context: Baclofen ( Gablofen, Lioresal) is a medication that treats stiff muscles and spasms, a condition called spasticity, that can happen to people with multiple sclerosis ( MS) and other nerve diseases. Normally, your muscles get electrical signals from your nerves that tell them when to tense and relax. Spasticity happens when these signals become uneven, usually because the nerves have been damaged. This makes muscles tense up or move when you don't want them to. Baclofen works by restoring the normal signals. It can help you move your muscles more normally. Side effects may include: Dizziness Drowsiness Headaches Nausea Weakness You can take baclofen as a pill or get it directly into an area of your spine called the intrathecal space. This part of your body is filled with the fluid that surrounds your spinal cord and nerve roots. This type of treatment, called intrathecal baclofen ( ITB), can help people who have a hard time with side effects of the pill form. It delivers the drug right to the spinal cord, so it doesn't circulate throughout the body first. You need only tiny doses for the drug to work. This keeps side effects to a minimum. Doctors use a pump system to deliver baclofen directly into the spinal fluid. It's made of a catheter (a small, flexible tube) and a pump. A surgeon puts the device -- a round metal disc, about 1 inch thick and 3 inches around -- under the skin of your belly near your waistline. The pump stores and releases the right amount of medicine through the catheter. A tiny motor moves the medication from the pump through the catheter. Your treatment team can use a small computer outside your body to send messages to the pump and make adjustments in the dose, rate, and timing of the medication. You can also turn the system off when you don't need it. People with the pump must go back to their doctor's office for pump refills and medication adjustments, typically every 1 to 3 months. At the end of the battery's life span (usually 5 to 7 years), your doctor will remove and replace the system. If baclofen pills haven't helped your spasticity, you can try a pump system. It tends to work better for spasticity in the legs rather than the arms. Before you get ITB, you will meet with a treatment team that may include a doctor who specializes in rehabilitation (a physiatrist or neurologist), a physical therapist, an occupational therapist, a nurse, and a social worker. All of these professionals work together to check your spasticity symptoms and to set a treatment plan that fits your personal needs. Many doctors who specialize in pain management, called anesthesiologists, also manage ITB pumps. Any surgery comes with risks, and implanting the baclofen pump is no exception. They include: A bad reaction to anesthesia Infection Bleeding Trouble with bladder control Pump malfunction: If the pump stops working (this is rare), it may give you too much medicine at once. That can cause symptoms such as drowsiness, dizziness, weakness, trouble sleeping, lightheadedness, nausea, constipation, vomiting, loose muscles, trouble with vision, coma, respiratory depression, seizures, dry mouth, double vision, poor concentration, or diarrhea. If this happens, go to the nearest emergency room right away. A doctor can give you a drug called physostigmine to counteract baclofen. Kinked catheter: If the catheter stops working well, you may need surgery to replace it. If your treatment team recommends the baclofen pump system, you'll try it out to see how well it works. Your doctor will inject baclofen into your spine with a small needle. Then the team checks how well it works over 2 to 4 hours. If your muscles don't relax during the first try, you may get a larger dose to see if that makes a difference. If it works, you can decide with your doctor and family members if you should have a baclofen pump system implanted.