Carla Gentile Matas

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 tardios em indivíduos com queixa de zumbido

UNLABELLED Long latency auditory evoked potentials (LLAEP) alterations in individuals with tinnitus are suggestive of dysfunction in the central auditory pathways at a cortical level. AIM To characterize the LLAEP in individuals with and without tinnitus exposed to occupational noise. METHOD Cross-sectional contemporary cohort, prospective study. Sixty subjects exposed to occupational noise, ranging in age from 29 to 50 years underwent LLAEP assessment; 30 of them had tinnitus complaint and 30 did not have tinnitus. RESULTS We observed significant statistical difference regarding the mean values of latencies of waves N1 (p<0.001), P2 (p=0.002) and P300 (p=0.039) when we compared individuals with and without tinnitus. In individuals with tinnitus we also noticed a greater number of altered results concerning components N1 (60%) and P2 (66.7%), although only component P2 presented significant statistical difference (p=0.010). For the LLAEP, the latency increase was the only type of alteration found (p=1.000). We found a greater association between bilateral tinnitus and bilateral alteration for all components N1(73%), P2(73%) and P300(50%). CONCLUSION It is relevant to study LLAEP in individuals with tinnitus exposed to high occupational sound pressure levels.Long latency auditory evoked potentials (LLAEP) alterations in individuals with tinnitus are suggestive of dysfunction in the central auditory pathways at a cortical level. AIM: to characterize the LLAEP in individuals with and without tinnitus exposed to occupational noise. METHOD: Cross-sectional contemporary cohort, prospective study. Sixty subjects exposed to occupational noise, ranging in age from 29 to 50 years underwent LLAEP assessment; 30 of them had tinnitus complaint and 30 did not have tinnitus. RESULTS: we observed significant statistical difference regarding the mean values of latencies of waves N1 (p<0.001), P2 (p=0.002) and P300 (p=0.039) when we compared individuals with and without tinnitus. In individuals with tinnitus we also noticed a greater number of altered results concerning components N1 (60%) and P2 (66.7%), although only component P2 presented significant statistical difference (p=0.010). For the LLAEP, the latency increase was the only type of alteration found (p=1.000). We found a greater association between bilateral tinnitus and bilateral alteration for all components N1(73%), P2(73%) and P300(50%). CONCLUSION: It is relevant to study LLAEP in individuals with tinnitus exposed to high occupational sound pressure levels.

Estudo dos potenciais evocados auditivos em autismo

BACKGROUND: electrophysiological assessment of hearing in autistic individuals. AIM: to characterize the findings obtained in the electrophysiological assessments of autistic individuals, as well as to compare these to the results obtained for individuals of the same age who present typical development. METHOD: 16 individuals with autism (study group) and 25 normal individuals (control group), ranging in age from eight to 20 years underwent anamnesis, pure tone audiometry, speech audiometry, acoustic immitance measures, brainstem auditory evoked potential (BAEP), middle latency response (MLR) and cognitive potential (P300). RESULTS: the study group presented altered results in all auditory evoked potentials, showing statistically significant differences when compared to the control group. Concerning the types of alterations found in the study group the following results were observed: higher occurrence of lower brainstem alteration in the BAEP, both (electrode and ear effects occurring simultaneously) in the MLR, and absence of response in the P300. In the quantitative data analysis, statistically significant differences between the groups were found only for the BAEP regarding the latencies of waves III and V and interpeaks I-III and I-V. CONCLUSION: autistic individuals present altered BAEP and P300, suggesting impairment in the brainstem auditory pathway and corticals / subcorticals areas.

