Strouse A L, Hall J W, Burger M C
Division of Hearing and Speech Sciences, School of Medicine, Vanderbilt University, Nashville, Tennessee, USA.
Ear Hear. 1995 Apr;16(2):230-8. doi: 10.1097/00003446-199504000-00010.
This investigation was designed to determine whether people in the early to middle phases of Alzheimer's disease (AD) show impaired central auditory processing as compared with nondemented elderly.
A peripheral and central auditory test battery was administered to 10 subjects diagnosed with mild-to-moderate AD based on a neuropsychological test battery and radiographic techniques, and a control group of 10 subjects with no evidence of dementia, matched for age, gender, and average degree of hearing loss. Immittance audiometry, pure-tone and speech audiometry, and otoacoustic emissions were recorded in all subjects. Central auditory assessment included the synthetic sentence identification with ipsilateral competing message, dichotic digits, dichotic sentence identification, pitch patterns, and duration patterns.
Peripheral auditory status was statistically similar between subject groups. Neither average high frequency hearing sensitivity nor mean speech recognition ability was significantly different. However, a significant difference was noted between groups for average low frequency hearing sensitivity in the left ear (p < 0.05). Subjects with AD showed slightly poorer low frequency thresholds versus matched controls. Based on analysis of performance on each measure of the central auditory test battery, the AD group scored significantly lower than the matched control group on four of the five measures utilized. Differences for right versus left ear performance were found among AD subjects.
Overall patterns in findings cannot be easily explained as artifacts of cognitive decline. Results support screening for central auditory dysfunction in the AD population, since impaired processing could influence psychiatric assessment of cognitive deficit as well as audiologic management of peripheral hearing loss in this population.
本研究旨在确定与未患痴呆症的老年人相比，处于阿尔茨海默病（AD）早期至中期的患者是否存在中枢听觉处理受损的情况。
对10名根据神经心理测试组和放射学技术被诊断为轻度至中度AD的受试者，以及10名无痴呆症迹象、年龄、性别和平均听力损失程度相匹配的对照组受试者，进行了外周和中枢听觉测试组评估。记录了所有受试者的声导抗测听、纯音和言语测听以及耳声发射情况。中枢听觉评估包括同侧竞争信息的合成句子识别、双耳分听数字、双耳分听句子识别、音高模式和时长模式。
两组受试者的外周听觉状态在统计学上相似。平均高频听力敏感度和平均言语识别能力均无显著差异。然而，两组左耳的平均低频听力敏感度存在显著差异（p < 0.05）。与匹配的对照组相比，AD患者的低频阈值略高。根据对中枢听觉测试组各项指标表现的分析，在使用的五项指标中，AD组在其中四项上的得分显著低于匹配的对照组。在AD受试者中发现了右耳与左耳表现的差异。
研究结果的总体模式不易解释为认知衰退的假象。结果支持对AD人群进行中枢听觉功能障碍筛查，因为处理能力受损可能会影响该人群认知缺陷的精神评估以及外周听力损失的听力学管理。
