Deaf Subjects Research Articles

Temporary Neurotrophin Treatment Prevents Deafness-Induced Auditory Nerve Degeneration and Preserves Function.

After substantial loss of cochlear hair cells, exogenous neurotrophins prevent degeneration of the auditory nerve. Because cochlear implantation, the current therapy for profound sensorineural hearing loss, depends on a functional nerve, application of neurotrophins is being investigated. We addressed two questions important for fundamental insight into the effects of exogenous neurotrophins on a degenerating neural system, and for translation to the clinic. First, does temporary treatment with brain-derived neurotrophic factor (BDNF) prevent nerve degeneration on the long term? Second, how does a BDNF-treated nerve respond to electrical stimulation? Deafened guinea pigs received a cochlear implant, and their cochleas were infused with BDNF for 4 weeks. Up to 8 weeks after treatment, their cochleas were analyzed histologically. Electrically evoked compound action potentials (eCAPs) were recorded using stimulation paradigms that are informative of neural survival. Spiral ganglion cell (SGC) degeneration was prevented during BDNF treatment, resulting in 1.9 times more SGCs than in deafened untreated cochleas. Importantly, SGC survival was almost complete 8 weeks after treatment cessation, when 2.6 times more SGCs were observed. In four eCAP characteristics (three involving alteration of the interphase gap of the biphasic current pulse and one involving pulse trains), we found large and statistically significant differences between normal-hearing and deaf controls. Importantly, for BDNF-treated animals, these eCAP characteristics were near normal, suggesting healthy responsiveness of BDNF-treated SGCs. In conclusion, clinically practicable short-term neurotrophin treatment is sufficient for long-term survival of SGCs, and it can restore or preserve SGC function well beyond the treatment period. Significance statement: Successful restoration of hearing in deaf subjects by means of a cochlear implant requires a healthy spiral ganglion cell population. Deafness-induced degeneration of these cells can be averted with neurotrophic factors. In the present study in deafened guinea pigs, we investigated the long-term effects of temporary (i.e., clinically practicable) treatment with brain-derived neurotrophic factor (BDNF). We show that, after treatment cessation, the neuroprotective effect remains for at least 8 weeks. Moreover, for the first time, it is shown that the electrical responsiveness of BDNF-treated spiral ganglion cells is preserved during this period as well. These findings demonstrate that treatment of the auditory nerve with neurotrophic factors may be relevant for cochlear implant users.

Satisfaction With Cochlear Implants in Postlingually Deaf Adults and Its Nonaudiological Predictors

A postlingually deaf patient who receives a cochlear implant (CI) acquires multiple benefits, not just audiological but also nonaudiological: improvement in quality of life, psychological well-being, and social interaction. The aim of the study was to ascertain the relationship between the CI satisfaction experienced by adult, postlingually deaf individuals and their level of psychological distress, stress coping strategies, and global self-esteem. We also considered sociodemographic variables (such as sex, age, education, marital/partner status, and employment/study status), variables related to their deafness, and their length of experience with a CI. The study had a cross-sectional design in which participants were asked to fill in a mailed personal inquiry form seeking sociodemographic data and one question related to CI satisfaction, and the following questionnaires: General Health Questionnaire-28, the Brief Coping Orientation to Problems Experienced, and the Rosenberg Self-Esteem Scale. This study included 98 patients with postlingual deafness between 19 and 85 years old who had unilateral CIs. For some analyses, the patients were also divided into two groups: younger (≤60 years) and older (>60 years). Two other subgroups were those with shorter CI experience (1 to 2 years) and those with longer CI experience (5 to 6 years). As an objective reference, speech perception scores in quiet and in noise were also used. The majority of postlingually deaf subjects rated their CI satisfaction as high or very high, and this was at similar levels in younger and older subjects, as well as in those who had used CIs for either a short or a long time. CI satisfaction was not related to speech perception scores, duration of deafness, length of CI use, or other sociodemographic factors. Positive self-esteem, having less severe symptoms of depression, and the use of humor or self-distraction were conducive to CI satisfaction. Using a coping strategy of denial had a negative association with CI satisfaction. Coping strategies and symptoms of mental distress varied between younger and older subjects. For younger subjects, higher CI satisfaction was associated with lower severity of depressive symptoms, whereas for the elderly, higher CI satisfaction was associated with less severe social dysfunction symptoms. Over the years of using a CI, the same strategy may have a different psychological function in providing satisfaction: for example, venting, which in the group with a short CI experience is negatively correlated to satisfaction, is positively correlated to satisfaction for those with longer CI experience. The results show that psychological factors—self-esteem, distress, and coping strategies—are important for CI satisfaction in postlingually deaf CI users. The results point to advantages in widening the availability of various tailored forms of psychological intervention for patients with postlingual deafness after receiving a CI.

