Use of pectoralis major myofascial flap on the prevention of pharyngocutaneous fístula in salvage laryngectomy after chemoradiotherapy.

Background: Pharyngocutaneous fístula (PCF) is a major complication of salvage laryngectomies, mainly secondary to the effect of radiotherapy. Aims/objectives: Our main objective is to study the effect of pectoralis major myofascial flap (PMMF) on the prevention of PCF. Materials and methods: We studied all total laryngectomies (TL) performed between 2001 and 2018, noting the use of previous chemoradiation, the type of suture and the use of flaps. We recorded and compared the incidence of PCF in all groups. Results: A total of 146 patients were included, divided into a primary TL group (117 patients) and salvage TL (29 patients). PMMF was used in 62% of salvage TLs. The rates of PCF were 5.98% in primary TL and 17.2% in salvage procedures. Among the salvage TL group, in patients with pharyngeal closure alone, a PCF developed in 36.4% of cases, compared to 5.56% in the PMMF group. We found a similar rate of fistulae when comparing primary TL and salvage TL with PMMF, highlighting the protective effect of the flap. Conclusions and significance: The use of PMMF in salvage TL reduces the incidence of PCF, achieving a rate similar to that attained with primary TL.

A N400 ERP Study in letter recognition after passive tactile stimulation training in blind children and sighted controls.

BACKGROUND: We previously demonstrated that using a sensory substitution device (SSD) for one week, tactile stimulation results in faster activation of lateral occipital complex in blind children than in seeing controls. OBJECTIVE: We used long-term haptic tactile stimulation training with an SSD to test if it results in stable cross-modal reassignment of visual pathways after six months, to provide high level processing of tactile semantic content. METHODS: We enrolled 12 blind and 12 sighted children. The SSD transforms images to a stimulation matrix in contact with the dominant hand. Subjects underwent twice-daily training sessions, 5 days/week for six months. Children were asked to describe line orientation, name letters, and read words. ERP sessions were performed at baseline and 6 months to analyze the N400 ERP component and reaction times (RT). N400 sources were estimated with Low Resolution Electromagnetic Tomography (LORETA). SPM8 was used to make population-level inferences. RESULTS: We found no group differences in RTs, accuracy of identifications, N400 latencies or distributions with the line task at 1 week or at 6 months. RTs on the letter recognition task were also similar. After 6 months, behavioral training increased accurate letter identification in both seeing and blind children (Chi 2 = 11906.934, p = 0.000), but the increase was larger in blind children (Chi 2 = 8.272, p = 0.004). Behavioral training shifted peak N400 amplitude to left occipital and bilateral parietal cortices in blind children, but to left precentral and postcentral and bilateral occipital cortices in sighted controls. CONCLUSIONS: Blind children learn to recognize SSD-delivered letters better than seeing controls and had greater N400 amplitude in the occipital region. To the best of our knowledge, our results provide the first published example of standard letter recognition (not Braille) by children with blindness using a tactile delivery system.

Cartilage invasion patterns in laryngeal cancer.

