International journal of audiology
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Salicylate, a common drug frequently used long term in the clinic, is well known for causing reversible hearing loss and tinnitus. Our previous study, however, demonstrated that chronic administration of salicylate progressively raised the amplitude of distortion product of otoacoustic emissions (DPOAEs), which are mainly caused by (outer hair cell) OHC electromotility. How salicylate affects OHC electromotility to cause this paradoxical increase remains unclear. ⋯ These levels returned to baseline 14 days after treatment stopped. Acute injection of salicylate (single injection, 400 mg/kg) did not affect prestin levels. These data reveal that chronic salicylate administration markedly, but reversibly, increased prestin levels which may contribute to the enhanced DPOAE amplitudes we observed previously with similar salicylate treatment, which may be responsible for salicylate-induced tinnitus generation.
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When vertigo and dizziness are diagnosed in a child, this is a matter of concern for the physician and the child's family. Prior to a comprehensive otological, neurological, and vestibular clinical examination, physicians often request CT or MRI scanning, although in most cases such expensive testing is unnecessary. The present work is based on the results of a 14-year study conducted with a sample of more than 2,000 children referred for vertigo and balance disorders to the functional vestibular evaluation unit of the ENT pediatric department at Robert Debre Hospital (Paris). The clinical signs of vestibular deficit and the most frequent aetiologies of vertigo and dizziness in children are detailed (migraine equivalent, ophthalmologic disorders, benign paroxysmal idiopathic pediatric vertigo, and temporal bone fracture), which has been helpful in determining the best diagnostic procedure and therapy for vertigo in children.
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In order to develop a sensitive audiometric protocol for identifying ototoxicity in children, a retrospective study of 16 children treated with cisplatin and/or carboplatin was performed. Audiometric testing was done by means of pure-tone threshold audiometry (PTA), high-frequency audiometry (HFA), and distortion product otoacoustic emissions (DPOAEs). Cisplatin caused a sensorineural high-frequency hearing loss in the study group compared to the controls (p < 0.01). ⋯ An excellent correlation was found between DPOAE levels and results obtained by audiometry (r = 0.82). Patients exposed to cisplatin are at significant risk for the development of drug-induced sensorineural hearing loss. Because of the several advantages of DPOAEs (noninvasive, objective, rapid, easy to use, sensitive) this method should be added in the audiological follow-up in infants and toddlers.
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A computational model of the electrically evoked compound action potential (ECAP) has been developed. In addition to being a useful research tool, it serves as an excellent introduction to the basic biophysics of ECAP recording techniques. ECAPs are modeled as a sum of single-fiber action potentials (SFAPs) in response to an electrical stimulus. ⋯ The factors that alter SFAP and ECAP morphology and latency are discussed, as are the mechanisms of stimulus artefact and the advantages and limitations of different artefact-suppression techniques. The assumptions of the model are presented, as are potential ways of improving the physiologic data available from clinical recordings. Potential applications of this technology in the investigation of the biophysical mechanisms of the implanted cochlea are suggested.
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The identification of anxiety and depressive disorders in tinnitus patients is important from a therapeutic point of view. We have addressed this question by investigating the screening performance of the Hospital Anxiety and Depression Scale (HAD) in a consecutive series of tinnitus patients (n = 82) without severe socially disabling hearing loss referred to an audiological clinic. The structured clinical interview for DSM-III criteria was used as the gold standard. ⋯ The optimal cut-off score for the subscales was > or = 5 when we were screening for any anxiety or depressive disorder as well as for major depression. The performance of the HAD depression subscale was superior, especially when we were screening for major depression only (sensitivity 1.00; specificity 0.75). The findings of the study suggest that the HAD Scale is more useful for screening for depression than for anxiety disorders in tinnitus patients