[Botulinum A in the treatment of equinus dynamic spasticity in children with cerebral palsy. Preliminary study]

The purpose of this clinical prospective study is to better assess the efficacy of intramuscular injections of botulinum-A toxin in the treatment of spastic dynamic equinus deformities in children with cerebral palsy.

Ten walking children (14 feet) with cerebral palsy were treated with botulinum-A toxin (the American type, Botox) for spastic dynamic equinus, equinovalgus or equinovarus deformity of the foot. The mean age was 6 years (range 4 to 12 years of age).

Two units of botulinum-A toxin per kilogram were injected in each involved extremity: the lateral and medial gastrocnemius were injected in equinus or equinovalgus foot and one more injection was done in the tibialis posterior in equinovarus foot. A clinical assessment (based on opinion of caretakers, functional evaluation of gait, detailed orthopaedic clinical evaluation and video of the gait) and a gait analysis were performed prior to the first injections and then at 1, 3 and 6 months afterwards.

All patients showed a clinical improvement. The functional possibilities increased in 6 out of the 10 children. Five children showed a better endurance in their walking capacities. The clinical orthopaedic exam showed improvement for 10 out of the 14 injected feet in passive dorsiflexion from 3 to 15 degrees at one month. Twelve feet improved their score on the Physician Rating Scale from 1 to 4 points. For gait analysis, 6 children (8 feet) had an improvement often minor of their curves in terms of improvement of the dorsal flexion of the ankle and the EMG of the gastrocnemius was improved in terms of decrease of spastic activity in 7 children (10 feet). The response to the injections was seen within 10 days (3 to 10 days) and lasted 3 to 6 months except in one child where it stopped already after 1 month. No side effect was noted.

All ten patients of our study showed some type of improvement even if only minor or limited in time in some of them. These data corroborate previous studies performed by other authors. Since this study, the recommended dosage has greatly increased (from 2 U/kg up to 10 U/kg or even more). The most interesting new element is that we noted that it seems to increase the endurance of the patient regarding walking distance.

The intramuscular injection of botulinum-A toxin in spastic dynamic equinus deformities in children with cerebral palsy is an useful treatment modality, but the indications have to be respected scrupulously. The subject needs more study with the higher dosage and clinical evaluation to confirm the possible increased endurance.