Research Paper on the Effect of Botox Injections on Children with Cerebral Palsy

Research Paper on the Effect of Botox Injections on Children with Cerebral Palsy

A lot of research has been done in regards to the effect of using Botulinum Toxin Type A, also known as Botox, injections in children with cerebral palsy. During my internship, I have seen several patients that have received these injections and have seen improvements in their mobility, which allows the physical and occupational therapists to get better, more full range of motion out of them during their sessions. I wanted to know why Botox injections make such an improvement and if they work in most populations.

Cerebral palsy is “characterized by aberrant control of movement or posture of a patient, appearing early in life (secondary to a central nervous system lesion, damage, or dysfunction), and not the result of a recognized progressive or degenerative brain disease” (Russman, Tilton, and Gormley S181). Cerebral palsy is often recognized early on by the child’s inability to achieve early motor skill milestones. Along with not achieving or having a delay in the normal motor milestones, children with cerebral palsy tend to have a persistence in primitive reflexes, the presence of pathologic reflexes, and the failure to develop protective reflexes (Russman, Tilton, and Gormley S181). Also, a progression from hypotonia to hypertonia is normal for children with cerebral palsy. However, the opposite is not common and there should also be no loss of previous achieved milestones. These problems suggest a condition other than cerebral palsy (Russman, Tilton, and Gormley S181). Cerebral palsy causes spasticity in the muscles, or an exaggeration of the tonic stretch reflex (Koman, Smith, and Balkrishnan 12).

The main problem muscles with such heightened tone presents are contracture. Children without disability stretch their muscles as part of their daily lives, whether it is from playing or simply performing their activities of daily living. Children with cerebral palsy, however, do not get this type of stretching as part of their daily routine so it must be incorporated elsewhere. Without incorporating the stretching somewhere else in the child’s life, these high toned muscles run the risk of developing a contracture (Russman, Tilton, and Gormley S181). This can be especially problematic because this can prevent the muscles from growing with the child, leading to more tightness and problems down the road. If the muscles, even though they are spastic, receive an adequate stretch, they will continue to grow. This is why a treatment program needs to be created that puts a stretch on the muscles that need to grow and removes the stretch from the muscles that need to be shortened (Russman, Tilton, and Gormley S181). This is especially important in preventing or prolonging the child from having to undergo a major lengthening surgery.

In order to get their daily stretching regiment, children with cerebral palsy are generally in therapy, either physical, occupational, or both. Some children receive both outpatient therapies and therapy in school. They need this therapy in order to regain strength they’ve lost from being immobile and to regain range of motion because they tend to have a lot of muscle tone which leads to having very tight muscles (Russman, Tilton, and Gormley S183). At times cerebral palsy patients end up with contractures because of their dyskinesia. Some of the more high-functioning cases work on things like walking and writing, but if the child is not high-functioning they may work on things like head control and reaching for objects. The disability cannot be corrected, however it is important for therapists to help the child work around their disability to the best of his/her ability and learn to perform tasks in an adapted way, based on his/her limitations.

The main limitation children with cerebral palsy have is their increased muscle tone and spasticity. Physical therapy can attempt to decrease tone by using certain positioning techniques and facilitation, however the results of such methods are temporary (Russman, Tilton, and Gormley S184). Oral medications such as diazepam, baclofen, and dantrolene are often prescribed to decrease the muscle tone, as well. However, these medications are linked to side effects such as lethargy, irritability, and impaired cognitive skills, none of which are necessarily desired (Russman, Tilton, and Gormley S184). Orthotics, casting, and bracing are also useful tools to help with the increased tone associated with cerebral palsy. They are often used to increase muscle length to the norm in order to prolong or completely avoid resulting to lengthening surgeries. However, lengthening surgeries are best performed when the child’s gait is fairly mature, between the ages of six and ten years old, and are best when the spastic muscles are released all at once, instead of in stages. This can be a fairly involved surgery. Botox injections can also achieve the same results as the orthotics, casting, and bracing when injected into the muscles that are spastic or dystonic (Russman, Tilton, and Gormley S184).

Many of the parents of children with cerebral palsy will take their child to several therapy sessions a week in order to prevent the contractures and tight muscles. However, therapy is not always able to completely prevent these things from happening. The next step is often to try orthotics, bracing, and casting because these are the next least invasive procedures. Once these procedures are no longer working as well as the child needs, Botox is generally the next step. These injections can be guided by sonography, which makes the likelihood of an unaffected muscle being injected far less (Berweck and Heinen S165). It is far less invasive than surgery, but more invasive than the previous two methods. Surgery is usually the last option and is often postponed as long as possible.

Since Botox has to be injected directly into the spastic muscles that makes the procedure somewhat invasive and, as with any form of injection, there can be side effects. However, a study performed by Edward Goldstein, MD, found the procedure to be safe for the use of decreasing spasticity in a pediatric population (191). As for the side effects, the first is pain at the injection site during the injection itself. This pain can be managed anywhere from no intervention at all to general anesthesia (Koman, Smith, and Balkrishnan 17). Patients, or the patients’ parents, can choose to have no pain blocker, topical anesthetic, topical thermal techniques, conscious sedation, or general anesthesia. Obviously using anything more than a topical pain blocker would make the procedure more dangerous for the patient, as with any surgical procedure requiring anesthesia. Other side effects include pain, redness, or bruising at the injection site post-injection and muscle weakness following the procedure.