Cross-modal activation of auditory regions during visuo-spatial working memory in early deafness.

Early deafness can reshape deprived auditory regions to enable the processing of signals from the remaining intact sensory modalities. Cross-modal activation has been observed in auditory regions during non-auditory tasks in early deaf subjects. In hearing subjects, visual working memory can evoke activation of the visual cortex, which further contributes to behavioural performance. In early deaf subjects, however, whether and how auditory regions participate in visual working memory remains unclear. We hypothesized that auditory regions may be involved in visual working memory processing and activation of auditory regions may contribute to the superior behavioural performance of early deaf subjects. In this study, 41 early deaf subjects (22 females and 19 males, age range: 20-26 years, age of onset of deafness < 2 years) and 40 age- and gender-matched hearing controls underwent functional magnetic resonance imaging during a visuo-spatial delayed recognition task that consisted of encoding, maintenance and recognition stages. The early deaf subjects exhibited faster reaction times on the spatial working memory task than did the hearing controls. Compared with hearing controls, deaf subjects exhibited increased activation in the superior temporal gyrus bilaterally during the recognition stage. This increased activation amplitude predicted faster and more accurate working memory performance in deaf subjects. Deaf subjects also had increased activation in the superior temporal gyrus bilaterally during the maintenance stage and in the right superior temporal gyrus during the encoding stage. These increased activation amplitude also predicted faster reaction times on the spatial working memory task in deaf subjects. These findings suggest that cross-modal plasticity occurs in auditory association areas in early deaf subjects. These areas are involved in visuo-spatial working memory. Furthermore, amplitudes of cross-modal activation during the maintenance stage were positively correlated with the age of onset of hearing aid use and were negatively correlated with the percentage of lifetime hearing aid use in deaf subjects. These findings suggest that earlier and longer hearing aid use may inhibit cross-modal reorganization in early deaf subjects. Granger causality analysis revealed that, compared to the hearing controls, the deaf subjects had an enhanced net causal flow from the frontal eye field to the superior temporal gyrus. These findings indicate that a top-down mechanism may better account for the cross-modal activation of auditory regions in early deaf subjects.See MacSweeney and Cardin (doi:10/1093/awv197) for a scientific commentary on this article.

GJB2 mutations in deaf population of Ilam (Western Iran): a different pattern of mutation distribution.

Hearing loss is the most common sensory defect caused by heterogeneous factors. Up to now, more than 60 mutations in genes have been documented for nonsyndromic hearing loss. Hence, finding the causal gene in affected families could be a laborious and time-consuming process. GJB2 mutations, here, were investigated among deaf subjects of Ilam for the first time. In this study, we studied 62 unrelated patients with non-syndromic autosomal recessive deafness from 62 families. The most common mutation of GJB2, 35delG was checked, followed by direct sequencing of the GJB2 gene for determination of other mutations. In silico analyses were also performed using available software. In nine families, mutations in the connexin 26 gene were observed. In the studied population, R32H was the most common mutation. 35delG, W24X, and R127H were other mutations found in this study. In silico analyses showed pathogenicity of 35delG, R32H, and W24X but not R127H. Low frequency of GJB2 mutations in this population is probably indicative of the fact that other genes may be involved in nonsyndromic hearing loss in Ilam populations. In the other hand, the vicinity of Ilam and Iraq suggests that GJB2 mutations have likely a low frequency in this population.

