Koman LA, Mooney JF 3d, Smith BP, Walker F,
Leon JM, the BOTOX Study Group. Botulinum toxin type A neuromuscular
blockade in the treatment of lower extremity spasticity in cerebral
palsy: a randomized, double-blind,
placebo-controlled trial. J Pediatr Orthop. 2000 Jan-Feb;20:108-15.
Question: In children with cerebral palsy and dynamic
equinus foot deformity, is neuromuscular blockade with botulinum
toxin type A (BTX) effective and safe for improving ankle function?
Design: Randomized (unclear allocation concealment),
double-blind, placebo-controlled trial with 12-week follow-up.
Setting: Clinical centers in the United States,
Canada, and Spain.
Patients: 114 children (60% boys) who were 2 to
16 years of age, were hemiplegic or diplegic, and had spasticity
of 1 or both lower limbs with equinus positioning of the foot during
the stance phase of gait. Exclusion criteria included evidence of
fixed contracture; severe athetoid movements in the target leg(s);
a substantial length difference (>5 cm) between legs; obvious atrophy
of the calf muscles of the target leg(s); current need for surgery;
previous surgery of the foot, leg, or ankle; previous injections
of phenol or alcohol into the muscles to be injected in the study;
or previous or current use of BTX. 108 children completed the study.
Intervention: Children were allocated to BTX, 4
U/kg of body weight, in a 4-mL solution for hemiplegic children
or in an 8-mL solution for diplegic children (n =
56), or to placebo (n = 58). A second injection
was given at week 4, unless medical contraindications existed (i.e., excessive
weakness, gross muscle atrophy, or development of a fixed contracture
of the injected muscles).
Main outcome measures: Dynamic gait pattern during
active walking (Physician Rating Scale [PRS] total and component
scores), passive and active ankle range of motion (measured with
a goniometer), adverse events, and antibodies to BTX.
Results: More children in the BTX group than in
the placebo group improved by 2 grades on the PRS composite scores
at week 2 (P = 0.007), week 4 (P =
0.028), week 8 (P < 0.001) (Table), and week
12 (P = 0.022). Children in the BTX group had greater
improvement than did patients in the placebo group on component
PRS scores for gait pattern (P £ 0.012 for all
assessments except at week 4) and ankle position at foot strike
(P £ 0.012 for all assessments). Active ankle dorsiflexion
was greater in the BTX group (mean increase from baseline ranged from
3° at week 2 to 7° at week 12) than in the placebo group at weeks
4 and 12 (P < 0.05). Passive ankle dorsiflexion
did not differ between groups. More children in the BTX group than
in the placebo group had adverse effects (17% vs 4%, P =
0.013), but no patient withdrew from the study because of adverse
effects. Antibodies to BTX were not detected in any patient's blood
sample at baseline or at week 12.
Conclusion: In children with cerebral palsy and
dynamic equinus foot deformity, botulinum toxin type A was effective
for improving gait function and ankle range of motion.