The cartilaginous invasion determines the T and is one of the most common sources of mistake in tumor staging. Also it is of great importance when planning any therapeutic alternative. In the latest revision of the TNM classification a clear distinction is made between infiltration of cartilage without going through it, considered a T3 recently and that would be a T4 according to the previous classification, and those going through the cartilage, classified as T4a. While this classification makes the difference in depth of infiltration, it does not emphasize the extent of invasion. This paper provides a detailed description of the laryngeal cartilage tumor infiltration by whole organ serial section in which the invasion is considered both horizontal (transcartilaginous) and vertical (extent of invasion) and establishing patterns of three-dimensional infiltration of the cartilage. This is a cross-sectional study of prevalence. 275 records of patients treated for laryngeal squamous cell carcinoma between 1995 and 2000 were reviewed. The pathological processing of laryngectomy surgical specimens was performed following the method of whole organ serial section described by G. F. Tucker. The following patterns of cartilaginous infiltration were defined: (1) transcartilaginous infiltration; (2a) partial focal infiltration of the cartilage: infiltration not going through the cartilage but occupying one third or less of its extent; (2b) partial extensive infiltration of the cartilage: infiltration occupying two thirds or more of its length and (3) no cartilage infiltration: tumor in contact with the cartilage (paraglottic space) but without affecting it. 161 patients met the inclusion criteria. The most frequent tumor location was supraglottic (58 cases) followed by glottic (47). 109 patients (67.7 %) were treated with total laryngectomy. Partial surgical techniques were performed in the remaining cases. TNM tumor staging was performed according to the results of pathological study (pTNM). 72.06 % (116) were classified as advanced laryngeal tumors (pT3 and pT4). 46 % of patients showed some extent of laryngeal cartilage infiltration (thyroid, cricoid, arytenoids, epiglottis). The cartilage most frequently infiltrated was the thyroid in 48 patients (29.8 %) and when it is affected, in most cases (66.7 %), the infiltration is transcartilaginous. The next most common pattern is partial focal infiltration (27 %). In the cricoid cartilage, the most common pattern of infiltration is focal partial infiltration (52.6 %). Of the 19 cases with infiltration of the cricoid, there are 12 cases with extra laryngeal invasion through a cricothyroid membrane perforation. The study of laryngeal cancer by laryngeal whole serial section has been proved to be very useful in offering a high precision pTNM staging and a detailed description of the infiltration of cartilage. We have seen that when the thyroid cartilage is infiltrated the tumor often passes through the cartilage. However, there are cases where the tumor is extremely aggressive, being very widespread in cartilage thickness without actually crossing it. The isolated infiltration of the cricoid cartilage is exceptional.

Differences in Early Stages of Tactile ERP Temporal Sequence (P100) in Cortical Organization during Passive Tactile Stimulation in Children with Blindness and Controls.

Compared to their seeing counterparts, people with blindness have a greater tactile capacity. Differences in the physiology of object recognition between people with blindness and seeing people have been well documented, but not when tactile stimuli require semantic processing. We used a passive vibrotactile device to focus on the differences in spatial brain processing evaluated with event related potentials (ERP) in children with blindness (n = 12) vs. normally seeing children (n = 12), when learning a simple spatial task (lines with different orientations) or a task involving recognition of letters, to describe the early stages of its temporal sequence (from 80 to 220 msec) and to search for evidence of multi-modal cortical organization. We analysed the P100 of the ERP. Children with blindness showed earlier latencies for cognitive (perceptual) event related potentials, shorter reaction times, and (paradoxically) worse ability to identify the spatial direction of the stimulus. On the other hand, they are equally proficient in recognizing stimuli with semantic content (letters). The last observation is consistent with the role of P100 on somatosensory-based recognition of complex forms. The cortical differences between seeing control and blind groups, during spatial tactile discrimination, are associated with activation in visual pathway (occipital) and task-related association (temporal and frontal) areas. The present results show that early processing of tactile stimulation conveying cross modal information differs in children with blindness or with normal vision.

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[Passive tactile stimulation and its clinical and neurophysiological repercussions (P300) in blind children with symptoms of attention deficit disorder]. / Estimulación táctil pasiva y su repercusión clínica y neurofisiológica (P300) en niños ciegos con sintomatología de trastorno por déficit de atención.

INTRODUCTION: Tactile stimulation is key for the posterior brain re-organization activity and attention processes, however the impact of tactile stimulation on attention deficit disorder (ADD) in blind children remains unexplored. SUBJECTS AND METHODS: We carried out a study with children having or not ADD (four per group). The subjects have been exposed during six months to tactile stimulation protocol consisting in two daily sessions (morning and afternoon sessions) of 30 minutes each. We have measured the ability to detect an infrequent tactile stimulus, reaction time, latency of P300, sources of brain activity, and ADD clinical symptoms, before and after tactile training. RESULTS: Passive tactile stimulation significantly improves ADD clinical symptoms, particularly attention, behavior and self-control of involuntary movements and tics. In addition, tactile stimulation changes the pattern of brain activity in ADD blind children inducing activity in frontal and occipital areas, which could be associated to a compensation of the attention deficit. CONCLUSION: Passive tactile stimulation training may improve ADD clinical symptoms and can reorganize the pattern of brain activity in blind ADD children.

