Although dystonia is a medical condition in its own right (known as primary dystonia), it can also be a symptom of several other diseases or syndromes (known as secondary or symptomatic dystonia), including Parkinson’s.
It can affect people of all ages, but for people with Parkinson’s, dystonia is more common when the onset of the disease was at a young age. It tends to develop gradually, and may worsen as the condition progresses. The side of the person where Parkinson’s symptoms are more pronounced is usually most affected. However, dystonia can be experienced in more than one part of the body. In fact, when the onset of Parkinson’s is after the age of around 40, dystonia usually remains focal, affecting a single area of the body. But when onset of Parkinson’s is young, dystonia is likely to affect a number of parts of the body, or become generalised (where most of the body is affected).
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.
Sustained dystonic spasms cause varying degrees of pain, from mild to severe, and sometimes such spasms are mistaken for the muscle cramps that result from rigidity and bradykinesia in Parkinson’s.
Less commonly, dystonia may appear as:
- ‘writer’s cramp’ in the hands (a type of focal dystonia) which only occurs during handwriting
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cervical dystonia (spasmodic torticollis) affecting the neck muscles, which causes the head to twist to one side, forwards or occasionally backwards
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blepharospasm in which the eyelid muscles contract and makes the eye close involuntarily. this is often experienced as excessive blinking, intolerance to light, a burning feeling in the eye or irritation
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spasmodicor laryngea dystonia affecting the vocal chords or speech muscles causing strained and difficult speaking
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oromandibular dystonia affecting 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 in Parkinson’s may be a symptom of the condition, but it can also be a side effect of the medication levodopa. Levodopa-related dystonia tends to last longer than symptomatic dystonia and is very complicated. The wearing off side effects that some people experience with this medication (where the drug becomes less effective before the next dose is due) can cause off-dystonia. This is particularly common in the morning and many people find that when they wake they have difficulties 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 the brain, as this over-stimulates the muscles and causes spasms.
Dystonia or cramps?
Muscle cramps, which are common in Parkinson's, are very different to dystonia. Rather than contracting muscles, cramps are caused by the muscular rigidity and reduced movement (bradykinesia). But, like dystonia, cramps can also be painful and very distressing. Normal painkillers do not usually relieve them, but muscle 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 methods do not help, then your doctor may prescribe muscle relaxants.
