Changes in Muscle Mass after Botulinum Toxin Injection in Children with Spastic Hemiplegic Cerebral Palsy

Area of Science:

• Pediatrics
• Neurology
• Rehabilitation Medicine

Background:

• Spastic hemiplegic cerebral palsy (CP) affects children, often involving lower limb spasticity.
• Botulinum toxin (BoNT) injections are used to manage spasticity in CP.
• Understanding the impact of BoNT on muscle mass is crucial for treatment efficacy.

Purpose of the Study:

• To evaluate changes in lean body mass (LBM) in children with hemiplegic CP after BoNT injection.
• To assess the temporal effects of BoNT on the affected limb's muscle mass.

Main Methods:

• Prospective study of 15 children (2-12 years) with hemiplegic CP and spastic equinus foot.
• BoNT administered to the affected leg.
• Lean body mass (LBM) of both legs and total limbs measured using dual-energy X-ray absorptiometry (DXA) at baseline, 4 weeks, and 12 weeks post-injection.

Main Results:

• Overall LBM of both legs and total limbs increased significantly over 12 weeks, reflecting normal growth.
• The ratio of affected leg LBM to total limbs and unaffected leg LBM decreased significantly at 4 weeks post-injection.
• This ratio significantly increased at 12 weeks compared to 4 weeks, indicating muscle mass recovery.

Conclusions:

• BoNT injection in the affected leg of children with hemiplegic spastic CP leads to a temporary decrease in muscle mass at 4 weeks.
• Muscle mass in the affected leg shows significant recovery by 12 weeks after BoNT injection.
• These findings highlight the dynamic changes in muscle mass following BoNT treatment in pediatric CP.