Use of Botulinum Toxin A in Cerebral Palsy

Abstract

Botulinum toxin A (BTX-A) is widely used worldwide to overcome the significant problem in spastic cerebral palsy (CP). In the past three decades, botulinum toxin serotype A (BTX-A) has been introduced as a selective treatment option for spasticity in children with cerebral palsy. BTX-A is an acetylcholine-blocking agent that causes presynaptic neuromuscular blocking when injected into the muscle. Its action of decreasing or nor-malization of tone prevent the development of contractures and deformities and avoid or postponed surgical intervention particularly when combined with other treatment modalities such as physiotherapy, casting, orthosis, etc. Equinus deformity, scissoring and crouch gait in the lower limbs, and different spastic deformities like pronation of forearm, elbow flexion, wrist flexion, fisting, or abnormal dystonic posture of upper limb deformities were the main indications wherein botulinum toxin injection is needed in spastic cerebral palsy; moreover, its benefit of relieving pain that are associated with muscular hypertonia and palpation of the muscle, particularly the large one, remains the cornerstone for injection of BTX in CP patient for most experts worldwide, but it needs a well of knowledge in anatomy and its landmark. Invasive procedure like electromy-ography (EMG) is more difficult to be applied successfully in children than in adults. Spasticity is considered a positive phase of muscle function. Therefore, when relaxing the muscle, the patient's condition might get worse functionally in some instance. So, the first question clinician put in his account before injecting BTX is whether hypertonia is impeding or improving function; therefore, injection is tailored individually by an expert physician. Generally, the adverse side effects of BTX-A are seldom to occur providing that the physician strictly adheres to the dose ranges and reinjection period. The inter-injection period must be at least 12 weeks to avoid antibodies ands. So far, BTX-A is considered to be safe to some extent if used professionally; however, long-term adverse effect particularly with multilevel therapy are still not clear.