What type of drug treatments are available to treat a person with cerebral palsy?
Oral medications such as diazepam, baclofen, dantrolene sodium, and tizanidine are usually used as the first line of treatment to relax stiff, contracted, or overactive muscles. These drugs are easy to use, except that dosages high enough to be effective often have side effects, among them drowsiness, upset stomach, high blood pressure, and possible liver damage with long-term use. Oral medications are most appropriate for children who need only mild reduction in muscle tone or who have widespread spasticity.
Doctors also sometimes use alcohol “washes” — injections of alcohol into muscles — to reduce spasticity. The benefits last from a few months to 2 years or more, but the adverse effects include a significant risk of pain or numbness, and the procedure requires a high degree of skill to target the nerve.
The availability of new and more precise methods to deliver antispasmodic medications is moving treatment for spasticity toward chemodenervation, in which injected drugs are used to target and relax muscles.
Botulinum toxin (BT-A)
Injected locally, BT-A has become a standard treatment for overactive muscles in children with spastic movement disorders such as cerebral palsy. BT-A relaxes contracted muscles by keeping nerve cells from over-activating muscle. Although BT-A is not approved by the Food and Drug Administration (FDA) for treating cerebral palsy, since the 1990s doctors have been using it off-label to relax spastic muscles. A number of studies have shown that it reduces spasticity and increases the range of motion of the muscles it targets.
The relaxing effect of a BT-A injection lasts approximately 3 months. Undesirable side effects are mild and short-lived, consisting of pain upon injection and occasionally mild flu-like symptoms. BT-A injections are most effective when followed by a stretching program including physical therapy and splinting. BT-A injections work best for children who have some control over their motor movements and have a limited number of muscles to treat, none of which is fixed or rigid.
Because BT-A does not have FDA approval to treat spasticity in children, parents and caregivers should make sure that the doctor giving the injection is trained in the procedure and has experience using it in children.
Therapy uses an implantable pump to deliver baclofen, a muscle relaxant, into the fluid surrounding the spinal cord. Baclofen works by decreasing the excitability of nerve cells in the spinal cord, which then reduces muscle spasticity throughout the body. Because it is delivered directly into the nervous system, the intrathecal dose of baclofen can be as low as one one-hundredth of the oral dose. Studies have shown it reduces spasticity and pain and improves sleep.
The pump is the size of a hockey puck and is implanted in the abdomen. It contains a refillable reservoir connected to an alarm that beeps when the reservoir is low. The pump is programmable with an electronic telemetry wand. The program can be adjusted if muscle tone is worse at certain times of the day or night.
The baclofen pump carries a small but significant risk of serious complications if it fails or is programmed incorrectly, if the catheter becomes twisted or kinked, or if the insertion site becomes infected. Undesirable, but infrequent, side effects include overrelaxation of the muscles, sleepiness, headache, nausea, vomiting, dizziness, and constipation.
As a muscle-relaxing therapy, the baclofen pump is most appropriate for individuals with chronic, severe stiffness or uncontrolled muscle movement throughout the body. Doctors have successfully implanted the pump in children as young as 3 years of age.