RESUMEN
The efficacy of local injection of botulinum toxin A in selected skeletal muscles to relieve muscle hypertonia and muscle contracture, and increase range of motion in children with cerebral palsy was studied in an open ABA (baseline-treatment-posttreatment phase) type of study. The first 6 months were the baseline phase, the day of injection the treatment phase, and the next 6 months the posttreatment phase. The patients acted as their own controls. Fifteen children with cerebral palsy (mean age: 6 years, 8 months) were included in the study. All had limb deformities associated with non-fixed joint contractures that had not responded to physical therapy. Clinical assessment of passive and active muscle tone was performed using a modified Ashworth scale. The range of motion to passive movement was measured with a manual goniometer. Botulinum toxin was injected directly into the muscle at several sites. The postinjection scores of muscle hypertonia were significantly lower (P < .01) and the range-of-motion values demonstrated a significant increase (P < .001). Functional improvement was measured by decreased scissoring on standing in all 6 children with adductor muscles injected; all 6 children with knee flexor muscles injected were able to straighten the knees. The 3 children with injected gastrocnemius muscles were able to achieve heel-strike while bare-footed. The study provides evidence that the intramuscular injection of botulinum toxin A in selected skeletal muscles decreases muscle tone and contractures, and increases range of motion and motor function.