30 subjects--23 with amyotrophic lateral sclerosis (ALS), 4 with Charcot-Marie Tooth atrophy, 2 with progressive spinal muscle atrophy and 1 with radiation myelopathy--were given chronic low-dose TRH therapy. The effects of treatment were assessed on the scale of Norris et al. (1974). The outcome of the study, in agreement with some and at variance with other studies, was that TRH induced a statistically significant neurological improvement in 17 of the 23 ALS patients but little or none in the other ALS patients and in patients with other neurological diseases.