Periodic limb movement of sleep

Related Terms

Dysesthesias, dyskinesia, insomnia, leg cramps, neurological disorder, paresthesias, periodic limb movement of sleep, PLMS, polysomnography, radiculopathy, restless legs, RLS, shaky leg syndrome, sonography.

Background

Restless legs syndrome (RLS) is a neurological (brain) disorder that causes an individual's legs to feel extremely uncomfortable when sitting or lying down. These unpleasant sensations may feel like burning, tugging, or like insects are crawling inside the legs. Often called paresthesias (abnormal sensations) or dysesthesias (unpleasant abnormal sensations), the symptoms range in severity from mildly uncomfortable to painful.
RLS causes an uncontrollable urge to stand up or walk around. When the person gets up, the symptoms start to go away. As a result, it often makes it difficult for the patient to relax, sleep comfortably, or travel.
It is estimated that RLS affects 10-15% of Americans, with men and women affected equally. However, the condition is often unrecognized or misdiagnosed as nervousness, stress, insomnia, or muscle cramps. RLS can develop at any age, but it usually is not diagnosed until 10-20 years after symptoms develop. In some patients, the condition may worsen with age. Some patients may experience short periods of remission that may last for days, weeks, or months.
More than 80% of RLS patients also experience a more common condition called periodic limb movements of sleep (PLMS). This condition causes the legs to involuntarily twitch or jerk during sleep every 5-60 seconds. Sometimes this jerking movement continues throughout the entire night. The symptoms repeatedly wake up the patient, his/her bedmate bate, and severely disrupt sleep. Although many patients with RLS develop PLMS, most people with PLMS do not experience RLS. Like RLS, the cause of PLMS is unknown.
RLS is generally a lifelong condition because there is currently no cure. However, simple lifestyle changes and medications have been shown to improve symptoms of the disorder.

Signs and symptoms

General: Restless legs syndrome can develop at any age. Symptoms vary in severity and duration among patients. They generally begin when the patient is sitting or lying down for extended periods of time and lessen when the patient moves the affected legs. In some patients, the condition may worsen with age. Some patients may experience short periods of remission that may last for days, weeks, or months.
Symptoms during inactivity: Symptoms develop when the individual sits or lies down for an extended period of time, especially during sleep.
Symptoms typically include unpleasant sensations, such as burning, tingling, aching, jittery, or crawling sensations, in the legs. These sensations typically occur deep inside the leg, between the knee and ankle. In rare cases, the sensations may also occur in the feet, thighs, arms, or hands. Both sides of the body are usually affected, although it is possible for symptoms to occur on just one side. These feelings cause an uncontrollable urge to move.
Symptoms go away with movement: Once the patient stands up, walks, or moves the legs around, the symptoms start to go away. Patients may frequently stand up, pace, jiggle their legs, or toss and turn during sleep.
Periodic limb movement of sleep: More than 80% of patients with RLS experience a condition called period limb movement of sleep (PLMS). Although many patients with RLS also develop PLMS, most people with PLMS do not experience RLS. This condition causes the patient to involuntarily twitch or jerk the legs during sleep. Oftentimes, the patient is unaware of these symptoms. Patients who have severe RLS may have more serious symptoms of PMLS that cause significant leg jerking that can occur while the individual is awake. PMLS is more common among adults older than middle age.

Diagnosis

During a physical examination, a healthcare provider will first rule out other medical conditions, such as muscle diseases, joint conditions, nerve problems, and circulation problems, which may be causing symptoms.
The International Restless Legs Syndrome Study Group has developed four diagnostic criteria for RLS. However, RLS is still a difficult condition to diagnose because healthcare providers primarily depend on the patients' descriptions of their symptoms. The diagnostic criteria include: 1) the patient has a desire to move the limbs, often associated with abnormal sensations (called paresthesias) or unpleasant abnormal sensations (called dysesthesias); 2) symptoms that are worse or only present during rest are partially or temporarily improved with physical activity; 3) the patient experiences motor restlessness; and 4) symptoms are the worst during sleep.
Although most patients with RLS have period limb movements of sleep (PLMS), it is not necessary for a diagnosis. If PLMS is suspected, the patient may be asked to spend the night at a sleep center. When the patient is asleep, researchers monitor the electrical activity of the brain and heart, the movement of the muscles, the movements of the eyes, and breathing patterns.

Complications

Insomnia and daytime fatigue: Restless legs syndrome (RLS) may make it difficult to fall asleep at night. This is because symptoms are generally worse when the individual is lying down for extended periods of time. Period limb movement of sleep (PLMS), which often occurs in RLS patients, may also disrupt sleep in some patients. Sometimes limb movement may also wake up the patient's bedmate.
When individuals do not get enough sleep, they may experience excessive daytime drowsiness. During the day, patients may feel tired, inattentive, or unable to concentrate.
Quality of life: Symptoms of RLS may interfere with an individual's quality of life. Patients who experience symptoms are encouraged to visit their doctors because lifestyle changes and medications can help reduce symptoms of the disorder.

