Original ArticleA prevalence study of restless legs syndrome in Turkish children and adolescents☆
Introduction
Restless legs syndrome (RLS) is a sleep-related sensory and motor disorder characterized by an irresistible urge to move the legs, usually associated with or caused by unpleasant and uncomfortable sensations, which begin or worsen during rest, are relieved by movement and occur or worsen in the evening or at night.
After the introduction of the criteria of the International RLS Study Group (IRLSSG) in 1995 [1] and, later, a modification of these criteria in 2003 [2], several large population-based epidemiological surveys have reported prevalence rates of RLS in adults between 5.5% and 11% in Western countries [3], [4], [5], [6] and lower rates in Asia [7], [8].
Over the last 15 years there has been increasing recognition that RLS occurs in children. In 1994, Walters et al. [9] described the occurrence of RLS in a small series of children. One of the first reports of the common occurrence of RLS in children came from a study on adults with RLS which retrospectively reported the onset of symptoms in 18% of cases by age 10 and another 25% between the ages of 11 and 20 years [10]. Recent series of familial cases with RLS supported these findings [11]. Clinical studies reported high prevalence rates of RLS in a special population of children with attention deficit disorder [12], periodic leg movements in sleep [13] or growing pains [14]. A Canadian study, which aimed to examine various parasomnias, found the prevalence of leg restlessness to be 31.7% in children aged 11–13 years before pediatric criteria of RLS were defined [15]. The prevalence rate of RLS diagnosed using pediatric criteria was 5.9% in 538 children referred for sleep–wake problems to a clinic [16]. Although the prevalence of RLS in children and adolescents has been reported increasingly during the past two decades in clinical studies, epidemiological data in the pediatric population are very limited. To our knowledge, the only other population-based study of pediatric RLS using IRLSSG criteria, by Picchietti et al. [17], found a prevalence of definite RLS to be 1.9% for school-aged children and 2% for adolescents.
Some factors limit epidemiological surveys of RLS. Subjects with RLS usually do not seek medical care even though they have moderate or severe symptoms of RLS. Data based on outpatient or clinical studies could underestimate the prevalence. The second factor is misdiagnosis of RLS because of sensory symptoms which can be better accounted for by another condition, such as positional discomfort, leg cramps, arthralgias, or arthritis. While a medical history or diagnostic work-up can help to exclude other conditions, no clinical or laboratory test diagnostic of RLS is available. The other challenging factor in the diagnosis of pediatric RLS is the lack of emergence of typical symptoms at very young ages and limitations in the recognition and expression of symptoms. A retrospective analysis of children referred to sleep clinics with a sleep complaint demonstrated that the interval between the onset of clinical sleep disturbance and the diagnosis of definite RLS was 11.6 years [13]. Epidemiological studies done with face-to face interviews with questionnaires based on diagnostic criteria [2] and clinical evaluation, including a differential diagnosis to exclude other common conditions, would give a more accurate view of prevalence rates. Considering these ideal conditions, the present study aims to examine the prevalence of RLS during the past 12 months in a sample of school children and adolescents aged 10–19.
Section snippets
Study design
This cross sectional study was carried out in the Umraniye District of Istanbul Province between April and June 2009. Umraniye has a population of 553 935. The study took place in three primary and four high schools, which were randomly selected (approx. 6.5% of the total public primary and high schools in the municipality) and included a total of 4346 students. The survey aimed to include all students from 4 to 12th grade.
A formal consent was obtained from the Education Bureau and Governorship
Prevalence of RLS
The total number of our sample was 4346 subjects, and the participation rate was 99.95%. Of 4344 subjects (2115, 48.7% female) who gave valid answers to the questionnaire, 181 were positive responders to questions 4–6 as well as “yes” to either 1 or 2, or to both 1 and 2 (Fig. 1). Based on the diagnostic criteria of the IRLSSG, 119 (75 female, 66%) were diagnosed to be “definite RLS” (Table 2, Fig. 1); thus the yearly prevalence of “definite RLS” in this population was estimated to be 2.74%.
Discussion
To our knowledge, the present study is the second epidemiological survey done in children and adolescents based on criteria proposed by IRLSSG [2] and the first one conducted in a country outside of North America and Western Europe. We found a comparable prevalence rate (2.74%) of definite RLS in our total population to the rates (1.9% prevalence in children aged 8–11 years and 2% in adolescents aged 12–17 years) reported in the previous population-based study done in the United Kingdom and
Financial disclosure
This project proposed by D. Turkdogan and N. Bekiroglu was supported by the Marmara University Scientific Research Committee (No.: SAG-B-300609-0207).
Conflict of interest
There is no conflict of interest for any of the three authors.
Acknowledgements
We would like to thank the principals, deans and counselors of the schools for their invaluable support in communication with the students and the families. We also acknowledge Prof. R. W. Guillery for English editing.
References (46)
- et al.
Restless leg syndrome: diagnostic criteria, special considerations, and epidemiology A report from the restless leg syndrome diagnosis and epidemiology workshop at the National Institutes of Health
Sleep Med
(2003) - et al.
Prevalence of restless leg syndrome and periodic limb movement disorder in the general population
J Psycho Res
(2002) - et al.
Impact, diagnosis and treatment of restless leg syndrome (RLS) in a primary care population: the REST (RLS epidemiology, symptoms, and treatment) primary care study
Sleep Med
(2004) - et al.
Restless leg syndrome in childhood and adolescence
Pediatr Neurol
(1994) - et al.
Defining the phenotype of the restless leg syndrome (RLS) using age-of-symptom-onset
Sleep Med
(2000) - et al.
Epidemiology of restless leg syndrome in Turkish adults on the western Black Sea coast of Turkey: a door-to-door study in a rural area
Sleep Med
(2010) - et al.
Race and restless leg syndrome in an adult community sample in east Baltimore
Sleep Med
(2006) Is there a subpopulation of children with growing pains who really have restless legs syndrome? A review of the literature
Sleep Med
(2002)- et al.
Childhood and adult factors associated with restless leg syndrome (RLS) diagnosis
Sleep Med
(2007) - et al.
Validation of the Hopkins telephone diagnostic interview for the restless legs syndrome
Sleep Med
(2008)
The Johns Hopkins telephone diagnostic interview for the restless legs syndrome: preliminary investigation for validation in a multi-center patient and control population
Sleep Med
The four diagnostic criteria for Restless Leg Syndrome are unable to exclude confounding conditions (“mimics”)
Sleep Med
Toward a better definition of the restless leg syndrome. The International Restless Leg Syndrome Study Group
Mov Disord
Restless leg syndrome prevalence and impact: REST general population study
Arch Intern Med
Sex and the risk of restless leg syndrome in the general population
Arch Intern Med
Restless leg syndrome in an Asian population: a study in Singapore
Mov Disord
Prevalence of restless leg syndrome in a rural community in Japan
Mov Disord
A questionnaire study of 138 patients with restless leg syndrome: the “Night Walkers” survey
Neurology
Associations between symptoms of inattention, hyperactivity, restless legs, and periodic leg movements
Sleep
Early manifestations of restless leg syndrome in childhood and adolescence
Sleep Med
Some children with growing pains may actually have restless leg syndrome
Sleep
Development of parasomnia from childhood to early adolescence
Pediatrics
Childhood-onset restless leg syndrome
Ann Neurol
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The work was performed at Marmara University, Institute of Neurological Sciences, and Department of Pediatric Neurology.