Eye problems in children with hearing impairment

PurposeTo compare the prevalence of refractive errors, amblyopia, and strabismus between hearing-impaired and normal children (7–22 years old) in Mashhad. MethodsIn this cross-sectional study, cases were selected from hearing-impaired children in Mashhad. The control group consisted of children with no hearing problem. The sampling was done utilizing the cluster sampling method. All of the samples underwent refraction, cover test, and visual examinations. Results254 children in the hearing-impaired group (case) and 506 children in the control group were assessed. The mean spherical equivalent was 1.7 ± 1.9 D in the case group, which was significantly different from the control group (0.2 ± 1.5) (P < 0.001). The prevalence of hyperopia was 57.15% and 21.5% in deaf and normal children, respectively, but myopia was mostly seen in the control group (5.5% versus 11.9%, P = 0.007). The mean cylinder was 0.65 ± 1.3 D and 0.43 ± 0.62 D in deaf and normal subjects, respectively (P = 0.002). 12.2% of deaf subjects and 1.2% of normal subjects were amblyopic (P < 0.001), and the prevalence of strabismus was 3.1% in the case group and 2.6% in the control group (P = 0.645). ConclusionIn a comparison of children of the same ages, hearing-impaired children have significantly more eye problems; therefore, a possible relation between deafness and eye problems must exist. Paying attention to eye health assessment in hearing-impaired children may help prevent adding eye problems to hearing difficulties.

La Audiología del siglo XXI es una ciencia multidisciplinar

La creación del término y concepto de Audiología se atribuye a diferentes autores, Schier, Nowak, Canfield, Hargrave. En 1946, Carhart y colaboradores definieron la Audiología como la ciencia que se ocupa de las alteraciones auditivas tanto en oído normal como patológico. El termino Audiología, aun hoy, carece de definición precisa, sigue sin tener una referencia en el diccionario de la Real Academia de la Lengua Española, lo que refleja la complejidad de esta ciencia para poder referenciarla en una parcela concreta del conocimiento. La Audiología es la rama de la ciencia estudia y analiza los procesos fisiológicos que permiten a través del mecanismo de la audición, interpretar “lo que se oye” pudiendo diferenciar en “como y cuanto se oye”. Esta diferenciación del cuanto y como se oye hace de la Audiología una ciencia cuantificable permitiendo determinar el grado de pérdida auditiva, lo que facilita la intervención, tratamiento y adaptación protésica con el fin de suplir y restaurar cualquier deficiencia auditiva. El progreso del conocimiento en Audiología como cualquier otra rama clínica de Ciencias de la Salud se sustenta en la investigación básica. La evolución de la investigación básica en Audiología no ha dejado de progresar y aportar conocimiento sobre la naturaleza de los elementos estructurales a nivel periférico y sistema nervioso central. El complejo funcionamiento de estos elementos estructurales no solo relacionados con le proceso auditivo sino la estrecha relación de audición con la interpretación del lenguaje oral, con otros órganos sensoriales como la vista el olfato, el equilibrio, la memoria, están permitiendo que en este siglo XXI, la Audiología se haya convertido en una disciplina compartida, analizada y utilizada por diferentes profesionales, siendo por tanto una ciencia multidisciplinar. El periodo comprendido entre los años 1960-1970 donde la Audiología es principalmente clínica y se la define como rama de la Otología, relacionada con otras especialidades clínicas de Ciencias de la Salud como la Foniatría, la Geriatría, la Pediatría, la Neurología, la Psiquiatría. A partir de los años 1980-2000, la investigación básica en Audiología arranca con gran profusión de publicaciones científicas donde se da a conocer los diferentes elementos y estructuras que conforman la cóclea y como estas estructuras tienen una estrecha correlación funcional con la transformación de la onda sonora en un mensaje sináptico. Las cócleas (audición periférica), así como la vía y corteza auditiva (audición central) de todos los mamíferos incluido el humano procesan la transformación de la señal auditiva de forma muy similar, lo que permite generar modelos experimentales que permiten analizar las patologías auditivas acaecidas en la clínica diaria. El avance en el conocimiento morfológico, estructural y funcional del oído y la vía auditiva, ha permitido el desarrollo de la Electroacústica y la construcción de diferentes sistemas y aparataje electrónico al servicio de la Audiología. Los diferentes tipos de registros electrofisiológicos permiten identificar cuantificar y evaluar con mayor precisión la representación de la actividad del sistema auditivo periférico y central tras aplicar un estimulo sonoro. En la actualidad la corroboración de los resultados morfológicos con los resultados audiológicos permite mejorar la precisión de “como y cuanto se oye”. En el ser humano el lenguaje oral hace que la Audiología alcance un rango máximo de complejidad, ya que audición y lenguaje están directamente relacionados. A finales del siglo XX, el avance en el conocimiento de la Psicología, la Logopedia, la Lingüística va a permitir a la Audiología, conocer e interpretar cuantitativa y cualitativamente el proceso auditivo desde el receptor periférico hasta la corteza auditiva en un sujeto normal, sordo, hipoacúsico, e hiperacúsico. La Audiología del siglo XXI está caracterizada por ser una Ciencia obligatoriamente Multidisciplinar, ya que profesionales y estudiosos de ambas ramas del saber (Ciencias de la Salud y Ciencias Sociales) van ampliando el conocimiento y la relación de la audición con otras funcionales vitales, sensoriales y sociales del ser humano. Esta multidisciplinaridad favorece el binomio investigación básica y clínica y permitirá sin duda avanzar por diferentes caminos, que convergerán sin duda en ampliar el conocimiento en audición y len guaje. A pesar del desarrollo en las tecnologías de la comunicación, estas no podrán suplir a la comunicación oral y por ello esta siendo fundamental ofrecer al paciente con deficiencias o alteraciones auditivas una mejoría en la recuperación de la audición perdida y la reinterpretación del sonido independientemente que la deficiencia se haya producido en un periodo prelocutivo o postlocutivo. Esta revista Audito, por tratarse de una revista online, pretende de forma casi inmediata dar a conocer los resultados obtenidos, así como intercambiar los conocimientos y proyectos con diferentes profesionales de lengua hispana que estén interesados en el proceso de “como y cuanto oímos”.

