Botulinum toxin type A injections for treatment of spastic equinus in cerebral palsy: a secondary analysis of factors predictive of favorable response.

OBJECTIVE: To investigate markers predicting favorable botulinum toxin injection outcomes in treating spastic equinus gait in children with cerebral palsy.
DESIGN: Thirty-six children (21 boys and 15 girls, aged 1.5-9.6 yrs; 20 with unilateral and 16 with bilateral cerebral palsy levels I to IV with the Gross Motor Function Classification System) with 49 treated lower limbs were included. Passive range of movement, selective dorsiflexion, dynamic muscle length (modified Tardieu Scale), calf tone (modified Ashworth Scale), attainment of anticipated gait pattern (Goal Attainment Scale), and video gait analysis (Observational Gait Scale) were assessed before and 1, 2, and 4 mos after intervention. Participants were classified as poor or good responders, according to the Goal Attainment Scale response at 2 mos.
RESULTS: Good response was noted in 23 (64%) children and 29 (59%) legs, whereas 13 (36%) children and 20 (41%) legs were defined as poor responders. In a multivariate regression analysis, the best predictors of good response per child were higher initial Observational Gait Scale total scores, one-level treatment, and normal cognition; and the best predictors per leg were good initial selective motor control in the ankle and capability of occasional flatfoot contact at pretreatment.
CONCLUSIONS: These results suggest that children with less severe functional deficit, fair to good selective motor control in the ankle, and mild equinus gait respond best to focal botulinum toxin type A treatment, with an eye to flatfoot or heel strike contact. Likewise, children with higher cognitive level seem to derive functional benefit from the treatment.