Overview

Your clinician will inject botulinum toxin directly into your muscles. The toxin affects the nerves where they meet the muscles and reduces the excess muscle activity caused by dystonia. It acts as a blocker preventing release of the chemical messenger acetylcholine which is responsible for making the muscle contract. As a result, the signals that would normally be telling your muscle to contract are halted and the muscle spasms are reduced or in some cases may cease completely for the length of the treatment.

Botulinum toxin is produced naturally by a bacterium called Clostridium botulinum which is also associated with causing botulism, a rare form of blood poisoning. Although this means botulinum toxin is exceptionally toxic, when it is purified and used in small, controlled doses it is safe and can be effective. The injections are administered by trained medical professionals, usually a doctor, physiotherapist or dystonia nurse.

Process

To find the area for injection, the doctor will observe your abnormal postures or movements and feel for the muscle spasm or use an electromyography machine (EMG) which measures muscle activity. The number of injections will vary depending on the severity of your dystonia.
The injections usually take a few days to have an effect and can last from 12 to 16 weeks. 

Suitability

Botulinum toxin injections are generally more suitable for treating dystonias which are limited to one or two areas of the body rather than generalised dystonia. However, sometimes the injections are used to treat a specific part of the body in generalised dystonia as part of a wider treatment regime.

Botulinum toxin can be used in adults and children. It is not licensed for pregnant or lactating women but it has been used in these cases with no adverse effect reported. However, this has not been studied formally. In these cases the decision on whether to proceed with treatment should be discussed with your clinician.

You should not be given botulinum toxin if you have had a previous allergic reaction to it or any of its ingredients.

Benefits

Unlike most oral medication, the injection can be targeted specifically to the muscles affected by dystonia.

Risks

As with any medicine there are potential side effects. Usually, if experienced, these are mild and wear off quickly. Possible side effects are:

• Pain from the injection
• Flu-like symptoms
• Pain and bruising at the injection site
• Unwanted or excessive muscle weakness around the injected muscles

There are side effects that are specific to the injection site. For example:

• In neck dystonia people can experience difficulties swallowing
• Injections for eye dystonia can cause issues with or around the eyes

Success

Botulinum toxin injections can provide significant relief for many people. 

Access

The British Neurotoxin Network (BNN)’s website has lists of hospitals and clinics in the UK providing botulinum toxin services.