Although Botox tends to be a procedure that produces longer lasting results than other methods, excluding lengthening surgery, it is still only temporary. Since Botox is a temporary solution to the spasticity the rounds of injections often have to be repeated to continue to achieve the same results. Due to this, most children build up a tolerance to the Botox so the injections are not as effective after a while and some may build up enough tolerance to the injections that they are totally non-effective. However, in a study of Botox use in the upper extremities of children with cerebral palsy the results tended to peak at around two weeks, according to the children’s parents’ perceptions of his/her tone, and last with significant decreases in tone and increases in use and smoothness of movement for about three months. After the third month the results seen tended to start to head down a steady decline back to the baseline. Children were still considered significantly better than their baseline up to sometime after the six month mark (Wallen, O’Flaherty, and Waugh 195). Another study showed that previous constantly rigid muscles became more flaccid three weeks after the injections and the flaccidity of the muscles continued without any major change for four to six months (Calerdon-Gonzalez, et al. 287).

Botox injections have been proven to decrease muscle tone in children with spasticity caused by cerebral palsy. It is a great way to put off the necessity of lengthening surgeries as long as possible, or at least until the recommended time of between ages six and ten years old when the gait is mature (Russman, Tilton, Gormley S186). These injections work by blocking the synaptic release of acetylcholine from cholinergic nerve terminals, which takes place at the neuromuscular junction. This toxin causes an irreversible loss of motor endplates which paralyzes the muscle until new junctions are formed by nerve sprouting (Wong 85). This procedure is most indicated for a patient who is hypertonic and either dystonic or spastic and his/her hypertonic muscles are interfering with normal function. It is also indicated for patients who are at risk of developing a contracture as they grow (Russman, Tilton, Gormley S186).

Although Botox injections can be a wonderful alternative to surgery, it is not for everyone. There are contraindications that need to be considered. If the child is less than eighteen months old, the procedure should not be done due to a lack of research on the long-term effects of the use of Botox in children (Russman, Tilton, Gormley S187). If the child already has a contracture, the Botox injections should not be used unless they are necessary to facilitate serial casting, but even then still should not be used without careful consideration (Russman, Tilton, Gormley S187). A third contraindication is if the patient has diffuse hypertonia. However, it can still be used to treat focal points of spasticity in such patients (Russman, Tilton, Gormley S187).

Although there is no cure for the disabilities caused by cerebral palsy, these injections are in invaluable tool available to help improve the functionability of children with cerebral palsy and to bring some much needed reassurance and help to their families. To most parents, the idea of their child having to undergo a major surgery is hard pill to swallow. With things like physical therapy, casing, bracing, use of orthotics, and Botox injections, a major lengthening surgery can be significantly postponed. Since Botox injections decrease the child’s muscle tone the changes in the child’s ability to function can be extraordinary. There have not only been increases in range of motion and decreases in pain caused by the spasticity in these children, but significant improvement in gross motor function, grading of spasticity, and improvements in gait have been recorded (Wong 86). Botox injections used in conjunction with physical therapy and bracing or orthotics is the best treatment plan for the child and provides the best results (Reddihough, et al 825).
Based on the research I have found, I would conclude that the use of Botox injections in children with cerebral palsy, along with the use of physical therapy and bracing/orthotics/casting is a great way to prolong lengthening surgeries. I have also determined that putting off lengthening surgeries as long as possible is the best option for the child and parents. The earlier it is done, the greater the chance that it will have to be done again as the child continues to grow. Even though Botox injections are temporary and the child may build up a tolerance to the injections making them less effective, I would use them for as long as possible but start using them as late as possible. The longer the child can get away with getting good enough results from therapy and casting/bracing/orthotics the better, but Botox is a good middle step between those methods and surgery.

Reference:

Berweck, Steffen, and Florian Heinen. "Use of Botulinum Toxin in Pediatric Spasticity (Cerebral Palsy)." Movement Disorders. 19.8 (2004): S162-S167.

Calderon-Gonzalez, Raul, Raul Calderon-Sepulveda, Moises Rincon-Reye, Jorge Garcia-Ramirez, and Eugenia Mino-Arango. "Botulinum Toxin A in Management of Cerebral Palsy." Pediatr Neurol. 10. (1994): 284-288.

Goldstein, Edward M. "Safety of High-Dose Botulinum Toxin Type A Therapy for the Treatment of Pediatric Spasticity." J Child Neurol. 21. (2006): 189-192.

Koman, L, Beth Smith, and Rajesh Balkrishnan. "Spasticity Associated with Cerebral Palsy in Children: Guidelines for the Use of Botulinum A Toxin." Pediatric Drugs. 5.1 (2008): 11-23.

Reddihough, Dinah S., Jane A. King, Grahame J. Coleman, et al. "Functional outcome of botulinum toxin A injections to the lower limbs in cerebral palsy." Developmental Medicine & Child Neurology. 44. (2002): 820-827.

Russman, Barry S., Ann Tilton, and Mark E. Gormley, Jr. "Cerebral Palsy: A Rational Approach to a Treatment Protocol, and the Role of Botulinum Toxin in Treatment." Muscle Nerve. 20.6 (1997): S181-S193.

Wallen, Margaret, Stephen J. O'Flaherty, and Mary-Clare A. Waugh. "Functional Outcomes of Intramuscular Botulinum Toxin Type A in the Upper Limbs of Children With Cerebral Palsy: A Phase II Trial." Arch Phys Med Rehabil. 85. (2004): 192-200.

Wong, Virginia. "Evidence-based approach of the use of Botulinum toxin type A (BTX) in cerebral palsy." Pediatric Rehabilitation. 6. (2003): 85-96.