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The effect of botulinum toxin A on gastrocnemius length: magnitude and duration of response

N W Eames1, R Baker, N Hill

  • 1The Gait Analysis Laboratory, Musgrave Park Hospital, Belfast, N Ireland.

Developmental Medicine and Child Neurology
|June 4, 1999
PubMed

Insights

Botulinum toxin A injections for spastic cerebral palsy in children effectively reduced spasticity, with hemiplegia cases showing longer-lasting effects. These treatments may help delay the need for surgery by managing muscle shortening.

Area of Science:

  • Pediatric Neurology
  • Rehabilitation Medicine
  • Movement Disorders

Background:

  • Spastic cerebral palsy (CP) often involves gastrocnemius muscle spasticity.
  • Botulinum toxin A injections are used to manage spasticity in children with CP.

Purpose of the Study:

  • To prospectively evaluate the efficacy of botulinum toxin A injections in the gastrocnemius muscle.
  • To correlate spasticity components with treatment response and duration.
  • To compare outcomes between children with hemiplegia and diplegia.

Main Methods:

  • Prospective study of 39 ambulant children with spastic CP (hemiplegia and diplegia).
  • Gastrocnemius muscle length measurement to assess spasticity and response to botulinum toxin A.
  • Analysis of correlation between dynamic spasticity, response magnitude, and duration.

Main Results:

  • Strong correlation found between pre-injection dynamic spasticity and post-injection response magnitude.
  • Duration of response strongly correlated with the dynamic component of spasticity.
  • Children with hemiplegia experienced twice the duration of response compared to diplegia for the same dose.
  • No long-term muscle lengthening observed, but some responses persisted at 12 months.

Conclusions:

  • Botulinum toxin A injections are effective in managing dynamic spasticity in children with CP.
  • Injections may delay the need for surgical intervention by managing muscle shortening.
  • Treatment is well-tolerated with minimal side effects.

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