Restless legs syndrome (RLS) is a disorder that affects more than 5 million adults in the United States, according to the National Institute of Neurological Disorders and Stroke (NINDS). Also, about 1 million school-age children suffer from moderate to severe RLS. The disorder occurs twice as frequently in women than in men, according to the NINDS.
The characteristic sign of RLS (sometimes called restless leg syndrome) is an intense urge to move the legs. The impulse can be so strong that an individual is unable to resist moving the legs. There are several other symptoms of RLS, including a creepy-crawly feeling, itching and a sensation of pulling. Also, some individuals experience a burning feeling. Symptoms can range from uncomfortable to painful.
Though it is usually felt in the legs, other parts of the body — such as the arms, trunk or head — can also be affected. Sometimes, only half of the body will be affected, according to NINDS.
Typically, the sensations appear when an individual is trying to relax, or sitting for long periods. Moving diminishes the sensations, but in the evening and during sleep, symptoms worsen, according to the Mayo Clinic.
According to the National Sleep Foundation, many people who have RLS can also have a disorder called periodic limb movements in sleep (PLMS). Signs of this disorder are quick movements of the legs every 20 to 40 seconds during the night.
In many cases, the cause of RLS is unknown. However, research points to three factors: iron deficiency, lower dopamine production and heredity, according to the Johns Hopkins Center for Restless Legs Syndrome.
Autopsies of people with RLS have shown that their brains were not storing sufficient levels of iron, especially in dopamine-producing cells. Dopamine is a neurotransmitter that is necessary for smooth muscle activity and movement. Studies have also shown that treatment of iron deficiency improves — and, in some cases, eliminates — RLS symptoms, according to Johns Hopkins.
RLS may also be caused by a dysfunction in the brain's basal ganglia circuits, according to NINDS. Basal ganglia are structures in the brain that are responsible for involuntary movements. This dysfunction disrupts the production of dopamine and may cause the jerky motions of RLS.
The most common type of restless legs syndrome, called primary RLS, often runs in families, according to the National Sleep Foundation. Researchers have found an RLS gene, which was shown to account for about half of RLS cases. Researchers cautioned, however, that having the gene does not guarantee that a person will have RLS.
Secondary RLS is thought to be a condition of another disease or a side effect of certain drugs. Stress and environmental factors can also play a part in someone's development of secondary RLS.
Diagnosis & tests
The diagnosis of restless legs syndrome is quite simple. According to the Mayo Clinic, the doctor will listen the patient's symptoms and see if they match the four criteria of RLS:
- The patient has strong and irresistible urges to move his legs and uncomfortable sensations that often accompany the urges.
- The symptoms start or get worse while the patient is lying down or resting.
- The symptoms get better or are relieved somewhat when the patient moves.
- The symptoms are worse at night.
The doctor may also try to determine if the symptoms are caused by other factors, so blood or nerve tests may also be a part of diagnosis. A general practitioner also may refer patients to a sleep specialist for an overnight examination.
Treatment & medication
Treatment of RLS is usually focused on relieving symptoms, according to NINDS. Moving the affected limbs may provide temporary relief. Sometimes, RLS symptoms can be controlled by finding and treating an associated medical condition, such as peripheral neuropathy or diabetes.
"You should approach treatment by addressing the two areas linked to RLS: the brain and the muscles," said Dr. Michael A. Smith, senior health scientist for Life Extension Foundation in Fort Lauderdale, Florida.
To boost dopamine production in the brain, a doctor may prescribe drugs such as levodopa, pramipexole, ropinirole and rotigotine. These medications are also used to treat Parkinson's disease; however, there is no indication that RLS is related to Parkinson's disease, according to Johns Hopkins.
Johns Hopkins cautions that dopamine-related medications have side effects that may occur after extended use, including excessive sleepiness, increased compulsive behavior and more commonly, paradoxical worsening of symptoms, referred to as “augmentation.”
There are also natural ways to boost the production of dopamine, Smith said. For example, velvet-bean extracts provide a natural compound called L-dopa, which converts into dopamine. Other nutrients that may help boost dopamine production are some amino acids, such as tyrosine, phenylalanine and folic acid, as well as vitamin B1 and chromium.
"As far as the muscles go, they need magnesium," Smith said. A small study published in the journal Sleep indicated that magnesium treatment might be a "useful alternative therapy" in treating patients with insomnia related to PLMS or RLS.
"Some doctors may suggest iron as well," Smith said. "However, I suggest using iron only if nothing else has worked or if you're iron deficient." NINDS also recommends iron supplements only for individuals with low iron levels.
Other medications that are not specifically designed to treat RLS — such as opiates, benzodiazepines and alpha-2 delta drugs — may relieve some of the symptoms, according to John Hopkins. Often, individuals have to try several medications before an effective treatment is found.
The Food and Drug Administration has approved gabapentin enacarbil for the treatment of moderate to severe RLS, according to NINDS.
Certain lifestyle changes and activities that may reduce symptoms in people with mild to moderate symptoms include the decreased use of caffeine, alcohol and tobacco, according to NINDS. Activities that relax muscles and relieve stress — such as warm baths, massages and yoga — can improve symptoms. The Mayo Clinic suggests alternating between warm and cool compresses to reduce the leg sensations associated with RLS.
This article is for informational purposes only, and is not meant to offer medical advice.
- The Mayo Clinic offers tips for coping with restless legs syndrome.
- The Willis-Ekbom Disease Foundation (formerly the Restless Leg Syndrome Foundation) provides answers to frequently asked questions, information about treatment options and access to support groups.
- The Johns Hopkins Center for Restless Legs Syndrome conducts research, provides training and information, and supports other programs on the cause, diagnosis, prevention and treatment of restless legs syndrome.