Investigation of the factors effecting static balance in deaf subjects

Iletisim: Dr. Nihal Buker. Pamukkale Universitesi Fizik Tedavi ve Rehabilitasyon Yuksekokulu, 20200 Denizli Tel: 0258 296 22 99 Basvuru tarihi: 30.04.2013 Kabul tarihi: 02.12.2013 Online baski: 10.03.2015 e-posta: nasuk@pau.edu.tr Ozet Amac: Bu calisma isitme engeli olan bireylerin denge yeteneklerini isitme engeli olmayan saglikli bireylerle karsilastirmak ve antigravite kaslarinin kuvveti ile kas kisaliklarinin denge uzerine etkilerini belirlemek amaciyla yapilmistir.

The influence of cochlear implants on behaviour problems in deaf children.

This study seeks to analyse the relationship between behaviour problems in deaf children and their auditory and communication development subsequent to cochlear implantation and to examine the incidence of these problems in comparison to their hearing peers. This study uses an ex post facto prospective design with a sample of 208 Spanish children, of whom 104 were deaf subjects with cochlear implants. The first objective assesses the relationships between behaviour problems, auditory integration, and social and communication skills in the group of deaf children. The second compares the frequency and intensity of behaviour problems of the group of deaf children with their hearing peers. The correlation analysis showed a significant association between the internal index of behaviour problems and auditory integration and communication skills, such that deaf children with greater auditory and communication development had no behaviour problems. When comparing behaviour problems in deaf children versus their hearing peers, behavioural disturbances are significantly more frequent in the former. According to these findings, cochlear implants may not guarantee adequate auditory and communicative development that would normalise the behaviour of deaf children.

