Unknown: Restless Legs Syndrome

Definition

Restless legs syndrome is sometimes defined as a movement disorder and sometimes as a sleep disorder, because patients who suffer from it often develop insomnia. It is also known as Ekbom's syndrome, named for Karl-Axel Ekbom, a Swedish doctor who published a paper about eight patients with RLS in 1945. The oldest description of the disorder, however, was written by Thomas Willis (1621–1675), an English doctor who is considered the father of modern neurology.

Description

Patients with RLS often find the condition difficult to describe; they may speak of it as an almost irresistible urge to move the legs, usually when they are trying to sleep. The sensations are usually only bothersome but may be painful for some patients. People with RLS may use words like “pins and needles,” “like ants crawling under my skin,” “stinging,” “tugging,” “like an electrical shock,” “burning,” or “creeping” to explain to the doctor what their sensations feel like.

The patient often tries to relieve the uncomfortable feelings by moving the legs or rubbing them. The person may change position in bed or get up and walk around for a few minutes. The unpleasant sensations are usually relieved while the patient is moving around but come back when the patient is trying to rest. Many people have a daily pattern to RLS, with the symptoms worsening at night and going away around daybreak.

Demographics

It is thought that between 2 and 15 percent of the American population has RLS. Most people have only a mild form of the disorder, but others are severely affected.

RLS is more common in adults and often gets worse with age; however, it can occur in children and teenagers. One study of people with severe RLS found that a third of them had their first symptoms before they were twenty; by age fifty they had their sleep disrupted almost every night by the disorder.

RLS is thought to affect men and women equally, although some researchers report that it is more common in women.

Causes and Symptoms

Restless legs syndrome has two subtypes, primary RLS, which runs in families; and secondary RLS, which may be caused by iron deficiency, pregnancy, kidney failure, or abnormalities of the nerves in the legs. Restless legs syndrome is not caused by mental disorders or by stress, but it can make them worse or be made worse by them. In some cases RLS is a side effect of certain medications—particularly cold remedies, decongestants, some types of allergy medications, and some drugs given to stop nausea and vomiting.

Several theories have been offered about the cause of RLS but none have been proven. Dr. Ekbom thought that RLS might be caused by slow circulation of the blood in the leg veins. Other suggestions include abnormal levels of neurotransmitters, which are chemicals produced by the brain that transmit impulses from one nerve cell to the next. Neurotransmitters affect muscle movement as well as moods and emotions. In 2007 a group of researchers in Iceland discovered a gene that increases a person's risk of developing RLS.

The central symptom of restless legs syndrome is uncomfortable sensations in the legs combined with an urge to move the legs in order to

relieve the sensations. About 85 percent of patients with RLS also have periodic leg movements during sleep, and about 90 percent have trouble getting a good night's sleep. Many of these patients have problems with daytime drowsiness and depression related to loss of sleep.

Diagnosis

There is no laboratory test for restless legs syndrome. Any imaging tests or other medical tests that are performed are done to rule out other disorders of the muscles or nervous system. The doctor usually bases the diagnosis on the patient's descriptions of how his or her legs feel and what makes them feel better. There are four criteria that define RLS, listed in 1995 by an international committee:

• The person has a strong urge to move the legs that is impossible to resist. The need to move the legs is combined with uncomfortable sensations in the legs.
• The symptoms become worse when the person is resting or sitting still.
• The symptoms are relieved very quickly when the person starts moving the legs.
• The symptoms are worse at night, especially when the person is lying down.

Treatment

Some patients can be helped without prescription medications by cutting down on beverages containing caffeine (coffee, tea, and cola drinks), limiting their use of alcohol, and getting a healthful amount of physical exercise. Other non-drug treatments include hot baths, massaging the legs, or applying hot or cold packs.

Yoga Therapy for RLS

Yoga is increasingly recommended as a treatment for restless legs syndrome (RLS), as a good overall form of exercise for maintaining flexibility of joints and muscles, and a relaxation technique to relieve stress.

Typical yoga workouts consist of a series of body postures (asanas), usually involving gentle stretching or twisting movements; the person moves gradually into the asana and holds it for a few seconds while using breathing exercises.

Asanas that increase blood circulation in the lower legs are recommended for RLS. Alice Christensen, founder of the American Yoga Association, recommends the knee squeeze and the spine twist. For the former, the person lies flat on the back with arms at the sides. Breathing in to a count of three, the person raises the right knee to the chest, wraps the arms around the knee, and holds his or her breath for a count of three while squeezing the knee against the chest. Then the person breathes out to a count of three, straightening the leg until it rests on the floor. This is repeated with the left leg.

In the spine twist, the person lies with the shoulders flat on the floor and gently rotates the spine by twisting at the waist. One knee is bent, brought up, and crossed over the body while the other leg remains on the floor.

Patients who are not helped by these treatments may be given one or more types of drugs to relieve their symptoms. One type of drug works

by changing the levels of neurotransmitters in the brain. Other groups of drugs used to treat RLS include tranquilizers, painkillers, and drugs used to treat epilepsy. The doctor may have to try more than one type of medication before finding one that will work for the specific patient.

Patients who have RLS because of an iron deficiency in their blood can be given iron supplements.

Prognosis

The prognosis of the disorder depends on the person's age and whether he or she has the primary form or the secondary form of RLS. Older people are less likely to benefit from treatment. Women who develop RLS during pregnancy often feel better after the baby is born.

Prevention

There is no known way to prevent RLS because the causes of the disorder are not fully understood.

The Future

Genetic research may help scientists to better understand the causes of RLS and then develop a treatment that will work for everyone with the disorder.

WORDS TO KNOW

Neurology : The branch of medicine that studies and treats disorders of the nervous system.

Neurotransmitters : Chemicals produced in the brain that transmit nerve impulses to other nerve cells and eventually to muscles.

Primary disease : A disease that develops by itself and is not caused by a previous disease or injury.

Secondary disease : A disease that is caused by another disease or condition or by an injury.

For more information

BOOKS

Buchfuhrer, Mark J., Wayne A. Hening, and Clete A. Kushida. Restless Legs Syndrome: Coping with Your Sleepless Nights. New York: Demos/AAN Press, 2007.

Yoakum, Robert H. Restless Legs Syndrome: Relief and Hope for Sleepless Victims of a Hidden Epidemic. New York: Fireside Books, 2006.

WEB SITES

American Academy of Family Physicians (AAFP). Restless Legs Syndrome: What It Is and How to Cope. http://familydoctor.org/online/famdocen/home/seniors/common-older/868.printerview.html (updated March 2008; accessed April 14, 2008).

Johns Hopkins Center for Restless Legs Syndrome. About RLS. http://www.neuro.jhmi.edu/rls/edu.html (accessed April 14, 2008).

National Institute of Neurological Disorders and Stroke (NINDS). Restless Legs Syndrome Information Page. http://www.ninds.nih.gov/disorders/restless%5Flegs/restless_legs.htm (updated December 11, 2007; accessed April 14, 2008).

Restless Legs Syndrome Foundation. About RLS: Frequently Asked Questions. http://www.rls.org/NETCOMMUNITY/Page.aspx?&pid=543&srcid=481 (accessed April 14, 2008).