Despite the efforts of many workers, the cause and therapy has not been 
clarified. We carried out the therapeutic trial of thyrotropin releasing hormone 
(TRH) for amyotrophic lateral sclerosis (ALS) from January, 1979 to January, 
1983. There were 16 subjects. The patients were given a low dose (0.5-2 mg) of 
TRH intravenously or intramusculary. Mild to moderate improvement was found in 9 
(56%) of 16 patients. TRH has been reported to have the activating effects on 
the pyramidal tract, brainstem motor nuclei, and motoneuron in the spinal cord 
as a neurotransmitter or neuromodulator. We thought such action of TRH to be 
useful to the therapy of ALS.