Restless Legs Syndrome (RLS) is a neurologic sensorimotor disorder that is characterized by an overwhelming urge to move the legs when they are at rest. The urge to move the legs is usually, but not always, accompanied by unpleasant sensations. It is less common but possible to have RLS symptoms in the arms, face, torso, and genital region. RLS symptoms occur during inactivity and they are temporarily relieved by movement or pressure. Symptoms of RLS are most severe in the evening and nighttime hours and can profoundly disrupt a patient's sleep and daily life.
RLS affects approximately 10% of adults in the U.S. Researchers believe that RLS is commonly unrecognized or misdiagnosed as insomnia or other neurological, muscular or orthopedic condition. RLS may also be confused with depression. According to the Restless Legs Syndrome Foundation, approximately 40% of people with RLS complain of symptoms that would indicate depression if assessed without knowledge or consideration of a sleep disorder.
RLS runs in families and may have a genetic component. In a recent study, the first RLS gene was discovered and was shown to account for approximately 50% of RLS cases. However, the researchers who identified the RLS gene cautioned that having it does not guarantee RLS. Rather, there are likely to be medical, environmental or other factors involved in translating RLS genetic susceptibility into RLS symptoms. Another recent RLS study also found that a genetic variant may account for about half of RLS cases and revealed an association between RLS and a gene for limb development, suggesting the possibility that RLS has components of a developmental disorder.
RLS also affects about 2% of children, according to a recent study of more than 10,000 families in the U.S. and U.K. The study also found a strong genetic component to RLS; more than 70% of children with RLS had at least one parent with the condition. There is also evidencesuggesting that children with attention deficit hyperactivity disorder (ADHD) and a family history of RLS are at risk for more severe ADHD.
RLS affects both men and women and can start at any age. It may be confused with growing pains or restlessness when experienced by children. In addition, the severity of the disorder appears to increase with age. Older patients experience symptoms more frequently and for longer periods of time.
The exact cause of RLS is unknown but it has a primary form, not related to other disorders, and a secondary form related to an underlying condition such as kidney failure, pregnancy, or iron deficiency anemia. It may also be caused or made worse by certain medications. This is considered secondary RLS. When no other cause is found for RLS symptoms, it is considered a primary disorder. Primary RLS accounts for 40-60% of RLS diagnoses.
Recently, several research teams have taken a closer look at what might cause primary RLS. In particular, recent studies at Johns Hopkins and Pennsylvania State Colleges have found evidence for brain iron deficiency as a cause for primary RLS. This was first demonstrated in cerebrospinal fluid studies and more recently by the first-ever autopsy analysis of the brains of people with RLS. The autopsy studies reported that cells from the portion of the brain called the substantia nigra showed a deficit in one of the proteins that regulates iron status. However, this evidence suggests that the iron insufficiency in the brain of RLS patients comes directly from a failure of normal iron regulation. In terms of finding a cure, this is good news. The results of this study show that there is no brain damage in people with RLS and that drugs that target the problem of iron uptake may be one way to approach future developments of a treatment.
More than 80 percent of people with RLS also suffer from a condition know as periodic limb movement disorder (PLMD). Characteristics of PLMD include involuntary leg twitching or jerking movements during sleep that occur repeatedly throughout the night and result in disrupted sleep.
In addition to poor quality and short sleep at night, research has shown that people with RLS generally experience a reduced quality of life in the absence of treatment.
Symptoms include an urge to move the legs often associated with uncomfortable feeling in the legs (e.g. tingling, creepy, itching, pulling or aching) during periods of inactivity, including both sleep and wakefulness. Symptoms may also include involuntary jerking of the limbs that intensifies in the evening or at night and is relieved by movement. People with RLS tend to have difficulty falling or staying asleep and suffer from chronic sleep loss, leaving them with the cognitive and tired feelings that occur with sleep loss.
There is no specific diagnostic test for RLS. If you suspect you may have the disorder, talk to your doctor as soon as you can. If possible, bring a diary of your sleep as well as a record of the occurrence and severity of your symptoms with you. Your doctor will conduct tests to rule out factors that may be causing the symptoms such as pregnancy, iron deficiency and end-stage renal failure. You can expect that he or she will ask what time your symptoms occur, when they are most severe, what you were doing before the onset of symptoms, and how much time elapses before you are able to get to sleep due to your RLS. Your doctor will also need a record of your sleep quality and quantity during the time when symptoms appear and whether or not you experienced any pain along with the RLS symptoms.
