Basic guide to intrathecal baclofen

The aim of this advice is to give you basic information about intrathecal baclofen therapy. Intrathecal baclofen therapy is used as a way of controlling spasticity and spasms.

Before using intrathecal baclofen the doctor will consider such things as:

• the effectiveness of your child’s current treatment program
• your child’s response to traditional medicines
• the level of side effects your child experiences with traditional treatments
• the progression and current state of your child’s condition
• whether your child’s body size and weight will accommodate the pump
• your child’s current emotional and psychological well being

What is spasticity?

We think spasticity happens because of damage to the brain or spinal cord. Spasticity is described as tightness or stiffness in muscles, which make movements difficult or uncontrolled. Spasticity may limit function, reduce mobility, cause pain and deformities, complicates sleep patterns and generally interferes with an someone’s quality of life.

What is baclofen?

Baclofen is a medication that relieves spasticity. It is supplied in either tablet or liquid form. Baclofen can be taken by mouth or through a gastrostomy (systemic drug delivery) or directly into the space around the spinal cord (intrathecal drug delivery).

When using oral baclofen, sometimes children need very high doses in order to manage their spasticity effectively. These high doses may cause side effects such as sleepiness, weakness, dizziness and nausea. When using intrathecal baclofen the doses are generally smaller and act directly at the area of the spinal cord.

What is intrathecal baclofen therapy?

Intrathecal baclofen therapy is a treatment option that delivers an injectable form of baclofen directly in to the fluid surrounding the spinal cord (the intrathecal space), using a programmable pump and catheter that are placed within the body during an operation under general anaesthetic.

The baclofen is delivered continuously in small, precisely controlled doses throughout the day. The amount of baclofen delivered can be regulated to give different doses throughout the day and night. This means that the child can get more baclofen at the time they really need it.

If oral baclofen is not helping, why would intrathecal baclofen help?

Oral baclofen circulates throughout the whole body (systemic drug delivery). However, even when taking high doses, only relatively small amounts can pass from the blood into the brain and space around the spinal cord. With intrathecal baclofen the drug is delivered directly to where it is most effective – the space around the spinal cord. This helps to minimise the systemic side effects such as sleepiness, weakness, dizziness and nausea.

What is an intrathecal baclofen pump?

The pump itself is a round metal battery powered device. It stores and delivers baclofen according to the instructions provided by your child’s doctor. The pump is surgically placed, usually just under the skin of the abdomen. The pump delivers the baclofen through a small tube (called a catheter) through the body to the lower back. Here it goes into the space around the spinal cord. This operation needs another short hospital stay. The pump should not interfere with movement or positioning and should not cause any discomfort.

How is the pump programmed?

The pump is programmed so your child can receive varying amounts of baclofen over 24 hours for when they most need it. For example a child may experience an increase in spasms overnight, so their pump is programmed to give a larger dose of baclofen during the night than in the daytime.

The dose of the baclofen is decided by the doctor. The baclofen is then pumped continuously into the intrathecal space. A portable computer programs the pump to deliver the baclofen at varying rates. The dose of baclofen is adjusted by holding the computer’s programming wand near the skin over the pump. The computer allows the doctor and nurse to program doses to provide the most comfort and ability.

Does the pump run out of medication?

The pump needs to be refilled with baclofen periodically using the programming computer.

Refill dates are scheduled based upon:

• the amount of baclofen the pump holds
• the concentration of the medication your child is receiving
• the rate at which the pump delivers the baclofen
• the frequency of dosing changes required by your particular treatment plan

Will the intrathecal baclofen affect my child’s whole body?

The effects of intrathecal baclofen are most noted on the lower limbs and lower torso rather than the arms, upper torso and head.

Side effects such as sleepiness, nausea and dizziness are reduced when using intrathecal baclofen.

How do I know if intrathecal baclofen will work for my child?

To tell if your child would benefit from intrathecal baclofen, the neurosurgeon would carry out a test dose on your child. This involves a short hospital stay, where your child has an anaesthetic and the surgeon places a small catheter into your child’s lower back. The surgeon will then inject the liquid baclofen into the intrathecal space (lower back).

Following this procedure your child will be monitored on the surgical ward. The medication takes around 30 minutes to 1 hour to relax the muscles. It will be most effective around 4 hours after the injection. If this first baclofen dose does not reduce your child’s spasticity, then a second or third higher dose may be given. This means that the hospital stay may vary from 1 to 3 days.

During your child’s stay, they will compare how your child’s spasticity has been affected by the intrathecal baclofen injection. The test lets you and your child, as well as your doctors, nurses and therapists to see if intrathecal baclofen would be good for your child.

Would intrathecal baclofen cure my child’s problems?

No, intrathecal baclofen is used to help to manage spasticity but can not take away the cause. Intrathecal baclofen therapy is not a cure for spasticity or the conditions that are associated with it.

Will intrathecal baclofen improve my child’s comfort and physical ability?

Spasticity can be painful and can limit some children’s activities. As intrathecal baclofen therapy aims to manage spasticity. Your child may feel more comfortable and not feel as limited in some of their abilities. For example, they may feel more comfortable when sleeping or have more tolerance of positioning in their equipment such as a wheelchair or standing frame.

What happens at the time for refill?

The nurse or doctor will refill the pump with a simple injection through the skin of the abdomen directly into the reservoir of the pump. The skin is prepared using local anaesthetic cream before the injection. The computer is used to recalculate the dose of the baclofen and a new date is given for the next pump refill.

Are there risks in using intrathecal baclofen therapy?

Yes. No treatment is completely risk free and some complications can happen. Since the device is placed surgically under the skin, infections can happen. Sometimes there may be complications such as catheter kinks, dislodgements, or breaks in the catheter that delivers the drug from the pump to the spinal fluid. Drug side effects are usually temporary and can be managed by adjusting the dose. Possible side effects include excessive muscle looseness, drowsiness, nausea and vomiting, headache and dizziness.

Glossary

Spasticity

Presents as tight, stiff muscles that makes movements difficult or uncontrolled. It is caused by damage within the brain or spinal cord.

Spinal cord

The column of nerve tissue in the spine that carries messages between the brain and the rest of the body.

Intrathecal space

The area surrounding the spinal cord, filled with cerebro spinal fluid.

Systemic drug delivery

The drug is delivered throughout the entire body, rather than to a specific location.

Intrathecal drug delivery

The drug is delivered directly into the intrathecal space.

Catheter

A flexible, silicone tube that connects to the pump. The pump delivers medication through the catheter into the intrathecal space.

Programmable pump

Round, metal disc that stores and releases liquid medicine at a rate that is programmed by a doctor or nurse.

Programmer

The doctor or nurse that sets or adjusts the amount of baclofen delivered by the pump using the pump’s computer programming wand.

General anaesthetic

Medication that is used by doctors called ‘anaesthetists’ to put patients into a sleep like state (unconsciousness), in order to perform an operation.

Refill

To fill the pump with new drug.

Reservoir

An area inside the pump that holds the medicine.

Test dose

A dose of baclofen that is injected directly into the intrathecal space in order to see how well the drug works before the pump implanted.