TITLE: Estimulacion tactil pasiva y su repercusion clinica y neurofisiologica (P300) en niños ciegos con sintomatologia de trastorno por deficit de atencion.Introduccion. La estimulacion tactil es clave en la reorganizacion de la actividad cerebral y en los procesos de atencion, pero todavia no esta clara su eficacia en trastornos por deficit de atencion (TDA) en niños ciegos. Sujetos y metodos. Para valorar la eficacia de la estimulacion tactil realizamos un estudio en niños ciegos con TDA y sin TDA, consistente en un protocolo de estimulacion tactil diaria en dos sesiones (mañana y tarde), de media hora por sesion, durante seis meses. Se midio la capacidad para detectar un estimulo tactil infrecuente, el tiempo de reaccion, la latencia P300, las fuentes de actividad cerebral y la sintomatologia del TDA, tanto al inicio como al final del entrenamiento. Resultados. La estimulacion tactil en los niños ciegos con TDA mejora significativamente la sintomatologia del TDA, especialmente la atencion, la conducta y el autocontrol de los movimientos involuntarios y tics. Ademas, se observa que el entrenamiento tactil en niños ciegos con TDA cambia el patron de actividad cerebral induciendo una mayor actividad en las areas frontales y occipitales, que podrian estar asociadas a una compensacion del deficit de atencion. Conclusion. La estimulacion tactil pasiva diaria mejora la sintomatologia clinica y reorganiza la actividad cerebral en areas frontooccipitales de niños ciegos con TDA.

Estimulación táctil pasiva y su repercusión clínica y neurofisiológica (P300) en niños ciegos con sintomatología de trastorno por déficit de atención / Passive tactile stimulation and its clinical and neurophysiological repercussions (P300) in blind children with symptoms of attention deficit disorder

Introducción. La estimulación táctil es clave en la reorganización de la actividad cerebral y en los procesos de atención, pero todavía no está clara su eficacia en trastornos por déficit de atención (TDA) en niños ciegos. Sujetos y métodos. Para valorar la eficacia de la estimulación táctil realizamos un estudio en niños ciegos con TDA y sin TDA, consistente en un protocolo de estimulación táctil diaria en dos sesiones (mañana y tarde), de media hora por sesión, durante seis meses. Se midió la capacidad para detectar un estímulo táctil infrecuente, el tiempo de reacción, la latencia P300, las fuentes de actividad cerebral y la sintomatología del TDA, tanto al inicio como al final del entrenamiento. Resultados. La estimulación táctil en los niños ciegos con TDA mejora significativamente la sintomatología del TDA, especialmente la atención, la conducta y el autocontrol de los movimientos involuntarios y tics. Además, se observa que el entrenamiento táctil en niños ciegos con TDA cambia el patrón de actividad cerebral induciendo una mayor actividad en las áreas frontales y occipitales, que podrían estar asociadas a una compensación del déficit de atención. Conclusión. La estimulación táctil pasiva diaria mejora la sintomatología clínica y reorganiza la actividad cerebral en áreas frontooccipitales de niños ciegos con TDA (AU)

Introduction. Tactile stimulation is key for the posterior brain re-organization activity and attention processes, however the impact of tactile stimulation on attention deficit disorder (ADD) in blind children remains unexplored. Subjects and methods. We carried out a study with children having or not ADD (four per group). The subjects have been exposed during six months to tactile stimulation protocol consisting in two daily sessions (morning and afternoon sessions) of 30 minutes each. We have measured the ability to detect an infrequent tactile stimulus, reaction time, latency of P300, sources of brain activity, and ADD clinical symptoms, before and after tactile training. Results. Passive tactile stimulation significantly improves ADD clinical symptoms, particularly attention, behavior and selfcontrol of involuntary movements and tics. In addition, tactile stimulation changes the pattern of brain activity in ADD blind children inducing activity in frontal and occipital areas, which could be associated to a compensation of the attention deficit. Conclusion. Passive tactile stimulation training may improve ADD clinical symptoms and can reorganize the pattern of brain activity in blind ADD children (AU)

[Is the early brain organisation of spatial information conveyed by tactile stimuli performed in different ways in congenital and acquired blind children? A pilot study]. / Es distinta la organizacion cerebral temprana de la informacion espacial transmitida a traves de estimulos tactiles en ninos invidentes congenitos y adquiridos?: un estudio piloto.

