Application of tremor analysis in differential diagnosis of essential tremor and Parkinson's disease
- Author:
Le ZHANG
1
Author Information
- Publication Type:Journal Article
- Keywords: Accelerometry; Differential diagnosis; Essential tremor; Parkinson's disease; Tremor analysis
- From: Journal of Xi'an Jiaotong University(Medical Sciences) 2019;40(4):624-628
- CountryChina
- Language:Chinese
- Abstract: Objective: To explore the value of tremor analysis using accelerator combined with electromyography (EMG) in differential diagnosis of essential tremor (ET) and Parkinson's disease (PD). Methods: We made a retrospective analysis and comparison of 61 ET patients in the outpatient department of Neurology, The First Affiliated Hospital of Xi'an Jiaotong University, and 49 PD patients. Tremor analysis was performed in the two groups, and differences in tremor characteristics between the two groups were compared. Results: ① General information: 61 ET patients, including 27 males (44.3%), aged 21-84 years (mean 58.8±15.8 years), with an average duration of 8.8 years (8.2 years). There were 49 PD patients including 23 males (46.9%), aged 44-84 years (mean 64.3±9 years). ② Tremor waveform: ET group had single wave crest. 72.1% patients had double peaks after loading. 95.9% patients in PD group were mainly harmonic, and no double peaks appeared. ③ The muscle contractile modes in the two groups were mutually antagonistic in tremor. ET group had mainly synchronous contraction, while PD group had synchronous contraction and alternating contraction mode (P<0.05) simultaneously. The characteristics of tremor wave: the frequency of ET group was higher than that of PD group (6.62±1.70 vs. 4.77±0.67, P<0.05), and the half width of wave peak was larger (0.95±0.30 vs. 0.82±0.21, P<0.05), but there was no significant difference in the half width power between the two group (χ2=49.22, P<0.05).The multiple factor analysis showed that significant differences between the two groups in the double wave peak, harmonic phenomenon, tremor position and tremor after the weight negative. The surrounding waves were positively correlated with ET. The appearance of the surrounding waves was more inclined to diagnose ET (P=0.003, OR value=90.496). The harmonic phenomenon was positively related to ET, and the harmonic phenomenon was more inclined to appear in PD (P=0.014, OR value=0.042). The area under the ROC curve of the peak frequency of the tremor after 1000g was 0.845. The best diagnostic boundary value of ET was 5.445 0 Hz, the sensitivity was 77%, the specificity was 85.7%, the positive predictive value was 87%, and the negative predictive value was 75%. Conclusion: ET and PD differ significantly in tremor frequency, muscle contraction mode, half-width value, frequency after loading and waveform changes. Tremor analysis is of high value in differentiating ET from PD tremor.