Diferentes pronúncias em uma língua não sonora? Um estudo da variação na produção de sinais da libras

Estudos fonético-fonológicos sobre a língua de sinais americana (ASL) demonstraram que os itens lexicais dessa língua se constituem de unidades distintivas (parâmetros) e que estas, por sua vez, podem apresentar variação em sua manifestação concreta. Pouco se sabe sobre os parâmetros constitutivos dos sinais da língua brasileira de sinais (libras), tampouco sobre sua variação. Este trabalho representa um primeiro passo rumo a um entendimento de como se dá a variação na produção de sinais da libras a partir do estudo das produções, por 12 sinalizadores, de 60 sinais dessa língua. A análise dessas produções, eliciadas através de imagens combinadas com glosas em português, não apenas ratificou a ocorrência da variação inter-sujeito nos parâmetros configuração de mão, localização, movimento, orientação, número de mãos e marcações não-manuais, observada na sinalização espontânea, mas revelou também variação em outros aspectos articulatórios dos sinais, entre os quais está o contato entre os articuladores. Além disso, o estudo também evidenciou a ocorrência de variação intra-sujeito em todos os parâmetros analisados.

Visualizando a elaboração da linguagem em surdos bilíngues por meio da ressonância magnética funcional

As línguas de sinais são línguas naturais que compartilham as propriedades das línguas orais. Este estudo buscou visualizar as áreas corticais ativadas em surdos bilíngues em Língua Brasileira de Sinais e em Língua Portuguesa. As tarefas envolveram a elaboração da linguagem. Foram feitos treze exames de Imagem por Ressonância Magnética Funcional. Foi utilizada, ainda, uma sequência de imagem ecoplanar para a aquisição BOLD (Blood Oxygen Level Dependent) e, para corregistro, foram buscadas imagens de alta resolução de todo o encéfalo. Os mapas estatísticos foram obtidos com o Modelo Geral Linear, utilizando o programa Brain Voyager.TM A tarefa de elaboração da linguagem em Língua Brasileira de Sinais proporcionou ativações mais significativas do que a tarefa de elaboração em Língua Portuguesa, sugerindo que os surdos bilíngues apresentam maior competência linguística em língua de sinais.

Optogenetic stimulation of the auditory nerve.

Direct electrical stimulation of spiral ganglion neurons (SGNs) by cochlear implants (CIs) enables open speech comprehension in the majority of implanted deaf subjects(1-) (6). Nonetheless, sound coding with current CIs has poor frequency and intensity resolution due to broad current spread from each electrode contact activating a large number of SGNs along the tonotopic axis of the cochlea(7-) (9). Optical stimulation is proposed as an alternative to electrical stimulation that promises spatially more confined activation of SGNs and, hence, higher frequency resolution of coding. In recent years, direct infrared illumination of the cochlea has been used to evoke responses in the auditory nerve(10). Nevertheless it requires higher energies than electrical stimulation(10,11) and uncertainty remains as to the underlying mechanism(12). Here we describe a method based on optogenetics to stimulate SGNs with low intensity blue light, using transgenic mice with neuronal expression of channelrhodopsin 2 (ChR2)(13) or virus-mediated expression of the ChR2-variant CatCh(14). We used micro-light emitting diodes (µLEDs) and fiber-coupled lasers to stimulate ChR2-expressing SGNs through a small artificial opening (cochleostomy) or the round window. We assayed the responses by scalp recordings of light-evoked potentials (optogenetic auditory brainstem response: oABR) or by microelectrode recordings from the auditory pathway and compared them with acoustic and electrical stimulation.

