Screening for Sleep Disorders: Recognizing the Features and Presentations of Restless Legs Syndrome
Richard P. Allen, PhD
Restless legs syndrome (RLS) is an often misunderstood and misdiagnosed sensorimotor condition characterized by a strong urge or compelling need to move the legs often, but not always, associated with unusual, uncomfortable feelings in the legs. RLS affects patients’ sleep, quality of life, and ability to work and incurs substantial health care costs.1–3 Understanding misconceptions about and features of RLS will help clinicians recognize this neurologic condition.
Overcoming Misconceptions About RLS
Several misconceptions about RLS can hinder making an accurate diagnosis. Clinicians may doubt the validity of the condition, and patients may be embarrassed to admit symptoms because they think the sensations or urges to move are common or trivial. Even the name of the condition may be associated with stigma.
Misleading name. A misconception about RLS is that restlessness is an annoying but harmless feeling. However, patients describe the sensation in their legs as ants crawling, electric currents, burning veins, and itching bones.4 To overcome the trivialization of RLS, IRLSSG chose the new name Willis-Ekbom Disease (WED) in 2011.5 The hope is that WED will eventually become an accepted alternative to RLS.
Insignificant problem. The public may not recognize the impairments associated with medically significant RLS, but symptoms can negatively impact patients’ emotional well-being, social and occupational functioning, and physical health.3 For example, patients with chronic, persistent RLS have reduced quality of life compared with the general population (AV 1).3 RLS also affects work productivity; patients with primary RLS have a mean productivity loss of 1 workday per week.1 RLS has been associated with coronary artery disease, cardiovascular disease, and increased mortality in men.6,7
Common condition. Another misconception about RLS is that its prevalence is perhaps as high as 20%,4 but this percentage is likely inflated due to conditions that mimic RLS. A population-based study3 found that chronic, persistent RLS has a prevalence of 3%, and RLS of any frequency was 7%.3 Medically significant physician-diagnosed RLS is estimated to be about 2% to 3% of patients in general medical practices in Europe, and close to 1% of these patients have RLS severely disrupting their health.8 The mean age at onset is 34±20 years,9 but RLS may appear in children and the elderly.4 Prevalence rates are higher in certain populations including women, older adults, and iron-deficient people.3,10
Although patients with RLS have substantial problems, this condition remains underdiagnosed. In a large European study,8 primary care physicians diagnosed RLS in 58% of 630 patients who screened positively for RLS symptoms. Of the 58% of diagnosed patients, 91% had not been previously diagnosed. Another study3 revealed that only 6% of patients with chronic, persistent RLS who discussed their symptoms with a primary care physician received the correct diagnosis. Misdiagnoses included poor circulation, arthritis, back/spinal problems, and varicose veins. A clinical history is the primary diagnostic tool for RLS, so clinicians must be familiar with the diagnostic criteria and associated features of RLS to make an accurate diagnosis of this condition.
Diagnostic criteria. The revised diagnostic criteria11 specify that the following essential features be present for a diagnosis of RLS:
The urge to move the legs (and any accompanying unpleasant sensations):
- Occurs suddenly, usually accompanied or caused by uncomfortable and unpleasant sensations
- Begins or worsens during rest or inactivity (ie, lying down, sitting)
- Are partially or totally relieved by movement (eg, walking, stretching) as long as the movement continues
- Occur or are worse in the evening or night
- Are not solely accounted for by another medical or behavioral condition (eg, positional discomfort, habitual foot tapping) (AV 2)12
The fifth criterion was added because of confusion between RLS and conditions that “mimic” the symptoms. For example, patients who habitually tap a foot are usually unaware of doing so, but patients with RLS are painfully aware of the urge to move and must continue to move to experience relief. Someone who experiences positional discomfort relieves pain by changing to another position and does not have to keep moving for the relief to continue.
Course specifiers such as intermittent RLS and chronic-persistent RLS describe the frequency and impairment of RLS. Intermittent RLS is when symptoms occur less than twice per week for the past year but at least 5 times in a patient’s lifetime. Chronic persistent RLS occurs at least twice weekly. Significant impairment entails decreased role functioning due to the impact of RLS on sleep, energy, mood, behavior, cognition, and daily activities.
Associated features. Sleep disturbance is one of the primary reasons that patients with RLS seek medical attention (AV 3).3,4 Clinicians should consider RLS in any patient who presents with insomnia or daytime fatigue and take a thorough sleep history.12 Patients with mild RLS may report minor sleep disturbances and are mainly bothered by symptoms while awake (eg, they are unable to sit for long periods at conferences or on long flights), but patients with moderate-to-severe RLS are more likely to experience frequent sleep interruptions and decreased sleep time (eg, <5 hours/night).4
Other features of RLS, which may not occur in every patient, include a family history of RLS, especially among first-degree relatives; periodic limb movements (PLM) during wakeful resting or sleep; and a positive response to dopaminergic therapy.4 By gathering information on these associated features, clinicians can confirm a diagnosis of RLS.
