Effects of the amplitude threshold on the separability of neuropathic and myopathic from normal EMG using parameters of the turns/amplitude analysis.

Objective: In this study, the relationship between the amplitude threshold used for the determination of the turns of the electromyographic (EMG) interference pattern and the parameters of the turns/amplitude analysis was examined. It was investigated whether the discrimination of myopathic and neuropathic from normal muscles could be optimized by an appropriate amplitude threshold.

Methods: The interference patterns of the tibialis anterior muscle of 15 patients with myopathies, 30 patients with neuropathies and 56 controls were recorded, using concentric needle electrodes.