Figure 9-2.

Electrophysiologic demonstration of tremor entrainment in a patient with psychogenic tremor. Accelerometry recordings from an accelerometer attached to the hand affected by tremor (AccXR) and to the unaffected hand (AccXL). Below are EMG recordings from the affected hand (RFCR = right flexor carpi radialis; RECR = right extensor carpi radialis). Tremor frequency analysis by fast Fourier transformer shows a 7-Hz peak frequency of tremor (from 92.5 to 98.5 ms); finger tapping of unaffected hand at 4 Hz entrained the affected hand at the same frequency (from 103 to 109.5 ms).