Restless Legs Syndrome/Willis-Ekbom Disease Diagnostic Criteria: Why Change?

During this session, Daniel Picchietti, MD, described the need for changes in the criteria for the diagnosis of restless leg syndrome (RLS), which is also known as Willis-Ekbom disease (WED). Picchietti also discussed the methodology underlying the revision and the changes in the diagnostic criteria as of 2013, for example, the addition of specifiers of clinical significance, specifiers of clinical course, and pediatric criteria for RLS. Finally, he examined some of the controversy surrounding the changes in the criteria for RLS diagnosis.

A better understanding of the changes to guidelines for the diagnosis of WED/RLS, the rationale behind these changes, and the controversy surrounding discrepancies between guidelines published by different societies will help clinicians, healthcare professionals, and the managed care community to recognize cases of this potentially painful disease.

The 2003 diagnostic criteria published by the International Restless Legs Syndrome Study Group (IRLSSG) and National Institutes of Health (NIH) have been cited over 1100 times in peer-reviewed literature. Since 2003, investigators have published over 3000 new publications on the topic of RLS. Thus the IRLSSG/NIH criteria merited revision in light of recent advances in the understanding of RLS.

Examining the changes in diagnostic criteria, Picchietti spoke about 5 prior incarnations of the guidelines for diagnosis of RLS/WED dating back to 1960. The most recent revision to the diagnostic criteria was published after a 2008 IRLSSG meeting featuring a collaboration of over 50 experts.

The new guidelines include 4 major changes. Changes include specifiers for clinical significance, specifiers for clinical course, and addition of a fifth essential feature characteristic of RLS/WED, in addition to the 4 existing features. The fifth criterion involves recognition of conditions that might mimic RLS. For instance, leg cramps, positional discomfort, myalgia, leg edema, arthritis, and habitual foot tapping do not constitute RLS. This change may improve the sensitivity and specificity of diagnosis of RLS. RLS may still occur in patients with conditions that mimic RLS.

Dr Picchietti added that a mild, nuisance form of RLS also exists in the community. This mild form, which does not often lead to a consultation with a physician, has led to difficulty in quantifying the epidemiology of RLS.

Aware of this, the study group included a specifier that defines clinical significance of RLS/WED. In general, the impact of RLS on sleep quality differentiates mild RLS from other forms that may not require treatment.

Although this guideline applies in clinical treatment, this guideline may not apply to clinical studies identifying genetic disorders related to RLS. For instance, in recruiting subjects for a control group of patients without RLS in a genetic study, it might be desirable to exclude patients with even mild symptoms of RLS, even if the 2013 diagnostic criteria do not qualify those patients for a diagnosis.

The study group also added a specifier that differentiates patients based on the clinical course of RLS. The guidelines now divide RLS into chronic-persistent and intermittent forms. Dr Picchietti noted that chronic-persistent RLS might have a greater effect in terms of negative cardiovascular outcomes compared with intermittent forms of RLS.

Regarding the diagnosis of RLS in pediatric patients, Dr Picchietti explained that phrases such as “need to move,” “want to move,” “my legs want to kick,” and similar statements are typical ways that children express the symptoms of RLS. These differ from the way adults might express RLS symptoms. For instance, adults might say, “I have an urge to move my legs.”

The Diagnostic and Statistical Manual of Mental Disorders, 5th edition, diagnostic criteria for RLS/WED, in contrast to the IRLSSG/NIH criteria, includes a stipulation that severe RLS must include at least 3 instances of RLS per week. However, many physicians have noted that patients with extreme symptoms of RLS often experience fewer than 3 instances of RLS per week. During a question/answer session, an expert in RLS, Dr Allen, confirmed that the stipulation of 3 instances of RLS per week, as a diagnostic criterion, was inconsistent with clinical experience.