Neural and Behavioral Indices of Balance Performance in Individuals with sensory loss

摘要 患有单侧前庭功能减退(VH，内耳周围疾病)的人 认为会发展成视觉依赖。他们在复杂的视觉中会感到头晕和失去平衡 环境。与静态或闭眼相比，它们在动态视觉上的摆动更大 与公开赛相比。UHL患者不会定期接受平衡功能评估，但那些 至少有中度听力损失的人摔倒的风险更高。来自力学研究的数据 我们实验室的研究人员已经证明，UHL患者不会增加身体姿势的摆动。 与健康对照组一样，存在复杂的视觉场景，这表明他们不像健康对照组那样依赖 视觉输入来维持它们的平衡。基于这些发现，我们假设个人 UHL可能会将注意力资源重新分配到运动平衡控制(有意识的运动 处理)以补偿听觉提示的损失。检验视觉的假说 VH中的依赖和UHL中的有意识运动加工，这一建议将结合 平衡性行为评估和基于网络的功能连接性分析 静息状态功能磁共振成像(FMRI)。这项研究的长期目标是 是确定解释平衡行为的神经生物学指标，并开发一种干预措施 针对功能连接差异的方法，最大限度地提高功能移动性 感觉丧失的人。在目前的项目中，我们将解决以下具体目标：AIM 1：确定VH和UHL患者的平衡配置文件。患有VH、UHL和对照的个人 (n=24)将进行一系列平衡测量，包括静态、动态、步态和测试 以平衡的感觉和认知方面为目标。我们还将分析他们的姿势摇摆从 当它们在虚拟现实环境中测试时，强制车牌数据。目标2：确定网际网络 VH、UHL和健康对照的功能连接性差异。静息状态的fMRI数据将 从VH和UHL(每个N=12)获得，并与健康对照数据的分布进行比较。 目标3：确定平衡能力(目标1)与神经生物学相关的程度 VH和UHL中的数据(目标2)。我们将计算姿势摆动数据和比率之间的相关性 从注意力-运动连接到注意力-视觉连接。 如果我们实现了我们的目标，我们将确定哪些平衡域受影响最大 前庭和听力损失以及是否应该定期对UHL患者进行筛查 平衡性能。我们将确定哪些大脑连接会因感觉丧失而改变 对平衡的影响。这一知识将对以下方面的公共卫生产生重要影响 改进了对VH和UHL未来干预措施的平衡和发展的评估。

ABSTRACT People with unilateral vestibular hypofunction (VH, peripheral disease of the inner ear) are thought to develop visual dependence. They get dizzy and off balance in complex visual environments. They sway more with dynamic visuals compared to static or with eyes closed compared to open. Individuals with UHL are not regularly assessed for balance function, but those with at least moderate hearing loss show increased risk for falls. Data from mechanistic studies in our lab have demonstrated that individuals with UHL do not increase postural sway in the presence of complex visual scenes as much as healthy controls, suggesting they are not as reliant on visual input to maintain their balance. Based on these findings, we hypothesize that individuals with UHL may reallocate attentional resources to motor control of balance (conscious movement processing) to compensate for the loss of auditory cues. To test the hypotheses of visual dependence in VH and conscious movement processing in UHL, this proposal will combine behavioral assessments of balance with analyses of network-based functional connectivity from resting-state functional magnetic resonance imaging (fMRI). The long-term goal of this research is to identify the neurobiological index explaining balance behavior and develop an intervention approach targeting functional connectivity differences that maximizes functional mobility gains in people with sensory loss. In the current project we will address the following Specific Aims: Aim 1: Identify balance profiles for people with VH and UHL. Individuals with VH, UHL and controls (N=24 each) will perform a battery of balance measures including static, dynamic, gait, and tests targeting sensory and cognitive aspects of balance. We will also analyze their postural sway from force plate data as they are tested in a virtual reality environment. Aim 2: Identify internetwork functional connectivity differences in VH, UHL, and healthy controls. Resting-state fMRI data will be acquired from VH and UHL (N=12 each) and compared to a distribution of healthy control data. Aim 3: Determine the extent to which balance performance (Aim 1) correlate with neurobiological data (Aim 2) in VH and UHL. We will calculate correlations between postural sway data and ratio of attention-motor connectivity to attention-vision connectivity. If we accomplish our aims, we will identify which balance domains are most affected by vestibular and hearing loss and whether people with UHL should be regularly screened for balance performance. We will establish which brain connections are altered by sensory loss and the implications for balance. This knowledge will have important implications to public health for improved assessment of balance and development of future interventions in VH and UHL.