Dystonia occurs when your muscles do not relax after they have tightened or shortened. Why this happens is not fully understood but it seems to be related to changes in the messages that the basal ganglia area of the brain sends to the muscles.
These messages or signals become irregular, often due to reduced dopamine levels. As a result, opposing muscles contract simultaneously and repeatedly over a prolonged period of time which leads to dystonia - painful involuntary twisting and difficulty controlling movement. These spasms cause varying degrees of pain, from mild to severe.
Although dystonia is a medical condition in its own right (primary dystonia), it can also be a symptom of several other conditions (secondary or symptomatic dystonia), including Parkinson’s.
Dystonia can affect:
- one part of the body - known as focal dystonia
- two parts - known as segmental dystonia
- several parts - known as multifocal dystonia
- most of the body - known as generalised dystonia.
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Causes in Parkinson’s
Dystonia can occur at any age, but it is more common in people who are diagnosed with Parkinson’s before they are 40. It tends to develop gradually, and may worsen as Parkinson’s progresses.
Dystonia tends to affect the side of you which is most affected by Parkinson’s symptoms, although it can affect more than one part of the body. If Parkinson’s onset is after the age of around 40, dystonia usually remains focal (affects a single area of the body). But if onset is below the age of around 40, dystonia is likely to affect a number of parts of the body, or become generalised (affects most of the body).
Dystonia in Parkinson’s may be a symptom of the condition, but it can also be a side effect of the medication levodopa.
Off-dystonia is caused by wearing off (when levodopa becomes less effective before the next dose is due). This is particularly common in the morning and you may have difficulty getting out of bed until the next dose of medication starts to take effect.
On-dystonia can also occur when levodopa reaches its peak of effectiveness and there is too much dopamine in your brain. This over-stimulates your muscles and causes spasms.
How might dystonia be experienced?
- Feet: people with Parkinson’s mainly experience dystonia in their feet. Typically the toes curl up into a claw-like position, the foot turns inwards at the ankle, and occasionally the big toe sticks up. This position, caused by spasms in the calf muscles, can be very uncomfortable and makes it hard to fit feet into tight shoes.
- Hands: ‘writer’s cramp’ in the hands (a type of focal dystonia) only occurs during handwriting.
- Neck: cervical dystonia (spasmodic torticollis) affects the neck muscles, which causes the head to twist to one side, forwards or occasionally backwards.
- Eyelids: the eyelid muscles may contract and make the eye close involuntarily (known as blepharospasm). This is often experienced as excessive blinking, intolerance to light, a burning feeling in the eye or irritation.
- Vocal cords: dystonia affecting the vocal cords or speech muscles (known as spasmodic or laryngeal dystonia) makes speaking difficult or strained.
- Jaw area and side of the face: oromandibular dystonia affects the jaw area, tongue, mouth or one side of the face. The jaw may be pulled either open or shut, and speech and swallowing can be difficult.
Dystonia or muscle cramps?
Muscle cramps and dystonia occur when one of your muscles, or a group of muscles, tightens or shortens involuntarily.
Muscle cramps and dystonia can be confusing as they can feel very similar. You may not always be able to tell the difference between them, but they are caused by separate problems and are therefore treated differently.
Muscle cramps in Parkinson’s are generally caused by muscular rigidity and reduced movement (bradykinesia) rather than by muscles contracting. But, like dystonia, cramps can also be painful and very distressing.
Normal painkillers do not usually relieve them, but cramps often respond well to massage and the use of a hot water bottle or heated pad. Movement and exercise may also help to release cramps and reduce stiffness. If these do not help, then your doctor may prescribe muscle relaxants.
What treatment is available?
For treatment to be effective, it is essential to understand the trigger or cause of the dystonia. Certain medications may be effective for some people but not for others. Some work by interfering with neurotransmitters in the brain and disrupting the messages they send to muscles. Others work by relaxing the muscles to reduce shaking and improve muscle control.
Depending on the cause and severity of your dystonia, your doctor may suggest the following strategies:
- A controlled release form of levodopa at night, to alleviate or prevent off-dystonia in the morning. Medication is released slowly over a four to six hour period to stabilise levels of levodopa in your bloodstream.
- Crushing your first dose of medication each day so it takes effect faster but remember, not all tablets work effectively when crushed so this must be done only if suggested by your doctor or nurse. A dissolvable medication may also be prescribed.
- Smaller, more frequent doses of medication.
- The addition of a COMT inhibitor or dopamine agonist to improve the effectiveness of levodopa and reduce the likelihood of off-dystonia.
- If dystonia does not respond to changes in Parkinson’s medication then muscle relaxants or benzodiazepines may be prescribed. These reduce communication between the brain and the nervous system. Alternatively anticholinergic medications can be used to prevent the release of the chemical messenger acetylcholine. A medication may also be prescribed to reduce the release of spinal neurotransmitters which stimulate muscles.
- Botulinum toxin can be injected into the affected muscle to block the release of the chemical messenger acetylcholine and prevent it from stimulating the muscle contractions. The injected muscles are weakened and so dystonic spasms are reduced, but the treatment needs to be repeated every two or three months to remain effective. Unfortunately some people develop a resistance to this treatment over a period of time.
- Surgical procedures such as deep brain stimulation (DBS) have been found to be effective in managing dystonia in those who do not respond to medication. These are not appropriate for everyone so you will need to discuss surgical options with your doctor.
Remember that not all of these strategies will work for everyone so it is important to communicate well with your doctor so that, together, you can find the best solution for you.
Keeping a diary: If the dystonia is levodopa-related, it is a good idea to keep a 'motor diary' to record when dystonic spasms occur and how they relate to the timing of medications. This information can help your doctor adjust dosage and/or timings of medication to better manage your dystonia. For more information, see Keeping a diary.
How can I help myself?
You will need to try a variety of sensory ‘tricks’ to see what works for you as dystonia affects everyone differently.
Spasms may be reduced by touching the affected part of the body either before or during any movement known to trigger dystonia. Although this may not prevent or stop a spasm, touching can distract or trick the brain and reduce the length and intensity of a muscle contraction.
Simple massage exerting pressure on the foot, or the use of a hot water bottle or heated pad can also help, as can movement and exercise - see Coping Strategies - Tips & Tricks.
For eye spasms, some people find lying down, singing, yawning, laughing, chewing, putting pressure on the eyebrows or just talking can help. Spasms in the vocal cords may respond to yawning or sneezing.
Simply relaxing may also help so try taking a bath, having a massage or a calming activity such as yoga.
Content last reviewed: June 2018
Our thanks to Parkinson's UK for permission to use the following source(s) in compiling this information:
- Muscle Cramps and Dystonia