One of the most common symptoms of cerebral palsy is muscle stiffness and resulting spastic movements. Children living with cerebral palsy often struggle with their movements to varying degrees, and may even experience pain with these spastic movements. There are many different treatment options, but no cure for the muscle difficulties of CP.
A treatment that can help many children by reducing spasticity is an injection of botulinum toxin A, often referred to simply as Botox. This is a toxic substance that is created by bacteria, and which can be used medically in a way that is safe. There are some risks, but for a child for whom spastic movements cause difficulty moving, discomfort, and pain, it can provide significant relief.
What is Botox?
Botox is the brand name for an injectable drug made from a highly toxic substance created by bacteria, botulinum toxin A. The bacterium Clostridium botulinum produces this potent neurotoxin. When ingested, it is extremely toxic and deadly. Food that has spoiled and been contaminated by this bacteria causes the illness known as botulism. It is a possibly fatal type of food poisoning.
In smaller doses, and injected locally rather than injected, botulinum toxin A can be used for cosmetic and medical reasons. The company Allergan developed Botox and got approval for it from the U.S. Food and Drug Administration (FDA) in 1989.
The FDA has approved it for a number of uses, including overactive bladder and urinary incontinence, and migraines, and a number of conditions and symptoms involving the muscles. It is also used cosmetically to smooth wrinkles and to reduce sweating.
Botox works for these medical treatments by weakening or completely paralyzing specific muscles into which it is injected, or by blocking specific nerves from firing. The paralysis or weakening effect is not permanent and eventually wears off. This action has the effect of relaxing muscles and decreasing pain, as well as other related effects. Used as a local injection Botox is not likely to cause botulism, but there are some risks and potential side effects.
Botox for Spasticity
Among the approved uses for Botox are several that relate to muscle function. It is approved to treat muscle spasticity in adults as well as dystonia of the neck, which is repetitive and abnormal muscle movement that can be painful or even debilitating. It is important to note that the FDA has not approved Botox to be used in children with lower limb spasticity, but this is exactly how it is used in some children with CP.
Because a medication is not approved for a specific use does not mean that it is banned for that use. Doctors are allowed to use professional discretion to determine if the benefits outweigh the risks. Some children benefit from Botox, specifically for spasticity in the lower body. Other uses may include injecting Botox into specific muscles, anywhere in the body, that are experiencing spasms.
Some of the benefits that these children may see from injections include better range of motion, better positions of limbs and joints, fewer spastic movements, less pain, and a better walking gait. The relief it provides also means that surgery to correct muscle and joint problems may be delayed until the child is older and there are fewer risks.
How Botox is Administered
Botox is administered by injecting the medication directly into the location it is needed. This can be done in a doctor’s office on an outpatient basis. To minimize a child’s discomfort with getting a shot, the area to be injected can be first sprayed with a numbing substance.
The area will also be disinfected first to ensure that infection is avoided. The treatment may include one or more injections depending on the size of the muscle group being treated and the severity of symptoms.
Possible Side Effects
Localized injections of Botox do help some children feel better and move better, but Botox is not without its risks. The packaging in formation for the medication specifically states that it is not known whether these injections are useful or safe for treating lower limb muscle stiffness. This is a statement that is required since there have been no clinical trials for this particular use of the medication and the FDA has not approved it for spasticity in children.
The FDA has also required that Botox packaging include a special black box warning. This is the type of warning that is reserved for the most serious and potentially life-threatening possible side effects of a drug. For Botox that warning states that it is possible that the toxin will spread beyond the injection site and cause symptoms of botulism.
In cases in which this has been reported the symptoms occurred anywhere between a couple of hours and a couple weeks after the injection. This effect can lead to death and the risk is greatest in children being treated for spasticity.
The warning should be taken seriously, but the risk is not high that a child will develop botulism or die from a localized injection of Botox. There are some more common and less serious side effects, though. These include general weakness, weakness in the limb injected with Botox, pain at the injection site, and infection at the injection site.
Long-Term Potential
An injection of Botox is not currently considered a permanent solution for muscle spasticity in children with CP. The effects of a Botox injection—no matter what the use—is temporary. How long it lasts depends on the individual, the amount injected, and the purpose of the injection. Studies have, however, looked into whether or not these injections could improve a child’s muscle tone and movement over time.
In one study the researchers concluded that multiple injections over a period of two years did have some positive long-term effects. Muscle tone and gross motor function were measured in these children before any injections, and nearly two years later after the repeated injections.
The muscle tone did not seem to change over the time period, but the researchers saw improvements in gross motor function. In other words, the children still had high tonicity, but were better able to move.
Botox injections have the potential to help a child struggling with spastic muscle movements because of CP. There are risks and the potential for side effects, not to mention the potential for a life-threatening infection. Parents, along with doctors, must decide if the risks are worth the benefits that the child will receive in terms of movement, comfort, and pain relief.