Treatment

General: Restless legs syndrome (RLS) is generally a lifelong condition because there is currently no cure. In some cases, treating an underlying medical problem, such as peripheral neuropathy or iron deficiency, may help relieve symptoms of RLS. For most patients, simple lifestyle changes and medications have been shown to improve symptoms of the disorder.
Patients with RLS should stay in close contact with their doctors. Sometimes RLS medications may become less effective over time, and a new medication or dose may be needed. Other patients who take mediations may start to notice that symptoms return earlier in the day. This is called augmentation. When augmentation occurs, a new medication may be recommended.
Most medications used to treat RLS are not recommended for pregnant women. Instead, most healthcare providers recommend lifestyle and self-care techniques to reduce symptoms.
Pain relievers: Mild symptoms of RLS may be treated with over-the-counter pain relievers, such as ibuprofen (Motrin? or Advil?).
Warm or cool packs: Applying a warm or cold pack, or alternating between the two, may help reduce symptoms of RLS. Cold packs should not be used for longer than 10 minutes at a time. In addition, soaking in a warm bath and massaging the legs may relax the muscles.
Relaxation techniques: Stress has been show to worsen symptoms of RLS. Patients may benefit from relaxation techniques, such as meditation or yoga. These techniques may be especially beneficial before sleep.
Establish good sleep habits: When patients feel tired, symptoms of RLS may be aggravated. It is recommended that patients have a quiet and comfortable sleeping environment. It is also important to have a regular sleep schedule and to get enough sleep each night in order to feel well rested the next day.
Exercise: Regular moderate exercise may help improve or relieve symptoms of RLS. In general, most experts recommend about 30 minutes of moderate exercise on all or most days of the week. However, patients should be careful not to overwork themselves. Too much exercise may actually worsen symptoms. Patients should talk to their healthcare providers before starting new exercise programs.
Avoid caffeine: Avoiding caffeine (such as coffee, tea, and soda) may help reduce symptoms of RLS. It may also help patients sleep better at night.
Avoid alcohol and tobacco: Patients should avoid or limit their consumption of alcohol and tobacco. These substances have been shown to worsen or trigger symptoms of RLS.
Medications to avoid: Some medications, including H2-histamine blockers (e.g. Zantac? or Tagamet?), some antidepressants (e.g. Elavil?), anti-nausea drugs, and calcium channel blockers, may also worsen symptoms of RLS. Patients should talk to their doctors before taking any drugs, herbs, or supplements, to make sure they will not aggravate their conditions.
Dopamine agents: Patients with RLS often take medications that are normally used to treat a movement disorder called Parkinson's disease. These drugs, called dopamine agents, affect the level of dopamine in the brain. As a result, symptoms of RLS are reduced when taken regularly. Commonly prescribed dopamine agents include pramipexole (Mirapex?), ropinirole (Requip?), and carbidopa/levodopa (Sinemet?).

Integrative therapies

Unclear or conflicting scientific evidence:
Vitamin B12: Vitamin B12 is a water-soluble vitamin that is commonly found in many foods, including fish, shellfish, meats, and dairy products. Preliminary clinical reports show that vitamin B12 may help relieve tremors associated with shaky-leg syndrome. Further research is needed to confirm these results.
Vitamin B12 is generally considered safe when taken in amounts that do not exceed the recommended dietary allowance (RDA). Avoid vitamin B12 supplements if allergic to cobalamin, cobalt, or any other product ingredients. Avoid with coronary stents or Leber's disease. Use cautiously if undergoing angioplasty.
Traditional or theoretical uses lacking sufficient evidence:
5-HTP: 5-HTP is the precursor for serotonin. Serotonin is the brain chemical associated with sleep, mood, movement, feeding, and nervousness. It has been suggested that 5-HTP supplements may offer some benefit to patients with restless leg syndrome. However, scientific evidence is necessary in order to make a firm conclusion in this area.
Avoid if allergic to 5-HTP. Avoid with eosinophilia (low number of white blood cells, called eosinophils), Down's syndrome, or mitochondrial encephalomyopathy (mitochondrial defect that affects the brain). Avoid if taking monoamine oxidase inhibitors (MAOIs). Use cautiously with gastrointestinal disorders or kidney disorders. Use cautiously if taking antidepressants because it may cause a life-threatening condition called serotonin syndrome. Use cautiously if taking carbidopa, phenobarbital, pindolol, reserpine, tramadol, or zolpidem. Avoid if pregnant or breastfeeding.
Acupressure, shiatsu: During acupressure, finger pressure is applied to specific acupoints on the body. Acupressure is used around world for relaxation, wellness promotion, and the treatment of many health problems. It has been suggested, but not proven, that acupressure may help treat restless leg syndrome. Additional research is warranted in this area.
With proper training, acupressure appears to be safe if self-administered or administered by an experienced therapist. No serious long-term complications have been reported, according to scientific data. Hand nerve injury and herpes zoster ("shingles") cases have been reported after shiatsu massage. Forceful acupressure may cause bruising.
Folate (folic acid): Folate and folic acid are forms of a water-soluble B vitamin. Folate occurs naturally in food, and folic acid is the synthetic form of this vitamin. Although it has been proposed that folate may help treat restless leg syndrome, scientific evidence is lacking. Until studies evaluate the safety and efficacy of this treatment, a firm conclusion cannot be made.
Avoid if allergic to folate or any of the product ingredients. Folate is generally considered safe when taken in the recommended doses. Avoid with coronary stents. Use cautiously with seizure disorders.
Hypnotherapy, hypnosis: Hypnosis is a trance-like state in which a person becomes more aware and focused and is more open to suggestion. Hypnotherapy has been used to treat health conditions and to change behaviors. Until scientific studies are performed, it remains unknown if hypnotherapy can help treat restless leg syndrome.
Use cautiously with mental illnesses (e.g. psychosis/schizophrenia, manic depression, multiple personality disorder, or dissociative disorders) or seizure disorders.
Valerian: Valerian is an herb native to Europe and Asia. Today, the herb grows in most parts of the world. Scientific studies are needed to determine if valerian is a safe and effective treatment for restless leg syndrome.
Use cautiously if allergic to valerian or other members of the Valerianaceaefamily. Use cautiously with livers disorders. Use cautiously before surgery. Avoid if driving or operating heavy machinery, as it may cause drowsiness. Avoid if pregnant or breastfeeding.

