More MS news articles for Nov 2001

Restless Legs: Treatable, if Recognized

November 27, 2001
At least 12 million people in this country have a condition affecting their limbs that could give even the calmest among them the heebie-jeebies. It goes by the exceedingly apt name of restless legs syndrome and is characterized by a variety of discomforting sensations that occur at rest and compel sufferers to get up and move around.

People describe the sensations as creeping, tingling, pulling, twitching, tearing, aching, throbbing, prickling or grabbing; some feel as if insects are crawling on them or an electric current is running through their limbs. Some even use the word painful. But whatever the nature of the sensation, the result is the same: an uncontrollable urge to relieve it by moving the affected limb.

Yet, as common as this condition apparently is, most people have never heard of it and only about one in 10 sufferers has actually been given the diagnosis. And, since there are effective treatments, millions of people, for lack of a diagnosis, may suffer needlessly or resort to a host of unproven remedies to try to find relief.

When Symptoms Strike

The disturbing symptoms can occur whenever a person has to sit or lie still for any length of time, like in a theater or concert hall, at a meeting, on an airplane, or while dining out, riding in a car, reading a book, watching television or a movie or, most often and distressing of all, when going to bed. As one might expect, restless legs syndrome can cause insomnia. Falling asleep can be particularly difficult, since as soon as sufferers are lying quietly, they are likely to be forced to get up and walk around to relieve the discomfort.

When walking is not an option, those affected may resort to rocking, shaking, stretching, bending, marching in place or otherwise acting like a person who simply cannot sit still.

After finally falling asleep, many sufferers also experience "periodic limb movements in sleep" repetitive, jerky movements that typically occur every 25 to 40 seconds during nondream sleep. When severe, these movements can disrupt sleep and often also disrupt the sleep of bed partners.

Chronic daytime fatigue and sleepiness is a common consequence of the insomnia caused by restless legs syndrome and the interruptions in sleep caused by periodic limb movements. Not infrequently, bed partners resort to sleeping elsewhere.

Both restless legs syndrome and periodic limb movements in sleep can occur in children, especially if a parent has one or both problems, since they tend to run in families. Both problems also become increasingly common with age; more than 30 percent of people over 65 are plagued by periodic limb movements during sleep. Sometimes symptoms will diminish significantly or disappear on their own for a time, but more often they get worse with time.

In addition to leg symptoms, some 20 percent to 30 percent of people with restless legs syndrome experience similar sensations in their arms and in some people the disturbing feelings occur even in the trunk of the body.

According to a study described in June to a meeting of professional sleep researchers, in at least one part of the country nearly one patient in five who visits a primary care doctor suffers from this frequently undiagnosed yet treatable condition.

The study was conducted by a team of sleep specialists led by the renowned sleep researcher Dr. William C. Dement, director of the Stanford University Sleep Clinic and Research Center. The researchers questioned nearly 1,700 primary care patients in the mountain town of Moscow, Idaho.

In this population, primarily of northern European descent, more than 400 patients, or nearly 25 percent who visited a primary care doctor for any reason, had clear-cut symptoms of restless legs syndrome, a prevalence twice that observed in previous studies.

The National Institutes of Health, for example, estimates that 5 percent to 10 percent of the population, or at least 12 million people in this country, suffer from the syndrome.

The researchers suggested that there might be something unusual about the Idaho population that could lend further insight into the causes of restless legs syndrome.

Causes and Treatments

Neurologists describe restless legs syndrome as a sensorimotor disorder, mainly involving the subcortical areas of the brain, although exactly what part of the nervous system is involved is still a matter of debate.

Drug studies have offered the main clues, suggesting that the central nervous system, particularly brain functions that depend on the action of the brain chemical dopamine, are involved. This is the same substance that is depleted in Parkinson's disease.

Low doses of L-dopa as well as other drugs that stimulate dopamine activity have been found to provide some patients with almost complete relief from restless legs syndrome for as long as the drug is taken.

Other drugs that are sometimes helpful include sedatives, opioid painkillers and anticonvulsants. But to date, the Food and Drug Administration has not approved any drug specifically for the treatment of restless legs or periodic limb movements.

Probably the most common curable cause of the syndrome is iron deficiency, which may explain the high rates of the condition and the almost universal problem of periodic limb movements in sleep experienced by pregnant women, especially during the last months of pregnancy. Iron deficiency may also explain the high rates of restless legs syndrome in people with kidney failure, both before and after they start kidney dialysis.

Studies have found abnormally low levels of iron in virtually everyone with the syndrome. In fact, iron may explain the relationship between restless legs syndrome and dopamine, since iron deficiency disrupts the production of dopamine in the brain. Thus, everyone with restless legs syndrome should be checked first for iron status.

There is also some evidence that a magnesium deficiency, correctable with supplements, may be involved in the syndrome.

According to information from the Restless Legs Syndrome Foundation Inc., other helpful measures include maintaining a regular sleep schedule; doing daily but moderate physical activities, especially those for the limbs; taking very hot or cold baths; engaging in engrossing mental activities and avoiding caffeine, alcohol, antihistamines and antiemetics, as well as drugs like Reglan, calcium-channel blockers and others that suppress dopamine.

For more information about restless legs syndrome, contact the foundation at 819 Second St. SW, Rochester, Minn. 55902-2985, or call toll-free (877) 463-6757. The foundation publishes a free information booklet, "Living With Restless Legs," and a quarterly newsletter, "Nightwalkers," and provides a network of support groups. More medical information is available on the foundation's Web site:
Copyright 2001 The New York Times Company