Gago Miguel F, Fernandes Vítor, Ferreira Jaime, Yelshyna Darya, Silva Hélder David, Rodrigues Maria Lurdes, Rocha Luís, Bicho Estela, Sousa Nuno
Neurology Department, Centro Hospitalar do Alto Ave, EPE, Guimarães, Portugal.
Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal.
J Alzheimers Dis. 2015;46(2):441-9. doi: 10.3233/JAD-150131.
Postural stability requires the integration of multisensory input information and translation into appropriate motor responses. Surprisingly, few previous studies have addressed the role of auditory input on postural stability in healthy subjects, and none has investigated this in Alzheimer's disease (AD).
To assess the influence of the visual and auditory systems on postural stability in patients with AD and healthy subjects.
Twenty-four patients with AD and healthy age-matched subjects were examined by kinematic postural analysis (inertia measurement units placed at the center of mass of the body) under four different conditions: stance with eyes open and eyes closed, with and without suppression of background noise (using ear defenders). The effects of visual and auditory influences were analyzed independently and in conjunction.
In both groups, visual suppression had a negative impact on postural stability, while suppression of background noise, non-specifically and without spatial cues, significantly benefited postural stability. We also observed that in both groups, the positive effect of background noise suppression was insufficient to compensate for the negative effect of visual suppression, to which the patients were significantly more vulnerable.
Audition, albeit less significant than vision, also plays a role in the multi-sensorial dynamic control of postural stability by the central nervous system. In everyday life, audition is likely to be a relevant factor in postural stability. This is especially relevant in AD in which, even when the peripheral sensory system is intact, the central processing is impaired and sensory dependence is re-weighted.
姿势稳定性需要整合多感官输入信息并转化为适当的运动反应。令人惊讶的是，之前很少有研究探讨听觉输入对健康受试者姿势稳定性的作用，且尚无研究在阿尔茨海默病（AD）患者中对此进行调查。
评估视觉和听觉系统对AD患者及健康受试者姿势稳定性的影响。
对24例AD患者和年龄匹配的健康受试者进行运动姿势分析（将惯性测量单元置于身体重心处），共四种不同条件：睁眼和闭眼站立，有和无背景噪声抑制（使用隔音耳罩）。分别独立及联合分析视觉和听觉影响的效果。
在两组中，视觉抑制均对姿势稳定性产生负面影响，而在无空间线索的情况下非特异性抑制背景噪声则显著有益于姿势稳定性。我们还观察到，在两组中，背景噪声抑制的积极作用不足以补偿视觉抑制的消极作用，且患者对视觉抑制更为敏感。
听觉在中枢神经系统对姿势稳定性的多感官动态控制中也发挥作用，尽管不如视觉显著。在日常生活中，听觉可能是姿势稳定性的一个相关因素。这在AD中尤为相关，因为即使外周感觉系统完好，中枢处理也会受损，感觉依赖性会重新加权。
