Abobotulinumtoxin A (Dysport®) for Upper and Lower Limb Spasticity
What is spasticity and how is it typically treated?
Spasticity is a neuromuscular condition in which there is an abnormal increase in muscle tone, making the affected body parts stiff and difficult to move. Spasticity is a symptom associated with damage to the brain and/or spinal cord through conditions such as stroke, brain trauma or tumour, spinal cord injury, multiple sclerosis, Parkinson’s disease, cerebral palsy, etc. The presentation of spasticity can range from mild and barely noticeable to very bothersome, which can interfere with daily functioning, hygiene and comfort.
Botulinum toxin injections can be used to help relieve spasticity in specific areas. Botulinum toxin is produced by the bacteria Clostridium botulinum. Botulinum toxin works by blocking the release of the chemical messenger acetylcholine and interfering in the nerve-to-muscle signaling pathway. By blocking communication between the nerves and muscles, a reduction in muscle tension, spasticity and pain intensity occurs. Botulinum toxin also helps manage pain by blocking the release of several excitatory chemical messengers involved in pain signaling pathway (e.g., substance P, calcitonin gene-related peptide (CGRP), and glutamate).
In Canada, three types of botulinum toxin type A are available for spasticity management:
- Onabotulinumtoxin A (Botox®)
- Abobotulinumtoxin A (Dysport®)
- Incobotulinumtoxin A (Xeomin®)
Each botulinum toxin product is a unique prescription drug and cannot be exchanged with another. At present, there is little evidence to support the use of one specific product over another. Product selection is typically based on clinician and patient preference, availability, and drug coverage.