Structural alterations of brain grey and white matter in early deaf adults

Functional and structural brain alterations in the absence of the auditory input have been described, but the observed structural brain changes in the deaf are not uniform. Some of the previous researchers focused only on the auditory areas, while others investigated the whole brain or other selected regions of interest. Majority of studies revealed decreased white matter (WM) volume or altered WM microstructure and preserved grey matter (GM) structure of the auditory areas in the deaf. However, preserved WM and increased or decreased GM volume of the auditory areas in the deaf have also been reported. Several structural alterations in the deaf were found also outside the auditory areas, but these regions differ between the studies. The observed differences between the studies could be due to the use of different single-analysis techniques, or the diverse population sample and its size, or possibly due to the usage of hearing aids by some participating deaf subjects. To overcome the aforementioned limitations four different image-processing techniques were used to investigate changes in the brain morphology of prelingually deaf adults who have never used hearing aids. GM and WM volume of the Heschl's gyrus (HG) were measured using manual volumetry, while whole brain GM volume, thickness and surface area were assessed by voxel-based morphometry (VBM) and surface-based analysis. The microstructural properties of the WM were evaluated by diffusion tensor imaging (DTI). The data were compared between 14 congenitally deaf adults and 14 sex- and age-matched normal hearing controls. Manual volumetry revealed preserved GM volume of the bilateral HG and significantly decreased WM volume of the left HG in the deaf. VBM showed increased cerebellar GM volume in the deaf, while no statistically significant differences were observed in the GM thickness or surface area between the groups. The results of the DTI analysis showed WM microstructural alterations between the groups in the bilateral auditory areas, including the superior temporal gyrus, the HG, the planum temporale and the planum polare, which were more extensive in the right hemisphere. Fractional anisotropy (FA) was significantly reduced in the right and axial diffusivity (AD) in the left auditory areas in the deaf. FA and AD were significantly reduced also in several other brain areas outside the auditory cortex in the deaf.The use of four different methods used in our study, although showing changes that are not directly related, provides additional information and supports the conclusion that in prelingually deaf subjects structural alterations are present both in the auditory areas and elsewhere. Our results support the findings of those studies showing that early deafness results in decreased WM volume and microstructural WM alterations in the auditory areas. As we observed WM microstructural alteration also in several other areas and increased GM volume in the cerebellum in the deaf, we can conclude that early deafness results in widespread structural brain changes. These probably reflect atrophy or degradation as well as compensatory cross-modal reorganisation in the absence of the auditory input and the use of the sign language.

Dialogues on Disability: Social Media as Platforms for Scholarship - Social Media Trends in Medical History

Dialogues on Disability: Social Media as Platforms for Scholarship - <b>Social Media Trends in Medical History</b>

Reduced procedural motor learning in deaf individuals.

Studies in the deaf suggest that cross-modal neuroplastic changes may vary across modalities. Only a handful of studies have examined motor capacities in the profoundly deaf. These studies suggest the presence of deficits in manual dexterity and delays in movement production. As of yet, the ability to learn complex sequential motor patterns has not been explored in deaf populations. The aim of the present study was to investigate the procedural learning skills of deaf adults. A serial reaction-time task (SRTT) was performed by 18 deaf subjects and 18 matched controls to investigate possible motor alteration subsequent to auditory deprivation. Deaf participants had various degrees of hearing loss. Half of the experimental group were early deaf adults mostly using hearing aids, the remaining half were late-deaf adults using a cochlear implant (CI). Participants carried out a repeating 12-item sequence of key presses along with random blocks containing no repeating sequence. Non-specific and sequence-specific learning was analyzed in relation to individual features related to the hearing loss. The results revealed significant differences between groups in sequence-specific learning, with deaf subjects being less efficient than controls in acquiring sequence-specific knowledge. We interpret the results in light of cross-modal plasticity and the auditory scaffolding hypothesis.

Examining the Electro-Neural Interface of Cochlear Implant Users Using Psychophysics, CT Scans, and Speech Understanding

