RESUMEN
AIM: To assess the effect of single botulinum neurotoxin A (BoNT-A) injections into the calf muscles on the gross energy cost of walking in children with cerebral palsy (CP) and to evaluate the effect of BoNT-A on walking capacity, physical activity, perceived changes in mobility, and pain. METHOD: This was an industry-independent, randomized, quadruple-blind, placebo-controlled, multicentre trial (ClinicalTrials.gov registration: NCT02546999). Sixty-one children (33 male, median age [range] = 8 years [4-16 years]) with spastic CP and classified in Gross Motor Function Classification System (GMFCS) levels I and II allocated to single injections of either BoNT-A or 0.9% saline into the calf muscles. The main outcome was gross energy cost (J/kg/m); secondary outcomes were walking capacity, habitual physical activity, perceived change in mobility tasks, and calf pain at baseline, 4 weeks (P1), 12 weeks (P2), and 24 weeks (P3) after the injection. RESULTS: The mean change in energy cost did not differ significantly between groups at the primary time point P2 (-0.27 J/kg/m, 95% confidence interval - 0.91 to 0.36, p = 0.404), nor at P1 or P3. Regarding the secondary outcomes, there was some evidence of a larger reduction in pain intensity in the group given BoNT-A (p = 0.043). INTERPRETATION: One treatment with BoNT-A was not superior to placebo in making walking easier in children with CP classified in GMFCS levels I and II, at least in the short term. BoNT-A may have a pain-reducing effect.