In a session dedicated to neonate, infant and paediatric interventional radiology (IR), Hisham Alshehri (King Abdulaziz University, Jeddah, Saudi Arabia) gave a talk at the Pan Arab Interventional Radiology (PAIRS) annual congress (10–13 February, 2024, Dubai, United Arab Emirates) on the wide range of conditions that botulinum toxins (Botox) can treat.
First, explaining its mechanism of action, Alshehri detailed that Botox works by blocking the release of acetylcholine at the level of the neuromuscular junction, resulting in the relaxation of local muscles within two weeks of treatment. The injection effects typically last between three to six months.
The speaker detailed however that interventional radiologists should act with “careful consideration” when deciding dose for paediatric patients. “Botox affects children in a different way when compared with adults,” Alshehri explained, using hypertonia—a condition in which there is too much muscle tone which stiffens the arms, legs or neck, making them difficult to move—as an example. For patients with this condition, the underlying hypertonic disorder is superimposed onto two unique processes of childhood growth and development in contrast to adults.
Looking at appropriate dosage for paediatric patients, Alshehri noted that the total maximum body dose per visit must not exceed 12 units per kg or 400 units total, and the maximum volume per site should not exceed 0.5ml, except for certain cases that may require more.
Alshehri then discussed the niche indications that have shown to benefit from Botox treatment, such as upper and lower limb spasticity in children with cerebral palsy, congenital muscular torticollis, sialorrhea and brachial plexus palsy. The toxin can be used in all ages, but early research carried out by Barry Rawicki (Monash Medical Centre, Clayton, Australia) et al suggests a better response in children younger than eight years old.
Then, drawing the PAIRS 2024 audience’s attention to the current safety status of Botox treatment in paediatric patients, Alshehri detailed that serious side effects have been observed to date. These can include fever, muscle weakness, swallowing and respiratory difficulties, seizures, or death. Between 2006 and 2018 the US Food and Drug Administration (FDA) Adverse Event Reporting System recorded 51 cases of adverse reactions associated with Botox injections to children 17 years of age and younger.
However, he added that research in this area is still in its infancy. A meta-analysis carried out by Jean- Sébastien Bourseul et al found that, in 437 children who received Botox injections for musculoskeletal conditions, no severe side effects were reported. In another study by the same author, they found that in 74 infants younger than two years old who received Botox for spasticity, there was a 3.6% incidence of mild side effects in patients younger than one year and a 6.5% incidence in infants between one and two years old.
Surveying these results, Alshehri pointed out that there is no international consensus for the use of Botox in paediatric patients younger than two years of age. Due to the safety and effectiveness of this treatment however, Botox can be used off-label as an adjuvant to physical therapy and surgery in moderate to severe cases.
He concluded that many of these musculoskeletal conditions come with permanent sequelae causing a “high level” of disability. Botox for the treatment of these paediatric patients offers a minimally invasive means of providing relief and preventing long-term disability. Concluding, he asserted that interventional radiologists should use tools such as ultrasound to increase the effectiveness and accuracy of Botox treatments, to crucially minimise adverse events.
