Chronic treatment with l-threonine in amyotrophic lateral sclerosis: a pilot study

Thirty patients suffering from amyotrophic lateral sclerosis were included in an open therapeutical trial. They were randomized to receive either l-threonine (Thr), a precursor of the inhibitory amino acid glycine, or vitamin B or carnitine. Thirteen patients (9 patients on Thr and 4 control subjects) completed the 1-year trial. No statistical differences were observed between the treated group and the control patients in the decline of the clinical assessment score. Nevertheless, Thr-treated patients complained less frequently of respiratory failure than the control group despite bulbar involvement being more common in the Thr group at entry.