Professional research project (Au.D.)--University of South Florida, 2000. / Title from PDF of title page. / Document formatted into pages; contains 48 pages. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: The primary objective of the project was to survey recognized "experts" in the field of neurodiagnostic audiology and practicing audiologists regarding their referral criteria and referral patterns for administering an auditory brainstem response test (ABR). For purposes of this study, "expert" was defined as any recognized audiologist with at least two or more publications and/or seminarsin the field of auditory evoked potentials. / Responses of experts and practicing audiologists were compared and contrasted to establish: a) if there was a standard referral pattern; b) what, if any, were the apparent critical components of referral patterns; and, c) whether or not current practice reflected the utilization of such critical components. The survey was designed to establish whether the respondent was practicing, in what type of practice setting, and how often ABRs were performed. Specificity and sensitivity of ABR outcomes was also requested. / The survey was administered verbally, via telephone, to 3 experts and was sent via e-mail to 178 randomly selected audiologists in the United States. Of the latter 53 returned, 38 reported conducting ABRs. Thus, data analysis was reported on 38 respondents. The survey results did not reveal a consistent standard referral pattern. Critical components for referral were hypothesized based on the "expert" majority response. These include ABR referral based on the presence of: (1) asymmetric sensorineural hearing loss; (2) unilateral tinnitus; (3) positive reflex decay; and, (4) word recognition rollover. The majority of "non-expert" practitioners surveyed reported that these symptoms warranted consideration for referral, thus reflecting utilization of apparent critical components. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

Thesis (M. Communication Pathology)--University of Pretoria, 2009. / Includes bibliographical references.

Ten experiments examined the interactions between vision and audition in stimulusdriven spatial attention orienting and inhibition of return (IOR). IOR is the demonstration that subjects are slower to respond to stimuli that are presented at a previously stimulated location. In each experiment, subjects made go/no-go responses to peripheral targets but not to central targets. On every trial, a target was preceded by a sensory event, called a "cue," either in the same modality (intramodal conditions) or in a different modality (crossmodal conditions). The cue did not predict the location of the target stimulus in any experiment. In some experiments, the cue and target modalities were fixed and different. Under these conditions, response times to a visual target were shorter when it appeared at the same location as an auditory cue than when it appeared on the opposite side of fixation, particularly at short (100 ms) cue-target stimulus onset asynchronies (Experiments 1A and IB). Similarly, response times to an auditory target were shorter when it appeared at the same location as a visual cue than when it appeared at a location on the opposite side of fixation (Experiments 2A and 2B). These crossmodal effects indicate that stimulus-driven spatial attention orienting might arise from a single supramodal brain mechanism. IOR was not observed in either crossmodal experiment indicating that it might arise from modality specific mechanisms. However, for many subjects, IOR did occur between auditory cues and visual targets (Experiments 3A and 3B) and between visual cues and auditory targets (Experiment 4A and 4B) when the target could appear in the same modality as the cue on half of the trials. Finally, the crossmodal effects of stimulus-driven spatial attention orienting on auditory and visual event-related brain potentials (ERPs) were examined in the final two experiments. Auditory cues modulated the ERPs to visual targets and visual cues modulated the ERPs to auditory targets, demonstrating that the mechanisms for spatial attention orienting cannot be completely modality specific. However, these crossmodal ERP effects were very different from each other indicating that the mechanisms for spatial attention orienting cannot be completely shared.

