Intrathecal thyrotropin-releasing hormone does not alter the progressive course of ALS: experience with an intrathecal drug delivery system

Abstract

Evidence that thyrotropin-releasing hormone (TRH) has prominent trophic effects on the motor system led to several negative therapeutic trials in amyotrophic lateral sclerosis, a disease of the motor system. Since TRH crosses the blood-brain barrier poorly, if at all, we postulated that the negative parenteral clinical trials could be a result of insufficient drug-receptor interaction. We thus carried out a blinded, placebo-controlled, crossover study of intrathecal TRH in 36 patients by delivery through an implanted, constant infusion pump achieving a steady-state CSF level comparable with that shown to be effective in tissue culture experiments. Utilizing a quantitative measurement technique to assess motor unit loss, we did not observe any alteration of the progressive course during 6 months on TRH and 6 months on saline placebo. However, the implanted pump delivery system proved to be safe, reliable, and well tolerated.