Rapid Increase in Neural Conduction Time in the Adult Human Auditory Brainstem Following Sudden Unilateral Deafness

Individuals with sudden unilateral deafness offer a unique opportunity to study plasticity of the binaural auditory system in adult humans. Stimulation of the intact ear results in increased activity in the auditory cortex. However, there are no reports of changes at sub-cortical levels in humans. Therefore, the aim of the present study was to investigate changes in sub-cortical activity immediately before and after the onset of surgically induced unilateral deafness in adult humans. Click-evoked auditory brainstem responses (ABRs) to stimulation of the healthy ear were recorded from ten adults during the course of translabyrinthine surgery for the removal of a unilateral acoustic neuroma. This surgical technique always results in abrupt deafferentation of the affected ear. The results revealed a rapid (within minutes) reduction in latency of wave V (mean pre = 6.55 ms; mean post = 6.15 ms; p < 0.001). A latency reduction was also observed for wave III (mean pre = 4.40 ms; mean post = 4.13 ms; p < 0.001). These reductions in response latency are consistent with functional changes including disinhibition or/and more rapid intra-cellular signalling affecting binaurally sensitive neurons in the central auditory system. The results are highly relevant for improved understanding of putative physiological mechanisms underlying perceptual disorders such as tinnitus and hyperacusis.     

Vestibular Function Measurement Devices

Vestibular function laboratories utilize a multitude of diagnostic instruments to evaluate a dizzy patient. Caloric irrigators, oculomotor stimuli, and rotational chairs produce a stimulus whose accuracy is required for the patient response to be accurate. Careful attention to everything from cleanliness of equipment to threshold adjustments determine on a daily basis if patient data are going to be correct and useful. Instrumentation specifications that change with time such as speed and temperature must periodically be checked using calibrated instruments.     

美国的听力师教育

随着婴儿潮、人口老龄化及新技术的广泛应用，人们对听力保健的需求显著增加。在美国，听力保健服务由助听设备专员、耳鼻喉科医生和听力师3类人员提供，其中听力师提供除医疗、手术外宽泛的听力保健服务。美国的听力保健服务体系及听力师教育体系经历了一个渐进的过程：20年前对从业人员的学历要求是听力学硕士，随着对服务质量要求的提高和服务范围的扩大，美国听力师逐渐要求专业博士学位（Au.D），毕业后还需3～4年的专门教育才能成为一名听力师。听力师教育有统一的标准，大学课程要通过听力教育认证委员会（the Accreditation Commission for Audiology Education， ACAE）或学术认证委员会（the Council on Academic Accreditation，CAA）的多程序严格的认证才能被承认。美国听力师需求存在巨大缺口，但是各国听力学教育标准不统一及听力师收入与教育投资不匹配，阻碍了更多的人进入这一领域。美国试图通过改变教育模式，降低教育成本及革新教学方法等改善听力师教育状况，但是听力师教育体系远未完善。     

Association Between Patient and Physician Sex and Physician-Estimated Stroke and Bleeding Risks in Atrial Fibrillation

Background

Physicians treating nonvalvular atrial fibrillation (AF) assess stroke and bleeding risks when deciding on anticoagulation. The agreement between empirical and physician-estimated risks is unclear. Furthermore, the association between patient and physician sex and anticoagulation decision-making is uncertain.