Statistical motor unit number estimation and ALS trials: the effect of motor unit instability.

Although statistical MUNE has many positive attributes, it is inappropriate for use in multicenter ALS clinical trials. No other commonly used technique for MUNE possesses all the attributes necessary to be a valid and useful outcome measure in ALS trials. However, MUNE as a theoretical outcome measure remains extremely attractive and new techniques must be sought so that it can reach its full potential as a valid and reproducible outcome measure in ALS clinical trials.