Statistical characteristics of electromyogram in the diagnostics of Parkinson's disease

A comparative analysis of statistical characteristics of the surface electromyogram (EMG) was performed in patients with Parkinson's disease (PD), healthy middle-aged and elderly individuals: histograms of the amplitude distribution, dispersion, asymmetry coefficient, and excess coefficient. In order to identify a risk group for parkinsonism, these EMG characteristics were also studied in relatives of patients with PD. EMG of elbow flexors and extensors was recorded at rest. In healthy individuals, the critical values ​​of normal EMG characteristics were established: the amplitude range did not exceed 20 μV, dispersion - 7, asymmetry coefficient module - 0.2, and excess coefficient - 0.4. In PD patients, the parameters of these indicators were significantly increased (p < 0.001). A correlation (p < 0.01) was found between the excess coefficient and the clinical scale scores assessing tremor intensity. According to statistical parameters of EMG, 43% of the studied relatives showed signs of impaired muscle activity. In order to prevent the manifestation of PD for the risk group, recommendations were developed indicating drugs, the long-term use of which should be avoided.