What Causes It?

Although the cause is unknown in most cases, certain factors
may be associated with RLS:

* Family history. RLS is known to run in some families--parents may pass the condition on to their children.

* Pregnancy. Some women experience RLS during pregnancy, especially in the last months. The symptoms usually disappear after delivery.

* Low iron levels or anemia. Persons with these conditions may be prone to developing RLS. The symptoms may improve once the iron level or anemia is
corrected.

* Chronic diseases. Kidney failure quite often leads to RLS. Other chronic diseases such as diabetes, rheumatoid arthritis, and peripheral neuropathy may
also be associated with RLS.

* Caffeine intake. Decreasing caffeine consumption may improve symptoms.

Who Gets RLS?

RLS occurs in both sexes. Symptoms can begin any time, but are usually more common and more severe among older people. Young people who experience symptoms of RLS are sometimes thought to have "growing pains" or may be considered "hyperactive" because they cannot easily sit still in school.

How Is It Diagnosed?

There is no laboratory test that can make a diagnosis of RLS and, when someone with RLS goes to see a doctor, there is usually nothing abnormal the doctor can see or detect on examination. Diagnosis therefore depends on what a person describes to the doctor. The history usually includes a description of the typical leg sensations that lead to an urge to move the legs or walk. These sensations are noted to worsen when the legs are at rest, for example, when
sitting or lying down and during the evening and night. The person with RLS may complain about trouble sleeping or daytime sleepiness. In some cases, the bed partner will complain about the person's leg movements and jerking during
the night.

To help make a diagnosis, the doctor may ask about all current and past medical problems, family history, and current medications. A complete physical and neurological exam may help identify other conditions that may be associated with RLS, such as nerve damage (neuropathy or a pinched nerve) or abnormalities in the blood vessels. Basic laboratory tests may be done to assess general health and to rule out anemia. Further studies depend on initial findings. In some cases, a doctor may suggest an overnight sleep study to determine whether PLMS or other sleep problems are present. In most people with RLS, no new medical problem will be discovered during the physical exam or on any tests, except the sleep study, which will detect PLMS if present.

How Is It Treated?

In mild cases of RLS, some people find that activities such as taking a hot bath, massaging the legs, using a heating pad or ice pack, exercising, and eliminating caffeine help alleviate symptoms. In more severe cases, medications are prescribed to control symptoms. Unfortunately, no one drug is effective for everyone with RLS. Individuals respond differently to medications based on the severity of symptoms, other medical conditions, and other medications
being taken. A medication that is initially found to be effective may lose its effectiveness with nightly use; thus, it may be necessary to alternate between different categories of medication in order to keep symptoms under
control.

Although many different drugs may help RLS, those most
commonly used are found in the following three categories:

* Benzodiazepines are central nervous system depressants that do not fully suppress RLS sensations or leg movements, but allow patients to obtain more sleep despite these problems. Some drugs in this group may result in daytime drowsiness. Benzodiazepines should not be used by people with sleep apnea.

* Dopaminergic agents are drugs used to treat Parkinson's disease and are also effective for many people with RLS and PLMS. These medications have been
shown to reduce RLS symptoms and nighttime leg movements.

* Opioids are pain-killing and relaxing drugs that can suppress RLS and PLMS in some people. These medications can sometimes help people with severe,
unrelenting symptoms.

Although there is some potential for benzodiazepines and opioids to become habit forming, this usually does not occur with the dosages given to most RLS patients.

A nondrug approach called transcutaneous electric nerve stimulation may improve symptoms in some RLS sufferers who also have PLMS. The electrical stimulation is applied to an area of the legs or feet, usually before bedtime, for 15 to 30 minutes. This approach has been shown to be helpful in
reducing nighttime leg jerking.

Due to recent advances, doctors today have a variety of means for treating RLS. However, no perfect treatment exists and there is much more to be learned about the treatments that currently seem to be successful.