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Abstract Introduction Perinatal hypothyroidism has a negative repercussion on the development and maturation of auditory system function. However, its long-term effect on auditory function remains unsettled. Objective To evaluate the effect of prenatal hypothyroidism on the auditory function of adult offspring in rats. Methods Pregnant Wistar rats were given the antithyroid drug methimazole (0.02%-1-methylimidazole-2-thiol- MMI) in drinking water, ad libitum, from gestational day (GD) 9 to postnatal day 15 (PND15). Anesthetized offspring from MMI-treated dams (OMTD) and control rats were evaluated by tympanometry, distortion product otoacoustic emission (DPOAE), and auditory brainstem response (ABR) at PNDs 30, 60, 90, and 120. Results Our data demonstrated no middle ear dysfunction, with the OMTD compliance lower than that of the control group. The DPOAE revealed the absence of outer hair cells function, and the ABR showed normal integrity of neural auditory pathways up to brainstem level in the central nervous system. Furthermore, in the OMTD group, hearing loss was characterized by a higher electrophysiological threshold. Conclusion Our data suggest that perinatal hypothyroidism leads to irreversible damage to cochlear function in offspring.
ABSTRACT
ABSTRACT INTRODUCTION: Chemotherapy and radiotherapy in oncology have repercussions in hearing health, and can damage structures of the inner ear. These repercussions usually, result in a bilateral and irreversible hearing loss. OBJECTIVE: To identify sensorineural hearing loss cases with complaints of tinnitus and difficulty in speech understanding and investigate their relationship with the types of chemotherapy and radiotherapy the patients received. METHODS: Cross-sectional, clinical, observational, analytical, historical cohort study of 58 subjects treated in a public hospital in the state of Sergipe, diagnosed with neoplasia. The subjects were submitted to anamnesis, conventional pure tone audiometry, and speech recognition threshold. RESULTS: Of the 116 ears, 25.9% presented sensorioneural hearing loss characterized by changes in high frequencies. There was a positive correlation between hearing loss and the association of chemotherapy and radiotherapy ( p = 0.035; R = 0.196). The auditory complaint analysis shows that most of the subjects had tinnitus and speech understanding difficulty, even with a normal auditory threshold. CONCLUSIONS: Cancer treatment causes hearing loss, associated with the administration of chemotherapy and radiotherapy. Cyclophosphamide increased the risk of causing hearing loss. Complaints of tinnitus and speech understanding difficulty were observed.
RESUMO INTRODUÇÃO: O tratamento quimioterápico e radioterápico na oncologia tem repercussão na saúde auditiva e pode lesar estruturas da orelha interna. Ocasiona perda auditiva, geralmente bilateral e irreversível. OBJETIVO: Identificar casos de perda auditiva sensorioneural e sua relação com a média de sessões de quimioterapia e radioterapia, com queixas de zumbido e dificuldade de entendimento da fala, bem como sua relação com medicamentos quimioterápicos. MÉTODO: Estudo de coorte histórica com corte transversal, clínico, observacional, analítico e retrospectivo em 58 sujeitos de um hospital público de Sergipe diagnosticados com neoplasia. Realizou-se anamnese, avaliação audiológica tonal convencional e pesquisa do limiar de reconhecimento de fala. RESULTADOS: Das 116 orelhas; 25,9% apresentaram perda auditiva sensorioneural caracterizada por alterações nas frequências agudas. Observou-se correlação significativa entre perda auditiva e associação da quimioterapia e radioterapia (p = 0,035; R = 0,196). Na análise das queixas auditivas, verificou-se que a maioria apresentou zumbido e dificuldade de entendimento de fala, mesmo com limiares auditivos normais. CONCLUSÕES: O tratamento oncológico gera perda auditiva, que foi determinada pela associação da quimioterapia e radioterapia. Ciclofosfamida aumentou as chances de gerar perda auditiva. Verificou-se presença de queixas de zumbido e dificuldade de entendimento da fala.