Botulinum toxin A in the management of focal muscle overactivity in children with cerebral palsy.

Cerebral palsy comprises a heterogenous group of neurological disorders representing a continuum of pathologies and clinical phenotypes. Although cerebral palsy is not a focal disorder, it is appropriate to treat identified focal problems as long as the intervention is goal directed. This paper reviews principles of managing muscle imbalance in the growing, changing child using a range of complementary, carefully timed intervention options. Over the past two decades these options have increasingly included intramuscular injection of botulinum toxin-A to manage focal spasticity and dystonia. The predictable movement patterns and postures characteristic of spasticity enable a systematic clinical rationale to be developed to determine the role of botulinum toxin-A to manage the spasticity and subsequently improve function. The management of dystonia with botulinum toxin-A is more complex, particularly when spasticity and dystonia are present in combination. An active therapy programme remains central to the management of movement problems in the child with cerebral palsy, including task-specific motor training, maintenance of muscle lengths, and improved muscle strength, aiming to achieve carry over improvements that persist beyond the pharmacological effects of the botulinum toxin-A. A series of case examples are presented to highlight the role of botulinum toxin-A in the overall management of the child with focal muscle hyperactivity.