How might Parkinson’s affect pain?
People with Parkinson’s can experience many different types of pain, including:
1. musculo-skeletal pain
This is experienced in the muscles and bones and is usually felt as an ache around the joints in the arms and legs. Very common in Parkinson’s, it tends to be localised and static (rather than shooting down a limb). This type of pain can also be caused by cramps and spasms as a result of muscle rigidity. It often responds well to painkillers (e.g. paracetamol), regular exercise and, in some cases, physiotherapy.
2. radicular pain
A sharp pain that shoots down a limb and may affect fingers or toes. It is usually related to trapped nerves in the spinal cord and can feel similar to an electric shock, such as tingling or a burning sensation. Painkillers and exercise will generally settle the pain, although an x-ray may be required to locate the trapped nerves. Where severe pain persists, a referral to a neurologist might be necessary to check for compression of the nerve roots at the spinal cord. A neck collar may help to relieve pressure on the nerve in some cases.
3. dyskinetic pain
This is caused by the dyskinesias that can result from some Parkinson’s medications. It can affect any part of the body and feels like a deep ache. It tends to occur during the day just before, during or after dyskinesias occur. The twisting movements of severe dyskinesias may also cause pain and aggravate radicular pain caused by a trapped nerve.
Dyskinetic pain may also occur because of the wide ranges of responses an individual will have to their anti-Parkinsonian medications, depending on, for example, the time of day or whether an ‘off’ period is being experienced. Dystonia can result – particularly early in the morning or during the night - causing spasms and painful cramps from abnormal positioning of the body’s extremities (toes, fingers, ankles or wrists). Prolonging ‘on’ time when the medication is working can reduce this pain. This can be achieved in several ways, such as:
- taking small but frequent doses of levodopa
- combining levodopa with a COMT inhibitor
- using a long acting dopamine agonist .
If early morning pain is caused by dystonia resulting from an ‘off’ period, injections of apomorphine may help – this medication is quick to take effect and many people can be taught to self-administer it. Use of long acting dopamine agonists such as the rotigotine skin patch or cabergoline may also help early morning dystonia related to off periods. In severe cases injections of botulinum toxin may be tried.
Occasionally dyskinetic pain may occur when anti-Parkinsonian medications are at the peak of their effectiveness, in which case the doctor may suggest reducing the dosage of medication.
4. akathisia or restlessness pain
This is particularly common in the legs, especially at night (see Restless Legs Syndrome (RLS)). Akathisia is quite difficult to describe – it is often experienced more as a discomfort than a pain. A desire to move the limbs and fidget can interfere with sleep, and the only way to obtain relief is to move the legs or wander. Whilst akathisia tends to be a side effect of anti-Parkinsonian medication, it can respond well to a combination of medications. Controlled release levodopa or a long acting dopamine agonist can be beneficial, as well as sleep promoting agents.
5. muscle cramps
These may occur during the day or night and can disrupt sleep. Commonly causing pain in the legs and calf muscles, as well as restlessness. The wearing off effects that are a side effect of the medication can also cause cramps and painful dystonia.
Cramps may also occur in internal organs, particularly the bowel (causing abdominal pain) and the bladder (causing pain and an urgent need to go to the toilet). muscle relaxants can help, as can anti-Parkinsonian medication such as controlled release levodopa. If bowel cramps are related to severe ‘off’ periods, injections of apomorphine may alleviate them. Quinine sulphate tablets can also be beneficial, but this option must be discussed with a doctor first as they can cause blood abnormalities.
6. shoulder and limb pain
A constant ache that affects only one side of the body (generally an arm or leg) can be a sign of Parkinson’s onset. Such pain may be relieved by regular anti-Parkinsonian medications and physiotherapy. If pain persists, painkillers or a referral to a ‘pain clinic’ or rheumatologist may be necessary. A steroid injection is sometimes used to treat frozen shoulders.
7. coat hanger pain
This is rare in Parkinson’s, but can affect people who experience postural hypotension (a sharp drop in blood pressure on standing up). More commonly this type of pain occurs in those who have Multiple System Atrophy (MSA), another form of Parkinsonism.
The area of the body affected by this pain resembles a coat hanger, hence its name. It starts at the back of the neck and then radiates to the head and shoulder muscles. The cause is unclear, although some believe it occurs when the supply of blood to the muscles in the neck and shoulder is reduced as a result of postural hypotension.
Coat hanger pain should be discussed with the doctor. A referral may be needed to a specialist movement disorder centre or clinic.
8. headaches
For people with Parkinson’s, headaches can occur at any time and can be caused by medications such as dopamine agonists, amantadine and entacapone. Such headaches generally respond well to over-the-counter painkillers. Severe headaches that are not alleviated by painkillers are rare in Parkinson’s and should be investigated by a neurologist if they occur. It is important to consult your doctor about any headaches experienced as they can have many causes – not all necessarily related to Parkinson’s.
9. burning mouth
Pain or burning sensations felt in the mouth may be a result of anticholinergic medications, such as benzhexol, or poorly fitting dentures. Anyone who experiences this should consult their dentist. Regular use of an antiseptic mouthwash can help, as can keeping the mouth moist with sips of water or by sucking a sweet or ice chips. Poorly fitting dentures should be replaced. The anticholinergic medication may need reducing or even discontinuing as it can cause dry mouth, which exacerbates the problem.
10. akinetic crisis pain
This can occur if anti-Parkinson medications are withdrawn abruptly causing Parkinson’s symptoms to suddenly intensify, or if an infection sets in. Such pain can include severe stiffness or rigidity in the joints and muscles, headache, fever and sometimes pain affecting the whole body. It is usually relieved by treating with levodopa.