Medical evaluation. Clinicians should evaluate and test for factors and conditions that may exacerbate or mimic RLS symptoms.4 End-stage renal disease, pregnancy, and iron deficiency are all associated with RLS.4 Iron deficiency can also cause RLS symptoms; therefore, clinicians may test serum ferritin levels and transferrin-iron saturation percentage.4,12
The patient’s age at onset of RLS is also significant because, after age 45 years, the older the age of onset, the more other diseases or medications are likely to cause the symptoms. Medications that may increase RLS-like symptoms include dopamine receptor antagonists, antihistamines, and antidepressants (eg, TCAs and SSRIs).12 Comorbid conditions associated with RLS include depression, anxiety, and hypertension.2 Finally, the location of symptoms can help confirm RLS because it is rarely in the feet and is usually bilateral. Unilateral symptoms occur but are often associated with other neurologic conditions.
Diagnostic and severity tools. Some tools that can help evaluate RLS are the Hopkins Telephone Diagnostic Interview (HTDI)13 and the patient-completed Cambridge-Hopkins Restless Legs Syndrome Diagnostic Questionnaire (CH-RLSq).14 The HTDI, although usually better for clinical trials because it is a little longer than a standard clinical interview, provides useful questions for clinicians to differentiate RLS from other conditions.13 The CH-RLSq, which has 13 items, covers the diagnostic features of RLS and some basic differential diagnoses.14 To evaluate the severity of RLS, the 10-item International Restless Legs Syndrome rating scale (IRLS) can be used.15
RLS is a neurologic disorder that causes significant impairment and should be taken seriously. The symptoms are not just “restless legs” but are uncomfortable or painful sensations alleviated mostly by movement. Chronic RLS is experienced by about 3% of the population, but prevalence rates are higher for mild RLS, in women, and in older adults. Clinicians can use diagnostic criteria and associated features such as sleep disturbance, PLM, and iron deficiency when evaluating patients for RLS. Finally, a clinical and family history and diagnostic tools can help clinicians differentiate RLS from other psychiatric or medical conditions.
- Use diagnostic criteria to evaluate patients for RLS
- Watch for associated features that indicate RLS, such as sleep disturbance, PLM, family history of RLS, and dopaminergic treatment response
- Conduct a thorough medical evaluation and use diagnostic and severity tools to confirm the diagnosis of RLS
- CH-RLSq = Cambridge-Hopkins Restless Legs Syndrome questionnaire
- HTDI = Hopkins telephone diagnostic interview
- IRLS = IRLSSG rating scale
- IRLSSG = International Restless Legs Syndrome Study Group
- PLM = periodic limb movement
- RLS = restless legs syndrome
- REST = RLS Epidemiology, Symptoms, and Treatment study
- SF-36 = Short Form 36 Health Survey
- SSRI = selective serotonin reuptake inhibitor
- TCA = tricyclic antidepressant
- WED = Willis-Ekbom Disease
- Allen RP, Bharrnal M, Calloway M. Prevalence and disease burden of primary restless legs syndrome: results of a general population survey in the United States. Mov Disord. 2011;26(1):114–120. PubMed
- Salas RE, Kwan AB. The real burden of restless legs syndrome: clinical and economic outcomes. Am J Manag Care. 2012;18(suppl 9):S207–S212. PubMed
- Allen RP, Walters AS, Montplaisir J, et al. Restless legs syndrome prevalence and impact: REST general population study. Arch Int Med. 2005;165(11):1286–1292. PubMed
- Allen RP, Picchietti D, Hening WA, et al. Restless legs syndrome: diagnostic criteria, special considerations, and epidemiology: a report from the restless legs syndrome diagnosis and epidemiology workshop at the National Institutes of Health. Sleep Med. 2003;4(2):101–119. PubMed
- de Weerd A. Restless legs syndrome or Willis-Ekbom Disease: what is in a name? Sleep Med. 2013;14(4):381–382. PubMed
- Winkelman JW, Shahar E, Sharief I, et al. Association of restless legs syndrome and cardiovascular disease in the Sleep Heart Health Study. Neurology. 2008;70(1):35–42. PubMed
- Li Y, Wang W, Winkelman JW, et al. Prospective study of restless legs syndrome and mortality among men. Neurology. 2013;81(1):52–59. PubMed
- Allen RP, Stillman P, Myers AJ. Physician-diagnosed restless legs syndrome in a large sample of primary medical care patients in western Europe: prevalence and characteristics. Sleep Med. 2010;11(1):31–37. PubMed
- Ondo W, Jankovic J. Restless legs syndrome: clinicoetiologic correlates. Neurology. 1996;47(6):1435–1441. PubMed
- Allen RP, Auerbach S, Bahrain H, et al. The prevalence and impact of restless legs syndrome on patients with iron deficiency anemia. Am J Hematol. 2013;88(4):261–264. PubMed
- International Restless Legs Syndrome Study Group. Diagnostic criteria. http://irlssg.org/diagnostic-criteria. Published 2011. Accessed October 7, 2013.
