Restless Legs Syndrome vs. Growing Pains 

Pediatric Restless Legs Syndrome (RLS) represents an important morbidity with criteria for definite RLS met by 1.9% of children aged 8-11 years and 2% of adolescents aged 12-17 years and a considerable number complaining of a significant impact on quality of life [1]. Moderately or severely distressing RLS symptoms were reported to occur at least 2 times per week or more in 0.5% and 1.0% of children, respectively [1]. Growing pains (GPs) exist in a similar percentage of the pediatric population with similar morbidity [2,3]. The prevalence of growing pains widely varies from study to study, but conservative estimates suggest a prevalence of 4.7% [2].

The purpose of the RLS vs. GP Project is to:

• Compare the clinical features of childhood RLS to GPs and normal controls;

• Compare the iron binding protein ferritin and Vitamin D levels in these three groups; and

• Collect genetic samples from all three groups for future analysis.

Eleven clinical centres and one genetic coordinating center (represented by the USA, Canada, China, Australia, Spain, Taiwan and England) participated.

We have reviewed the literature comparing RLS to Growing Pains (4,5) and 3 commonalities emerge:

1. Based upon historical information only, the clinical features of both disorders are to a large degree overlapping—Both disorders involve large parts of the thighs, calves or both, both disorders tend to be worse at night and worse at rest, i.e. lying or sitting;  However, it is only in RLS that there is a desire to move because of the legs and it is only in RLS that there is relief of leg discomfort by moving;

2. The two disorders occur more commonly together in the same patient than one would expect by chance alone with a history of childhood growing pains often followed by adult RLS after a hiatus of many years;

3. Both disorders occur in a familial pattern suggestive of an autosomal dominant family history and a co-existing family history of both disorders in a single family is more common than one would expect by chance alone.

What this study adds:

There has never been any attempt to actually go into the homes of children with growing pains and objectively observe any potential movements during a symptomatic period and get a subjective report of any possible need to move and any relief of leg discomfort by activity when children are actually symptomatic. We are focusing on the exploration of symptoms in the home setting when the associated discomfort or pain presents.

References:

1. Picchietti D, Allen RP, Walters AS, Davidson JE, Myers A, Ferini-Strambi L. Restless legs syndrome: prevalence and impact in children and adolescents— The Peds REST study. Pediatrics 2007;120:253–66.

2. Peterson HA. Leg aches. Pediatr Clin North Am 1977;24:731–6.

3. Peterson HA. Growing pains. Pediatr Clin North Am 1986;33:1365–72.

4. Walters AS. Is there a subpopulation of children with growing pains who really have Restless Legs Syndrome?:  A Review of the literature. Sleep Medicine 3: 93-98; 2002.

5. Walters AS, Gabelia D, Frauscher B. Restless Legs Syndrome (Willis Ekbom Disease) and Growing Pains, are they the same thing ?: A side by side comparison of the diagnostic criteria for both and recommendations for future research. Sleep Medicine 14: 1247-1252; 2013.

Project Lead: Arthur Walters

Project Partners: International Restless Legs Syndrome Study Group 

Research Assistants (2019-Present): Nadia Beyzaei, Melvin Chan, Kevin Xiao

Funding: Kids Brain Health Network

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