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This page explains what spasticity is and is written for patients, their families and carers. It contains information on botulinum toxin and its use to treat conditions such as spasticity and dystonia which can occur after a stroke or brain injury.

Spasticity can be described as involuntary muscle over-activity which feels like stiffness. Spasticity is commonly seen in neurological conditions such as stroke, multiple sclerosis, cerebral palsy, brain or spinal cord injury, amongst others. The main feature of spasticity is stiffness or increased resistance when attempting to move a limb or joint.

Other features that may be associated with it include; spasms, pain, weakness and clonus (repetitive limb jerking). Spasticity can be described as generalised or focal depending on how many parts of the body are affected. It can vary from mild to severe and change over time.

Symptoms can be unpleasant but sometimes spasticity can be helpful, for example, when transferring from the bed to chair or even walking. In these cases treatment may not be needed.

Botulinum toxin is a naturally occurring chemical produced by a bacterium called Clostridium botulinum. When it is injected into muscles, it temporarily weakens them by blocking communication between the nerves and muscles. The weakened muscles should become less stiff. By weakening the problematic muscle or muscles, botulinum toxin injections may improve symptoms caused by spasticity (pain, stiffness, spasms).

This may help with participating in a therapy or stretching programme or putting on and taking off splints or other orthotic devices. In general, it will not improve function.

The doctors and therapists will assess the problem and decide with you if botulinum toxin injections are indicated and identify a goal of treatment.

All treatments and procedures have risks and we will talk to you about the risks of botulinum toxin injections. Botulinum toxin is generally very safe. Reported side effects include a skin rash, flulike illness and tiredness, but they are uncommon and tend to be mild and short lived; they very rarely require any treatment. A rare complication can be difficulty swallowing but this tends to be associated with injections into neck muscles.

Because botulinum toxin causes weakness it may be associated with a temporary reduction in your level of function, for example, grip strength or ease of lifting up your foot when walking. Specific personalised risks will be discussed with you in clinic.

The use of botulinum toxin is not advised during pregnancy or breast feeding as the safety of it has yet to be established. It also not recommended for patients with neurological conditions such as myasthenia gravis or those on certain antibiotics (streptomycin, gentamicin, tobramycin, amikacin).

The spasticity or dystonia may become worse and more difficult to manage.

There are alternative treatment options, such as medication, physiotherapy, splinting, orthotics and electrical stimulation which may help. Some of these options may have been tried already and we can advise accordingly.

No specific preparation is necessary, unless you are taking anti-coagulation medication). It is helpful to wear if you are wearing loose clothing so that we are able to easily access the muscles in your arm or leg. Please bring to the appointment with you any splints that you currently use and details of any local therapy teams that are involved in your treatment.

The injections will be administered during the clinic appointment and people often find it helpful to have someone accompany them on the day. If you are on medication to thin your blood (e.g. warfarin, rivaroxaban, digabatrin, apixaban, edoxaban, heparin injections), we will need to be aware of this prior to the appointment and we will liaise with you regarding altering the dose if necessary.

We will contact you by telephone approximately 10 days prior to your appointment in order to establish your current medications and put in place an appropriate plan. If you experience severe bleeding or bruising after the injection please seek medical advice.

We want to involve you in all the decisions about your care and treatment. If you decide to go ahead with treatment, by law we must ask for your consent and will ask you to sign a consent form. This confirms that you agree to have the procedure and understand what it involves. Staff will explain all the risks, benefits and alternatives before they ask you to sign a consent form.

If you are unsure about any aspect of your proposed treatment, please don’t hesitate to speak with a senior member of staff again.

Firstly, your skin will be cleaned with an antiseptic wipe. We will place two skin electrode pads close to the injection site which connect to an electromyography machine (EMG) which will allow us to ‘listen’ to the electrical muscle activity. An injection needle is attached to the EMG machine which helps us locate the correct muscle and inject it with botulinum toxin.

Several muscles may need to be injected, depending on how many are overactive. The injections are no more painful than other common procedures such as vaccinations. The whole consultation will take about 45 minutes; however, on occasion, it may take longer, for example when many muscles are involved.

At the end of the clinic appointment you will be provided with a sheet detailing the treatment you have received, the goals of treatment and information regarding follow-up plans. Botulinum toxin usually takes 2-5 days to begin to work and usually reaches its peak around 10-14 days later. Some muscles respond faster than others. The muscles injected should feel less stiff. The reduction in the stiffness depends on how tight the muscles were before the injection, how sensitive you are to the toxin and the dose of toxin injected. The effect of the toxin will wear off over time, usually about 10-12 weeks. However, the benefit may last much longer than this, especially when the botulinum treatment is combined with other treatments, such as physiotherapy, occupational therapy and / or splinting.

A specific exercise program involving either stretches or active exercises of the injected limb will help to maximise the effect of the injection. The team will arrange for you to be assessed by a physiotherapist or occupational therapist after the injections so that a programme can be tailored to your individual needs.

You may initially find some day-to-day activities more difficult to complete: please discuss any concerns you may have with your therapist.

The Spasticity Management Team
National Hospital for Neurology and Neurosurgery
Queen Square
London WC1N 3BG
Tel: 020 3448 3439 (If not available please leave a message on the answer phone / voicemail and your call will be returned as soon as possible. The line is confidential.)
Fax: 020 3448 4737

Page last updated: 11 June 2024

Review due: 01 May 2025