Restless legs syndrome, abbreviated RLS, is a disorder marked by an urge to move the legs, usually when at rest or in bed. It is a neurological disorder—a disorder of the nervous system. Moving the legs temporarily relieves the urge. RLS typically affects the legs. But it can affect the arms and other parts of the body as well. RLS may also involve such sensations as tingling, itching, or tickling in the limbs. RLS can severely reduce a person’s quality of life. It may disrupt sleep. RLS can also limit the person’s activities because the urge is dramatically worsened by situations that restrict leg movement, such as sitting in an automobile, airplane, or theater.
Medical experts estimate that about 10 percent of people worldwide experience RLS. However, RLS is more common among people of northern European descent. RLS occurs more often in women than men.
The most common form of RLS, called primary form RLS, has no apparent cause. Secondary form RLS is known to develop in association with certain conditions. These conditions include iron deficiency (unusually low levels of iron in the body), pregnancy, kidney disease, rheumatoid arthritis, Parkinson disease, and a condition called peripheral neuropathy. In peripheral neuropathy, nerve problems in the limbs are associated with odd sensations and muscle weakness.
Diagnosis.
Physicians diagnose RLS following a thorough evaluation of the patient’s symptoms. A diagnosis must include four findings. First, the patient must have an urge to move the limbs with or without such sensations as tingling. Second, activity relieves the urge. Third, the urge worsens with rest or inactivity. Finally, the urge worsens in the evening or night. Usually, physical and neurological examinations yield normal results and cannot explain these symptoms. Certain conditions, such as muscle cramps, can be confused with RLS. However, a physician can recognize these conditions.
Cause.
The cause of RLS is unknown. Scientists suspect that RLS appears to be associated with levels of dopamine in the brain. Dopamine is a neurotransmitter, a chemical that carries messages from one nerve cell to another. A lack of dopamine disrupts communication pathways among nerves that help control movement, contributing to RLS.
Certain drugs can worsen RLS. Such drugs include antidepressants and drugs used to treat allergies, nausea, and mental illnesses.
Scientists have observed that RLS often runs in families. They have also discovered several genes with variations that are associated with RLS. Genes help determine what traits living things inherit from their parents.
Treatment.
Physicians treat primary form RLS mainly with medications that act to increase the amount of dopamine in the brain. They may also administer some drugs used to treat epilepsy as well as certain pain relievers. Physicians treat secondary form RLS by treating the underlying condition. Patients may get some relief by following good sleep habits. Such habits include avoiding caffeine and going to bed and waking at consistent times.
