SOD1 and amyotrophic lateral sclerosis: In a study designed to evaluate drug efficacy, although SOD1-G93A ALS mice treated with riluzole showed no increase in time of disease onset or overall survival (24), there was good correlation between LP 50 kHz values and other biomarkers including paw grip endurance (PGE), and Compound Muscle Action Potential (CMAP) amplitude, supporting the conclusion that changes in surface EIM values reflect motor neuron loss and declining motor function.