Definition
Restless legs syndrome (RLS)—also known as Willis-Ekbom Disease, primary RLS, and idiopathic RLS—is a neurological disorder that causes unpleasant or uncomfortable sensations in your legs and an irresistible urge to move them. Symptoms commonly occur in the late afternoon or evening hours and are often most intense at night when you are resting. RLS can severely disrupt your sleep, making it difficult to fall asleep or return to sleep after waking up. Moving the legs or walking typically relieves the discomfort but the sensations often recur once the movement stops.
RLS is both a sleep disorder, because the symptoms are triggered by resting and attempting to sleep, and a movement disorder, because people with RLS are forced to move their legs in order to relieve symptoms.
It is estimated that up to seven to 10 percent of the U.S. population may have RLS, which can begin at any age. It occurs in both males and females, although females are more likely to have it. Many individuals who are severely affected are middle-aged or older, and the symptoms typically become more frequent and last longer with age.
RLS is generally a lifelong condition for which there is no cure. However, treatments are available to ease symptoms.
Few data are available about the prevalence of RLS in racial groups. However, it has been suggested that the Black American population is at lower risk than the white population.
Symptoms
If you have RLS, you may feel an irresistible urge to move, which is accompanied by uncomfortable sensations in your lower limbs that are unlike normal sensations experienced by someone without the disorder. The sensations in your legs may feel like aching, throbbing, pulling, itching, crawling, or creeping. These sensations less commonly affect the arms, and rarely the chest or head. Although the sensations can occur on just one side of your body, they most often affect both sides.
Common characteristics of RLS include:
- Sensations that begin after rest—They typically occur when you are inactive and sitting for extended periods (e.g., when taking a trip by plane or watching a movie).
- Relief of discomfort with movement—You may need to keep your legs (or other affected parts of the body) in motion to minimize or prevent the sensations. You might need to pace the floor or constantly move your legs while sitting.
- Worsening of symptoms at night with a distinct symptom-free period in the early morning—You might have difficulty falling asleep and staying asleep. You may also note a worsening of symptoms if your sleep is further reduced by events or activity.
RLS symptoms may vary from day to day, in severity and frequency, and from person to person. With moderately severe RLS, your symptoms might only occur once or twice a week but often result in a significant delay of sleep onset, with some disruption of daytime function. In severe cases of RLS, the symptoms occur more than twice a week.
RLS can cause you to experience the following:
- Changes in mood
- Exhaustion and daytime sleepiness
- Problems concentrating
- Impaired memory
- Decreased productivity
- Depression and anxiety
You might experience remissions—periods in which symptoms decrease or disappear for weeks or months—usually during the early stages of the disorder. In general, however, symptoms often reappear and become more severe over time.
More than 80 percent of people with RLS also experience periodic limb movement of sleep (PLMS). PLMS is characterized by involuntary leg (and sometimes arm) twitching or jerking movements during sleep that typically occur every 15 to 40 seconds, sometimes throughout the night. Although many individuals with RLS also develop PLMS, most people with PLMS do not experience RLS.
Risk Factors
In most cases, the cause of RLS is unknown. However, RLS often runs in families and specific gene variants have been associated with the condition. Low levels of iron in the brain also may be responsible for RLS.
RLS also may be related to a dysfunction in a part of your brain that controls movement. The basal ganglia uses the brain chemical dopamine to produce smooth, purposeful muscle activity and movement. Disruption of dopamine levels in the brain frequently results in involuntary movements. Individuals living with the movement disorder Parkinson’s disease have an increased risk of developing RLS.
RLS also appears to be related to or accompany the following factors or underlying conditions:
- End-stage renal disease and hemodialysis
- Neuropathy (nerve damage)
- Sleep deprivation and other sleep conditions such as sleep apnea
- Pregnancy or hormonal changes, especially in the last trimester. In most cases, symptoms usually disappear within four weeks after delivery
- Use of alcohol, nicotine, and caffeine
Certain medications may aggravate your RLS symptoms, such as some anti-nausea drugs, antipsychotic drugs, antidepressants that increase serotonin, and cold and allergy medications that contain older antihistamines.
Diagnosis
There is no specific test for RLS, so the condition is diagnosed by a doctor’s evaluation. The five basic criteria for clinically diagnosing RLS include:
- A strong and often overwhelming need or urge to move your legs that is often associated with abnormal, unpleasant, or uncomfortable sensations.
- The urge to move your legs starts or get worse during rest or inactivity.
- The urge to move your legs is at least temporarily and partially or totally relieved by movements.
- The urge to move your legs starts or is aggravated in the evening or night.
- The above four features are not due to any other medical or behavioral condition.
A neurological and physical exam, plus information about your medical and family history and list of current medications, may be helpful. You should talk with your doctor about the frequency, duration, and intensity of your symptoms—if movement helps to relieve them; how much time it takes to fall asleep; any pain related to symptoms; and, any tendency toward daytime sleep patterns and sleepiness, disturbance of sleep, or daytime function.
Blood tests may rule out other conditions that may be causing your RLS symptoms, such as kidney failure, low iron levels, and other causes of sleep disruption, such as sleep apnea and pregnancy. In fact, about 25 percent of pregnant females develop RLS but the symptoms often disappear after giving birth.
Diagnosing RLS in children may be especially difficult as it may be hard for children to describe their symptoms. Pediatric RLS can sometimes be misdiagnosed as “growing pains” or attention deficit hyperactivity disorder.
Treatment
There is no cure for RLS but some symptoms can be treated. Moving your affected limb(s) may provide temporary relief. Sometimes RLS symptoms can be controlled by treating an associated medical condition, such as peripheral neuropathy, diabetes, or iron deficiency anemia.
Medications for RLS include:
- Iron supplements
- Anti-seizure drugs—Anti-seizure drugs are the first-line prescription drugs for those with RLS. The U.S. Food and Drug Administration (FDA) approved gabapentin enacarbil for the treatment of moderate to severe RLS. Other anti-seizure drugs such as pregabalin can decrease such sensory disturbances and nerve pain.
- Dopaminergic agents—These drugs, which increase dopamine in the brain, can reduce symptoms of RLS when taken at night. The medications ropinirole, pramipexole, and rotigotine are FDA-approved to treat moderate to severe RLS. Levodopa plus carbidopa may be effective when used intermittently but not daily because long-term use of dopaminergic drugs can eventually worsen symptoms and cause other complications.
- Opioids—Drugs such as methadone, codeine, hydrocodone, or oxycodone are sometimes prescribed to treat individuals with more severe symptoms of RLS who do not respond well to other medications.
- Benzodiazepines—Medications such as clonazepam and lorazepam are generally prescribed to treat anxiety, muscle spasms, and insomnia, and can help individuals get more restful sleep.
Lifestyle Changes
The following lifestyle changes and activities may provide some relief if you have mild to moderate RLS:
- Avoid or decrease the use of alcohol, nicotine, and caffeine
- Change or maintain a regular sleep pattern
- Try moderate, regular exercise
- Massage the legs or take a warm bath
- Apply a heating pad or ice pack
- Use foot wraps specially designed for people with RLS, or vibration pads to the back of the legs
- Do aerobic and leg-stretching exercises of moderate intensity