Restless leg syndrome
Introduction
The symptoms of RLS can vary from being mild to severe. In severe cases, the condition can be particularly distressing and cause disruption to daily activities.
As well as experiencing unpleasant sensations in the legs, a person with RLS will also have an overwhelming urge to move their legs in order to get some relief.
RLS was first officially described in 1945 by a Swedish neurologist called Karl-Axel Ekbom. As a result, RLS is sometimes known as Ekbom syndrome.
Types of RLS
There are two types of RLS which are described below.
- Primary RLS - occurs naturally, often during early adulthood. Initially, the symptoms are mild and infrequent, before becoming more frequent and severe in later life. Primary RLS can cause difficulty sleeping and disturbed sleep.
- Secondary RLS - occurs as a complication of another health condition, such as iron deficiency anaemia, kidney failure, or Parkinson’s disease.
The exact cause of RLS is unknown, but it is thought to be related to an imbalance of a chemical in the brain called dopamine.
How common is RLS?
It is estimated that between 5-10% of adults in western countries will develop RLS at some point during their life, with over five million people in the UK being affected by the condition.
RLS can affect both sexes, although women tend to be affected more often than men. The condition is also more common in older people, and the symptoms tend to get worse and more persistent as a person gets older.
If the symptoms of RLS are very mild, no treatment will be necessary. In cases where RLS is more troublesome, simple lifestyle changes can often help to ease the symptoms. For severe RLS, a combination of lifestyle changes and medication is often recommended.
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Symptoms
The symptoms of Restless Legs Syndrome (RLS) can vary in severity from person to person. In the mildest form RLS can be uncomfortable, or irritating. If the symptoms are more persistent, or severe, they can be distressing or in very sever cases they can be disabling.
The main symptoms of RLS are:
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uncomfortable sensations deep within the legs,
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a compelling urge to move your legs,
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difficulty falling asleep and disturbed sleep, and
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periodic leg movements (involuntary jerking movements of the legs that occur throughout the night).
RLS is not a life-threatening condition but, if your symptoms are severe, it can have a considerable impact on your day-to-day life.
Uncomfortable leg sensations
The two medical terms that are sometimes used to describe the unpleasant sensations that are associated with RLS are:
It can be difficult for people with RLS to describe the sensations that they get in their legs. The uncomfortable feelings are often described as tingling, or pricking sensations. Some people have described the sensations as being ‘like an electric current’, ‘water running down your leg’, or like having ‘itching bones’.
Overwhelming urge to move
The symptoms of RLS usually occur at rest, such as when you are sitting, lying, or sleeping. They usually begin, or get worse, in the evening and during the night.
The sensations in your legs give you an overwhelming urge to move around in order to find relief. However, as moving around usually only brings temporary relief from the symptoms of RLS, you will become restless.
Periodic limb movements of sleep (PLMS)
About 4 out of 5 people with RLS also experience a condition that is known as periodic limb movements of sleep (PLMS).
If you have PLMS, you will experience jerky, or twitchy, leg movements at night, while you are asleep. The movements are involuntary (you have no control over them) and may occur every 10-60 seconds.
The leg movements of PLMS can be severe enough to wake up both you and your partner. They may also sometimes occur when you are awake and resting.
Scoring system for RLS
RLS is often described by healthcare professionals as being mild, moderate, or severe. The different severities are described in more detail below.
Mild RLS
If you have mild RLS, your symptoms will only occur episodically (occasionally), and you will experience minimal disruption to you sleep. The condition will not be too problematic and will not cause you too much distress.
Moderate RLS
If you have moderate RLS, you will experience symptoms once or twice a week, and you will find it difficult to get to sleep. As a result, you will be tired and it is likely that there will be some disruption to your daytime activities.
Severe RLS
If you have severe RLS, you will experience symptoms more than twice a week, you will find it very difficult to get to sleep, and your sleep will be severely affected. As a result, you will be exhausted during the day which will have a significant impact on your daytime activities.
Due to the disruption to your sleep, and the overall poor sleep quality caused by RLS, the condition can often affect a person’s personal and social life and their effectiveness at work.
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Causes
In many cases of restless legs syndrome (RLS) the exact cause is unknown. However, evidence suggests that the condition is related to an imbalance of brain chemicals called neurotransmitters and, in particular, a neurotransmitter called dopamine.
Dopamine
Dopamine is a naturally occurring substance that affects movement. In the evening, dopamine levels fall which may explain why the symptoms of RLS are often worse in the evening and during the night.
Primary and secondary RLS
Cases of RLS where the cause is unknown are often referred to as primary, or idiopathic, RLS. Idiopathic is a term that describes a condition that occurs spontaneously, without an obvious cause.
