Effects of riluzole on cortical excitability in patients with amyotrophic lateral sclerosis.

Using transcranial magnetic stimulation, the effect of riluzole (RLZ) on cortical excitability was studied in patients with amyotrophic lateral sclerosis (ALS). Paired-pulse inhibition (PPI) and paired-pulse facilitation (PPF) were reduced. RLZ partially restored deficient PPI in the first of 4 consecutive 3-month periods of testing, but left PPF unchanged. These findings substantiate the view that attenuation of glutamate-related excitotoxicity is an important factor contributing to the beneficial effect of RLZ in ALS.