Botulinum toxin is a muscle-relaxing medication that can be used to decrease spasticity related to multiple sclerosis and other neurological conditions.
What is spasticity?
Spasticity is a movement disorder that can occur in conditions which affect the brain or the spinal cord, such as multiple sclerosis, stroke, cerebral palsy, spinal cord injury, or brain injury. Spasticity is caused by an imbalance between signals that inhibit or stimulate the spinal cord. This results in hyperexcitable stretch reflexes, increased muscle tone, and involuntary movements.
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What are the symptoms of spasticity?
Spasticity causes muscle stiffness and tightness which interferes with voluntary movements. Spasticity can also cause muscle spasms (jerky involuntary movements) or clonus (repetitive involuntary movement).
Stiffness and spasms are often bothersome and sometimes painful, and they interfere with the ability to carry out daily activities. Spasms may also disrupt sleep and increase daytime fatigue. When spasticity is severe, contractures (fixed limitations of range of motion) may develop.
How can spasticity be treated?
Stretching, exercise, and rehabilitation are the first line of interventions for spasticity. Oral medications are often effective, but may cause side effects such as drowsiness. When spasticity affects only a few muscles, local injections of botulinum toxin can be helpful. When spasticity is diffuse and severe, intrathecal baclofen (ITB) may be a good treatment option.
What is botulinum toxin?
Botulinum toxin (BT) is a medication derived from a neurotoxin produced by bacteria (Clostridium Botulinum). In its natural form, this toxin causes botulism, a severe condition that can be fatal. The botulinum toxin medication is designed to be used safely without causing botulism. Three formulations of botulinum toxin A are approved by the FDA for the treatment of spasticity:
- Abobotulinum toxin A (Dysport®)
- Incobotulinum toxin A (Xeomin®)
- Onabotulinum toxin A (Botox®)
How does botulinum toxin work?
Normally, the brain sends messages to the muscles so they can contract and move. These messages are transmitted via the nerves to the muscles by a substance called acetylcholine. BT blocks the release of acetylcholine from the nerve to the muscle, therefore the muscle relaxes.
How do I know If I am a good candidate for botulinum toxin therapy?
BT therapy is usually considered when spasticity needs to be relieved in only a few muscle groups. It can be used in addition to other treatments for spasticity. If your healthcare provider thinks that you may be a candidate for BT therapy, you will be scheduled for an evaluation. During this visit, you will also be given detailed information about the treatment, so you can make an informed decision.