Several medications are effective on spasticity. Some are administered orally, some directly into the nervous system, and some locally, into or near the spastic muscle.
When there is diffuse spasticity (severe CP) medications such as baclofene, dantrolene or gabapentine are helpful. But sometimes side effects prevent their use.
They can be administered orally, or intra-thecally in contact with the nervous system. Implanted pumps can deliver a fixed amount of medication each day, for a long term effect.
Some medications can be administered locally, into a spastic muscle or its Motor nerves
Nerve branch enering a muscle and giving it the “command” to contract. All muscles have their own motor branch(es).. They aim at reducing the motor tone of the muscle. Their effect is only temporary. There are two types of local medications:
- botulinum toxin prevents the nerve impulse from being delivered to the muscle, by blocking the release of a substance (acetylcholine) which normally causes the muscle to contract. There are two main brands of botulinum toxin available for clinical use: Dysport ®, and Botox ®.
The target muscle is identified, usually with electro-stimulation or ultra-sounds. Then botulinum toxin is injected directly into the muscle via a syringe and a needle. In children it can be administered under sedation.
Its effect on the muscle starts after a few days, and lasts three to five months. During this period, the physical therapy is reinforced on the non spastic (antagonist) muscles, and splints may be indicated to fight deformities. This is reversible: spasticity returns as soon as the effect of the treatment has ceased.
It is indicated when a muscle becomes so spastic, despite all other treatments, that it impairs function, or nursing, or creates pain. It is also used in the planning of surgical treatment both for decision making, and for helping the patient to visualize what benefit he/she can gain from surgery.
- motor blocks are used nowadays mostly when botulinum is not available; They consist in injecting a substance (local anesthetics, alcohol, or phenol) around the motor nerve*, which blocks the nerve impulse and paralyses the muscle temporarily. The duration of the paralysis depends on the injected substance (one hour for local anesthetics, several weeks for phenol).
