July 20, 2012
By Harvey B. Simon, M.D.
Harvard Medical School
Although high-powered executives may deny it, sleep is actually a highly productive part of life. It may not show up on the corporate balance sheet, but it's essential to rest the mind, so it can be efficient and creative during the day. And sleep is just as important for the body. It gives muscles and joints time to recover from an active day and regroup for another go at the world.
But for at least 12 million Americans, it doesn't work that way. When they settle down for a good night's sleep, they have an irresistible urge to move their legs. The result is a miserable night of fragmented sleep, daytime sleepiness, personality changes and often a grumpy spouse. The problem is restless legs syndrome (RLS).
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What RLS Feels Like
Leg discomfort is the first symptom of RLS. People usually describe the feeling as tingling, pricking, bubbling, tearing or burning. People say it's like "ants crawling up my legs" or "soda pop in my veins."
Most often, the discomfort is felt deep inside the calves, but it can also occur in the thighs or feet. In most cases, both legs are equally affected. A few patients report temporary relief from massaging their legs. In severe RLS, symptoms can also develop in the arms.
Most types of leg pain are triggered by activity and relieved by rest, but in RLS, it's the reverse. The symptoms begin during rest and are most intense when the sufferer is or should be the most comfortable. RLS typically begins in bed at night, but it can also develop when people settle into a chair.
The symptoms usually begin shortly after bedtime. As RLS becomes more severe, the discomfort begins earlier and earlier in the day, but always gets worse at bedtime.
The only way people with RLS can stop the ants crawling through their legs is to move about. They fidget, adjust their legs, and toss and turn in bed. The urge to move is irresistible. In severe RLS, patients have to get out of bed and pace the floor to get relief.
The result is a truly bad night's sleep that causes:
- Morning headaches
- Fatigue or exhaustion
- Afternoon sleepiness
- Poor concentration
- Impaired memory and productivity
- Personality changes that range from grumpiness to depression and even bizarre or inappropriate behavior
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About 80% of people with RLS also have a related disorder, periodic limb movement disorder (PLMD). The legs jerk spasmodically ("Elvis legs") every 30 seconds or so during the nondreaming phases of sleep. Unlike the creepy discomfort of RLS, the jerking movements of PLMD occur during sleep, so the patient doesn't know they are occurring but his bed partner certainly does. And even if jerking legs don't wake a person up, they impair the quality of sleep (and, perhaps, the marriage).
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Who Gets RLS -- and Why?
RLS is very common. About 10% of all adults have it. Fortunately, only about a quarter of all people with RLS are affected seriously enough to require medical attention. RLS becomes more common as people get older, but it can begin surprisingly early in life. In early childhood RLS is often misdiagnosed as "growing pains" or attention deficit disorder. RLS is more common in females than males.
In most cases, the cause is unknown. About 50% of patients have a strong family history of RLS, and researchers have linked the disorder to specific genetic abnormalities. A genetic basis is particularly likely in patients whose symptoms begin before age 45 (early-onset RLS). RLS has also been linked to other medical problems. Iron deficiency is the most common, which is why RLS often develops in regular blood donors. It has also been linked to diabetes, kidney disease, varicose veins, rheumatoid arthritis and Parkinson's disease, among other problems. When an underlying disease is linked to this syndrome, it's called secondary RLS. But in most cases RLS strikes without rhyme or reason; then doctors call it primary RLS.
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Even in this age of CT scans and DNA sleuthing, there is no fancy test for RLS. Instead, the diagnosis depends on four simple criteria:
- There is a strong urge to move the legs brought on by a distressing sensation deep in the legs.
- The sensation is triggered by rest.
- It's worse at night or in the evening.
- Moving or walking relieves the symptom.
Many people, too, have uncontrollable leg movements while they are lying awake in bed and/or periodic jerking during sleep (PLMD).
Diagnosing RLS may sound simple enough. But up to 90% of people with RLS are not diagnosed properly. The symptoms are often mistaken for insomnia or other sleep disorders, arthritis, muscle cramps, peripheral artery disease, peripheral nerve disease or psychiatric disorders. It's a shame, because RLS can result in serious disability. It usually responds well to treatment if it's recognized for what it is.
To confirm RLS, most patients don't need anything more than simple blood tests for diabetes, kidney disease or iron deficiency. If it's not clear whether a patient has RLS or another sleep disorder, the doctor can do a sleep study. But it's expensive and inconvenient. If iron levels are low, iron tablets may help, but doctors should always find out why the iron levels are low. Most sufferers, however, need other treatments.
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The first step is to get a general check-up to make sure your overall health is good and to correct any problems your doctor may uncover. In particular, you should review your medications. Some drugs, such as those listed below, may aggravate RLS. Your doctor will consider switching you to other medications.
- If you smoke, stop. It may help relieve RLS, and it will surely help your health.
- If you drink alcohol, try stopping to see if it helps take the edge off your RLS. The same goes for caffeine cola and energy drinks, chocolate, coffee and tea.
- Get moderate exercise, such as walking, during the day. It may help calm your legs at night.
- Try leg-stretching exercises and a warm bath at bedtime.
- Some people with mild RLS may be able to get to sleep by simply massaging their calves or stretching their legs in bed. But most people with moderate to severe RLS need medication.
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Get Relief with Medications
Despite its name, RLS is not a disorder of the legs. It's a disorder of the nervous system. Many experts believe that it's caused by low levels of dopamine, a chemical that transmits signals between nerve cells. Parkinson's disease is also caused by a dopamine deficiency. But that disease is more serious because brain cells that produce dopamine are progressively damaged and destroyed. Even though RLS and Parkinson's disease are very different disorders, some of the best drugs for RLS were originally developed for Parkinson's.
The drugs ropinirole (Requip) and pramipexole (Mirapex) are approved for treating RLS. They mimic the action of dopamine. Doctors often start with a low dose two hours before bedtime and gradually increase the dose if necessary. Side effects are uncommon, especially in the low doses used for RLS, but may include nausea, constipation, fatigue and abnormal movements.
Other medications that can help include certain antiseizure medications, tranquilizers and pain relievers. But some drugs can make things worse. They include various antihistamines, some antidepressants, antinausea drugs (like compazine), calcium channel blockers (which are used for high blood pressure and angina) and metoclopramide (used for gastric disorders).
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Relax with Restless Legs
RLS is an old problem, but new treatments can bring relief to most patients. So if you have symptoms that may indicate RLS, check with your doctor. He may do a few simple blood tests, then take you off some medications or try you on others. One way or another, you should be able to move on to peaceful nights and productive days.
Leschziner, G, Gringras, P. "Restless leg syndrome." The British Medical Journal. 2012; 344:e3056.
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Harvey B. Simon, M.D. is an Associate Professor of Medicine at Harvard Medical School and a member of the Health Sciences Technology Faculty at Massachusetts Institute of Technology. He is the founding editor of the Harvard Men's Health Watch newsletter and author of six consumer health books, including The Harvard Medical School Guide to Men's Health (Simon and Schuster, 2002) and The No Sweat Exercise Plan, Lose Weight, Get Healthy and Live Longer (McGraw-Hill, 2006). Dr. Simon practices at the Massachusetts General Hospital; he received the London Prize for Excellence in Teaching from Harvard and MIT.