Restless Leg Syndrome

Restless Legs Syndrome (RLS) is a movement disorder characterized by an irresistible urge to move the legs when at rest, often accompanied by uncomfortable sensations in the calves or feet. Patients may experience a creepy/crawly feeling, sometimes associated with an aching, tingling, or moderate burning pain in the legs prior to sleep and find relief by moving them. The unpleasant sensations may affect other body parts such as the arms.

Symptoms

If you answer yes to the following questions, you may have RLS and should consult a qualified sleep medicine specialist to evaluate your symptoms, especially if they become severe.

• Do you feel a strong urge to move your legs that may be associated with an ache or creepy, crawly sensation?
• Are those sensations worse in the evening or at night at bedtime compared to other times of the day?
• Are the restless leg symptoms worse when sitting inactive, such as in a movie theater or a passenger in a car?
• Does walking, moving or stretching your legs at least partially relieve those sensations?

Causes

RLS can also be caused by other medical conditions such as iron deficiency, kidney disease, and pregnancy. Additionally, RLS symptoms may be brought out or exacerbated by some medications such as tricyclic antidepressants, selective serotonin reuptake inhibitors (SSRIs), antihistamines, decongestants, and anti-emetics (anti-nausea medications). More than 80 percent of patients with RLS also have periodic limb movements during sleep, characterized by involuntary limb movements or brief muscles twitches and upward dorsi-flexion of the foot, knee or hip during sleep. These limb movements are typically unknown to the patient but tend to disrupt sleep, leading to daytime sleepiness.

Characteristics

RLS affects approximately 10% of the adult population in the United States. It is more prevalent among women than men and can start at any age. RLS tends to run in families, with as many as 50% of cases suffering from genetically inherited RLS. Many patients can trace their symptom to childhood or can recognize another family member with similar symptoms. When occurring in childhood, some patients may be misdiagnosed as having "growing pains" or considered "hyperactive" because they can’t sit still and are constantly "fidgeting."

Consequences

RLS affects your ability to fall asleep or maintain adequate restorative sleep. When you suffer from a sleep loss, you are more prone to illness, impaired task performance, reduced concentration, decreased memory, altered mood, depression or anxiety. Delaying treatment can aggravate your mental and physical health. RLS often goes misdiagnosed for many years as nervousness, stress, insomnia, or muscle cramps, while symptoms slowly worsen until they become debilitating. Some patients even blame themselves for the symptoms, thinking that they have just “done too much” during the day. Although you may have difficulty describing your symptoms, don’t hesitate to talk with your physician or consult a qualified sleep medicine specialist.

Diagnosis

The diagnosis of RLS is primarily based on the patient’s history, followed by an examination to identify secondary causes such as iron deficiency anemia. Your may undergo testing to rule out an iron deficiency. You may want to keep a sleep diary to record your sleep quality or quantity as well as when your symptoms occur and their severity. If deemed necessary, you may be asked to undergo an overnight sleep study (polysomnogram) to rule out other sleep disorders such as obstructive sleep apnea that may worsen RLS.

Treatment

If an underlying condition such as iron deficiency causes RLS, you will be asked to take iron supplementation. For RLS not associated with an underlying medical condition, treatment also focuses on establishing lifestyle changes and healthier sleep habits which may help alleviate RLS symptoms. Finally, medications may be used when necessary.

Behavioral therapy
Establish good sleep hygiene by maintaining a consistent sleep-wake schedule, exercising regularly, and decreasing caffeinated beverages, as well as avoiding alcohol and tobacco.

• A warm bath prior to bedtime may be beneficial.
• Practice relaxation techniques such as stretching or yoga.
• You may try to make small changes to your sleep schedule so you may try to sleep when your symptoms are the least pronounced. This is particularly helpful for patients who do not have early morning obligations and who can stay up 1-2 hours later in the evening, going to bed somewhat later when RLS symptoms may subside in some patients.
• When your symptoms start, walk, or massage your limbs, apply hot or cold packs, or try a warm bath.

Medication therapy
A number of medications initially FDA approved for diseases other than RLS are also now approved and used to treat RLS. Treatment is administered according to the severity of the symptoms, the level of relief experienced with the drug and the patient’s tolerance for potential side effects. Patients may receive one or a targeted combination of several of the following prescription medications.

• Treating an iron deficiency. Low iron can trigger or exacerbate RLS. Of the numerous lab studies used by physicians to identify iron deficiency, serum ferritin appears to have the most specific correlation with RLS severity, but this lab test is often not included in routine evaluations for iron deficiency. Unless your physician has specifically requested an evaluation of serum ferritin, it was most likely not checked. Serum ferritin provides an indication as to how much iron stores are present in the body. Iron can be present in numerous forms, including free iron, but iron supplementation may be helpful in RLS patients even if these routine iron studies appear to be normal. The normal range for serum ferritin has a wide range from approximately 20-380 ng/ml. However, current data demonstrate that supplemental iron can improve RLS symptoms if the serum ferritin is less than 50 ng/ml. Therefore, patients with RLS who have a serum ferritin less than 50 ng/ml should be started on iron supplementation even if all other iron study results are normal. Patients are typically started on ferrous sulfate 325 mg per day. Your physician may have you also take 500 mg of vitamin C to aide in the gastrointestinal absorption of the iron. Iron levels generally take months to improve with oral iron. Finally, any patient with chronic low iron should see their primary care physician to evaluate the underlying cause.
• Dopaminergic Agonists. Initially used to treat the tremor and other symptoms in Parkinson’s disease patients, Requip (ropinirole) and Mirapex (pramipexole) are also very effective in improving RLS symptoms and are now FDA approved to treat moderate to severe RLS. These medications act on dopamine receptors in the brain. Some other medications used to treat Parkinson’s have also been used to treat RLS, but are not FDA approved for this condition. These medications include dopaminergic agents (levodopa plus carbidopa known as Sinemet) and older dopaminergic agonists (pergolide,). Although the same medications are used to treat both Parkinson’s and RLS, there is no evidence to suggest that patients with RLS have a higher risk for later developing Parkinson’s. Side effects from dopaminergic agonists such as Requip and Mirapex include nausea, lightheadedness and sleepiness. Patients are recommended to not drive a motor vehicle after taking dopaminergic agonists until they have some experience taking these medications.
• Epilepsy medications. Although there has been some suggestion that anti-seizure medications such as carbamazepine may help RLS, there is currently only adequate data available for gabapentin (Neurontin). Recent clinical trials have shown that a new formulation of gabapentin (gabapentin-enacarbil) is very effective for the treatment of RLS and is expected to soon obtain FDA approval for this indication.
• Narcotic analgesics. RLS symptoms are typically much improved following the administration of narcotic analgesic medications. These include opiates such as propoxyphene, methadone or oxycodone. Potential side effects include excessive sleepiness, hallucinations, nausea, constipation, and risk of addiction. Narcotic analgesics are only used in special cases of severe RLS and require the close supervision of a physician.

For More Information

For more information about RLS, visit the American Academy of Sleep Medicine at http://www.sleepeducation.com and the National Sleep Foundation at http://www.sleepfoundation.org