Riluzole has no acute effect on motor unit parameters in ALS.

Riluzole is the only drug to have been approved for the treatment of amyotrophic lateral sclerosis (ALS/MND). Its mechanism of action is complex and includes actions on NMDA and kainate receptors and modulation of voltage gated Na channels. In ALS, its effects on measurable parameters of the motor units utilising current neurophysiological techniques are unknown. In an acute randomized, double-blind, placebo-controlled, cross-over experiment, we serially assessed the effects of riluzole on motor units in muscles affected by ALS/MND using EMG. We discuss the results of our observations in the light of previous clinical trials, and their implications.