Potenciais evocados auditivos de longa latência e processamento auditivo central em crianças com alterações de leitura e escrita: dados preliminares

INTRODUCAO: Atualmente, admite-se que individuos com alteracoes de leitura e escrita podem apresentar atraso no desenvolvimento das habilidades auditivas, o que pode interferir no processo de aprendizagem. A avaliacao das habilidades auditivas pode ocorrer de forma comportamental, por meio dos testes do processamento auditivo central (PAC), ou por meio da avaliacao eletrofisiologica, destacando-se os potenciais evocados auditivos de longa latencia (PEALL). A utilizacao dos PEALL como meio de avaliacao complementar de individuos com alteracoes de leitura e escrita pode se tornar um importante dado tanto para uma caracterizacao mais detalhada das alteracoes, como para o direcionamento terapeutico dessa populacao. OBJETIVO: Caracterizar o PAC e o PEALL em criancas com alteracoes de leitura e escrita. METODO: Pesquisa aprovada pela Comissao de Etica da Instituicao sob no 305/10. A avaliacao do PAC e do PEALL foi realizada em 12 criancas com idade entre oito e 12 anos (media de 10,6 anos), com alteracao de leitura e escrita confirmada em avaliacao especifica. RESULTADOS: As habilidades do PAC mais alteradas foram ordenacao temporal e figura-fundo para sons linguisticos. Foram encontrados resultados alterados no P300 e no MMN. CONCLUSAO: Os individuos com alteracoes de leitura e escrita apresentaram desempenho abaixo do esperado em testes do PAC. O MMN possibilitou uma melhor caracterizacao da funcao auditiva desta populacao. Houve indicios de associacao entre resultados do PAC e alteracao nos PEALL.

Manifestações eletrofisiológicas em adultos com HIV/AIDS submetidos e não-submetidos à terapia anti-retroviral

BACKGROUND: auditory evoked potentials (AEP) assess the neuroelectric activity on the auditory pathway -from the auditory nerve to the cerebral cortex - in response to an acoustic stimulus or event. Studies have demonstrated electrophysiological abnormalities in individuals with HIV/AIDS. AIM: to characterize the hearing electrophysiological manifestations in adults with HIV/AIDS by comparing the results obtained in the group exposed to antiretroviral therapy with those obtained in the group not exposed to such treatment. METHOD: electrophysiological evaluation of hearing (Auditory Brainstem Response - ABR, Auditory Middle Latency Reponse - AMLR and P300) was conducted in 56 individuals with HIV/AIDS: 24 participants composed group I (not exposed to antiretroviral treatment) and 32 participants composed group II (exposed to treatment). RESULTS: alterations in every AEP were observed in individuals with HIV/ AIDS, especially in the ABR. Indeed, the group exposed to antiretroviral treatment presented more alterations. CONCLUSION: individuals with HIV/AIDS may present alterations on the central and peripheral auditory nervous system. The group exposed to antiretroviral therapy presents more alterations on the brainstem auditory pathway.

Estabilidade dos potenciais evocados auditivos em indivíduos adultos com audição normal

PURPOSE: To evaluate the stability of parameters of auditory evoked potentials in normal adults. METHODS: Forty-nine normal subjects with ages from 18 to 40 years (25 females and 24 males) were submitted to audiological and electrophysiological hearing evaluation (auditory brainstem response - ABR, middle latency response - MLR, and cognitive potential - P300). Subjects were reassessed three months after the initial evaluation. RESULTS: Significant differences were observed between genders regarding the wave latencies III and V and the interpeaks I-III and I-IV of ABR, and the amplitude N2-P3 of the P300. No differences were found between the results of initial and final assessments for the parameters of the ABR, MLR (Na, Pa latencies and Na-Pa amplitude) and P300 (P300 latency). CONCLUSION: Except for the N2-P3 amplitude, it was observed stability of the parameters of ABR, MLR and P300 in normal adults after a period of three months.

Comparação entre limiares de audibilidade e eletrofisiológico por estímulo tone burst

Studies have reported compatibility between hearing and electrophysiological thresholds in the auditory brainstem response (ABR) with tone burst stimuli. AIMS: to verify waves I, III, V and their latency times for tone bursts at 500, 1000, 2000 and 4000 Hz and at 80 dB HL, and to compare tone burst electrophysiological thresholds with those obtained from audiological and psychoacoustic evaluations. METHODS: audiological, psychoacoustic and electrophysiological evaluations of 40 male and female normal hearing individuals aged between 18 and 40 years were undertaken. RESULTS: only wave V was visualized at 80 dB HL and its latency values decreased with increased frequencies in both genders. At 1000, 2000 and 4000 Hz male subjects presented higher electrophysiological thresholds values than females at all frequencies. At 500, 1000 and 2000 Hz, electrophysiological, hearing, and psychoacoustic thresholds were statistically different in both genders. CONCLUSION: although ABR with tone burst stimulus is clinically applicable, further research is needed to standardize test techniques and results.

