Editor’s perspective: RLS/WED diagnostic criteria: an unfortunate conundrum in search of rectification

Abstract

Restless legs syndrome (RLS) is a sensorimotor neurological disorder that profoundly disturbs sleep and quality of life. RLS sufferers will tell you that this is a real disease yet even today, certain high impact prestigious journal continues to publish ‘‘Views and Reviews’’ trivializing the entity without any valid scientific argument. The fact that there are no diagnostic tests nor a specific laboratory marker for this disease inspired experts with considerable clinical experience and solid scientific research background to come up with certain essential clinical diagnostic criteria. These criteria have served well the RLS/WED scientific community to design valid epidemiological and rigorous clinical trials with measurable endpoints to authenticate the usefulness of certain drugs (not without long-term adverse consequences) to relieve the suffering of the unfortunate victims of the disease known popularly as restless legs syndrome, a name distorted by the media and the comedians to make it a laughable and ‘‘weird’’ entity. This compelled the RLS Patient Support Group spearheaded by the RLS Foundation as well as the international RLS experts to change the name to Willis–Ekbom Disease (WED) honoring the two original discoverers of this entity. Finally, as the diagnosis still depends on astute clinical evaluation despite rapid progress in the field limitations of the original diagnostic criteria of 1995 [1] forced the experts to come up with two revisions published in 2003 [2] and now with the current issue of the journal [3]. Allen [3], Picchietti [4], and collaborators described in an admirable manner the rationale, history, and evolution of the adult and pediatric diagnostic criteria. The adult and pediatric diagnostic criteria are now merged into one uniform set of essential criteria with slight modifications for the pediatric population. This document [3] based on consensus criteria established by the international experts in the field after careful deliberation should be the international gold standard for RLS/WED diagnosis in absence of a specific laboratory marker (which we are hoping will happen in the not too distant future). I must point out that these International Restless Legs Syndrome Study Group (IRLSSG) essential diagnostic criteria differ from those advocated by two other prestigious and highly influential societies dominated by physicians of the highest standard and integrity: the American Academy of Sleep Medicine (AASM) which produced ICSD-3 [5], and the American Psychiatric Association (APA) which composed the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) [6]. The AASM 2014 ICSD-3 RLS/WED diagnostic criteria must include what the IRLSSG called specifier for clinical significance (not included in IRLSSG consensus diagnostic criteria), although AASM made an exception for epidemiological and genetic studies. DSM-5, on the other hand, requires a frequency criterion of at least three times a week and a duration criterion of at least 3 months for symptoms. I am sure these experts in these other organizations must have their own reasoning and we must respect their rationale. This division, however, into three sets of different requirements amongst these groups of physicians is unfortunate. Allen and collaborators made a compelling argument as to why they did not think it is appropriate to include frequency, duration, and clinical significance in the five essential diagnostic criteria, and instead of repeating their reasoning, I refer the readers to the accompanying article in the Special Section of the current issue of the journal [3]. We sincerely hope that in the future these three groups would merge the criteria into a uniform and consistent diagnostic criteria to avoid confusion among clinicians and researchers in different specialties.