- Bogan RK, Cheray JA. Restless legs syndrome: a review of diagnosis and management in primary care. Postgrad Med. 2013;125(3):99–111. PubMed
- Hening WA, Allen RP, Washburn M, et al. Validation of the Hopkins telephone diagnostic interview for restless legs syndrome. Sleep Med. 2008;9(3):233–239. PubMed
- Allen RP, Burchell BJ, MacDonald B, et al. Validation of the self-completed Cambridge-Hopkins questionnaire (CH-RLSq) for ascertainment of restless legs syndrome (RLS) in a population survey. Sleep Med. 2009;10(10):1097–1100. PubMed
- Walters AS, LeBrocq C, Dhar A, et al. Validation of the International Restless Legs Syndrome Study Group rating scale for restless legs syndrome. Sleep Med. 2003;4(2):121–132. PubMed
From the Series:
Supported by an educational grant from UCB, Inc.
CME Background Information
Supported by an educational grant from UCB, Inc.
After completing this educational activity, you should be able to:
- Screen for sleep disorders, including RLS
The faculty for this CME activity and the CME Institute staff were asked to complete a statement regarding all relevant personal and financial relationships between themselves or their spouse/partner and any commercial interest. The CME Institute has resolved any conflicts of interest that were identified. No member of the CME Institute staff reported any relevant personal financial relationships. Faculty financial disclosure is as follows:
Dr Allen is a consultant for Xenoport, UCB Pharma, Pfizer, and Impax; has received grant/research support from Pharmacosmos, GlaxoSmithKline, and the NIH; and has received honoraria from UCB Pharma.
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To obtain credit for this activity, study the material and complete the CME Posttest and Evaluation.
Release, Review, and Expiration Dates
This Neurology Report was published in December 2013 and is eligible for AMA PRA Category 1 Credit™ through December 31, 2016. The latest review of this material was October 2013.
Statement of Need and Purpose
Restless legs syndrome (RLS) is a common neurologic disorder of unknown etiology that causes significant distress. The symptoms of RLS—uncomfortable sensations that create an urge to move the legs that worsen during periods of rest and are relieved temporarily by movement—can severely disrupt sleep, leading to a reduced quality of life, daytime tiredness, a lack of energy, a disturbance of daily activities, and a tendency to become depressed. The prevalence and severity of RLS increase with age, and, due to the aging of the population, the personal and societal burden of RLS will become ever greater in coming years, increasing the need for prompt and effective treatment. Due to the nature of RLS symptoms, patients may seek treatment from a variety of health care providers, including primary care physicians, psychiatrists, and neurologists. However, even though diagnostic criteria for RLS have been established, patients are often misdiagnosed. In many cases, patients should be screened for RLS even though they do not directly report RLS symptoms. Health care providers should also be aware that the majority of people with insomnia never discuss sleep problems with their physicians and patients should, therefore, be routinely screened for sleep disturbances. Once RLS has been diagnosed, treatment is generally pharmacologic because sleep hygiene behaviors that promote relaxation or comfort may worsen or trigger RLS symptoms. However, mild exercise may relieve the symptoms long enough to let the patient get to sleep. Unfortunately, many patients are currently prescribed therapies not known to be effective in RLS, including analgesics, anti-inflammatories, and medications for gout and cramps. Clinicians need education on recognizing and assessing RLS symptoms in clinical practice and then treating RLS effectively to improve patients’ outcomes and quality of life. This activity was designed to meet the needs of participants in CME activities provided by the CME Institute of Physicians Postgraduate Press, Inc., who have requested information on RLS.
Disclosure of Off-Label Usage
Dr Allen has determined that, to the best of his knowledge, no investigational information about pharmaceutical agents that is outside US Food and Drug Administration–approved labeling has been presented in this activity.
The entire faculty of the series discussed the content at a peer-reviewed planning session, the Chair reviewed the activity for accuracy and fair balance, and a member of the External Advisory CME Board who is without conflict of interest reviewed the activity to determine whether the material is evidence-based and objective.
This Neurology Report is derived from the planning teleconference series “Restless Legs Syndrome: Recognition, Diagnosis, and Treatment of a Common Sleep Disorder,” which was held in June and July 2013 and supported by an educational grant from UCB, Inc. The opinions expressed herein are those of the faculty and do not necessarily reflect the opinions of the CME provider and publisher or the commercial supporter.