The objective of the research is to examine the impact of auditory stimulus on improving reaching performance in children with cerebral palsy. A form of auditory stimulus, called rhythmic auditory stimulation (RAS), is well-established in neurological fields as well as in music-based rehabilitation and therapy. RAS is a method in which the rhythm functions as a sensory cue to induce temporal stability and enhancement of movement patterns by what is believed to be a temporal constraint of the patient’s internal optimized path of motion. In current neurological studies, it is suggested that activity in the premotor cortex may represent the integration of auditory information with temporally organized motor action during rhythmic cuing. Based on this theory, researchers have shown that rhythmic auditory stimulation can produce significant improvement in mean gait velocity, cadence, and stride length in patients with Parkinson’s disease. Evidence validating this observation was also seen in a study on hemiparetic stroke wherein patients displayed improvements in spatio-temporal arm control, reduction in variability of timing and reaching trajectories, and kinematic smoothing of the wrist joint during rhythmic entrainment. Lastly, studies have suggested an accompaniment of sound feedback in addition to visual feedback can result in a positive influence and higher confidence in patients who have had a stroke or spinal cord injury. Although an effect of rhythmic cuing on upper extremity therapy has been explored in areas where brain injury has occurred (such as patients who have incurred stroke, spinal injury, traumatic brain injury, etc.), what has not been explored is the effect of rhythmic cuing on upper extremity therapy for individuals with neurological movement disorders, such as cerebral palsy. Thus, in this research, we set out to explore the effect of RAS in therapeutic interventions for children with cerebral palsy. Through this investigation, we examine its effect on reaching performance as measured through range of motion, peak angular velocity, movement time, path length, spatio-temporal variability, and movement units. For this assessment, we created a virtual system to test the aforementioned principles. We established clinically based angular measurements that include elbow flexion, shoulder flexion, and shoulder abduction using a 3D depth sensor to evaluate relevant metrics in upper extremity rehabilitation. We validated the output of our measurements through a comparison with a Vicon Motion Capture System. We then confirmed the trends of the metrics between groups of adults, children, and children with cerebral palsy. Through testing our system with adults, children, and children with cerebral palsy, we believe we have constructed a system that may induce engagement, which is critical to physical therapy, and may also have a positive impact on the metrics. Although we see trends indicative of an effect through use of the system on children with cerebral palsy, we believe further testing is needed in order to establish or refute the effect and also to definitively establish or refute the effect of rhythmic auditory stimulation. The system, the angular measurements, and the metrics we employ could provide an excellent foundation for future research in this space.

[Truncated abstract] The mammalian cochlea receives an efferent innervation which originates in the superior olive. Known collectively as the olivocochlear system, this efferent innervation can be divided into lateral and medial systems. While the function of the lateral efferent system in the cochlea is still unknown, previous studies have identified both excitatory and inhibitory changes in sound-evoked and spontaneous cochlear responses attributable to the lateral efferent system. One of the neurotransmitters in the lateral efferents is the catecholamine dopamine, which in the central nervous system is known to exert inhibitory and excitatory effects by activating different receptor subtypes. The first experiments in this thesis were designed to determine if activation or blockade of different dopamine receptor subtypes in the cochlea could lead to both excitatory and inhibitory changes in sound-evoked and spontaneous cochlear responses. Adult guinea pigs were anaesthetised (Nembutal and Hypnorm) and highly specific D1/5 (SKF 38393, SKF 81297, SCH 23390), D2 ((+) PHNO, L 741, 626) and D3 (PD 128907, U 99194A) receptor agonists and antagonists were perfused through the cochlea for 15 minutes. Sound-evoked (compound action potential, summating potential, cochlear microphonic) and spontaneous cochlear responses were recorded before and after perfusion. Remarkably, activating or blocking D1/5 or D2 receptor subtypes resulted in the suppression of CAP amplitudes. These findings are paradoxical as the agonist data suggest that the D1/5 and D2 receptor subtypes are inhibitory, but the antagonist perfusions suggest that these receptors are excitatory. We propose that the presence of an agonist induces a process of receptor desensitisation which would elicit changes akin to receptor antagonism. If this is indeed the case then our agonist findings are spurious and require further interpretation. ... The suppression of the cochlear microphonic suggests that dopamine receptor influence is not confined to the primary afferent dendrite may also include the active process of the outer hair cells. The D1/5 and D2 antagonist data also suggests that dopamine receptors are activated by intrinsic dopamine. Therefore, we attempted to investigate the effects of putative dopamine depletion of the cochlea and found that application of the dopaminergic neurotoxin MPTP causes changes in both neural and hair cell responses which have not been reported before. However, we also demonstrated that tyrosine hydroxylase positive nerve fibres are still present in MPTP treated cochleae which suggests that dopamine is still present in these cochleae. Furthermore, we observed significant electrophysiological changes in these same cochleae when these were exposed to a D2 receptor antagonist which again supports the presence of intrinsic dopamine in these 'depleted cochleae'. These data suggest that the currently accepted method of acute dopamine depletion using MPTP is insufficient and different methods must be developed in the future.

Thesis (M. Sc.)--University of Hong Kong, 1998. / Includes bibliographical references (leaf 37-41).

