the middle ear the first filter of frequency selectivity?]. / Es el oído medio el primer filtro de selección frecuencial?

INTRODUCTION AND OBJECTIVES: The cochlea has traditionally been considered as the first frequency selection filter in the auditory pathway due to the contraction of its external ciliated cells. Yet, much evidence has emerged from work carried out during experiments with animals, some of which is anatomical (connections between the auditory pathway and motor nuclei of the middle ear muscles) and other physiological, which indicates that the middle ear might be the first filter through which specific sounds from noisy environments may initially be isolated. METHODS: In cooperation with the Department of Mechanical Engineering of the Technical School of Industrial Engineering at the University of Valladolid (UVa) we have developed and refined a new admittance meter capable of evaluating changes in impedance that occur in the human middle ear depending on frequency. Using this device we have measured variation in impedance in 7 otologically healthy volunteers submitted to a varied range of sound environments. RESULTS: We have found that hearing impedance is not constant but rather that the attention offered by the examined subjects when following a conversation in a noisy environment leads to variations in hearing impedance at high frequencies. CONCLUSIONS: In the light of these findings we feel that the middle ear does not play a merely passive role in hearing but rather that the contraction of the endotympanic muscles makes possible variations in impedance such that the resonance frequency of the ear shifts towards higher frequencies, thus enhancing sound discrimination in noisy environments.

[Inverted acoustic reflex: an analysis of its morphological characteristics in different physiological and pathological situations]. / Reflejo acústico invertido: análisis de sus características morfológicas en distintas situaciones fisiológicas y patológicas.

INTRODUCTION AND OBJECTIVES: Inverted acoustic reflex (IAR) or inverted acoustic effect is the name given to the positive deflexion observed during the carrying out of an admittancemetry when the ear is subjected to a high intensity sound, rather than the typical negative deflexion due to the contraction of the middle ear musculature. The objective of the paper is to analyze the morphology of the IAR by relating it to the situations (physiological or pathological) in which this effect appears with the aim of establishing a pathogenic hypothesis. METHODS: We study the admittance traces obtained in 50 patients on stimulating the ear with high sound intensities (between 100 and 110 dBs HL) in different situations (ageing, death, otosclerosis, facial palsy, perception hypoacusia and normoacusia). We analyse the morphologies of the resulting traces as well as the on-set and off-set latencies of the reflexes. RESULTS: The morphology and latency parameters are similar in all cases in which IAR appears, regardless of the physical conditions of the ear but always with the prior condition of the absence of any contraction of the stapes bone muscle. The inverted acoustic effect does not disappear after deep muscular relaxation induced by anaesthesia and is present in corpses at a time when neural activity can no longer take place. CONCLUSIONS: Although some of the characteristics of IAR cannot be explained by purely mechanical hypotheses, the appearance of this effect in a corpse and its non-disappearance with muscular relaxation means that we consider its origin to be a purely mechanical effect not mediated by any muscular reflex contraction in the human middle ear.

Reflejo acústico invertido: análisis de sus características morfológicas en distintas situaciones fisiológicas y patológicas / Inverted acoustic reflex: An analysis of its morphological characteristics in different physiological and pathological situations

Introducción y objetivos: Se denomina reflejo o efecto acústico invertido (RAI) a la deflexión positiva observada durante la realización de una admitanciometría al someter al oído a un sonido de intensidad elevada, en vez de la típica deflexión negativa debida a la contracción de la musculatura del oído medio. El objetivo del trabajo es analizar la morfología del RAI relacionándola con las situaciones (fisiológicas o patológicas), en las que este efecto aparece con el fin de establecer una hipótesis patogénica. Métodos: Estudiamos los trazados admitanciométricos obtenidos en 50 pacientes al estimular el oído con elevadas intensidades sonoras (entre 100 y 110dB HL) en distintas situaciones (envejecimiento, muerte, otosclerosis, parálisis facial, hipoacusia de percepción y normoacusia). Analizamos las morfologías de los trazados resultantes así como las latencias de aparición y de cese (on-set y off-set) de los reflejos. Resultados: La morfología y los parámetros de latencia son similares en todos los casos en los que el RAI aparece, independientemente de las condiciones físicas del oído, pero siempre con el condicionante previo de ausencia de contracción del músculo del estribo. El RAI no desaparece tras la relajación muscular profunda inducida por la anestesia y está presente en el cadáver cuando ya no puede aparecer actividad neural alguna. Conclusiones: Aunque algunas de las características del RAI no se pueden explicar sirviéndonos de forma exclusiva de hipótesis mecánicas, la aparición de ese efecto en el cadáver y la no desaparición con la relajación muscular hace que consideremos su origen como un efecto puramente mecánico no mediado por contracción refleja muscular alguna en el oído medio humano (AU)

Introduction and objectives: Inverted acoustic reflex (IAR) or inverted acoustic effect is the name given to the positive deflexion observed during the carrying out of an admittancemetry when the ear is subjected to a high intensity sound, rather than the typical negative deflexion due to the contraction of the middle ear musculature. The objective of the paper is to analyze the morphology of the IAR by relating it to the situations (physiological or pathological) in which this effect appears with the aim of establishing a pathogenic hypothesis. Methods: We study the admittance traces obtained in 50 patients on stimulating the ear with high sound intensities (between 100 and 110dBs HL) in different situations (ageing, death, otosclerosis, facial palsy, perception hypoacusia and normoacusia). We analyse the morphologies of the resulting traces as well as the on-set and off-set latencies of the reflexes. Results: The morphology and latency parameters are similar in all cases in which IAR appears, regardless of the physical conditions of the ear but always with the prior condition of the absence of any contraction of the stapes bone muscle. The inverted acoustic effect does not disappear after deep muscular relaxation induced by anaesthesia and is present in corpses at a time when neural activity can no longer take place. Conclusions: Although some of the characteristics of IAR cannot be explained by purely mechanical hypotheses, the appearance of this effect in a corpse and its non-disappearance with muscular relaxation means that we consider its origin to be a purely mechanical effect not mediated by any muscular reflex contraction in the human middle ear (AU)