Spasticity occurs when there is damage to areas of the brain involved in movement and posture and results in the muscles becoming stiff and difficult to move voluntarily. Spasticity can occur in a variety of conditions including cerebral palsy, acquired brain injury (ABI), spinal cord injury (SCI), genetic and metabolic conditions.
Spasticity can lead to difficulties with day to day activities such as nappy changes, dressing, sitting, walking, reaching for and grasping objects. Spasticity contributes to the development of contracture (muscle shortening) and joint instability.
Spasticity is usually accompanied by variable amounts of weakness and poor muscle coordination. Therefore decreasing spasticity does not necessarily improve a child’s functional abilities. It is therefore important to have a complete review from a specialist in movement disorders before determining whether a child is suitable for Botulinum Toxin-A therapy (BoNT-A).
Using BoNT-A to treat spasticity
Botulinum Toxin A (BoNT-A) is commonly known by its brand names ‘Botox’ and ‘Dysport’.
It is a treatment widely used for spasticity management. BoNT-A is a purified component of botulinum toxin which is formed from clostridium botulinum, a bacteria found in the environment.
BoNT-A is approved by the Therapeutic Drugs Association for use in children with cerebral palsy who walk on their toes as well as moderate to severe spasticity of the upper limbs in cerebral palsy patients. The Queensland Paediatric Rehabilitation Service also funds treatment for children with spasticity that affects ability to sit, stand and in other instances where spasticity causes discomfort or limits the ability to easily care for a child.
A large number of trials have been performed to determine the effects and safety of BoNT-A.
Adverse effects are uncommon. If they occur, they tend to be within the first week or two following injection and are temporary.
The most commonly reported adverse effects are:
- Temporary local weakness of the muscle/s injected (2–3% of children). The child may find that their balance is affected and this can initially lead to an increase in falls. Caution should therefore be taken when resuming normal activities
- Generalized weakness can occur but is less common (2-3%).
- A fever or flu-like illness (3%)
- Temporary pain, local irritation or bruising at the injection site
- Temporary loss of bladder or bowel control has been reported with injections into the muscles around the hip (1%)
- Difficulty swallowing is a commonly reported side effect of injection into the muscles around the neck (commonly used for adults) and has been occasionally reported after injections at other sites.
- There have been rare reports of rash, skin irritation and allergic reaction (less than 1%)
- There have been extremely rare reports of death, usually associated with other significant debility, following injection of BoNT-A.
- This product contains albumin, a derivative of human blood. Based on effective donor screening and product manufacturing processes, it carries an extremely remote risk for transmission of viral diseases.
Risk of resistance to the effects of BoNT-A
The literature suggests a small number of children do not respond to BoNT-A, or only have a short period of reduction in spasticity. The cause for lack of response in those cases is not fully understood.
The dosage and frequency of re-injection are felt to be two important factors affecting antibody formation (antibodies are associated with attaining immunity). Our practice is to maintain injecting periods with a minimum of six months between subsequent injections to reduce the likelihood of antibody formation.
What to expect
Your child may be referred to the Queensland Paediatric Rehabilitation Service by their GP or paediatrician. They are then assessed by a rehabilitation paediatrician and therapist to determine whether BoNT-A treatment is appropriate. If so, your child will be booked to a BoNT-A injecting list. These occur every week at the LCCH either on the medical day unit, the main operating theatres or at QPRS.
Your child will be given appointments to be reviewed by the rehabilitation paediatrician and nurse on the morning of their injections. This review is to ensure your child is medically fit to undergo the procedure and to review the dose and choice of muscles to be injected. If your child is able to walk, they may be required to attend QPRS for video analysis of their walking. Your child may also be reviewed by a physiotherapist, occupational therapist and orthotist, dependent on the goals of your child’s injections.
Following these appointments, your child will then be admitted to either the Medical Day Unit or the Surgical Day Unit at the Queensland Children’s Hospital.
The injection is given into the muscle. Depending on how many muscles are to be injected, the treatment goal and your child’s preference, we offer several treatment options. Some children will be able to have injections as an outpatient with a local anaesthetic (cream or cooling device to the skin), others will require an oral or intranasal sedation and local anaesthetic; or laughing gas with local anaesthetic. Some children will require short general anaesthesia which will take place in the operating theatre. Your doctor will discuss the sedation options for your child with you when planning for injections.
Follow-up will occur 2-3 months post injections. Assessment will take place to determine your child’s response to BoNT-A. This may include a review of your goals, musculoskeletal assessment and a repeat video analysis of walking or upper limb skills. A decision will then be made regarding ongoing treatment options.
Follow-up after injections
BoNT-A injections should be combined with an occupational therapy or physiotherapy program, or both.
To maintain the length of muscles and correct joint position, serial casting, splinting or orthoses may be prescribed for your child. We will facilitate provision of therapy and casting services for your child.
Queensland Paediatric Rehabilitation Service
Queensland Children’s Hospital
Level 6, 501 Stanley Street, South Brisbane 4101
t: 07 3068 2950
t: 07 3068 1111 (general enquiries)
f: 07 3068 3909
In an emergency, always call 000.
If it’s not an emergency but you have any concerns, contact 13 Health (13 43 2584). Qualified staff will give you advice on who to talk to and how quickly you should do it. You can phone 24 hours a day, seven days a week.