Restless Legs Syndrome (RLS) is a neurological disorder characterised by unpleasant sensations in the legs and the compelling need to move the legs, usually experienced when trying to sleep. The strange sensation, usually in the calves, has been described as a type of cramp, soreness or a creeping, crawling feeling. Some liken the sensation to shooting darts of electricity, or even squirming insects inside the legs. The sensations range in severity from uncomfortable to irritating to painful.
The most distinctive feature of the condition is that lying down and trying to relax brings on the symptoms. As a result, most people with RLS have difficulty falling asleep and staying asleep. Left untreated, the condition can cause exhaustion and daytime fatigue.
People with RLS feel uncomfortable sensations in their legs, especially when sitting or lying down, accompanied by an irresistible urge to move about. These sensations usually occur deep inside the leg, between the knee and ankle; more rarely, they occur in the feet, thighs, arms, and hands. Although the sensations can occur on just one side of the body, they most often affect both sides.
Because moving the legs (or other affected parts of the body) relieves the discomfort, people with RLS often keep their legs in motion to minimize or prevent the sensations. They may pace the floor, constantly move their legs while sitting, and toss and turn in bed.
More than 80 percent of people with RLS also experience a more common condition known as periodic limb movement disorder (PLMD). PLMD is characterized by involuntary leg twitching or jerking movements during sleep that typically occur every 10 to 60 seconds, sometimes throughout the night. The symptoms cause repeated awakening and severely disrupted sleep. Unlike RLS, the movements caused by PLMD are involuntary – people have no control over them.
Most people find the symptoms of RLS to be less noticeable during the day and more pronounced in the evening or at night, especially during the onset of sleep. For some people, the symptoms disappear by early morning, allowing for more refreshing sleep at that time. Other triggering situations are periods of inactivity such as long car trips, sitting in a movie theatre, long-distance flights, immobilisation in a cast, or relaxation exercises.
American research suggests that about five out of every 100 people will suffer from RLS at some time. Usually, both legs are affected, but it is not uncommon to experience the unpleasant sensations in only one leg.
The cause is unknown but people with a family history of RLS make up approximately 50% of cases, and people with low iron levels or anaemia, chronic diseases such as kidney failure, diabetes, Parkinson’s disease, and peripheral neuropathy, some pregnant women in their last trimester and people taking certain medications – such as anti-nausea, anti-seizure, and antipsychotic drugs, and some cold and allergy medications – appear to be more likely to suffer from RLS.
RLS can affect anyone of any age, although the disorder is more common with increasing age. It occurs in both genders, although the incidence may be slightly higher in women. Sometimes people will experience spontaneous improvement over a period of weeks or months. Although rare, spontaneous improvement over a period of years also can occur. If these improvements occur, it is usually during the early stages of the disorder. In general, however, symptoms become more severe over time.
The clinical diagnosis of RLS is difficult to make. Physicians must rely largely on patients’ descriptions of symptoms and information from their medical history, including past medical problems, family history, and current medications. Patients may be asked about frequency, duration, and intensity of symptoms as well as their tendency toward daytime sleep patterns and sleepiness, disturbance of sleep, or daytime function. If a patient’s history is suggestive of RLS, laboratory tests may be performed to rule out other conditions and support the diagnosis of RLS. Blood tests, studies to measure electrical activity in muscles and nerves, and Doppler tests be to evaluate muscle activity in the legs may be recommended. Such tests can document any accompanying damage or disease in nerves and nerve roots (such as peripheral neuropathy and radiculopathy) or other leg-related movement disorders. Negative results from tests may indicate that the diagnosis is RLS.
Movement brings temporary relief from the symptoms of RLS, but the disorder can be controlled by treating any underlying disorder such as diabetes or anaemia.
For patients where there is no apparent associated medical condition, treatment is directed at relieving symptoms. For those with mild to moderate symptoms many doctors suggest certain lifestyle changes and activities to reduce or eliminate symptoms, such as decreased use of caffeine, alcohol, and tobacco. It may be appropriate that certain individuals take supplements to correct deficiencies in iron, folate, and magnesium. Studies also have shown that maintaining a regular sleep pattern can reduce symptoms. Some individuals, finding that RLS symptoms are minimized in the early morning, change their sleep patterns. Others have found that a program of regular moderate exercise helps them sleep better; on the other hand, excessive exercise has been reported by some patients to aggravate RLS symptoms. Taking a hot bath, massaging the legs, or using a heating pad or ice pack can help relieve symptoms in some patients. Although many patients find some relief with such measures, rarely do these efforts completely eliminate symptoms.
A number of medications may be tried to treat the disorder, including central nervous system depressants, opioids and anticonvulsants. The major class of medication that helps in restless legs syndrome are those that increase dopamine transmission in the central nervous system. These include both common levodopa preparations (Sinemet and Madopar), as well as the dopamine agonists pergolide and cabergoline. These drugs are effective in the majority of RLS patients. However no one drug is effective for everyone with RLS. What may be helpful to one patient may actually worsen symptoms in another. Further, medications taken regularly may lose their effect, making it necessary to change them periodically.
RLS is generally a lifelong condition for which there is no cure. Symptoms may gradually worsen with age (though more slowly for those with the form of RLS not associated with any other disorder than for patients who also suffer from another medical condition such as those mentioned above). Nevertheless, current therapies can control the disorder, minimising symptoms and increasing periods of restful sleep. In addition, some patients have remissions – periods in which symptoms decrease or disappear for days, weeks, or months, although symptoms usually eventually reappear. A diagnosis of RLS does not indicate the onset of another neurological disease.
Further Information and Support
National Institutes of Neurological Disorders and Stroke (USA)
Reviewed by Dr Dominic Rowe, Neurologist, Royal North Shore Hospital, Australia
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