Patients with bilateral vestibular hypofunction (BVH) often suffer from imbalance, gait problems, and oscillopsia. Noisy galvanic vestibular stimulation (GVS), a technique that non-invasively stimulates the vestibular afferents, has been shown to enhance postural and walking stability. However, no study has investigated how it affects stability and neural activities while standing and walking with a 2 Hz head yaw turning. Herein, we investigated this issue by comparing differences in neural activities during standing and walking with a 2 Hz head turning, before and after noisy GVS. We applied zero-mean gaussian white noise signal stimulations in the mastoid processes of 10 healthy individuals and seven patients with BVH, and simultaneously recorded electroencephalography (EEG) signals with 32 channels. We analyzed the root mean square (RMS) of the center of pressure (COP) sway during 30 s of standing, utilizing AMTI force plates (Advanced Mechanical Technology Inc., Watertown, MA, USA). Head rotation quality when walking with a 2 Hz head yaw, with and without GVS, was analyzed using a VICON system (Vicon Motion Systems Ltd., Oxford, UK) to evaluate GVS effects on static and dynamic postural control. The RMS of COP sway was significantly reduced during GVS while standing, for both patients and healthy subjects. During walking, 2 Hz head yaw movements was significantly improved by noisy GVS in both groups. Accordingly, the EEG power of theta, alpha, beta, and gamma bands significantly increased in the left parietal lobe after noisy GVS during walking and standing in both groups. GVS post-stimulation effect changed EEG activities in the left and right precentral gyrus, and the right parietal lobe. After stimulation, EEG activity changes were greater in healthy subjects than in patients. Our findings reveal noisy GVS as a non-invasive therapeutic alternative to improve postural stability in patients with BVH. This novel approach provides insight to clinicians and researchers on brain activities during noisy GVS in standing and walking conditions in both healthy and BVH patients.

中文翻译：

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双侧前庭功能减退患者的嘈杂的电流前庭刺激（随机共振）改变脑电图活动和姿势控制

患有双侧前庭功能低下（BVH）的患者通常患有失衡，步态问题和骨质疏松症。嘈杂的电流前庭刺激（GVS）是一种无创刺激前庭传入的技术，已显示可增强姿势和行走稳定性。但是，尚无研究调查它如何在2 Hz偏航转弯时站立和行走时如何影响稳定性和神经活动。在本文中，我们通过比较在GVS嘈杂前后站立和行走过程中2 Hz头转向时神经活动的差异来研究此问题。我们在10名健康个体和7名BVH患者的乳突中应用了零均值高斯白噪声信号刺激，并同时通过32个通道记录了脑电图（EEG）信号。我们利用AMTI测力板（美国马萨诸塞州沃特敦的Advanced Mechanical Technology Inc.）分析了站立30秒钟时压力中心（COP）摇摆的均方根（RMS）。使用VICON系统（英国牛津的Vicon Motion系统有限公司）分析了在有和没有GVS的2 Hz偏航条件下行走时头部的旋转质量，以评估GVS对静态和动态姿势控制的影响。对于患者和健康受试者，站立GVS期间COP摆动的RMS均显着降低。在步行过程中，两组的噪声GVS均显着改善了2 Hz的头部偏航运动。因此，两组在行走和站立期间，在吵闹的GVS后，左顶叶的θ，α，β和γ带的脑电图功率均显着增加。GVS刺激后的作用改变了左，右中央前回和右顶叶的脑电活动。刺激后，健康受试者的脑电图活性变化大于患者。我们的研究结果表明，嘈杂的GVS可作为改善BVH患者姿势稳定性的非侵入性治疗选择。这种新颖的方法为临床医生和研究人员提供了健康和BVH患者站立和行走条件下嘈杂GVS期间大脑活动的见解。