Eye Movements Are Correctly Timed During Walking Despite Bilateral Vestibular Hypofunction
Eye Movements Are Correctly Timed During Walking Despite Bilateral Vestibular Hypofunction
复制标题
DOI：
10.1007/s10162-017-0626-8
复制
发表时间：
2017-08-01
影响因子：
2.4
通讯作者：
Jeka, John J.
中科院分区：
文献类型：
--
作者：
Anson, Eric R.;Kiemel, Tim;Jeka, John J.
双侧前庭功能减退 (BVH) 患者经常在行走时出现振荡症状（感觉世界在弹跳或不稳定）。输出复制/本体感觉有助于动物运动注视的稳定性，有时会抑制前庭眼反射（VOR）。凝视稳定性需要足够的眼球速度和适当的眼球运动时机。目前尚不清楚 BVH 患者在行走过程中眼速（VOR 增益）、时间（相位）或两者是否均受到损害。确定凝视稳定性受损的具体机制可以更好地为康复选择提供信息。研究人员测量了 8 名患有严重 BVH 的个体和 8 名年龄和性别匹配的健康对照者在跑步机行走期间执行注视固定任务时的注视稳定性。频率响应函数（FRF）是根据俯仰速度和头部速度计算的。进行单向方差分析以确定 FRF 的每个频率仓的组差异。计算 Pearson 相关系数以确定 FRF 的实部和虚部与振荡视觉模拟量表 (oVAS) 分数之间的关系。患有 BVH 的个体在高于 0.5 Hz 的频率下表现出明显低于健康对照的增益，但他们的相位对于低于 3 Hz 的频率是理想的补偿。较高的 oVAS 分数与较低的增益相关。尽管与健康对照组相比，患有 BVH 的人在行走时表现出了理想的垂直眼球运动时机，尽管其眼球运动速度低于理想水平。应开发以增强步行期间 VOR 增益为重点的康复干预措施，以利用此处报告的完整时间。具体来说，步行时训练 VOR 增益可能会减轻振荡的严重程度并提高生活质量。
Individuals with bilateral vestibular hypofunction (BVH) often report symptoms of oscillopsia (the perception that the world is bouncing or unstable) during walking. Efference copy/proprioception contributes to locomotion gaze stability in animals, sometimes inhibiting the vestibulo-ocular reflex (VOR). Gaze stability requires both adequate eye velocity and appropriate timing of eye movements. It is unknown whether eye velocity (VOR gain), timing (phase), or both are impaired for individuals with BVH during walking. Identifying the specific mechanism of impaired gaze stability can better inform rehabilitation options. Gaze stability was measured for eight individuals with severe BVH and eight healthy age- and gender-matched controls while performing a gaze fixation task during treadmill walking. Frequency response functions (FRF) were calculated from pitch eye and head velocity. A one-way ANOVA was conducted to determine group differences for each frequency bin of the FRF. Pearson correlation coefficients were calculated to determine the relationship between the real and imaginary parts of the FRF and the Oscillopsia Visual Analog Scale (oVAS) scores. Individuals with BVH demonstrated significantly lower gains than healthy controls above 0.5 Hz, but their phase was ideally compensatory for frequencies below 3 Hz. Higher oVAS scores were correlated with lower gain. Individuals with BVH demonstrated ideal timing for vertical eye movements while walking despite slower than ideal eye velocity when compared to healthy controls. Rehabilitation interventions focusing on enhancing VOR gain during walking should be developed to take advantage of the intact timing reported here. Specifically, training VOR gain while walking may reduce oscillopsia severity and improve quality of life.