Randomized trial of botulinum toxin to prevent pes cavus progression in pediatric Charcot-Marie-Tooth disease type 1A.

Pes cavus in Charcot-Marie-Tooth disease type 1A (CMT1A) is thought to be due to muscle imbalance of the lower leg. Botulinum toxin type A (BoNT-A) can modify foot deformity in other conditions of muscle imbalance. We tested the safety and effectiveness of BoNT-A on pes cavus progression in pediatric CMT1A. A 24-month, randomized, single-blind trial of BoNT-A was undertaken in 10 affected children (20 legs), aged 3-14 years. The treated leg received intramuscular BoNT-A injections at 6-month intervals in the tibialis posterior and peroneus longus. The control leg received no injections. Primary outcome was radiographic alignment at 24 months. Secondary outcomes were foot posture, ankle flexibility, and strength, assessed every 6 months. Radiographically, BoNT-A produced a small non-significant reduction in cavus progression. There was no effect of BoNT-A on secondary outcomes. There were no serious adverse events. At 24 months, the intramuscular BoNT-A injections proved safe and well-tolerated but did not affect the progression of pes cavus in CMT1A.