There is limited research on sensory acuity i.e., ability to perceive external perturbations via body-sway during standing in individuals with a traumatic brain injury (TBI). It is unclear whether sensory acuity diminishes after a TBI and if it is a contributing factor to balance dysfunction. The objective of this investigation is to first objectively quantify the sensory acuity in terms of perturbation perception threshold (PPT) and determine if it is related to functional outcomes of static and dynamic balance. Ten individuals with chronic TBI and 11 age-matched healthy controls (HC) performed PPT assessments at 0.33, 0.5, and 1 Hz horizontal perturbations to the base of support in the anterior-posterior direction, and a battery of functional assessments of static and dynamic balance and mobility [Berg balance scale (BBS), timed-up and go (TUG) and 5-m (5MWT) and 10-m walk test (10MWT)]. A psychophysical approach based on Single Interval Adjustment Matrix Protocol (SIAM), i.e., a yes-no task, was used to quantify the multi-sensory thresholds of perceived external perturbations to calculate PPT. A mixed-design analysis of variance (ANOVA) and post-hoc analyses were performed using independent and paired t-tests to evaluate within and between-group differences. Pearson correlation was computed to determine the relationship between the PPT and functional measures. The PPT values were significantly higher for the TBI group (0.33 Hz: 2.97 ± 1.0, 0.5 Hz: 2.39 ± 0.7, 1 Hz: 1.22 ± 0.4) compared to the HC group (0.33 Hz: 1.03 ± 0.6, 0.5 Hz: 0.89 ± 0.4, 1 Hz: 0.42 ± 0.2) for all three perturbation frequencies (p < 0.006 post Bonferroni correction). For the TBI group, the PPT for 1 Hz perturbations showed significant correlation with the functional measures of balance (BBS: r = −0.66, p = 0.037; TUG: r = 0.78, p = 0.008; 5MWT: r = 0.67, p = 0.034, 10MWT: r = 0.76, p = 0.012). These findings demonstrate that individuals with TBI have diminished sensory acuity during standing which may be linked to impaired balance function after TBI.

中文翻译：

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评估感觉敏锐度作为创伤性脑损伤后平衡功能障碍的标志：心理物理学方法

关于感觉敏锐度的研究有限，即在创伤性脑损伤 (TBI) 患者站立时通过身体摇摆感知外部扰动的能力。目前尚不清楚 TBI 后感觉敏锐度是否会降低，以及它是否是平衡功能障碍的一个促成因素。本次调查的目的是首先根据扰动感知阈值 (PPT) 客观地量化感官敏锐度，并确定它是否与静态和动态平衡的功能结果有关。10 名慢性 TBI 患者和 11 名年龄匹配的健康对照 (HC) 在前后方向对支撑基部的 0.33、0.5 和 1 Hz 水平扰动下进行了 PPT 评估，以及一系列静态和动态功能评估平衡和流动性 [伯格平衡量表 (BBS)，计时起跑 (TUG) 和 5 米 (5MWT) 和 10 米步行测试 (10MWT)]。基于单间隔调整矩阵协议 (SIAM) 的心理物理学方法，即是-否任务，用于量化感知外部扰动的多感官阈值以计算 PPT。使用独立和配对 t 检验进行混合设计方差分析 (ANOVA) 和事后分析，以评估组内和组间差异。计算 Pearson 相关性以确定 PPT 和功能测量之间的关系。与 HC 组 (0.33 Hz: 1.03 ± 0.6, 0.5 Hz: 0.89) 相比，TBI 组 (0.33 Hz: 2.97 ± 1.0, 0.5 Hz: 2.39 ± 0.7, 1 Hz: 1.22 ± 0.4) 的 PPT 值显着更高0.4, 1 Hz: 0.42 ± 0.2) 对于所有三个扰动频率（p < 0.006 post Bonferroni 校正）。对于 TBI 组，1 Hz 扰动的 PPT 显示与平衡的功能测量显着相关（BBS：r = -0.66，p = 0.037；TUG：r = 0.78，p = 0.008；5MWT：r = 0.67，p = 0.034，10MWT：r = 0.76，p = 0.012）。这些发现表明，TBI 患者站立时感觉敏锐度下降，这可能与 TBI 后平衡功能受损有关。