Electrophysiologic endpoint measures in a multicenter ALS drug trial

We report the analysis of a battery of secondary electrophysiologic measure ments to assess the progression of amyotrophic lateral sclerosis (ALS) in a two center, six month, double-blind, three arm trial comparing branched ch ain amino acids to L-threonine with pyridoxal 5-phosphate to placebo. The e ndpoint measurements were chosen to separately assess the effects of lower motor neuron loss and collateral reinnervation. For tests of inter-center r eliability, we found no differences that could not be readily explained by variations in electrophysiologic testing techniques. Since the drug study w as negative for the primary endpoint measure (muscle strength), we combined data from both centers and the three treatment arms. For measures of progr ession, all measures changed in the expected direction during the 6 months of the trial. We conclude that a battery of electrophysiologic measures can be used in a multicenter ALS drug trial to provide information on changes in lower motor neuron numbers and the effects of collateral reinnervation. (C) 2001 Elsevier Science B.V. All rights reserved.