Article

With evidence for an atrophic effect of botulinum toxin type A (BoNT-A)
documented in typically developing muscles, this study investigated the immediate
morphological alterations of muscles in children with cerebral palsy (CP) after
BoNT-A treatment. METHOD: Fifteen children (10 males, five females; age range
5-11y, mean age 8y 5mo, SD 1y 10mo) with spastic diplegic CP [Gross Motor
Function Classification System Levels I (n=9) and II (n=6)] receiving BoNT-A
injections for spasticity management were included. None of the children was a
first-time receiver of BoNT-A. Magnetic resonance imaging and Mimics software
assessed muscle volume, timed 2 weeks before and 5 weeks after injection. All
participants received BoNT-A bilaterally to the gastrocnemius muscle, and five
participants also received BoNT-A bilaterally to the medial hamstring muscles.
Functional assessment measures used were the 6-Minute Walk Test (6-MWT), the
Timed Up and Go (TUG) test, and hand-held dynamometry. RESULTS: Whilst total
muscle group volume of the injected muscle group remained unchanged, a 4.47%
decrease in the injected gastrocnemius muscle volume (p=0.01) and a 3.96%
increase in soleus muscle volume (p=0.02) was evident following BoNT-A. There
were no statistically significant changes in function after BoNT-A as assessed by
the TUG. There was also no statistically significant change in distance covered
in the 6-MWT. Muscle strength, as assessed using hand-held dynamometry was also
not statistically different after BoNT-A treatment. INTERPRETATION: Muscle volume
decreases were observed in the injected muscle (gastrocnemius), with synergistic
muscle hypertrophy that appeared to compensate for this decrement. The 4% to 5%
decrease in the volume of BoNT-A injected muscles are not dramatic in comparison
to reports in recent animal studies, and are a positive indication for BoNT-A,
particularly as it also did not negatively alter function.
CI - (c) 2013 Mac Keith Press.

Langue : ANGLAIS