Assessment of Restless Legs
Periodic Limb Movements
Restless legs syndrome (RLS) is a neurological disorder characterized by unpleasant sensations in the legs and an uncontrollable urge to move when at rest in an effort to relieve these feelings. RLS sensations are often described by people as burning, creeping, tugging, or like insects crawling inside the legs. These sensations range in severity from uncomfortable to irritating to painful.
The most distinctive aspect of the condition is that lying down and trying to relax activates the symptoms. As a result, most people with RLS have difficulty falling asleep and staying asleep. Left untreated, the condition causes exhaustion and daytime fatigue. Many people with RLS report that their job, personal relations, and activities of daily living are strongly affected as a result of their exhaustion. They are often unable to concentrate, have impaired memory, or fail to accomplish daily tasks. Some researchers estimate that RLS affects as many as 12 million Americans.
More than 80 percent of people with RLS also experience a more common condition known as periodic limb movement disorder (PLMD). PLMD is characterized by involuntary leg twitching or jerking movements during sleep that typically occur every 10 to 60 seconds, sometimes throughout the night. The symptoms cause repeated awakening and severely disrupted sleep. Unlike RLS, the movements caused by PLMD are involuntary-people have no control over them. Although many patients with RLS also develop PLMD, most people with PLMD do not experience RLS. Like RLS, the cause of PLMD is unknown.
In most cases, the cause of RLS is unknown. A family history of the condition is seen in approximately 50 percent of such cases, suggesting a genetic form of the disorder. People with familial RLS tend to be younger when symptoms start and have a slower progression of the condition.
People with low iron levels or anemia may be prone to developing RLS. Once iron levels or anemia is corrected, patients may see a reduction in symptoms. Chronic diseases such as kidney failure, diabetes, Parkinson's disease, and peripheral neuropathy are associated with RLS. Treating the underlying condition often provides relief from RLS symptoms.
Certain medications such as antinausea drugs, antiseizure drugs, antidepressant drugs, and caffeine, alcohol, or tobacco may induce or aggravate symptoms. Patients can talk with their physicians about the possibility of changing medications.
RLS is usually diagnosed by a specialist who recognizes the patient's symptoms and evaluates the patient's medical history, including past medical problems, family history, and current medications. Patients may be asked about frequency, duration, and intensity of symptoms as well as their tendency toward daytime sleep patterns and sleepiness, disturbance of sleep, or daytime function. Periodic Limb Movement Disorder can be diagnosed from findings on an overnight polysomnogram.
Physicians may suggest a variety of medications to treat RLS. Dopaminergic agents, largely used to treat Parkinson's disease, have been shown to reduce RLS symptoms and PLMD and are considered the initial treatment of choice. Benzodiazepines (sleeping pills) may be prescribed for patients who have mild or intermittent symptoms. These drugs help patients obtain a more restful sleep but they do not fully alleviate RLS symptoms and can cause daytime sleepiness. For more severe symptoms, opioids such as codeine or oxycodone may be prescribed for their ability to induce relaxation and diminish pain. Anticonvulsants are also useful for some patients, as they decrease the sensory disturbances (creeping and crawling sensations).
Unfortunately, no one drug is effective for everyone with RLS. What may be helpful to one individual may actually worsen symptoms for another. In addition, medications taken regularly may lose their effect, making it necessary to change medications periodically. Your physician will need to tailor your treatment and follow you closely to ensure your symptoms are under control.