What is Botulinum Toxin?
Commonly known as Botox® is known for its wide use in cosmetic surgery. Botulinum Toxin (BTX) which is a toxin derived from Clostridium Botulinum, is a gram-negative bacilli (Bacteria), there are various serotypes, the commonest one used is BTX-A.
How does BTX -A act on spastic muscle?
BTX-A binds with the Motor nerve terminal. BTX-A blocks the release of Acetylcholine (Ach), a neurotransmitter from axon endings. This chemical denervation causes a temporary reduced muscular activity in the injected muscles.
What are the indications?
- Spastic muscle causing limitation of movement
- Spasticity more than Ashworth Gr 2
- Progression of spasticity
- To avoid contractures during a growth spurt
What is the appropriate age group?
The optimum age group is between 2-6 years.
What is the safe dose?
The maximum safe dose is 400units for the Injection Botox® Each muscle has a different dosage varying from 0.5- 6 u/kg per muscle.
Which muscles are commonly injected?
The muscles commonly injected are Gastrocnemius, Hamstrings, Tibialis posterior and Rectus in lower extremity, while the common ones in the Upper extremity are: Pronator teres, Flexor carpi ulnaris and Adductor pollicis.
What is the procedure?
It is performed under anesthesia, preferably Ultrasound-guided, and a splint or plaster cast might be needed post injection.
Is it a permanent treatment modality?
It is a reversible, temporary modality. The BTX- A effect starts to wean off by 6 months to one year, although whatever therapy is done during this period shows lots of benefit, in terms of strength gain and the BTX-A injection helps to avoid contractures in kids with Cerebral Palsy.
Can it be used along with other procedures?
It can be used in conjunction to musculotendinous junction lengthening of same muscle or other muscle during a Single Event Multilevel Surgery. It can also be used during a constrained induced therapy cast, which accentuates the effect of the injection.
What are the side effects or contraindications?
There are no known side effects, the injection is contraindicated in history of existing pseudobulbar palsy, GER, Myasthenia Gravis, Amyotrophic Lat Sclerosis and Eaton Lambert Syndrome.