Abstract：
Quantitative biomarkers are needed for the diagnosis, monitoring and therapeutic assessment of postural instability in movement disorder patients. The goal of this study was to create a practical, objective measure of postural instability using kinematic measurements of the pull test. Twenty-one patients with normal pressure hydrocephalus and 20 age-matched control subjects were fitted with inertial measurement units and underwent 10-20 pull tests of varying intensities performed by a trained clinician. Kinematic data were extracted for each pull test and aggregated. Patients participated in 103 sessions for a total of 1555 trials while controls participated in 20 sessions for a total of 299 trials. Patients were separated into groups by MDS-Unified Parkinson\'s Disease Rating Scale (MDS-UPDRS) pull test score. The center of mass velocity profile easily distinguished between patient groups such that score increases correlated with decreases in peak velocity and later peak velocity onset. All patients except those scored as \"3\" demonstrated an increase in step length and decrease in reaction time with increasing pull intensity. Groups were distinguished by differences in the relationship of step length to pull intensity (slope) and their overall step length or reaction time regardless of pull intensity (y-intercept). NPH patients scored as \"normal\" on the MDS-UPDRS scale were kinematically indistinguishable from age-matched control subjects during a standardized perturbation, but could be distinguished from controls by their response to a range of pull intensities. An instrumented, purposefully varied pull test produces kinematic metrics useful for distinguishing clinically meaningful differences within hydrocephalus patients as well as distinguishing these patients from healthy, control subjects.
摘要：
诊断需要定量生物标志物，运动障碍患者姿势不稳定的监测和治疗评估。这项研究的目的是创造一个实用的，使用拉力测试的运动学测量来客观测量姿势不稳定性。对21名正常压力脑积水患者和20名年龄匹配的对照受试者进行了惯性测量单元，并由训练有素的临床医生进行了10-20次不同强度的拉力测试。提取每个拉力测试的运动学数据并进行汇总。患者参加了103个疗程共1555项试验，而对照组参加了20个疗程共299项试验。采用MDS-统一帕金森病评定量表(MDS-UPDRS)牵拉试验评分将患者分组。质心速度分布容易区分患者组,使得分数增加与峰值速度的降低和稍后的峰值速度开始相关。除评分为“3”的患者外，所有患者均表现出随着拉力强度的增加，步长增加，反应时间减少。通过步长与拉强度（斜率）的关系以及它们的整体步长或反应时间的差异来区分组，而与拉强度（y截距）无关。在MDS-UPDRS量表上评分为“正常”的NPH患者在标准化扰动期间与年龄匹配的对照受试者在运动学上没有区别，但可以通过对一系列拉力强度的反应与对照组区分开来。一个仪器，有目的地变化的拉力试验产生的运动学指标有助于区分脑积水患者的临床意义差异，以及区分这些患者与健康，控制主体。