Cortical reorganization after congenital blindness is not sufficiently known yet it does offer an optimum window of opportunity to study the effects of absolute sensorial deprivation. Cross-modality in people with blindness has been documented, but it may differ in congenital blindness and in early blindness. Vibrotactile passive stimulation of lines and letters generates different electroencephalographic patterns with different source localizations in two children with blindness, aged 9 and 10, respectively with congenital blindness and early blindness with some remnants of vision. Most of the brain electrical activity is centered in auditive areas in P50 and P100 in the case of the child with congenital blindness, while the other shows activity in multiple areas. Reaction times to letters are shorter than to lines of different orientation in both children.

¿Es distinta la organización cerebral temprana de la información espacial transmitida a través de estímulos táctiles en niños invidentes congénitos y adquiridos?: un estudio piloto / Is the early brain organisation of spatial information conveyed by tactile stimuli performed in different ways in congenital and acquired blind children? A pilot study

La reorganización cortical subyacente a la ceguera congénita no se conoce suficientemente, pero esta última ofrece una ventana óptima para el estudio de los efectos de la deprivación sensorial absoluta. Se sabe también que existe cross-modality en el cerebro de los invidentes, pero ésta difiere en niños con ceguera congénita y aquellos otros con restos de visión. La estimulación vibrotáctil pasiva de líneas y letras genera patrones electroencefalográficos y de localización de fuentes distintos en dos niños de 9 y 10 años, respectivamente, con ceguera congénita y ceguera con restos de visión. En la niña con ceguera congénita, la mayor actividad eléctrica cortical se centra en áreas auditivas en P50 y P100, mientras que en el niño invidente con restos de visión, la actividad se distribuye en múltiples áreas. Los tiempos de reacción a las letras son menores que a las líneas de diferente orientación en ambos niños (AU)

Cortical reorganization after congenital blindness is not sufficiently known yet it does offer an optimum window of opportunity to study the effects of absolute sensorial deprivation. Cross-modality in people with blindness has been documented, but it may differ in congenital blindness and in early blindness. Vibrotactile passive stimulation of lines and letters generates different electroencephalographic patterns with different source localizations in two children with blindness, aged 9 and 10, respectively with congenital blindness and early blindness with some remnants of vision. Most of the brain electrical activity is centered in auditive areas in P50 and P100 in the case of the child with congenital blindness, while the other shows activity in multiple areas. Reaction times to letters are shorter than to lines of different orientation in both children (AU)

Electrophysiological monitoring of hearing function during cochlear perilymphatic perfusions.

CONCLUSION: The cochlear perilymphatic perfusion produces, by itself, significant effects in the cochlear physiology that could be associated with the surgical procedure. These effects need to be well characterized to allow a reliable quantification of the effects of the experimental agent being tested. OBJECTIVES: The study focused on the accurate description of the electrophysiological effects on the cochlear potential recordings of perilymphatic perfusions. METHODS: Two successive cochlear perilymphatic perfusions were carried out. The first used artificial perilymph. The second used artificial perilymph alone or a kainic acid (KA) solution in artificial perilymph. The compound action potential of the auditory nerve (CAP-AN) was recorded: (1) before the first perfusion, (2) after the first perfusion and (3) after the second perfusion, and compared between groups. RESULTS: The first intracochlear perfusion with artificial perilymph produced significant effects in the CAP-AN that could be related to the surgical procedure. These effects were analysed separately from the effects produced by the KA. In particular, the KA administered intracochlearly produced a significant increase in the latency and a decrease in the amplitude of the CAP-AN N1 wave compared with the controls that were perfused twice with artificial perilymph.

