Restless legs syndrome
Restless Legs Syndrome (RLS) is a sensorimotor neurological disorder characterized by uncomfortable sensations in the limbs, particularly during periods of rest, such as when trying to sleep. Individuals with RLS often experience an intense urge to move their legs or walk to alleviate these sensations, which can be painful or distressing. The exact cause of RLS remains uncertain, but it is thought to involve abnormalities in the brain's dopaminergic system and may be linked to certain medical conditions like chronic kidney disease, diabetes, and iron deficiency. Symptoms are usually more pronounced in the evening and can disrupt sleep and daily activities. Treatment options range from dopaminergic medications and anticonvulsants to lifestyle modifications, including reducing caffeine and alcohol intake. RLS affects a significant portion of the population, with a higher prevalence in women and older adults. While research has advanced in understanding and treating RLS, ongoing efforts are needed to develop more effective therapies and address the challenges posed by the condition.
Restless legs syndrome
ALSO KNOWN AS: Periodic limb movement
ANATOMY OR SYSTEM AFFECTED: Brain, muscles, musculoskeletal system, nervous system, psychic-emotional system
DEFINITION: A sensorimotor disorder characterized by uncomfortable and even painful sensations in the limbs, especially the legs, when at rest or trying to sleep
CAUSES: Unknown, though likely involves abnormalities in brain’s dopaminergic system
SYMPTOMS: Evening or nighttime “inner” restlessness (akathisia), discomfort, pain, and/or need to move limbs or walk
DURATION: Varies from episodic to chronic
TREATMENTS: Dopaminergics, benzodiazepines, opioids, anticonvulsants; lifestyle modifications (decreasing the use of caffeine, alcohol, and tobacco, especially starting in the afternoon)
Causes and Symptoms
Restless legs syndrome (RLS) is a neurological disorder in which patients experience unpleasant sensations, especially in the evening or at night, that drive them to move their limbs in order to alleviate the discomfort. Patients typically describe an inability to tolerate sitting, lying, or remaining still for even short periods of time, accompanied by an intense urge to walk, run, or move about.
The specific of RLS remains to be determined, although a number of theories have been proposed. It appears to occur more often in people with certain conditions, including chronic kidney disease, diabetes, iron deficiency in the central nervous system (CNS), Parkinson disease, peripheral neuropathy, and multiple sclerosis, and therefore may be linked to one or more of these. It also seems to be more prevalent in people who use caffeine, nicotine, or alcohol; are stopping sedative use; or are taking certain medications, including some antinausea drugs (specifically metoclopramide or prochorperazine), antipsychotic drugs (specifically dopamine antagonists that cross the blood-brain barrier), antidepressants (specifically those that increase serotonin), and sedating antihistamines. The syndrome may accompany pregnancy, in which cases it is usually temporary.
According to the National Institute of Neurological Disorders and Stroke (NINDS), there is "considerable evidence" that RLS may be linked to a disruption of dopaminergic basal ganglia circuits in the brain. Between 40 and 90 percent of patients report at least one immediate family member who also has RLS, suggesting a genetic component. There appears to be a distinction between early-onset and late-onset RLS; the early-onset form of the syndrome is believed to be more likely to have a genetic basis, as it often coincides with multiple cases in the same family.
Although excessive leg movements can be demonstrated during a sleep-study test (nocturnal polysomnography), RLS is diagnosed by history only. Four essential criteria are used in diagnosis: (1) the patient experiences a compelling urge to move the legs (or other affected limbs) as a result of unpleasant sensations; (2) these symptoms are worse during the evening or at night and are minimal or absent in the morning; (3) the symptoms worsen during periods of inactivity or rest, including sitting in a chair or lying in bed; and (4) the symptoms are partially or completely relieved by activity, including stretching or walking, but only for as long as the activity continues. In addition, patients reporting symptoms of RLS should undergo toxicology studies and have their iron, electrolyte, and medication levels checked.
The symptoms and sensations of restless legs syndrome are typically depicted in negative terms—“fidgety,” “creepy crawlies,” “insect crawlies,” “painful,” and “electric,” among other descriptors. Most report that these sensations can become so intense that they must “jiggle” or “shake,” before ultimately resorting to getting up and walking. Spouses may also complain that patients move their limbs while asleep, thus disturbing the quality of sleep for both partners.
RLS is not limited to the evening hours, bedtime, or sleeping, nor is it necessarily limited to the lower extremities. It can involve an inability to tolerate confinement or immobility at any time of the day, such as in airplanes, buses, or cars, or simply during activities that involve remaining still for a period of time. More severe cases can also involve other areas of the body, including the hips, upper back, shoulders, and arms. Patients report that it is difficult or impossible to ignore the negative sensations, which adversely affect not only sleep but also daily activities.
Treatment and Therapy
Difficulties arise when attempting to treat restless legs syndrome, as the disorder appears to involve multiple brain processes. Initial treatment usually involves anti-seizure drugs such as gabapentin. Other options include low-dose dopaminergics (drugs that increase dopamine in the brain), which are also used to treat Parkinson disease. Ropinirole, pramipexole, and rotigotine are dopaminergic agents that have been approved by the US Food and Drug Administration (FDA) for treatment of moderate to severe RLS. Doses of these medications are slowly titrated until therapeutic results are attained. Side effects are representative of dopamine agonists as a class: headaches, nausea, insomnia, “sleep attacks,” and problems related to impulse control (gambling, drinking, shopping, hypersexuality). In addition, long-term use may result in worsening of RLS symptoms. Anticonvulsants, opioids, and sedative-hypnotics have also been used to treat RLS, all with varying success depending on individual patient profiles.
Patients should be instructed to stay away from caffeine, tea, chocolate, alcohol, or tobacco in the evening (after 5:00 p.m.). They should also engage in good sleep hygiene (obtain sufficient hours of rest, have a regular time to retire and awaken), avoid exercising too close to bedtime, avoid aggravating medications, and take ferrous sulfate supplements if iron studies show this to be warranted.
Perspective and Prospects
The US National Library of Medicine reports that RLS affects an estimated 5 to 10 percent of adults and 2 to 4 percent of children in the United States. It is more likely to affect women than men, and its prevalence increases with age.
RLS is an underappreciated disorder that causes millions of people a great deal of distress and misery. While many may think of the condition as a new disease, it has been described for centuries. Yet only since the 1980s has this complex neurological disorder captured the attention of medical scientists and researchers. Such interest has led to the development of medical therapies tailored to relieve the symptoms of RLS, although much remains to be done. In modern times primary care physicians, neurologists, psychiatrists, rheumatologists, and other health care professionals take this problem seriously as a disorder with a significant resulting from chronic interruption of sleep and daily activities. Further, future directions in will hopefully take into account the need for longer-acting medications and nondopaminergic options.
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