Use of botulinum toxin type A in children with cerebral palsy.

Cerebral palsy is one of the most common causes of activity limitation in children. The central nervous system (CNS) lesion causing the disorder of posture and movement is nonprogressive, but the manifestations of the lesion may change over time. Children with cerebral palsy may display a range of movement disorders, alone or in combination, including dystonia, athetosis, ataxia, and spasticity.(1) Spasticity is a complex phenomenon and has been defined as "a motor disorder characterized by a velocity-dependent increase in tonic stretch reflexes (muscle tone) with exaggerated tendon jerks, resulting from hyperexcitability of the stretch reflex, as one component of the upper motoneuron syndrome."(2(p485)) Spasticity can be associated with co-contraction, clonus, and hyperreflexia. Children with spastic cerebral palsy generally have a typical pattern of muscle weakness, impairment in selective motor control, and sensory impairment, in addition to spasticity.(1) In some centers, traditional management for children with spastic cerebral palsy has included physical therapy interventions and use of orthotic devices, with the goal of postponing orthopedic Surgery until the child is older (eg, after age 6 years).(3) These interventions aim to optimize function and strive to delay or treat deformity resulting from spasticity, but they do not effect any sustainable change in the amount of spasticity.