Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, National Center for Neurological Disorders, Beijing, China.
Innovation Center for Neurological Disorders, Department of Neurology, Xuanwu Hospital, Capital Medical University, National Center for Neurological Disorders, Beijing, China.
Alzheimers Dement. 2022 Jun;18(6):1085-1099. doi: 10.1002/alz.12464. Epub 2021 Sep 27.
Speech comprehension in noisy environments depends on central auditory functions, which are vulnerable in Alzheimer's disease (AD). Binaural processing exploits two ear sounds to optimally process degraded sound information; its characteristics are poorly understood in AD. We studied behavioral and electrophysiological alterations in binaural processing among 121 participants (AD = 27; amnestic mild cognitive impairment [aMCI] = 33; subjective cognitive decline [SCD] = 30; cognitively normal [CN] = 31). We observed impairment of binaural processing in AD and aMCI, and detected a U-shaped curve change in phase synchrony (declining from CN to SCD and to aMCI, but increasing from aMCI to AD). This improvement in phase synchrony accompanying more severe cognitive stages could reflect neural adaptation for binaural processing. Moreover, increased phase synchrony is associated with worse memory during the stages when neural adaptation apparently occurs. These findings support a hypothesis that neural adaptation for binaural processing deficit may exacerbate cognitive impairment, which could help identify biomarkers and therapeutic targets in AD.
在嘈杂环境中进行言语理解依赖于中枢听觉功能，而该功能在阿尔茨海默病（AD）中较为脆弱。双耳处理利用双耳声音来优化处理退化的声音信息；但其在 AD 中的特征尚未得到充分理解。我们研究了 121 名参与者（AD = 27；遗忘型轻度认知障碍[aMCI] = 33；主观认知下降[SCD] = 30；认知正常[CN] = 31）的双耳处理行为和电生理改变。我们观察到 AD 和 aMCI 中双耳处理受损，并且在相位同步中检测到 U 形曲线变化（从 CN 到 SCD 和 aMCI 下降，但从 aMCI 到 AD 增加）。这种伴随着更严重认知阶段的相位同步改善可能反映了双耳处理的神经适应。此外，在神经适应显然发生的阶段，相位同步增加与记忆更差相关。这些发现支持了这样一种假设，即双耳处理缺陷的神经适应可能会加剧认知障碍，这有助于确定 AD 的生物标志物和治疗靶点。