Pharyngo-cutaneous fistula: an old problem revisited.

CONCLUSION: Pharyngo-cutaneous fistula is the most common complication after total laryngectomy (TL), with many factors linked to its emergence. However, it has rarely been associated with the type of pharyngeal suture. We conclude that the technique of surgical closure of the pharynx and care in the tightness of the suture seem to be fundamental factors for pharyngo-cutaneous fistula development. OBJECTIVE: The aim of present work was to determine whether the type of pharyngeal suture can be considered as a major risk factor for developing a pharyngo-cutaneous fistula following TL. METHODS: We carried out a series of 157 consecutive TLs. In the first 90 procedures, we performed a pharyngeal closure technique with T-shaped interrupted stitches reinforced with constrictors. In the other 67 cases, a doubled continuous suture technique with reinforcement with the cutaneous flap was developed. RESULTS: In all, 25.5% of the cases sutured with the interrupted stitches developed a fistula while only 2.9% of the patients that underwent continuous suture developed a fistula.

The impact of comorbidity on the survival of patients with laryngeal squamous cell carcinoma.

UNLABELLED: Abstract Conclusions: In survival analysis, the combined Charlson comorbidity index (CCI) can be considered as a prognostic factor independent of the tumor node metastasis (TNM) classification, tumor stage, and tumor location. Severe comorbidity was the factor that had the greatest impact on prognosis in cases of initial tumor. OBJECTIVE: To study the influence of comorbidity on the survival of patients undergoing surgery for larynx cancer. METHODS: This was a retrospective study of the survival of 231 patients with laryngeal cancer who underwent surgery between 1995 and 2002. The CCI was used to assess comorbidity, the Kaplan-Meier method was used for survival analysis, and the Cox proportional risk regression model was used to identify independent prognostic factors. RESULTS: The multivariate analysis of specific mortality showed that patients classified as having severe comorbidity (CCI) were more likely to die (adjusted hazard ratio (adjHR) 1.85, 95% confidence interval (CI) 1.07-3.17). This difference was more important in patients with early tumor stages than in those with advanced stages.

Estenosis congénita del orificio piriforme y megaincisivo central único / Congenital nasal pyriform aperture stenosis and solitary maxillary central incisor: Case report

La estenosis congénita del orificio piriforme es una anomalía descrita recientemente en la literatura, provocada por un crecimiento excesivo de la apófisis ascendente del hueso maxilar, pudiendo ocasionar problemas respiratorios y alimenticios desde el periodo neonatal. Presentamos el caso de una recién nacida diagnosticada de esta patología asociada a un megaincisivo central único. La actitud elegida fue la observación, junto con la aplicación de medidas conservadoras. Un año después del diagnóstico, la paciente tiene un adecuado desarrollo ponderoestatural (AU)

Congenital nasal pyriform aperture stenosis has recently been described in the literature. It is caused by an upward overgrowth of the maxillary bone apophysis and may cause breathing and feeding problems from the neonatal period on. We present the case of a newborn girl diagnosed with this pathology associated with a solitary maxillary central incisor. Observation with conservative measures was the attitude chosen. One year after diagnosis the patient shows adequate height and weight development (AU)

In vitro long-term development of cultured inner ear stem cells of newborn rat.

The adult mammalian auditory receptor lacks any ability to repair and/or regenerate after injury. However, the late developing cochlea still contains some stem-cell-like elements that might be used to regenerate damaged neurons and/or cells of the organ of Corti. Before their use in any application, stem cell numbers need to be amplified because they are usually rare in late developing and adult tissues. The numerous re-explant cultures required for the progressive amplification process can result in a spontaneous differentiation process. This aspect has been implicated in the tumorigenicity of stem cells when transplanted into a tissue. The aim of this study has been to determine whether cochlear stem cells can proliferate and differentiate spontaneously in long-term cultures without the addition of any factor that might influence these processes. Cochlear stem cells, which express nestin protein, were cultured in monolayers and fed with DMEM containing 5% FBS. They quickly organized themselves into typical spheres exhibiting a high proliferation rate, self-renewal property, and differentiation ability. Secondary cultures of these stem cell spheres spontaneously differentiated into neuroectodermal-like cells. The expression of nestin, glial-fibrillary-acidic protein, vimentin, and neurofilaments was evaluated to identify early differentiation. Nestin expression appeared in primary and secondary cultures. Other markers were also identified in differentiating cells. Further research might demonstrate the spontaneous differentiation of cochlear stem cells and their teratogenic probability when they are used for transplantation.

