Restless legs syndrome

(This article was first printed in the September 2007 issue of the Harvard Men’s Health Watch. For more information or to order, please go to http://www.health.harvard.edu/mens.)

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 is essential to rest the mind, allowing it to function efficiently and creatively during the day. And sleep is just as important for the body, giving 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, their repose is shattered by 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).

A matter of record

The first modern account of RLS dates to 1945, when a Swedish physician, Dr. K. A. Ekbom, recognized the problem and named it. But an English physician, Sir Thomas Willis, actually beat him to the punch by 273 years when he wrote, “To some, when being a bed they betake themselves to sleep, presently in the… Leggs Leapings and Contractions… and so great a Restlessness and Tossing of their Members ensue, that the diseased are no more able to sleep than if they were in a place of the greatest Torture.” The symptoms have not changed since 1672, but treatment can now put an end to the torture.

Symptoms

Leg discomfort is the first symptom of RLS. It’s usually described not as pain but as a tingling, pricking, bubbling, tearing, or burning sensation like “ants crawling up my legs” or “soda pop in my veins.” Most often, the discomfort is centered deep inside the calves, but it can also occur in the thighs or feet. In most cases, both legs are equally affected, but touching the skin or pressing on the muscles does not increase the discomfort; in fact, some patients report temporary relief from massaging their restless 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 comfortable chair. The symptoms usually begin shortly after bedtime. As RLS becomes more severe, the discomfort begins earlier and earlier in the day but always intensifies 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, causing morning headaches, fatigue, or exhaustion, afternoon somnolence, poor concentration, impaired memory and productivity, and personality changes ranging from grumpiness to depression and even bizarre or inappropriate behavior.

Double trouble

About 80% of people with RLS also have a related disorder, periodic limb movement disorder (PLMD). PLMD produces repetitive involuntary leg muscle contractions: The legs jerk spasmodically (“Elvis legs”) every 30 seconds or so during the non-dreaming 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 or her bed partner certainly does. And even if jerking legs don’t wake a person up, they impair the quality of sleep (and, perhaps, marriage).

Who gets RLS, and why

RLS is common. Various surveys report it in 5% to 25% of all adults; most peg the prevalence at about 10%. 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. In all age groups, 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 the age of 45 (early-onset RLS).

Some cases of RLS are tied 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.

Diagnosis

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:

1. A distressing sensation deep in the legs that produces a strong urge to move the legs and is
2. Brought on by rest and
3. Worse at night or in the evening and
4. Relieved by moving or walking.

It sounds simple, but some 90% of people with RLS are not diagnosed properly. The symptoms are often mistaken for insomnia, sleep apnea or other sleep disorders, arthritis, muscle cramps, peripheral artery disease, peripheral nerve disease, or psychiatric disorders. It’s a shame, since RLS can result in serious disability but usually responds well to treatment if it’s recognized for what it is.

Doctors can evaluate possible RLS by performing a sleep study (polysomnography), but this inconvenient and expensive test is important only if it’s not clear whether a patient has RLS or another sleep disorder, such as sleep apnea. In most cases, patients don’t need anything more than simple blood tests for diabetes, kidney disease, and iron deficiency. If iron levels are low, iron tablets may help — but doctors should always find out why the iron levels are low. In most sufferers, however, other treatments are necessary.

Help yourself

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 may aggravate RLS.

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 — and that means cola and energy drinks and chocolate, as well as coffee and tea.

Getting moderate exercise during the day may help calm your legs at night; walking is a fine example. Special leg-stretching exercises at bedtime may also help (see figure). Some people find that cold showers are beneficial, but others prefer heat. Finally, 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.

Medication

Despite its name, RLS is not a disorder of the legs but 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 since 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.

Some patients with RLS respond well to a simple tranquilizer (such as diazepam, or Valium) at bedtime, and others do well with a pain reliever (such as propoxyphene, or Darvon). But drugs that boost the brain’s supply of dopamine or mimic its effect in the brain appear more effective, especially for moderate to severe RLS.

The first drug that proved useful is levodopa, which is converted by the brain into dopamine. It is usually administered along with carbidopa in a single tablet (Sinemet). Because higher doses and daily therapy can actually make RLS worse, it is wise to reserve Sinemet for patients with occasional RLS who respond to low doses of the drug and need treatment no more than two or three times a week. Other side effects may include nausea, lightheadedness, hallucinations, and insomnia.

A better approach is to use drugs that mimic the action of dopamine. Ropinirole (Requip) and pramipexole (Mirapex) are approved by the FDA specifically for RLS. 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, nasal stuffiness, and fatigue. A related dopamine mimic, cabergoline (Dostinex), can also relieve RLS, but unlike the preferred drugs, it has been linked to heart valve scarring when used in high doses for Parkinson’s disease.

Certain antiseizure medications present another choice. Gabapentin (Neurontin) is an example. Some patients respond well to as little as 100 to 300 mg at bedtime, but doctors can gradually increase the dose, if necessary. Side effects may include fatigue, sedation, dizziness, and clumsiness.

It’s good that so many medications can help, but others 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).

Relaxing 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.

(This article was first printed in the September 2007 issue of the Harvard Men’s Health Watch. For more information or to order, please go to http://www.health.harvard.edu/mens.)

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