Orientador: Ana Cláudia Figueiredo Frizzo / Banca: Liliane Desgualdo Pereira / Banca: Vitor Engrácia Valenti / Resumo: Introdução: Os potenciais corticais auditivos e a variabilidade da frequência cardíaca são temas amplamente estudados na literatura nacional e internacional. Embora sejam escassos estudos que relacionam esses dois parâmetros de avaliação do sistema nervoso. Objetivo: Analisar a associação entre os potenciais corticais auditivos e a modulação autonômica cardíaca frente a diferentes estímulos acústicos. Métodos: Participaram desta pesquisa 60 mulheres saudáveis, com idade entre 18 e 25 anos. Os critérios de inclusão foram: ausência de distúrbios cardiorrespiratórios, cognitivos, psiquiátricos, neurológicos e tratamento medicamentoso que influencie a regulação autonômica cardíaca; indivíduos que não ingeriram bebidas alcoólicas em excesso nas últimas 24 horas e que deixaram de ser tabagistas há pelo menos um ano; audiometria tonal liminar com resultados normais e imitânciometria com curva tipo A e reflexos ipsi e contralaterais presentes. Antes do exame do Potencial cortical, foram mensuradas a pressão arterial e a frequência cardíaca em repouso com auxílio de estetoscópio e esfigmomanômetro e do cardiofrequencímetro Polar RS800CX. Após a coleta dessas medidas, foi iniciado o exame do potencial cortical simultaneamente com a coleta da variabilidade da frequência cardíaca. Os índices lineares nos domínios do tempo e da frequência foram analisados através do software Kubios HRV analysis - versão 2,0. A análise estatística descritiva foi analisada por meio da média e desvio padrão, ao passo que para a análise inferencial foram aplicados os seguintes testes: teste de correlação de Pearson para distribuições paramétricas e de Spearman para distribuições nãoparamétricas. Resultados: Foram observadas correlações entre os potenciais corticais auditivos e os índices da ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Introduction: The auditory cortical potentials and heart rate variability are widely studied topics in the national and international literature. Although few studies associating these two endpoints of the nervous system. Objective: To analyze the association between auditory cortical potentials and cardiac autonomic modulation due to different acoustic stimuli. Methods: We analyzed 60 healthy women, aged between 18 and 25 years. Inclusion criteria were: absence of cardiorespiratory disorders, cognitive, psychiatric, neurological and medical treatment to influence the cardiac autonomic regulation; individuals who did not drink alcohol in excess in the last 24 hours and no longer in smokers for at least one year; pure tone audiometry and impedance tests with normal results with type A curve and ipsilateral and contralateral reflexes present. Before examining the cortical potential, were measured blood pressure and heart rate at rest with stethoscope and sphygmomanometer aid and heart rate monitor Polar RS800CX. After collecting these measures, started the examination of cortical potential while the collection of heart rate variability. Linear indices in the field of time and frequency were analyzed using the Kubios HRV analysis software - version 2.0. Descriptive statistical analysis was analyzed by mean and standard deviation, whereas for the inferential analysis the following tests were applied: Pearson correlation test for parametric and Spearman distributions to non-parametric distributions. Results: Correlations were observed between the auditory cortical potentials and indexes of heart rate variability. When analyzed in the time domain, SDNN index correlated with the P3a latency and amplitude of P2, and P3a; the RMSSD index correlated with the latencies of N1, P2, N2 and amplitudes of P3a and MLM and ... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2016-03-07T19:20:45Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-11-16. Added 1 bitstream(s) on 2016-03-07T19:24:26Z : No. of bitstreams: 1 000858904.pdf: 2531633 bytes, checksum: 4551b73aba444c4c6ff7fc36ac3cf544 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Introdução: Os potenciais corticais auditivos e a variabilidade da frequência cardíaca são temas amplamente estudados na literatura nacional e internacional. Embora sejam escassos estudos que relacionam esses dois parâmetros de avaliação do sistema nervoso. Objetivo: Analisar a associação entre os potenciais corticais auditivos e a modulação autonômica cardíaca frente a diferentes estímulos acústicos. Métodos: Participaram desta pesquisa 60 mulheres saudáveis, com idade entre 18 e 25 anos. Os critérios de inclusão foram: ausência de distúrbios cardiorrespiratórios, cognitivos, psiquiátricos, neurológicos e tratamento medicamentoso que influencie a regulação autonômica cardíaca; indivíduos que não ingeriram bebidas alcoólicas em excesso nas últimas 24 horas e que deixaram de ser tabagistas há pelo menos um ano; audiometria tonal liminar com resultados normais e imitânciometria com curva tipo