Until recently, there were no FDA-approved drugs for the treatment of RLS. In May 2005, a drug called Requip® (ropinirole hydrochloride) that is commonly used to treat Parkinson disease was given FDA approval at lower doses for the treatment of moderate-to-severe primary RLS after patients in clinical trials enjoyed more and better quality sleep as early as one week after starting treatment. In 2006, a drug by the name of Mirapex® was also approved by the FDA for the treatment of moderate-to-severe primary RLS. In clinical trials of Mirapex® it was shown that lower doses (than used for Parkinson’s disease) improve RLS symptoms, sleep satisfaction, and quality of life. Both drugs may cause side effects such as nausea and dizziness and may cause patients to fall asleep without any warning, even while doing normal daily activities such as driving.
In addition to Requip® and Mirapex®, there are several drugs approved for other conditions that have been shown to alleviate RLS symptoms. They are:
- Dopaminergic agonists -- reduce RLS symptoms
- Dopaminergic agents -- reduce RLS symptoms
- Benzodiazepines -- allow for a more restful sleep
- Opiates -- induce relaxation and diminish pain
Side effects may include daytime sleepiness (dopaminergic agonists and benzodiazepines), hallucinations and nausea (dopaminergic agents) or constipation and dependency (opiates). Before taking any medication, discuss the possibility of side effects with your doctor.
In 1996, Drs. Allen and Earley from Johns Hopkins University described a phenomenon called augmentation, in which RLS symptoms are more severe, spread to parts of the body other than the legs, and begin earlier in the evening as a result of taking dopaminergic agents to treat RLS symptoms. If augmentation occurs it can be managed with dose and medication adjustments.
There are also a number of self-directed activities for managing the symptoms of RLS including walking, massaging the legs, stretching, hot or cold packs, vibration, and acupressure. Practicing relaxation techniques such as meditation or yoga have been known to alleviate symptoms. For many people, treating an underlying cause or effective pharmacological treatment of primary RLS and implementation of coping strategies provides relief from most symptoms. However, sometimes medications need to be changed over time or doses adjusted and regular consultation with a physician is recommended.
The following are some tips for coping with RLS:
- Don't hide your symptoms -- talk to your friends, family, and colleagues about RLS so they know what to expect
- Practice yoga, Pilates, or other stretching techniques regularly, preferably late in the day
- Arrange your schedule to be able to sleep when your symptoms are least pronounced
- Choose an aisle seat at the movies or on airplanes so that you are able to move around if necessary
- Plan travel hours when symptoms are least severe and allow times for breaks
There are also a number of RLS support groups around the country and they can help you learn new information about how others cope with RLS. For a list of such groups, go to www.rls.org or www.rlshelp.org.
2005 poll: 15% of the adult population responding to the NSF Sleep in America poll have symptoms of RLS a few nights a week or more, which could include unpleasant feelings in the legs such as creepy, drawly or tingling feelings, and 10% met the criteria for being at risk for RLS because – of those who experienced these symptoms -- such feelings were worse at night (146 persons).
Of those who have symptoms of RLS, 86% are also likely to have insomnia symptoms and sleep just 6.3 hours per weeknight, which is less than the mean for all respondents of 6.8 hours. Almost half (47%) of those experiencing RLS symptoms also take 30 minutes or more to fall asleep at night. Although 28% of all adults state that they missed work because of being too sleepy, 52% of those with RLS symptoms reported missing work or other events due to a sleep problem.
2002 poll: Even though 40% of adults polled rated their sleep as very good/excellent, just 20% of those with RLS symptoms reported the quality of their sleep this way. Also, of the total number of adults polled, 16% report experiencing RLS symptoms at least a few nights per week; however, just 4% have been diagnosed with the disorder. 32% of those with symptoms have used a sleep aid while 46% of those diagnosed used a sleep medication. Persons with RLS symptoms are more likely (60%) compared to the total (37%) to have daytime sleepiness a few days a month or more. Quality of life is affected by RLS symptoms. Those with these symptoms report being tired (35% vs. 20%), pessimistic (16% vs. 10%), prefer to be alone (34% vs. 22%), stressed (37% vs. 21%) and be angry (15% vs. 6%) during a typical day.
Reviewed by Richard P. Allen, Ph.D.and Merrill M. Mitler, Ph.D.