Sierra-Pacific Mental Illness Research, Education, and Clinical Center, VA Palo Alto Health Care System, Palo Alto, CA 94304, USA.
J Clin Neurosci. 2013 Jun;20(6):827-30. doi: 10.1016/j.jocn.2012.06.015. Epub 2013 Apr 29.
Over the past two decades, several studies have aimed to quantify the kinetic properties of tremor with primary focus on the upper limbs. However, there is a lack of investigation into the properties of tremor in the lower limbs. The objective of this preliminary study was to investigate the properties of oscillatory movement, at rest and in posture, in both the upper and lower limbs of Parkinson's disease (PD) patients with clinically undetectable to modest rest/postural tremor and healthy controls. PD patients (N = 16) and controls (N = 8) were examined clinically by a movement disorders specialist and oscillatory movements in all four extremities were evaluated using a portable biaxial accelerometer. While tremor intensity and frequency did not differ between groups, the intraindividual variability of rest and postural tremor frequency in the dexterity-dominant lower limb was lower in people living with PD than in healthy adults. Additionally, rest tremor frequency was discrepant between upper and lower limbs in PD. Our work introduces the possibility that minute variations in lower limb movements, which are imperceptible upon expert clinical exam, can be used to differentiate a diseased sample from a healthy one. These preliminary findings suggest that additional work using objective tremor measurement may improve our understanding of lower limb motor dysfunction in PD and lead to the refinement of current, and the development of new, metrics to enhance early diagnosis, differential diagnosis, and symptom quantification.
在过去的二十年中，已有多项研究旨在量化震颤的动力学特性，主要集中在上肢。然而，对于下肢震颤的特性研究还很缺乏。本初步研究的目的是调查帕金森病（PD）患者和健康对照者在静止和姿势时上肢和下肢的振荡运动特性，这些患者的震颤临床检测不到或仅为轻度震颤。PD 患者（N=16）和对照组（N=8）由运动障碍专家进行临床检查，使用便携式双轴加速度计评估四肢的振荡运动。尽管震颤强度和频率在两组之间没有差异，但在惯用手优势的下肢中，PD 患者静止和姿势震颤频率的个体内变异性低于健康成年人。此外，PD 患者的上肢和下肢的静止震颤频率存在差异。我们的工作提出了一种可能性，即下肢运动的微小变化，即使经过专家临床检查也无法察觉，可能用于将患病样本与健康样本区分开来。这些初步发现表明，使用客观震颤测量的进一步研究可能有助于我们理解 PD 患者的下肢运动功能障碍，并改进当前的指标，开发新的指标，以提高早期诊断、鉴别诊断和症状量化的能力。
