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| Author(s): |
Fernanda Cristina Leite Magliaro
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Medicina (FM/SBD) |
| Defense date: | 2009-08-18 |
| Examining board members: |
Carla Gentile Matas;
Maria Inês Vieira Couto;
Alessandra Giannella Samelli;
Maria Francisca Colella dos Santos
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| Advisor: | Carla Gentile Matas |
| Field of knowledge: | Health Sciences - Speech Therapy |
| Indexed in: | Banco de Dados Bibliográficos da USP-DEDALUS; Biblioteca Digital de Teses e Dissertações - USP |
| Location: | Universidade de São Paulo. Biblioteca Central da Faculdade de Medicina; FM W4.DB8 SP.USP FM-2 2009; M175av |
| Abstract | |
INTRODUCTION: The ischemic cerebral stroke (ICS) is the most frequent event among cerebral strokes. It is characterized by the interruption of blood supply to the brain, which can lead to cell damage and alterations in neurological functions. The clinical manifestations of this disease may include alterations in motor, sensory, cognitive, perceptual and language functions among others. Therefore, the identification of possible alterations in both peripheral and central auditory pathways that may impair the quality of life of these individuals is extremely important. OBJECTIVE: To characterize the findings of behavioral, electrophysiological and electroacoustic hearing evaluations in right-handed individuals with right hemisphere ischemic lesion, and to compare such data to those obtained in normal individuals with the same age. METHODS: Pure tone audiometry, speech audiometry, acoustic immittance measures, brainstem auditory evoked potential (BAEP), Auditory Middle-Latency Response (AMLR) and cognitive potential (P300) were carried out in 17 subjects with right hemisphere lesions (research group) and 25 normal individuals (control group), aged between 20 and 70 years. RESULTS: No alterations were found on the qualitative data analysis of the hearing behavioral assessment of both groups. Both groups showed alterations in the BAEP and AMLR results, with statistically significant differences between groups for both potentials and a higher occurrence of alterations in the research group. The lower brainstem was the most frequent alteration type in the BAEP, and a statistically significant difference between groups was observed, with higher occurrence of such alteration in the research group. With regards the AMLR, the alteration predominantly observed was the Both type one (ear effect and electrode effect occurring concurrently) for the research group, and the electrode effect type one for the control group. In the analysis of quantitative data (performed only for the auditory evoked potentials), a statistically significant difference between groups was observed with respect to the BAEP latencies of waves III, V and interpeaks I-III and I-V. Regarding the AMLR measures, a statistically significant difference between groups was observed only for the Na wave latency in the C3/A1 position. For the P300, a difference between groups was observed, with higher mean latencies for the research group. In addition, there was a trend to statistically significant difference between right and left ears in the research group, which showed increased latency of P300 wave in the right ear. CONCLUSION: Right-handed individuals with right hemisphere lesion showed hearing thresholds within normal limits in the behavioral hearing assessment. However, they presented results indicative of central auditory nervous system deficits on the electrophysiological assessment of hearing. Alterations were observed in lower brainstem and in sub-cortical and cortical regions. Hearing difficulties were not perceived by these individuals, suggesting that this signal can probably be related to an auditory hemineglect. Further studies that evaluate the central auditory pathway of individuals with ICS are needed to better characterize the electrophysiological findings (AU) | |