Sometimes, RLS can occur as a complication of a chronic (long-term) health condition, or as a ‘side-effect’ of pregnancy. This is known as secondary RLS.
Primary RLS
Primary, or idiopathic, RLS occurs naturally. It can begin at any age, but often starts during early adulthood (under 45 years of age), with the onset of mild, occasional symptoms.
However, as the condition progresses, the uncomfortable leg symptoms often become more frequent and severe, resulting in badly disturbed sleep. This usually happens later in life (after 50 years of age).
There is some evidence to suggest that primary RLS runs in families. For example, one study found that in people who developed RLS before 45 years of age, 50% of their immediate family also had the condition. However, if the condition developed after 45 years of age, just 10% of close relatives were also affected.
Secondary RLS
Secondary RLS usually occurs as a complication of another condition, or it can develop as a result of another health-related factor.
For example, you may develop secondary RLS if you:
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have a chronic (long-term) health condition - such as diabetes, kidney failure, Parkinson's disease, or peripheral neuropathy (a condition where the nerve fibres become damaged or diseased),
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are pregnant - particularly during the last trimester (week 27 to birth); in most cases the symptoms of RLS disappear within four weeks of giving birth, or
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are taking certain types of medication - such as certain anti-epileptic medication (phenytoin or droperidol) and certain anti-psychotic medication (haloperidol or phenothiazines).
Some types of cold or allergy medications have also been known to aggravate the symptoms of RLS. If the medication you are taking is causing RLS, you should speak to your GP about the possibility of changing to an alternative.
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Diagnosis
There is no single test that is currently available for diagnosing restless legs syndrome (RLS). The condition is usually diagnosed based on your symptoms and your previous medical and family history.
The International Restless Legs Syndrome Study Group has identified four basic criteria for diagnosing RLS. These are:
- a desire to move the limbs - which is often associated with paresthesias (abnormal sensations) or dysesthesias (unpleasant abnormal sensations),
- symptoms that are present, or get worse, only during rest and are partially or temporarily relieved by activity,
- motor restlessness, and
- worsening symptoms at night.
Questioning
In order to confirm a diagnosis of RSL, your GP will ask you a number of questions about your symptoms.
In the past, RLS was a poorly understood and often misdiagnosed condition. However, it is now a recognised medical condition, so you should not be embarrassed about explaining your symptoms to your GP in detail.
Your GP will ask you questions about the type of symptoms that you have, how often they occur, how long they last for, and how severe they are. They will also want to know whether you have problems sleeping, whether you experience disturbed sleep patterns, and whether your daytime activities are adversely affected.
Blood tests
If your GP suspects that you have RLS, they may refer you for a number of tests in order to confirm or rule out a number of possible underlying causes. For example, you may have blood tests to rule out health conditions such as anaemia, diabetes, and problems with the functioning of your kidneys.
Muscle function tests
Muscle function tests can be a useful way of identifying whether conditions such as peripheral neuropathy have caused nerve damage in your legs.
Tests, such as electromyography and nerve conduction tests may be recommended to measure the electrical activity in your muscles and nerves.
Doppler sonography is another technique that measures the muscle activity in your legs. In this technique, ultrasound waves are used to assess the consistency and density of the muscles in the legs.
Sleep tests
If you have RLS and you are experiencing severe disruption to your sleep, sleep tests, such as polysomnography may be recommended.
Polysomnography is a test that measures your breathing rate, brain waves, and heartbeat throughout the course of a night. This type of test will be able to confirm whether you have periodic limb movements of sleep (PLMS).
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Treatment
Secondary RLS
If you have secondary restless legs syndrome (RLS) - where the condition is caused by another underlying health condition - diagnosing and treating that condition will help to alleviate your symptoms of RLS.
For example, if your RLS is caused by iron deficiency anaemia, taking iron tablets will increase the number of red blood cells in your blood, which may help to reduce your RLS symptoms.
In cases where pregnancy is the cause of RLS, the symptoms will usually disappear within four weeks following the birth.
Primary RLS
If you have primary (idiopathic) RLS - where the condition develops naturally, without an obvious cause - treatment will mainly be aimed at relieving your symptoms.
In cases of mild to moderate RLS, the symptoms can often be improved by making some simple lifestyle changes. In more severe cases, a combination of lifestyle changes and medication may be recommended.
If you have been diagnosed with RLS, you should discuss the treatment options with your GP.
Lifestyle changes
There are a number of lifestyle changes that may help to ease your symptoms of RLS:
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Avoid stimulants such as caffeine, tobacco and alcohol.
