A study of thyrotropin-releasing hormone for the treatment of spinal muscular atrophy - A preliminary report

Objective: To determine whether thyrotropin-releasing hormone (TRH) can inc rease muscle strength in children with spinal muscular atrophy types 2 and 3. Design: A randomized, double-blinded, controlled, 5-wk drug trial of six su bjects and three controls. Subjects and controls ranged from 4 to 8 yr of a ge and were randomly assigned to treatment and placebo groups in a ratio of 2:1. TRH (protirelin) or placebo was delivered intravenously through percu taneous intravenous catheters at a dose of 0.1 mg/kg (in 50 ml of normal sa line) for a total of 29 days. Patients were evaluated using electromyograph y and handheld dynamometry of the deltoids, biceps, triceps, wrist extensor s, hip flexors, quadriceps, hamstrings, and grip strength before and immedi ately after 5 wk of treatment. A unidirectional 5 test was used to compare mean values. Results: Dynamometry improved significantly only for the six treated subjec ts (P < 0.02). Peroneal nerve conduction velocities were significantly fast er in the treatment group (paired t test, P = 0.036). The parents of the tr eated children also provided anecdotal evidence of improvements in function . Improvements lasted 6-12 mo. Conclusions: TRH may be a useful treatment for spinal muscular atrophy. A l arger, crossover design group comparison study is warranted.