Medium‐term response characterisation and risk factor analysis of botulinum toxin type A in the management of spasticity in children with cerebral palsy

We prospectively studied the medium‐term effects of botulinum toxin type A (BTX‐A) treatment in 197 children with cerebral palsy. Between one and four target muscles were selected according to functional goals and biomechanical assessments, and were injected at multiple sites with BTX‐A (BOTOX®). The mean total dose administered was 10.5 U BOTOX®/Vkg body weight. In 37% of treatment episodes, children were safely treated with high doses, 12–16 Ukg body weight. Significant improvements were seen in the Modified Ashworth and Tardieu scales at 3 and 12 weeks post‐injection, and in muscle length, as determined by joint range of motion, at 3,12 and 24 weeks post‐treatment. Significant improvements in gait were noted using the Modified Physicians' Rating Scale, and joint kinematics and kinetics. Forty‐five per cent of children were subsequently managed by repeated BTX‐A injections, 17% proceeded to single‐level soft tissue surgery and 38% proceeded to multi‐level surgery after mean intervals of 12.8, 16.4 and 173 months, respectively. Side effects were noted in 10 children (6.2% of total treatment occasions) and included local pain (1.2%), bruising (0.7%), temporary generalised weakness (0.3%), temporary incontinence (1.2%) and pneumonia (1.2%). In summary, BTX‐A was safe and effective in the management of spasticity in children with cerebral palsy. Side effects were infrequent, usually minor and self‐limiting.