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Not smoking.
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Take regular, daily exercise - but avoid exercising near bedtime (see prevention section).
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Establish a regular sleeping pattern by getting up and going to bed at the same time each day, not napping during the day, taking time to relax before going to bed, and avoiding stimulants, such as caffeine, close to bedtime.
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Avoid medicines that trigger the symptoms of RLS, or make them worse - if you think that a medicine you are taking may be causing your symptoms continue taking it, and make an appointment to see your GP.
Other things that you may find help to relieve your symptoms of RLS include:
- Stretching and massaging your legs.
- Applying a hot, or cold, compress to your leg muscles,
- Taking a hot bath in the evening.
- Doing activities that distract your mind, such as reading, or watching television.
Medication
If your symptoms are severe, and making the above lifestyle changes does not help, your GP may suggest trying medication.
Not all medicines which are used to treat restless leg syndrome are licensed in the UK. If a medicine is licensed, it means that it has been approved by the Medicines and Healthcare Regulatory Agency (MHRA) as a safe and effective form of treatment.
Medicines that are unlicensed are not necessarily unsafe, and can be prescribed if a health professional feels the medicine will be of benefit , without causing you harm.
The medicine may be unlicensed because there is not enough commercial interest in marketing the treatment, or because it is awaiting approval for a license. If a medicine is unlicensed, it will be up to the discretion of your GP as to whether they prescribe it to you.
Dopamine agonists
Dopamine agonists are the most common form of medication used to treat RLS. This type of medication is also sometimes used to treat Parkinson's disease. However, you should note that if you have RLS, you do not have an increased risk of developing Parkinson's disease.
Dopamine agonists work by increasing the low level of dopamine (a chemical in the brain) that is believed to be the main cause of RLS.
There are three dopamine agonists that are licensed to treat RLS in the UK. These are:
Ropinirole and Pramipexole have been shown in clinical trials to be effective in treating RLS, and are usually the first choice dopamine agonists to be prescribed. In some cases, rotigotine may be prescribed to treat the symptoms of primary RLS in adults.
As with most forms of medication, dopamine agonists can sometimes cause side effects such as:
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nausea,
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vomiting,
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dizziness,
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sleepiness,
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indigestion, and
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confusion.
If your GP recommends a dopamine agonist, you should discuss the options with them so that you can weigh up the benefits against any possible side effects.
Unlicensed dopamine agonists
In the UK, roprinole, pramipexole, and rotigotine are the three types of dopamine agonists that are licensed to treat RLS. However, GPs, or other health professionals, may sometimes prescribe other types of dopamine agonists, such as cabergoline, if they feel they will benefit their patient.
However, these medicines will usually only be prescribed in severe cases of RLS, where other types of medicine have proved to be ineffective. This is because dopamine agonists, such as cabergoline, can cause serious side effects.
For example, cabergoline can cause inflammation, thickening, and scarring of both the lining of the abdomen, and the tissue which surrounds the heart and lungs. This inflammation is known as fibrosis. If you develop fibrosis, you may also experience breathlessness, coughing, and chest pain.
Cabergoline can also cause heart valve damage. Therefore, if you are prescribed it, you will have to have regular heart check-ups.
If you have been prescribed cabergoline to treat RLS, and you are experiencing side effects, do not stop taking it suddenly. Talk to your GP about whether there are any alternative medicines which may be more suitable.
Other medicines
In rare situations, where dopamine agonists prove unsuccessful in controlling the symptoms of RLS, other medicines, such as carbamazepine, gabapentin, and benzondiazepines, may be recommended.
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Prevention
To reduce the disruption that is often caused to daily activities by restless legs syndrome (RLS), you should ensure that you have a good sleep routine. For example, you should:
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ensure that your sleeping environment is quiet and comfortable,
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go to bed at the same time each night, and try to go to sleep and wake up at the same times every day,
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avoid exercising directly before going to bed,
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avoid eating late, or having caffeinated, or alcoholic, drinks late in the evening,
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avoid taking naps during the day and in the early evening, and
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try to relax before going to bed - for example, by taking a warm bath or having a hot milky drink.
Exercise
Studies have shown that taking regular exercise during the day may help reduce the symptoms of RLS, as well as reducing the effects of periodic limb movements of sleep (PLMS).
For example, a study that looked at the effects that exercise had on the symptoms of a group of people with RLS, who exercised three times a week, compared with a group who did not exercise, found significant improvements in the exercising group. This was a small study and further, larger trials are required in order to support the findings.
However, as regular exercise is generally thought to help improve the symptoms of RLS, it is a good idea to incorporate it into your daily routine.
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