Intrathecal Baclofen Therapy(for MS)
What is baclofen?
Baclofen is a muscle relaxant medicine commonly used to decrease spasticity related to multiple sclerosis, spinal cord injuries, or other
neurological diseases. Spasticity is a motor disorder characterized by tight or
stiff muscles that might interfere with voluntary muscle movements.
How does baclofen work?
Spasticity is caused by an imbalance of excitatory and inhibitory input in the spinal cord.
This imbalance causes hyperactive muscle stretch reflexes. These reflexes result
in involuntary spasms and increased muscle tone.
Baclofen (a gamma-aminobutyric acid (GABA) agonist) works by restoring the
balance of excitatory and inhibitory input to reduce muscle hyperactivity. In
this way, it allows more normal motor movements.
What are the side effects?
Oral and intrathecal baclofen can have potential side effects. Some side effects of
baclofen include dizziness, drowsiness, headaches, nausea, and weakness.
Why is intrathecal baclofen preferred over oral baclofen?
Baclofen can be taken orally or delivered into the intrathecal space. The intrathecal
space contains the cerebrospinal fluid, the fluid surrounding the spinal cord
and nerve roots. Oral baclofen causes side effects that might limit its usefulness.
Of the oral baclofen delivered throughout the body, only a small portion goes
to the spinal fluid where it is needed to work.
An intrathecal delivery system, which provides the baclofen right to the
target site in the spinal cord, is an effective way to deliver the medicine.
What is the baclofen pump system?
The baclofen pump system is the intrathecal (directly into the spinal fluid) method
of delivering the medicine. The system consists of a catheter (a small,
flexible tube) and a pump. The pump, a round metal disc, about one inch thick
and three inches in diameter, is surgically placed under the skin of the abdomen near the waistline.
The pump stores and releases prescribed amounts of medicine through the
catheter. The pump is refilled by inserting a needle through the skin into a
filling port in the center of the pump. With a programmable pump, a tiny motor
moves the medicine from the pump reservoir through the catheter. Using an
external programmer, your treatment team can make adjustments in the dose, rate,
and timing of the medicine.
Patients must return to their doctor's office for pump refills and medicine
adjustments, typically every two to three months. The pump is taken out and replaced
at the end of the battery's life span, which is usually five to seven years.
Who is a candidate for the pump system?
Anyone who has spasticity and is not responsive to oral medicine can be considered
for the baclofen pump system.
What are the advantages of the baclofen pump system?
- It efficiently reduces spasticity and involuntary spasms, promoting a more
active lifestyle, better sleep, and reduced need for oral medicines.
- It continuously delivers baclofen in small doses directly to the spinal
fluid, increasing the therapeutic benefits, and causing fewer and less severe
side effects compared to the oral medicine.
- It can be individually adjusted to allow infusion rates that vary over a 24-hour period.
- It can be turned off if spasticity reduction has shown no benefit.
- Pain and discomfort from spasms and spasticity are often reduced or eliminated.
Baclofen therapy evaluation
If you are considering intrathecal baclofen therapy, you will likely have an initial evaluation
by a treatment team that might include a doctor who specializes in rehabilitation (physiatrist), a physical therapist, an
occupational therapist, a nurse, and a social worker. All of these professionals work as a team to provide a comprehensive
evaluation of your spasticity symptoms and to establish a treatment plan adapted to your personal needs.
How will my doctor know if the baclofen pump system will work?
If your treatment team recommends the baclofen pump system after your evaluation,
you will have a trial of the intraspinal therapy to test the potential
effectiveness of the medicine.
During the medicine trial, baclofen is injected into the spinal canal
(using a small needle) and you are assessed by the treatment team over two to
four hours to determine how well the medicine treats the spasticity. If your muscles
don't relax during the first trial, a larger dose might be given on a later date
to determine its effectiveness.
Patients who experience positive results with the intrathecal medicine can
decide with their doctor and family members if they should have a baclofen pump
system implanted during a surgical procedure. Prior to surgery, you will meet
with the surgeon and nurse to ask questions about the procedure.
What happens after the procedure?
After the implantation procedure, you will stay in the hospital a few days so your
recovery can be closely monitored. While you are in the hospital, the dose of
baclofen will be adjusted. You will have follow-up visits with your doctor.
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