Effect on weakness and spasticity in amyotrophic lateral sclerosis of thyrotropin-releasing hormone.

Very high intravenous doses (2-19 mg/min) of thyrotropin-releasing hormone (TRH, L-pyroglutamyl-L-histidyl-L-prolinamide) given to 12 patients with amyotrophic lateral sclerosis (ALS) produced a moderate to marked improvement of functions caused by deficiency of lower motor neurons (weakness) and upper motor neurons (spasticity). The improvement was sustained throughout the infusion and for about 1 h thereafter; sometimes a slight improvement was evident 20 h after infusion. At a given dose benefits and side-effects were more evident in men than in women. Whether TRH is replacing an ALS-associated deficiency or is simply a symptomatic treatment is unknown. The results of this study raise the possibility of a treatment for ALS, and may provide new insight into its pathogenesis. The potential response to TRH of spasticity and/or lower motor neuron involvement of other causes is proposed.