Neuroplasticidad cerebral en áreas occipitales en adolescentes ciegos / Brain neuroplasticity in occipital areas in blind teenagers

Introducción y desarrollo. La neuroplasticidad es un proceso mediante el cual las neuronas consiguen aumentar sus conexiones con otras neuronas y estabilizar dichas conexiones a consecuencia de la experiencia, el aprendizaje y la estimulación sensorial y cognitiva. Diferentes autores han documentado la existencia de un gran proceso de plasticidad cerebral hacia otras áreas sensoriales, principalmente auditivas y visuales, en sujetos ciegos. Desde el punto de vista anatómico, numerosos trabajos han encontrado diferencias significativas en el cerebro de los sujetos ciegos, principalmente en estructuras relacionadas con la visión, como consecuencia de la falta de actividad de dichas áreas, que trae consigo una menor plasticidad neuronal y consecuentemente un menor volumen estructural; también se han encontrado diferencias en el volumen de estructuras subcorticales relacionadas con la visión, como el esplenio y el istmo del cuerpo calloso. Metodología. Se estimuló táctil y pasivamente a un adolescente mediante un estimulador de 1.500 táxels. La estimulación se llevó a cabo diariamente, durante una hora, a lo largo de tres meses, y consistió en líneas verticales, horizontales y oblicuas. Los resultados obtenidos en un adolescente indican una progresión de la actividad electroencefalográfica desde áreas parietales de sensibilidad táctil hacia áreas occipitales visuales a medida que avanza la estimulación. Conclusión. Cabe plantearse si la repetición sistemática, ordenada y organizada de los estímulos táctiles en sujetos ciegos permite una mayor plasticidad cerebral, consiguiendo poco a poco colonizar otras áreas cerebrales como las occipitales, responsables de la visión humana (AU)

Introduction and development. Neuroplasticity is a process by which neurons increase their connectivity with other neurons in a stable fashion as a consequence of experience, learning and both sensitive and cognitive stimulation. Different authors have shown a huge process of brain plasticity in blind subjects towards other sensorial areas, mainly auditive and visual ones. From an anatomical standpoint many data show significant differences in blind subjects brains, mainly in visual pathways and structures as a result of lack of activity on those areas. This brings a lesser neuroplasticity and, therefore, a decrease in structural volumes. They have also found differences in subcortical structures volumes related to vision, such as splenium or corpus callosum istmus. Methodology. An adolescent was administered passive tactile stimulation with an 1,500 taxels stimulator. This was carried out daily for an hour, for three months, and stimulation consisted of vertical, horizontal and oblique lines. The results obtained in an adolescent indicate a clear progression of EEG activity from tactile sensory parietal areas to visual occipital ones as stimulation progresses. Conclusion. Therefore one can speculate if systematic and organized repetition of tactile stimuli in blind subjects leads to a greater neuroplasticity which expands towards occipital areas, largely responsible for human vision (AU)

[Congenital nasal pyriform aperture stenosis and solitary maxillary central incisor: case report]. / Estenosis congénita del orificio piriforme y megaincisivo central único.

Congenital nasal pyriform aperture stenosis has recently been described in the literature. It is caused by an upward overgrowth of the maxillary bone apophysis and may cause breathing and feeding problems from the neonatal period on. We present the case of a newborn girl diagnosed with this pathology associated with a solitary maxillary central incisor. Observation with conservative measures was the attitude chosen. One year after diagnosis the patient shows adequate height and weight development.

Cellular and molecular bases of neuroplasticity: brainstem effects after cochlear damage.

