Renata Aparecida Leite

Audiological and electrophysiological evaluation of children with acquired immunodeficiency syndrome (AIDS)

We examined the peripheral auditory system and the auditory brainstem pathway of children with Acquired Immunodeficiency Syndrome (AIDS). One hundred and one children, 51 with AIDS diagnosis and 50 normal children were evaluated. Audiological assessment included immittance measures, pure tone and speech audiometry and auditory brainstem response (ABR). The children with AIDS more frequently had abnormal results than did their matched controls, presenting either peripheral or auditory brainstem impairment. We suggest that AIDS be considered a risk factor for peripheral and/or auditory brainstem disorders. Further research should be carried out to investigate the auditory effects of HIV infection along the auditory pathway.

Potenciais evocados auditivos de longa latência em crianças com transtorno fonológico

BACKGROUND: auditory evoked potentials in children with phonological disorder. AIM: to characterize the long latency auditory evoked potentials (LLAEP) results N1, P2, N2 and P300 of children with phonological disorder and to verify the improvement of such potentials with speech therapy. METHOD: 25 children without phonological disorder (control group) and 41 with phonological disorder (study group) underwent a basic audiological evaluation and LLAEP. The study group was divided into two subgroups: subgroup A composed by 22 children, underwent 12 sessions of speech therapy and were submitted to audiological retesting after this period, and subgroup B composed by 19 children, who were also reassessed three months after the initial testing. RESULTS: statistically significant differences between groups for the P2 and P300 latencies and P300 amplitude were observed. Comparison between the first and the second audiological assessments indicated no significant statistical differences between both subgroups regarding wave latencies. However, a significant statistical difference was verified for the P300 (study subgroup A) and P2/N2 (study subgroup B) wave amplitudes. The study group presented higher percentage of altered results in the P300; wave latency increase was the most frequent type of alteration. After speech therapy, the results of all components improved, however, there was no association between the improvement of LLAEP results with the background of otitis, as well as with the Percentage of Consonants Correct-Revised. CONCLUSION: children with phonological disorder present altered P300 suggesting involvement of the central auditory pathway, probably due to alterations in the auditory processing, presenting improvement in all components of LLAEP results after speech therapy.

Estudo das latências e amplitudes dos potenciais evocados auditivos de média latência em indivíduos audiologicamente normais

Contemporary cohort cross-sectional study. Introduction: The auditory middle latency response (AMLR) is generated between 10 and 80 ms and has multiple generators, with a greater contribution from the thalamus-cortical pathways. The establishment of normality criteria for latency and amplitude values is necessary for clinical use. AIM: to analyze the latency and amplitude of the AMLR in individuals without audiological disorders, and verify the reliability of Pa-Nb amplitude. MATERIALS AND METHODS: The AMLR of 25 individuals was collected during 2005 and the Na, Pa, Nb components were analyzed for each tested ear (A1 and A2), and electrode positioning (C3 and C4). RESULTS: A statistically significant difference was noticed among middle latency values for C3A1 and C4A1 regarding components Na and Pa, and no difference for component Nb and mean values for amplitudes Na-Pa and Pa-Nb. Conclusions: We established average and standard deviation values for latency and amplitude parameters for components Na, Pa, Nb and Na-Pa and Pa-Nb, under conditions C3A1, C4A1, C3A2, C4A2, providing a parameter for the analysis and interpretation of this potential.

Estudo do efeito de supressão no potencial evocado auditivo de tronco encefálico

TEMA: o efeito de supressao com ruido branco contralateral verificado sobre o potencial evocado auditivo de tronco encefalico pode ter influencia do sistema auditivo eferente. OBJETIVOS: avaliar o efeito de supressao com ruido branco contralateral no potencial evocado auditivo de tronco encefalico em individuos com limiares auditivos dentro da normalidade. METODOS: participaram desta pesquisa 25 individuos, de 18 a 30 anos de idade, de ambos os sexos, que foram submetidos a anamnese, inspecao do meato acustico externo, audiometria tonal liminar, logoaudiometria e medidas de imitância acustica, com o objetivo de selecionar os individuos com acuidade auditiva normal. Em seguida os individuos selecionados realizaram o potencial evocado auditivo de tronco encefalico sem e com ruido branco contralateral. RESULTADOS: na comparacao entre as condicoes sem e com ruido branco contralateral verificou-se diferenca estatisticamente significante para a amplitude da onda I e para as latencias absolutas das ondas III e V, porem nao foi observada diferenca estatisticamente significante com relacao as latencias interpicos. CONCLUSOES: o presente estudo verificou aumento nas latencias e diminuicao nas amplitudes das ondas I, III e V na presenca de ruido contralateral, quando comparadas as condicoes com e sem ruido. Estes resultados sugerem uma possivel influencia do sistema nervoso auditivo eferente na modulacao das respostas do potencial evocado auditivo de tronco encefalico quando se utiliza ruido branco contralateral.

Auditory evoked potentials: predicting speech therapy outcomes in children with phonological disorders

OBJECTIVES: This study investigated whether neurophysiologic responses (auditory evoked potentials) differ between typically developed children and children with phonological disorders and whether these responses are modified in children with phonological disorders after speech therapy. METHODS: The participants included 24 typically developing children (Control Group, mean age: eight years and ten months) and 23 children clinically diagnosed with phonological disorders (Study Group, mean age: eight years and eleven months). Additionally, 12 study group children were enrolled in speech therapy (Study Group 1), and 11 were not enrolled in speech therapy (Study Group 2). The subjects were submitted to the following procedures: conventional audiological, auditory brainstem response, auditory middle-latency response, and P300 assessments. All participants presented with normal hearing thresholds. The study group 1 subjects were reassessed after 12 speech therapy sessions, and the study group 2 subjects were reassessed 3 months after the initial assessment. Electrophysiological results were compared between the groups. RESULTS: Latency differences were observed between the groups (the control and study groups) regarding the auditory brainstem response and the P300 tests. Additionally, the P300 responses improved in the study group 1 children after speech therapy. CONCLUSION: The findings suggest that children with phonological disorders have impaired auditory brainstem and cortical region pathways that may benefit from speech therapy.

