EMGLAB: objective outcome measures in neurophysiological testing

The aim of this work was to objectively measure and quantify the results of various neurophysiological tests and indirectly provide objective outcome measures for neurological therapy and rehabilitation. We have studied the silence of Electromyographic (EMG) activity after evoking motor potentials with magnetic cortical stimulation. Since different criteria were previously used to determine the level where the silence of muscle activity ends, an objective computer aided method was developed. This analysis was further developed to include objective testing of surface EMG, long latency reflexes, reciprocal inhibition of the H-reflex, H-reflex recovery curve and decrement testing. Responses were recorded at different sampling frequencies, depending on the application, time window, filter settings, etc. The developed software proved to be a fast and objective tool, able to standardize the determination of different neurophysiological tests, and as such a valuable tool facilitating multi-center studies and diminishing human bias. The software reduced the study time with each patient. Until date we have used the software with the Medtronic, Medelec and BTS EMG instruments.