New Perspectives for Computer-Aided Discrimination of Parkinson’s Disease and Essential Tremor

Figure 3

Neural drive to left and right wrist flexors and extensors in a representative ET patient during the arms outstretched task. (a) Neural drive as estimated by low-pass filtering of the cumulative motor unit spike train. All muscles exhibit tremulous drive, whereas voluntary drive is also present in the right extensor muscle. (b) Cross-correlations (CC) of neural drives; EXT L: left wrist extensors, FLE L: left wrist flexors, EXT R: right wrist extensors, and FLE R: right wrist flexors. The -axis denotes the correlation lag in seconds. Voluntary drive is filtered out, whereas the tremulous drive is enhanced by the correlation function. Data from panels N1, N3, N4, and N5 are included into the calculation of the N1, N3, N4, and N5 tremor symmetry metrics (see text for details).

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