Preventive Neurology Unit, Wolfson Institute of Preventive Medicine, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK.
Physical and Analytical Chemistry Department, Jaume I University, Castelló de la Plana, Spain.
J Parkinsons Dis. 2021;11(4):1901-1915. doi: 10.3233/JPD-212683.
Bradykinesia is the defining motor feature of Parkinson's disease (PD). There are limitations to its assessment using standard clinical rating scales, especially in the early stages of PD when a floor effect may be observed.
To develop a quantitative method to track repetitive tapping movements and to compare people in the early stages of PD, healthy controls, and individuals with idiopathic anosmia.
This was a cross-sectional study of 99 participants (early-stage PD = 26, controls = 64, idiopathic anosmia = 9). For each participant, repetitive finger tapping was recorded over 20 seconds using a smartphone at 240 frames per second. From each video, amplitude between fingers, frequency (number of taps per second), and velocity (distance travelled per second) was extracted. Clinical assessment was based on the motor section of the MDS-UPDRS.
People in the early stage of PD performed the task with slower velocity (p < 0.001) and with greater frequency slope than controls (p = 0.003). The combination of reduced velocity and greater frequency slope obtained the best accuracy to separate early-stage PD from controls based on metric thresholds alone (AUC = 0.88). Individuals with anosmia exhibited slower velocity (p = 0.001) and smaller amplitude (p < 0.001) compared with controls.
We present a simple, proof-of-concept method to detect early motor dysfunction in PD. Mean tap velocity appeared to be the best parameter to differentiate patients with PD from controls. Patients with anosmia also showed detectable differences in motor performance compared with controls which may suggest that some were in the prodromal phase of PD.
运动迟缓是帕金森病（PD）的主要运动特征。使用标准临床评分量表评估存在局限性，尤其是在 PD 的早期阶段，可能会出现地板效应。
开发一种定量方法来跟踪重复敲击动作，并比较早期 PD 患者、健康对照者和特发性嗅觉丧失者。
这是一项横断面研究，共纳入 99 名参与者（早期 PD 患者 26 名、健康对照者 64 名、特发性嗅觉丧失者 9 名）。每位参与者使用智能手机以 240 帧/秒的速度记录 20 秒的手指重复敲击。从每个视频中提取手指之间的振幅、频率（每秒敲击次数）和速度（每秒移动距离）。临床评估基于 MDS-UPDRS 的运动部分。
早期 PD 患者的动作速度较慢（p<0.001），且频率斜率较大（p=0.003）。基于单一的度量标准阈值，速度降低和频率斜率增加的组合获得了最佳的准确性，能够将早期 PD 患者与对照组区分开来（AUC=0.88）。与对照组相比，嗅觉丧失者的速度较慢（p=0.001）且振幅较小（p<0.001）。
我们提出了一种简单的、概念验证的方法，用于检测 PD 中的早期运动功能障碍。平均敲击速度似乎是区分 PD 患者和对照组的最佳参数。与对照组相比，嗅觉丧失者的运动表现也存在可检测到的差异，这可能表明其中一些人处于 PD 的前驱期。