A e reflexos ipsi e contralaterais presentes. Antes do exame do Potencial cortical, foram mensuradas a pressão arterial e a frequência cardíaca em repouso com auxílio de estetoscópio e esfigmomanômetro e do cardiofrequencímetro Polar RS800CX. Após a coleta dessas medidas, foi iniciado o exame do potencial cortical simultaneamente com a coleta da variabilidade da frequência cardíaca. Os índices lineares nos domínios do tempo e da frequência foram analisados através do software Kubios HRV analysis - versão 2,0. A análise estatística descritiva foi analisada por meio da média e desvio padrão, ao passo que para a análise inferencial foram aplicados os seguintes testes: teste de correlação de Pearson para distribuições paramétricas e de Spearman para distribuições nãoparamétricas. Resultados: Foram observadas correlações entre os potenciais corticais auditivos e os índices da variabilidade da frequência cardíaca. Quando analisados no domínio do tempo, o índice SDNN correlacionou com a latência... / Introduction: The auditory cortical potentials and heart rate variability are widely studied topics in the national and international literature. Although few studies associating these two endpoints of the nervous system. Objective: To analyze the association between auditory cortical potentials and cardiac autonomic modulation due to different acoustic stimuli. Methods: We analyzed 60 healthy women, aged between 18 and 25 years. Inclusion criteria were: absence of cardiorespiratory disorders, cognitive, psychiatric, neurological and medical treatment to influence the cardiac autonomic regulation; individuals who did not drink alcohol in excess in the last 24 hours and no longer in smokers for at least one year; pure tone audiometry and impedance tests with normal results with type A curve and ipsilateral and contralateral reflexes present. Before examining the cortical potential, were measured blood pressure and heart rate at rest with stethoscope and sphygmomanometer aid and heart rate monitor Polar RS800CX. After collecting these measures, started the examination of cortical potential while the collection of heart rate variability. Linear indices in the field of time and frequency were analyzed using the Kubios HRV analysis software - version 2.0. Descriptive statistical analysis was analyzed by mean and standard deviation, whereas for the inferential analysis the following tests were applied: Pearson correlation test for parametric and Spearman distributions to non-parametric distributions. Results: Correlations were observed between the auditory cortical potentials and indexes of heart rate variability. When analyzed in the time domain, SDNN index correlated with the P3a latency and amplitude of P2, and P3a; the RMSSD index correlated with the latencies of N1, P2, N2 and amplitudes of P3a and MLM and interamplitude of N2-P3a; pNN50 index correlated with the latencies of N1 and P2 and with the amplitudes of P3a and MLM and...

Made available in DSpace on 2015-05-14T16:53:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-09-29Bitstream added on 2015-05-14T16:59:32Z : No. of bitstreams: 1 000824110.pdf: 554350 bytes, checksum: 9c0b2908c3d24487eea0470c66d6d425 (MD5) / A audição é um dos principais pontos do processo de comunicação com o meio ambiente tanto de seres humanos quanto de animais. O potencial evocado auditivo de tronco encefálico (BAEP-Brainstem Auditory Evoked Potential) é um método que tem sido utilizado em seres humanos, cães, gatos, bovinos e equinos com a finalidade de identificar possíveis alterações auditivas que não podem ser diagnosticadas durante o exame físico. O BAEP avalia a integridade das vias auditivas, desde a cóclea até o tronco encefálico e permite a identificação de animais com surdez neurossensorial e condutiva. Apesar da importância do BAEP, não foi encontrado nenhum estudo de padronização do seu uso em equinos no Brasil. Dessa maneira, o objetivo deste trabalho foi padronizar a metodologia para obtenção de registros que permitam verificar a latência das ondas obtidas no exame para essa espécie. Foram utilizados 21 equinos adultos, machos e fêmeas, sem histórico prévio de alterações auditivas. Para realização do teste, os animais foram sedados com cloridrato de detomidina. Foram identificadas as latências das ondas I, II, III, IV e V, bem como dos intervalos I-III, III-V e I-V. As médias das latências das ondas foram, onda I 2,4 ms; onda II 2,74 ms; onda III 3,61 ms; onda IV 4,61 ms e onda V 5,49 ms . As médias das latências dos interpicos foram I-III 1,37 ms; III-V 1,88 ms e I-V 3,26 ms. A descrição da metodologia utilizada e a disponibilização dos registros e das latências obtidas podem servir de referência para estudos realizados nessa espécie / Hearing is one of the main points of the communication process with the environment both humans and animals. The Auditory brainstem response (BAEP Brainstem Auditory-Evoked Potential) is a method that has been used in humans, dogs, cats, cattle and horses in order to identify possible hearing impairment that can’t be diagnosed during physical examination . The BAEP evaluates the integrity of the auditory pathway from the cochlea to the brainstem and allows the identification of animals with sensorineural and conductive deafness. Despite the importance of BAEP, no study to standardize its use in horses in Brazil was found. Thus, the objective of this study was to standardize the methodology for obtaining records to verify the wave latencies obtained in the examination for this species. 