Audiometria de resposta evocada de acordo com sexo e idade: achados e aplicabilidade Evoked response audiometry according to gender and age: findings and usefulness

A audiometria de respostas evocadas (ABR) é um registro não-invasivo de potenciais elétricos auditivos nos primeiros 12 milissegundos, da orelha média ao córtex auditivo. ABR é importante na avaliação otoneurológica. OBJETIVO: Esclarecer as utilidades do exame, faixas etárias e sexo com maior incidência e topodiagnóstico segundo as latências absolutas e os intervalos interpicos. CASUÍSTICA E MÉTODO: Neste estudo retrospectivo foram analisados 403 prontuários de ABR realizados em clínica particular na cidade de Jundiaí/SP, Brasil, suspeitos de alteração auditiva e/ou doença do SNC, com os pacientes divididos por sexo e faixa etária. RESULTADOS E CONCLUSÕES: ABR é um importante exame para determinar a integridade da via auditiva, limiares eletrofisiológicos e topodiagnóstico, embora o teste não indique a etiologia das alterações. Foi demonstrado que ocorreu maior incidência de achados retrococleares na faixa etária de 12-20 anos e sexo masculino, contudo crianças menores de um ano com fatores de risco não apresentaram um aumento na incidência de alterações condutivas, cocleares e retrococleares em relação à população geral estudada. As latências absolutas das ondas I, III e V foram maiores no sexo masculino e as alterações dos intervalos interpicos foram similares em ambos os sexos, sendo que o intervalo I-III foi o mais freqüentemente alterado.<br>Auditory evoked brainstem responses (ABR) is a non-invasive electrical potential registration which evaluates the auditory tract from the middle ear to the auditory cortex in the first 12 milliseconds (ms). The ABR is an important otoneurological evaluation. AIM: confirm the test's usefulness, major incidence and topography according to are range gender considering the absolute latencies of the waves and interpeak intervals. MATERIALS AND METHOD: we retrospectively analyzed 403 tests from a private clinic in the city of Jundiaí-São Paulo State-Brazil, from patients suspected of auditory damage or central nervous disorder, and the patients were broken down according to gender and age. RESULTS AND CONCLUSIONS: ABR is an important test to determinate the soundness of the auditory tract, the electrophysiological thresholds and topodiagnosis. We found no differences between type of loss and gender; there was a major incidence of retrocochlear findings among male patients between 12-20 years old; children under one year with risk factors did not present higher incidences of auditory findings when compared with all the population analyzed. The absolute latencies of waves I, III and V were higher in males, but the interpeak intervals were similar in both genders, showing that interval I-III was more frequently altered

A função vestibular em indivíduos usuários de implante coclear Vestibular function in cochlear implant users

A ocorrência de alteração no equilíbrio no período pós-cirúrgico ao implante coclear varia de 31 a 75%. OBJETIVO: Analisar a função vestibular no período pré e pós-operatório da cirurgia de implante coclear. MATERIAL E MÉTODO: Avaliou-se a função vestibular, por meio da vectoeletronistagmografia, de 38 pacientes, no pré e pós-cirúrgico de implante coclear. RESULTADOS: A principal queixa de desequilíbrio apresentada pelos pacientes foi a tontura, seguida pela vertigem postural e pela vertigem não-postural. Dos 38 pacientes avaliados, 13% deixaram de apresentar desequilíbrio após a cirurgia de implante coclear e apenas 5% referiram piora. Houve uma melhora na sintomatologia vestibular em 13% dos pacientes, sendo que esta possibilidade pode estar relacionada ao fenômeno de compensação vestibular e pela estimulação elétrica. Entretanto, foi observada na prova calórica uma piora na funcionalidade do sistema vestibular, tanto na orelha implantada como na orelha não-implantada. Assim, não há tendência de maior comprometimento na orelha implantada. CONCLUSÃO: O estudo demonstrou que o implante coclear pode comprometer o sistema vestibular em ambas as orelhas. Entretanto, a sintomatologia vestibular ocorre em menor proporção, podendo haver melhora no desequilíbrio após a cirurgia do implante coclear.<br>Balance alterations in the postoperative of cochlear implant surgeries varies from 31 to 75%. AIM: to analyze vestibular function in the pre and postoperative periods of cochlear implanted individuals. MATERIALS AND METHODS: the vestibular function was assessed, through electronystagmography, in 38 patients, in the pre and postoperative of cochlear implant procedures. RESULTS: The main complaint of unbalance reported by patients was dizziness, followed by postural vertigo and non-postural vertigo. Results: 13% of the patients did not show any balance disorder following cochlear implant surgery and just 5% showed symptoms worsening. 13 % of the patients showed an improvement, and this could be related to the vestibular compensation phenomenon and to electric stimulation. However, it was observed, in the caloric responses, a worsening in the vestibular system function, for both implanted and non-implanted ears. Thus, there is no evidence of more damage to the implanted ear. CONCLUSION: the study showed that cochlear implant surgeries could injure the vestibular system in both ears. However, the vestibular symptoms take place in a smaller proportion, and can improve after cochlear implant surgery

