How the Botulinum Toxin has shaped the treatment of Spasticity over the years in Children
Prof. S.I. Pascual Pascual, Madrid.
Botulinum toxin type A (BoNT-A) is being used in paediatric age since early 90´s. The most usual indication is the spasticity due to cerebral palsy, but there are other multiple indications. Not only spasticity but other hyperkinetic movement disorders, as dystonia, rigidity, dyskinesia, stereotyped movements and tremor can improve with BoNT-A.
Cerebral palsy is the most common movement disorder in children.
The consequences of the movement disorders in paediatric ages are bone deformities and joint limitation because of the body growth. Prevention of the fixed deformities needs a different procedure of infiltrations than those in adult pathology. Early intervention, dosage and complementary treatments and managements are essential. With appropriate approach we can change the natural evolution of CP giving the child more chances to achieve better activity and social participation.
Many randomized control trials (RCT) have proved the efficacy of BoNT-A in spasticity in the short term. In fact, it is the treatment with the strongest recommendation for it (level I). Several RCT have proved the efficacy on spasticity in the long term. There are few evidence-based data are on the effectiveness in other domains of the International Classification on Functioning, particularly on activity and participation, although many clinical data indicate thatBoNT-A changes the global evolution of cerebral palsy. Recent RCT have demonstrate improvement in function measured with GAS scale. It has to be used combined with physical and occupational therapies in order to get the best results and to reduce the number of surgical acts in the growth period of life.
Safety of BoNT-A has been extensively studied, since reports of adverse events. Few cases of severe adverse events have been reported. 20 RCT about safety have documented the good profile of safety at short and long term. The majority of reported adverse events are described as localized and minor. The incidence of any adverse events of BT-A is 6.2% to 10%, and it is more frequent with BoNT-B. The data of safety in infants younger than two years of age are similar to that of children.
Some reports indicated than adverse events were more frequent in more severe cerebral palsy (GMFCS levels IV and V), recommending to decrease the doses in these children, but recent RCTs indicate there is no difference of adverse events according the severity of cerebral palsy. Other factors can play a role on safety, as are sedation, the dose of by session of BoNT-A and the procedure in injection.