21 adult horses, males and females were used without previous history of hearing disorders. To perform the test, the animals were sedated with detomidine hydrochloride. Latencies of waves I, II, III, IV and V, as well as the intervals I-III, III-V and IV were identified. The mean latencies of the waves were, I wave 2.4 ms; wave II 2.74 ms ; wave III 3.61 ms; wave IV 4.61 ms and wave V 5.49 ms. The mean latencies of interpeaks were I-III 1.37; III-V 1.88 and I-V 3.26. The description of the methodology used and the availability of records and latencies can serve as a reference for studies in this species

Made available in DSpace on 2016-06-07T17:12:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-02-26. Added 1 bitstream(s) on 2016-06-07T17:16:40Z : No. of bitstreams: 1 000866228.pdf: 2025216 bytes, checksum: 03649865923809ae8153c9989f57557f (MD5) / Introdução: A avaliação auditiva em neonatos é realizada atualmente por testes objetivos, como as emissões otoacústicas e o potencial evocado auditivo de tronco encefálico (PEATE), porém, a principal limitação desses métodos de avaliação é a de não fornecer informações precisas sobre os limiares auditivos por frequência específica, especialmente nas graves. A resposta auditiva de estado estável (RAEE) é uma técnica complementar às existentes, para o diagnóstico da surdez na população pediátrica, sendo sua principal vantagem a de predizer, de forma objetiva e automática, os limiares auditivos por frequência específica. Objetivo: Verificar se há concordância entre os exames PEATE e RAEE na avaliação do limiar auditivo em lactentes. Metodologia: Estudo observacional analítico prospectivo. Critérios de inclusão: lactentes nascidos no local do estudo, com indicadores de risco para a deficiência auditiva e que realizaram os testes PEATE e RAEE na mesma sessão. Variáveis estudadas: dados pessoais, indicadores de risco para a deficiência auditiva e os achados dos exames de PEATE e RAEE. As comparações foram consideradas significativas para p<0,05. Resultados: Atenderam aos critérios de inclusão 66 neonatos, sendo 47% deles do sexo masculino (n=31), idade mediana de 1,2 meses, idade gestacional média de 31 semanas, peso médio ao nascimento 1601g. Treze neonatos tiveram PEATE alterado (20%), sendo que dez deles tinham mais de um indicador de risco acumulado. Os pontos de maior sensibilidade e especificidade na RAEE para as frequências de 500, 1000, 2000 e 4000Hz na orelha direita foram, respectivamente, 47,5; 62,5; 42,5 e 37,5 e na orelha esquerda 65; 45; 55 e 52,5. Conclusão: Houve concordância entre o PEATE e a RAEE em lactentes de risco para deficiência auditiva, sendo possível diferenciar os ouvintes daqueles com deficiência auditiva. Palavras-chave: audição, eletrofisiologia, indicador de risco,... / Introduction: The hearing assessment in neonates is currently done by objective tests, such as otoacoustic emissions and the brainstem auditory evoked potential (BAEP), however the main limitation of these assessment methods it is not to provide accurate information on the hearing threshold by specific frequencies, especially in low frequencies. Auditory steady-state response (ASSR) is a complementary technique to the ones existing for the deafness diagnosis in children and its main advantage is to, objectively and automatically predict the hearing thresholds by specific frequency. Objective: To verify if there is concordance between the BAEP and ASSR tests in the infants hearing threshold assessment. Methods: Prospective analytical study. Comprisal criterion: born infants in the study site, with risk indicators for hearing loss and who were submitted to ABR and ASSR tests in the same session. Variants studied: personal data, risks indicators for hearing loss and findings of BAEP and ASSR tests. Comparisons were considered significant for p <0.05. Results: 66 neonates were included, 47% were male (n = 31), median age of 1.2 months, mean gestational age of 31 weeks and mean birth weight 1601g. Thirteen infants had abnormal BAEP (20%), and ten of them had accumulated more than one risk indicator. Higher sensitivity and specificity points in the ASSR for the frequencies of 500, 1000, 2000 and 4000 Hz in the right ear were, respectively, 47.5; 62.5; 42.5 and 37.5 and the left ear 65; 45; 55 and 52.5. Conclusion: There was concordance between the ABR and ASSR tests in infants with risk for hearing loss, being possible to distinguish who have normal hearing from those with hearing loss