Diversity and Impacts of Mining on the Non-Volant Small Mammal Communities of Two Vegetation Types in the Brazilian Amazon

The CarajaÂs National Forest contains some of the largest iron ore deposits in the world. The majority of the minerals are found below a plant community known as Savana Metalo fila, or ªCangaº, which represents only 3% of the landscape within the CarajaÂs National Forest (CNF). The aim of our study was to understand the diversity of community of non-volant small mammals in the two predominant vegetation types: Ombrophilous Forest and Canga, and to examine how mining impacts these communities. Sampling was conducted from January 2010 to August 2011 in 11 sampling sites divided by the total area of Canga and 12 sampling sites in the forest, totalizing 23 sites. Of these, 12 sites (Canga and Forest) were considered impacted areas located close to the mine (\u3c\u3c 900 meters) and 11 sites (Canga and Forest), serving as controls, which were at least 7,000 meters from the mine. We recorded 28 species, 11 from the Order Didelphimorphia and 17 from the Order Rodentia. The two forest types shared 68.42% of the species found in the CNF. A gradient analysis (Non-metric multidimensional scaling) revealed that the first axis clearly separated the nonflying small mammal communities by vegetation type. Occupancy models showed that the detectability of species was affected by the distance from the mining activities. Of all the small mammals analyzed, 10 species were positively affected by the distance from mining in areas impacted (e.g. more likely to be detected farther from mining areas) and detectability was lower in impacted areas. However, three species were negatively affected by the distance from mining, with higher detectability in the impacted areas, and seven species showed no effect of their proximity to mining operations. To date, there are no studies in Brazil about the impact of mining on mammals or other vertebrates. This study reveals that the effect of mining may go beyond the forest destruction caused by the opening of the mining pits, but also may negatively affect sensitive wildlife species. Supplemental File 01 is attached below, in pdf and original docx file formats

Edge effects and landscape matrix use by a small mammal community in fragments of semideciduous submontane forest in Mato Grosso, Brazil

A community of small mammals was studied in seasonal semideciduous submontane forest in the state of Mato Grosso, Brazil. This study evaluated the use of edge and matrix pasture, by different small mammal species. Overall, 31 areas were studied, with a total sampling effort of 33,800 trap x nights. Only seven of the 25 species captured in the study sites were able to use the pasture matrix; we classified these species as generalists. Fourteen species were found to be intermediate in habits, being able to use forest edges. We found only four species habitat specialists, occurring only on transect lines in the interior of the fragment, at least 150 m from the edge. Transects located in the pasture matrix and 50 m from the edge had significantly lower species richness and abundance than transects located in the fragment edge or in the interior of the fragment. All transects located within the fragment had similar species richness and abundance, but transects located 50 m from the edge had slightly lower, but non-significant, species richness than transects located 100 m apart from edges. Rarefaction curves demonstrated that only medium-sized fragments (100 300 ha) reached an asymptote of species accumulation. The other areas require further sampling, or more sampling transect, before species accumulation curves stabilize, due to a continued increase in species number