This study examines the relationship between focused-stimulation thresholds, electrode positions, and speech understanding in deaf subjects treated with a cochlear implant (CI). Focused stimulation is more selective than monopolar stimulation, which excites broad regions of the cochlea, so may be more sensitive as a probe of neural survival patterns. Focused thresholds are on average higher and more variable across electrodes than monopolar thresholds. We presume that relatively high focused thresholds are the result of larger distances between the electrodes and the neurons. Two factors are likely to contribute to this distance: (1) the physical position of electrodes relative to the modiolus, where the excitable auditory neurons are normally located, and (2) the pattern of neural survival along the length of the cochlea, since local holes in the neural population will increase the distance between an electrode and the nearest neurons. Electrode-to-modiolus distance was measured from high-resolution CT scans of the cochleae of CI users whose focused-stimulation thresholds were also measured. A hierarchical set of linear models of electrode-to-modiolus distance versus threshold showed a significant increase in threshold with electrode-to-modiolus distance (average slope = 11 dB/mm). The residual of these models was hypothesized to reflect neural survival in each subject. Consonant-Nucleus-Consonant (CNC) word scores were significantly correlated with the within-subject variance of threshold (r(2) = 0.82), but not with within-subject variance of electrode distance (r(2) = 0.03). Speech understanding also significantly correlated with how well distance explained each subject's threshold data (r(2) = 0.63). That is, subjects with focused thresholds that were well described by electrode position had better speech scores. Our results suggest that speech understanding is highly impacted by individual patterns of neural survival and that these patterns manifest themselves in how well (or poorly) electrode position predicts focused thresholds.

Analysis of CABP2 c.637+1g>t mutation in Iranian families with autosomal recessive non-syndromic hearing loss

BACKGROUND AND OBJECTIVE: Congenital hearing loss is the most common sensorineural defect in human. The most common genetic mutations in this disease are GJB2 mutations which are followed by SLC26A4 mutations. Following a report for the first time in the world insist on CABP2 gene interference in hearing loss production, the present study was launched to analyze this mutation in Iranian patients with hereditary hearing loss. METHODS: This is a cross sectional study. Among samples with autosomal recessive familial hearing loss pattern, regarding pedigree and audiometric data 253 patients with moderate to profound hearing loss were selected and studied. The mutation c. 637+1G>T was investigated using PCR-RFLP method. FINDINGS: PCR-RFLP findings revealed that c.637+1G>T mutation was absent in the deaf subjects with hereditary moderate to profound hearing loss in analyzed provinces. CONCLUSION: The mutation c.637+1G>T in CABP2 gene does not play any role in the investigated Iranian subjects with hereditary hearing loss. © 2014, Babol University of Medical Sciences. All rights reserved.

Fast Eye Movements and Slow Eye Movements in Congenital Neurosensorial Deaf Subjects as Assessed by 2D video-Oculography™

Aims: There is evidence that the deprivation of a sensory system at early developmental stage may lead to a functional change of the remaining one(s). Even if this process has been widely studied, results are still controversial. In particular, the auditory system might affect the oculomotor control, since saccades or fast eye movements (FEMs) and slow eye movements (SEMs) are modulated by the cochleo-vestibular input. It follows that hearing impairment would affect the SEM and saccadic pattern. Therefore, in this study FEMs and SEMs have been evaluated in congenital deaf subjects in order to state whether early auditory deprivation has influence on the oculomotor function. Study Design: Case-control study.

Cyclic Alternating Pattern in congenital deaf – quantitative and topographic analysis