After a cochlear lesion or auditory nerve damage, afferent connections from auditory ganglia can be highly altered. This results in a clear reduction of auditory input and an alteration of connectivity of terminals on cochlear nuclei neurons. Such a process could stimulate the reorganization of the neural circuits and neuroplasticity. Cochlea removal has been demonstrated to be a good model in which to analyse brainstem neuroplasticity, particularly with regard to the cochlear nuclei. After cochlea removal three main periods of degeneration and regeneration were observed. Early effects, during the first week post lesion, involved acute degeneration with nerve ending oedema and degeneration. During the second and, probably, the third post lesion weeks, degeneration was still present, even though a limited and diffuse expression of GAP-43 started. Around 1 month post lesion, degeneration at the cochlear nuclei progressively disappeared and a relevant GAP-43 expression was found. We conclude that neuroplasticity leads neurons to modify their activity and/or their synaptic tree as a consequence of animal adaptation to learning and memory. For the human being neuroplasticity is involved in language learning and comprehension, particularly the acquisition of a second language. Neuroplasticity is important for therapeutic strategies, such as hearing aids and cochlear implants.

Cochlear microphonic audiometry: a new hearing test for objective diagnosis of deafness.

CONCLUSIONS: Objective audiometric tests could constitute a valuable tool for detection of deafness. This could be especially useful in children (universal newborn hearing screening) and non-collaborative patients, who are especially difficult candidates for classic audiometry. The cochlear microphonic audiometry (CMA) technique offers the possibility of obtaining objective audiometric profiles, highly correlated with those obtained by pure tone audiometry (PTA). Therefore, CMA could be used as an alternative test to obtain the audiometric profile of these patients. OBJECTIVE: The main purpose of the present study was to demonstrate that CMA provides objective audiometric profiles by avoiding active participation by the patient. Subjects and methods. CMA specific equipment, improved for non-invasive recording of cochlear microphonic potentials, was used. This tool plots the recordings obtained as the classic audiogram. Verification of the method was carried out in adult patients by comparing the PTA with the CMA audiometric profiles obtained for each patient. RESULTS: Our findings showed that audiometric profiles obtained from CMA are highly correlated, without statistical differences, to those obtained with PTA. More than 81% of patients explored (91.67% at 250 Hz) exhibited differences below 10 dB(HL) between tests at all exploration frequencies, while a low number of cases showed differences over 20 dB(HL).

Magnetoencephalography for research of auditory cortex.

CONCLUSION: The results could indicate that, during phylogeny and human ontogeny, the central nervous system has enhanced the speech activity from any other activity even though other frequencies could be relevant for survival. OBJECTIVE: People of all ages can experience alterations of auditory perception that progressively increase with aging. The whole approach to these alterations needs not only peripheral (cochlear) or brainstem studies but also an analysis of the auditory cortex. In fact, auditory evoked fields (AEF) may contribute to the understanding of the neural correlate of sound awareness. SUBJECTS AND METHODS: The M100 response after pure tone stimulation (five frequencies ranging from 500 to 8000 Hz) was analyzed in a group of nine adult subjects with normal hearing, older than 25 years of age and under 40 years old. Average M100 field intensity was calculated for all magnetoencephalography (MEG) channels in a 60 ms window around the M100 waveform. RESULTS: The results indicate a more intense cortical response to main speech frequencies (0.5 to 2 kHz) as compared with other frequencies not involved in human conversation.

Effects of aging on C57BL/6J mice: an electrophysiological and morphological study.

Presbycusis is a progressive hearing loss associated with aging that manifests as deafness linked to cochlear morphological degeneration. The effects of aging on the auditory system were studied in C57BL/6J mice using electrophysiological (brainstem auditory evoked potentials; BAEP) and morphological techniques. Cochleae of animals aged 1, 6, 9, 12, 15, 18, 21, or 24 months old were used for that purpose. The BAEP showed a progressive increase in latency and a reduction in amplitude. Morphological studies demonstrated total degeneration of the organ of Corti, which was replaced by a single epithelial layer. An affinity histochemistry study demonstrated minor modifications of glycoconjugates in the organ of Corti during the aging process.