Potenciais evocados auditivos de média e longa latências em adultos com AIDS

BACKGROUND: middle and late latency auditory evoked potentials. AIM: to verify the occurrence of middle and late latency auditory evoked potentials disorders in adults with Acquired Immunodeficiency Syndrome (AIDS). METHOD: middle and late latency auditory evoked potentials of 8 individuals with AIDS, with ages ranging from 10 to 51 years, with normal hearing, or with sensoryneural hearing losses up to moderate, and normal results in the Auditory Brainstem Response, comparing the results with the responses obtained for a control group which was composed by 25 individuals, with ages ranging from 19 to 24 years, with no hearing complaints and with normal hearing and normal results in the Auditory Brainstem Response. RESULTS: the Pa wave latency and amplitude averages in the C3/A2 and C4/A1 modalities, and the average of the P300 wave were analyzed. No significant differences were observed in the Pa wave amplitude and latency averages between the groups, although a non-statistically significant increase was observed in the latency and a decrease in the amplitude of such wave for the research group in the C3/A2 modality. The latency of the P300 wave was significantly longer to the left for the research group. It was also observed a longer latency to the right, although this was not statistically significant. CONCLUSION: adult individuals with AIDS do not present alterations in the middle latency auditory evoked potential and do present alterations in the cognitive potential, indicating a disorder in the cortical regions of the auditory pathway and a deficit in the cognitive processing of auditory information for this population. Such findings stress the importance of a careful investigation of the auditory function of individuals with AIDS, thus favoring the therapeutic planning.

P300 with verbal and nonverbal stimuli in normal hearing adults

UNLABELLED The P300 results from focusing attention on rare stimuli in the midst of other frequent stimuli; it tests recent attention and memory, both of which depend on discriminating among verbal or nonverbal stimuli. AIM To compare the P300 with verbal and nonverbal stimuli in normal-hearing adults. MATERIAL AND METHOD A prospective study was made of 15 male subjects aged from 22 to 55, with no hearing complaints. The subjects underwent short and long latency (P300) auditory evoked potentials with verbal and non-verbal stimuli. RESULTS The mean P300 latency with verbal stimuli was significantly higher than the P300 with nonverbal stimuli. The P300 amplitudes were significantly lower for verbal compared with non-verbal stimuli. CONCLUSION There were no differences between ears with respect to P300 latencies and amplitudes for both non-verbal and verbal stimuli. Latencies were higher with verbal stimuli; amplitudes had lower values.

Audiological and electrophysiological assessment of professional pop/rock musicians.

In the present study, we evaluated peripheral and central auditory pathways in professional musicians (with and without hearing loss) compared to non-musicians. The goal was to verify if music exposure could affect auditory pathways as a whole. This is a prospective study that compared the results obtained between three groups (musicians with and without hearing loss and non-musicians). Thirty-two male individuals participated and they were assessed by: Immittance measurements, pure-tone air conduction thresholds at all frequencies from 0.25 to 20 kHz, Transient Evoked Otoacoustic Emissions, Auditory Brainstem Response (ABR), and Cognitive Potential. The musicians showed worse hearing thresholds in both conventional and high frequency audiometry when compared to the non-musicians; the mean amplitude of Transient Evoked Otoacoustic Emissions was smaller in the musicians group, but the mean latencies of Auditory Brainstem Response and Cognitive Potential were diminished in the musicians when compared to the non-musicians. Our findings suggest that the population of musicians is at risk for developing music-induced hearing loss. However, the electrophysiological evaluation showed that latency waves of ABR and P300 were diminished in musicians, which may suggest that the auditory training to which these musicians are exposed acts as a facilitator of the acoustic signal transmission to the cortex.