Post-auricular muscle reflex in the Middle Latency Evoked Auditory Response

UNLABELLED The Middle Latency Auditory Evoked Response may be influenced by the post-auricular muscle reflex which occurs at the same latency of this potential. AIM to evaluate the muscle reflex influence on the middle latency response, identifying the most appropriate place for response recording. MATERIALS AND METHODS Prospective study in which 40 normal hearing individuals, ranging in age from 18 to 40 years old, were assessed by Middle Latency Response with electrodes placed first on the mastoids, and then on the earlobes. RESULTS significant statistical differences were seen between the values found with electrodes placed on the mastoids and on the earlobes concerning the Na-Pa amplitude in C3/A1, C3/A2 and C4/A2, concerning the Na wave latency in C3/A2 and C4/A2, and concerning the Pa wave latency in C3/A1 and C3/A2. We found a higher occurrence of the post-auricular reflex when the electrode was placed on the mastoids, in all studied modalities. CONCLUSION there was post-auricular muscle reflex interference upon the Middle Latency Response obtained when the electrodes were placed on the mastoid, and the most efficient electrode disposition in order to capture and to register more accurately this potential was on the earlobe.

Middle latency response study of auditory evoked potentials amplitudes and lantencies audiologically normal individuals

UNLABELLED Contemporary cohort cross-sectional study. INTRODUCTION The auditory middle latency response (AMLR) is generated between 10 and 80 ms and has multiple generators, with a greater contribution from the thalamus-cortical pathways. The establishment of normality criteria for latency and amplitude values is necessary for clinical use. AIM to analyze the latency and amplitude of the AMLR in individuals without audiological disorders, and verify the reliability of Pa-Nb amplitude. MATERIALS AND METHODS The AMLR of 25 individuals was collected during 2005 and the Na, Pa, Nb components were analyzed for each tested ear (A1 and A2), and electrode positioning (C3 and C4). RESULTS A statistically significant difference was noticed among middle latency values for C3A1 and C4A1 regarding components Na and Pa, and no difference for component Nb and mean values for amplitudes Na-Pa and Pa-Nb. CONCLUSIONS We established average and standard deviation values for latency and amplitude parameters for components Na, Pa, Nb and Na-Pa and Pa-Nb, under conditions C3A1, C4A1, C3A2, C4A2, providing a parameter for the analysis and interpretation of this potential.

Distúrbios de leitura e escrita em portadora do vírus da imunodeficiência humana: estudo de caso

This paper had the aim to describe the case of a human immunodeficiency virus-positive child with reading and writing disorders, analyzing the functional strategies and the results obtained in the pre and post speech-language therapy evaluations. A weekly closed speech-language therapeutic program (of 15 sessions), lasting 50 minutes each, was carried out with an 11 year-old female patient of the Speech and Hearing Investigation Laboratory in Reading and Writing. Different strategies focusing on auditory processing, phonological and phonemic awareness, reading and writing were used. Writing evaluations and audiological exams were performed at the beginning and the end of the aforementioned program. After the 15 sessions, an improvement was observed in words decoding and written production of small texts (adequate from the generic competence point of view), as well as in auditory information processing. The most motivating strategies were: activities with child poems, computer activities, crosswords, word search, and game of written stories for complementing. In this specific case, working with strategies that were interesting for the child and balancing the new with the unknown contributed to the functional success of the therapeutic process in reading and writing. The audiological assessment is important before and after a closed therapeutic program as it is crucial to both monitor the therapeutic evolution and to evaluate the relevance of this program.

Effect of hearing aids use on speech stimulus decoding through speech-evoked ABR

INTRODUCTION The electrophysiological responses obtained with the complex auditory brainstem response (cABR) provide objective measures of subcortical processing of speech and other complex stimuli. The cABR has also been used to verify the plasticity in the auditory pathway in the subcortical regions. OBJECTIVE To compare the results of cABR obtained in children using hearing aids before and after 9 months of adaptation, as well as to compare the results of these children with those obtained in children with normal hearing. METHODS Fourteen children with normal hearing (Control Group - CG) and 18 children with mild to moderate bilateral sensorineural hearing loss (Study Group - SG), aged 7-12 years, were evaluated. The children were submitted to pure tone and vocal audiometry, acoustic immittance measurements and ABR with speech stimulus, being submitted to the evaluations at three different moments: initial evaluation (M0), 3 months after the initial evaluation (M3) and 9 months after the evaluation (M9); at M0, the children assessed in the study group did not use hearing aids yet. RESULTS When comparing the CG and the SG, it was observed that the SG had a lower median for the V-A amplitude at M0 and M3, lower median for the latency of the component V at M9 and a higher median for the latency of component O at M3 and M9. A reduction in the latency of component A at M9 was observed in the SG. CONCLUSION Children with mild to moderate hearing loss showed speech stimulus processing deficits and the main impairment is related to the decoding of the transient portion of this stimulus spectrum. It was demonstrated that the use of hearing aids promoted neuronal plasticity of the Central Auditory Nervous System after an extended time of sensory stimulation.

Reflexo pós-auricular no Potencial Evocado Auditivo de Média Latência

The Middle Latency Auditory Evoked Response may be influenced by the post-auricular muscle reflex which occurs at the same latency of this potential. AIM: to...