Oral baclofen or intrathecal (in the spine) baclofen are used as a "muscle relaxant" to help decrease muscle tone in children. Baclofen also decreases stretch reflexes, the rate of muscle spasms and clonus, pain, and tightness and improves range of motion. Side effects may include sedation, drowsiness, weakness, decreased muscle tone, confusion, fatigue, nausea, dizziness, and more difficulty in controlling seizures in children with epilepsy. Both oral and intrathecal baclofen are approved by the FDA for treating children with spasticity.
Baclofen may also be delivered via a catheter into the space surrounding the spinal cord (the intrathecal space). Intrathecal Baclofen Therapy (ITB Therapy), also commonly referred to as a baclofen pump, is used to treat severe spasticity that is caused by damage to the brain or spinal cord.
- To determine whether ITB Therapy may be a helpful option for your child, a screening test or trial is performed. The screening test for ITB Therapy requires the administration of a test dose of baclofen via lumbar puncture (spinal tap) into the thecal space. Children who respond positively to the test dose/trial are referred to a neurosurgeon to surgically place a permanent battery-powered pump.
- The pump implantation requires two incisions: one in the lower abdomen to make a pocket for the pump under the skin, and another, smaller, incision in the lumbar region to insert the catheter. The procedure typically lasts about 1 hour. The entire hospital stay is usually about one week, during which time the pump is programmed to deliver the best possible dose of baclofen to reduce muscle tone.
- A decrease in the tone of spastic muscles is usually noticeable within several days of the operation, but significant improvements in function may take longer to be evident. The dose of baclofen can be adjusted whenever necessary by reprogramming the pump in the doctor's office.
- The pump also contains a programmable alarm that beeps softly when the reservoir is low or the batteries need replacing. The reservoir is refilled by injection as needed, usually every 1 to 3 months. When the batteries run low, about every 4 to 5 years, the entire pump is replaced.
- The side effects of ITB Therapy are the same as those for baclofen given by mouth but are usually milder because of the lower dose of medicine that is required with ITB Therapy. Additional problems may also occur:
- About 5% of children with a baclofen pump develop infections that require temporary removal of the pump.
- Other equipment-related risks include pump failure, tube kinking or breakage, or movement of the catheter (dislodgement) so that the baclofen no longer reaches the intrathecal space. Mechanical defects or failure to refill the pump reservoir can lead to sudden interruption of baclofen treatment. This can cause a life-threatening withdrawal syndrome. To prevent this, families must be educated about the signs of baclofen withdrawal and are usually encouraged to keep a supply of oral baclofen on hand for such possible emergencies.
- It is also possible for a child receiving ITB Therapy to receive too much medication (overdose). A baclofen overdose may cause drowsiness, lightheadedness, slowed or difficulty breathing, seizures, loss of consciousness, and coma. In the event of an overdose, it is very important for the patient or caregiver to immediately contact the patient's physician.