Treating MS With Botulinum Toxin

What Is Botulinum Toxin?

Botulinum toxin is a muscle-relaxing medication used to decrease spasticity related to multiple sclerosis and other neurological conditions.

Botulinum toxin is derived from the bacterium Clostridium botulinum and is in a class of drugs called neurotoxins. There are three types of botulinum toxin available for therapeutic use:

OnabotulinumtoxinA (Botox/Botox Cosmetic)
RimabotulinumtoxinB (Myobloc)
AbobotulinumtoxinA (Dysport)

Your doctor will decide which type of botulinum toxin is appropriate for you.

The FDA, despite the drug's effectiveness, has not yet approved the use of these treatments for MS-related spasticity . Botox, Myobloc, and Dysport are approved by the FDA for the treatment of a condition marked by repetitive contraction of the neck muscles (cervical dystonia).

What Is Spasticity?

Spasticity refers to a wide range of involuntary muscle contractions that result in muscle spasms or stiffness. Spasticity interferes with voluntary muscle movement and usually involves the muscles of the legs and/or arms.

Spasticity may vary, based on many factors, including infections, stress, pain, temperature, position and time of the day. Over time, severe spasticity may cause decreased range of motion in the affected limbs.

Spasticity is the result of an imbalance in the central nervous system, caused by a trauma or disease in the brain and/or spinal cord. This imbalance causes hyperactive muscle stretch reflexes, which result in involuntary contractions and increased muscle tone.

Some doctors believe that an increased sensitivity in the parts of the muscles that are responsible for contracting (tightening), relaxing and stretching the muscles contribute to spasticity.

How Does Botulinum Toxin Work?

Normally, the brain sends electrical messages to the muscles so that they can contract and move. This message is transmitted to the muscle by a substance called acetylcholine. Botulinum toxin works to block the release of acetylcholine; therefore the muscle doesn't receive the message to contract.

How Are Botulinum Toxin Treatments Given?

Botulinum toxin is given as an intramuscular injection (in the muscle). Your doctor will determine the muscle(s) in need of treatment.

If the muscles to be injected are small or difficult to reach, it may be necessary to send short electric impulses, or to record electric signals from the muscles, to ensure that the appropriate muscles are receiving the injected medication.

A very fine needle is used for the injection. Some people report minor and temporary discomfort from the injection. The medication does not sting or cause irritation after it has been injected.

You can expect the appointment to last from 1 to 2 hours.

The effects of the medication begin to appear from one to two weeks after the injection. The muscles injected should then relax.