Introduction Sleep is a reversible behavioral state with attenuation of sensorial modalities and relative preservation of auditory function. Cyclic Alternating Pattern (CAP) is related to sleep instability and arousal. It is formed by CAP (phases A (A1, A2, A3) + B) and NCAP cycles. A1 subtype indicates maintenance of NREM sleep neuronal mechanisms; A2 and A3 are related to sleep instability and onset REM mechanisms. Congenital deaf sleep is a good model of sustained auditory deprivation and an important tool in the study of noise effect in sleep. In this study we aim to 1. Evaluate if the absence of acoustic perturbation in deaf promotes sleep stability; and 2. Evaluate the effect of provoked arousals in congenital deaf and normal-hearing subjects sleep. Materials and methods Eight congenital deaf and eight normal-hearing volunteers were matched according to age and gender. Video-polisonography were made on two consecutive nights, in lab environment, and provoked arousals after every 5 min of stable REM were performed. CAP Rate, Duration, Time Distribution and Topographic Mapping of the frequency bands 0.2–2.5 Hz (FB 1) and 7–12 Hz (FB2) were measured to accomplish aim 1; for aim 2 CAP density (no. events/ sleep time) were obtained for the periods before (PB) and after provoked arousals (AA – 30 min period after the arousal). SPSS 16.0 was used for statistical analysis purposes using p Results Contrary to the expectations, the sleep of the congenital deaf is more unstable as it presents increased A3 rate (p = 0.017) and time variations (p = 0.045) as well as evidence of decreased A1 rate and duration. The deaf subjects have compromised CAP rhythmicity: CAP cycle (p = 0,133) and A1 subtype (p = 0,138) do not vary along the night and there is no clear repetitive and cyclical A2 and A3 pattern in association with REM-on mechanisms. These subjects presented higher spectral power in parieto-occipital regions for A1 (p = 0.049 – BF1) and temporal posterior for A2 (p = 0.015 – FB 1) and B (p = 0.049 – FB 1 e p = 0.033 – FB 2) possibly as a result of cerebral modifications due to deafness. Deaf subjects seem more sensitive to provoked sleep interruption with remarkable decrease of A1 (p = 0/015) in AA periods. Conclusion Deaf subjects have more unstable sleep and higher sensitivity to provoked sleep interruption; compromised CAP rhythmicity as well as cortical and spectral modifications in posterior regions, possibly related to their clinical condition. Acknowledgements Funded by: Fundacao BIAL (No. 107/02 ). Work supported by Helder Bertolo, Joana Pires and Rosa Santos.

Visual activity predicts auditory recovery from deafness after adult cochlear implantation

Modern cochlear implantation technologies allow deaf patients to understand auditory speech; however, the implants deliver only a coarse auditory input and patients must use long-term adaptive processes to achieve coherent percepts. In adults with post-lingual deafness, the high progress of speech recovery is observed during the first year after cochlear implantation, but there is a large range of variability in the level of cochlear implant outcomes and the temporal evolution of recovery. It has been proposed that when profoundly deaf subjects receive a cochlear implant, the visual cross-modal reorganization of the brain is deleterious for auditory speech recovery. We tested this hypothesis in post-lingually deaf adults by analysing whether brain activity shortly after implantation correlated with the level of auditory recovery 6 months later. Based on brain activity induced by a speech-processing task, we found strong positive correlations in areas outside the auditory cortex. The highest positive correlations were found in the occipital cortex involved in visual processing, as well as in the posterior-temporal cortex known for audio-visual integration. The other area, which positively correlated with auditory speech recovery, was localized in the left inferior frontal area known for speech processing. Our results demonstrate that the visual modality's functional level is related to the proficiency level of auditory recovery. Based on the positive correlation of visual activity with auditory speech recovery, we suggest that visual modality may facilitate the perception of the word's auditory counterpart in communicative situations. The link demonstrated between visual activity and auditory speech perception indicates that visuoauditory synergy is crucial for cross-modal plasticity and fostering speech-comprehension recovery in adult cochlear-implanted deaf patients.

Masking the Auditory Evoked Potential in TMS–EEG: A Comparison of Various Methods

There is growing interest in combining transcranial magnetic stimulation (TMS) with electroencephalography (EEG). Because TMS pulses are accompanied by a clicking sound, it is very likely that part of the response in the EEG consists of an auditory evoked potential (AEP). Different methods have been applied to mask the sound of TMS. However, it is unclear which masking method is most effective in reducing the AEP. In this study we explore the presumed contribution of the AEP to the response and evaluate different ways to mask the TMS clicking sound. Twelve healthy subjects and one completely deaf subject participated in this study. Eight different masking conditions were evaluated in nine hearing subjects. The amplitude of the N100-P180 complex was compared between the different masking conditions. We were not able to completely suppress the N100-P180 when the coil was placed on top of the head. Using an earmuff or exposing the subjects to white or adapted noise caused a small but significant reduction in N100-P180 amplitude, but the largest reduction was achieved when combining a layer of foam, placed between coil and head, with white or adapted noise. The deaf subject also showed a N100-P180 complex. We conclude that both the TMS clicking sound and cortical activation by the magnetic pulse contribute to the N100-P180 amplitude.