Elble R J, Higgins C, Leffler K, Hughes L
Department of Neurology, Southern Illinois University School of Medicine, Springfield 62794-9230.
Mov Disord. 1994 Nov;9(6):589-96. doi: 10.1002/mds.870090602.
Quantitative electromyography (EMG) and triaxial accelerometry were used to measure hand tremor, finger tremor, and forearm motor unit activity in 36 men and 23 women with essential tremor. Hand tremor was studied with and without 300-g mass loading. Tremor and EMG were recorded twice, with a 3-min rest interval, to assess the spontaneous intertrial variability in tremor amplitude, frequency, and motor unit entrainment. In general, the minimum detectable differences in tremor amplitude, frequency, and motor unit entrainment were roughly 30%, 5%, and 10% of the initial sample means, respectively, assuming a sample size of 30 patients, a statistical power of 0.9, and a significance level of 0.05. Linear regression analyses were performed to test the hypotheses that (a) there is an age-associated decrease in tremor frequency that is independent of symptom duration and (b) tremor frequency and motor unit entrainment make independent contributions to tremor amplitude. Our data supported both hypotheses.
采用定量肌电图（EMG）和三轴加速度测量法，对36名男性和23名女性特发性震颤患者的手部震颤、手指震颤及前臂运动单位活动进行了测量。在有和没有300克负重的情况下对手部震颤进行了研究。震颤和肌电图记录了两次，间隔3分钟休息时间，以评估震颤幅度、频率和运动单位夹带的自发试验间变异性。一般来说，假设样本量为30例患者、统计效能为0.9、显著性水平为0.05，震颤幅度、频率和运动单位夹带的最小可检测差异分别约为初始样本均值的30%、5%和10%。进行线性回归分析以检验以下假设：（a）存在与年龄相关的震颤频率下降，且与症状持续时间无关；（b）震颤频率和运动单位夹带对震颤幅度有独立贡献。我们的数据支持这两个假设。