Prevention

Once symptoms of restless legs syndrome (RLS) develop, there is no known way to prevent the condition from worsening. Individuals should take their medications exactly as prescribed and practice regular self-care techniques in order to manage symptoms.
Avoid or limit the consumption of alcohol and tobacco. These substances may trigger or worsens symptoms of RLS.
Some medications, including H2-histamine blockers (e.g. Zantac? or Tagamet?), some antidepressants (e.g. Elavil?), anti-nausea drugs, and calcium channel blockers, may worsen symptoms of RLS. Patients should talk to their doctors if these medications aggravate their conditions. A physician may be able to recommend a different dose or medication.
Stress has been show to worsen symptoms of RLS. Patients may benefit from relaxation techniques, such as meditation or yoga. These techniques may be especially beneficial before sleep.
Fatigue has been shown to aggravate symptoms of RLS. It is recommended that patients have a quiet and comfortable sleeping environment. It is also important to have a regular sleep schedule and to get enough sleep each night in order to feel well rested the next day.

Author information

This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Bibliography

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Koves P, Szakacs Z. Pathophysiology of restless leg syndrome and periodic leg movement disorder in view of the latest research findings. Article in Hungarian. Ideggyogy Sz. 2005 May 20;58(5-6):148-63.
Montplaisir J, Godbout R, Poirier G, et al. Restless legs syndrome and periodic movements in sleep: physiopathology and treatment with L-dopa. Clin Neuropharmacol. 1986;9(5):456-63.
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Causes

General: In many cases, there is no known cause of restless legs syndrome. Researchers believe that the disorder may be the result of an imbalance of a brain chemical called dopamine. This chemical sends messages to control muscle movement.
Genetics: About 50% of RLS cases appear to run in families. Scientists have identified specific locations on chromosomes where RLS genes may be present.
Other medical conditions: Most cases of RLS are not caused by underlying medical problems. However, RLS sometimes occurs in patients who have peripheral neuropathy, which damages the nerves in the hands and feet.
RLS may also occur in patients who have low levels of iron in their blood. RLS is common among patients who are undergoing dialysis. This is because patients who have kidney failure may also have iron deficiency, which may cause or worsen RLS.
In addition, many patients with Parkinson's disease also have RLS. However, it is important to note that having Parkinson's disease does not appear to increase the risk of developing RLS. Also, having RLS also does not appear to increase the risk of developing Parkinson's disease later in life.
Pregnancy: Some women experience RLS for the first time during pregnancy, especially during the last trimester. However, this condition is temporary for most pregnant women, and symptoms usually go away about one month after delivery.
Factors that may worsen symptoms: Stress has been shown to worsen symptoms of RLS. Pregnancy, hormonal changes, or iron deficiency may temporarily worsen symptoms. In addition, alcohol and tobacco may trigger or worsen symptoms of RLS. Certain medications, such as H2-histamine blockers (e.g. Zantac? or Tagamet?), some antidepressants (e.g. Elavil?), anti-nausea drugs, and calcium channel blockers, may also worsen symptoms.

How shaky leg syndrome is different than rls

Although shaky legs syndrome may sound similar to restless leg syndrome (RLS), they are two different conditions and they generally do not occur together.
Shaky leg syndrome is a rare disorder that causes the legs to visibly shake or jerk when the individual is standing. There typically is no feeling of pain or discomfort during the tremors. These symptoms go away when the person sits down, lies down, or leans against a wall. This disorder may interfere with the patient's quality of life, making it difficult for patients to get around independently throughout the day.
The cause of shaky leg syndrome remains unknown. Less than one percent of Americans have shaky leg syndrome.
There is currently no cure for shaky leg syndrome. Patients typically receive anticonvulsant medications, such asvalproic acid (Depakote?) or gabapentin (Neurontin?) to help control tremors.