A prevalence study of restless legs syndrome in Turkish children and adolescents

Restless legs symptoms in adolescents: epidemiology, heritability, and pubertal effects

AIMS

We aimed to determine the prevalence, pubertal effect, familial aggregation, and heritability of restless legs (RLS) symptoms in Chinese adolescents. In addition, the correlates and consequences of RLS symptoms were examined.

METHODS

This was a population-based family study that involved 1549 adolescents (probands), their parents and siblings. RLS symptoms were assessed by a single question measuring the core features of RLS. Subjects with RLS symptoms for at least once per week were considered as abnormal. Impairment of daytime functions, behavioral problems, health status, and lifestyle practice were also documented.

RESULTS

The prevalence of RLS symptoms was 2.8% in adolescents and 7.4% in their parents with female preponderance. Gender difference of RLS symptoms emerged in mid-pubertal adolescents (Tanner stage 3 or above). RLS symptoms were closely associated with various sleep problems (range of ORs=2.24 to 32.5, p<0.05), except habitual snoring. They were also independently associated with impairment of daytime functions, poor general health and frequent temper outbursts but not caffeine or alcohol intake or cigarette smoking after adjustment for age, sex, and other comorbid sleep problems. RLS symptoms presented with a modest familial aggregation and heritability (h²±SE=0.17±0.04, p<0.001).

INTERPRETATION

RLS symptoms are common in Chinese adolescents with significant health repercussions. Puberty plays a critical role in the emergence of gender difference of RLS symptoms, which are accounted for by both genetic and environmental factors.

The prevalence of migraine in restless legs syndrome

OBJECTIVE

While previous studies have investigated the prevalence of restless legs syndrome (RLS) in patients with migraine, we aimed to explore the prevalence and characteristics of migraine in adult patients diagnosed with RLS.

BACKGROUNDS

The association of primary headaches, especially of migraine, with RLS has recently attracted much attention. Migraine prevalence was reported to be higher in patients with RLS than in the general population, and the role of dopamine was strengthened.

METHODS

We evaluated 265 consecutive adult RLS patients (137 males and 128 females) followed up in a Sleep Disorders Unit and diagnosed according to criteria defined by the International Restless Legs Syndrome Study Group (IRLSSG). RLS characteristics, and the severity, were performed by using the IRLSSG severity scale. The diagnosis of headache subtypes was defined by the International Classification of Headache Disorders. Gender, age, age at RLS onset, duration of RLS, family history of RLS, family history of headache, presence of depression, any treatments given for RLS, and the change in headache following RLS treatment were questioned.

RESULTS

The mean age of the study population was 50.4 ± 12.8 years, mean age at RLS onset was 41.6 ± 13.2 years, and mean disease duration was 8.40 ± 8.6 years. Of these, 163 patients had headache; 40 of them were diagnosed to have migraine-type headache (15.1%). The presence of migraine-type headache was 9.4% in males with RLS, and 21.1% in female RLS patients. In RLS patients with migraine, 67.5% were females, while 48.0% of RLS patients with other types of headache were females (P = .032), and only 41.2% of RLS patients without headache were females (P = .005). The severity of RLS was significantly higher in patients with migraine compared with those without headache (P < .001). The presence of depression, the family history of RLS, and headache were also higher in patients with migraine compared with RLS patients with other types of headache or those without headache. Thirty-six patients with headache reported partial or substantial benefit from RLS treatment.

CONCLUSIONS

Our results did not suggest higher rates of migraine-type headache in RLS patients when compared with population-based prevalence studies from Turkey. Alternatively, the severity of RLS was significantly higher in patients with migraine. Although the increase in these scores does not constitute a relationship etiopathogenetic, it suggests a correlation between the type cross-model nociceptive systems. Moreover, the family history of RLS was higher in patients with migraine. The prevalence of migraine in patients with RLS, however, waits to be better demonstrated.

Associations between specific technologies and adolescent sleep quantity, sleep quality, and parasomnias

OBJECTIVE

We tested the hypothesis that weekday bedtime use of six technologies would be significantly associated with eight sleep parameters studied relating to sleep quantity, sleep quality, and parasomnias.

METHODS

In our cross-sectional study, we previously administered validated age-appropriate questionnaires (School Sleep Habits Survey, Technology Use Questionnaire). Participating adolescents (n=738; 54.5% boys) were aged 11-13 years and were from the Midlands region of the United Kingdom in 2010.

RESULTS

Frequent use of all technology types was significantly inversely associated with weekday sleep duration (hours). Frequent music listeners and video gamers had significantly prolonged sleep onset (β=7.03 [standard error {SE}, 2.66]; P<.01 and β=6.17 [SE, 2.42]; P<.05, respectively). Frequent early awakening was significantly associated with frequent use of all technology types. The greatest effect was observed in frequent television viewers (odds ratio [OR], 4.05 [95% confidence interval {CI}, 2.06-7.98]). Difficulty falling asleep was significantly associated with frequent mobile telephone use, video gaming, and social networking, with music listeners demonstrating the greatest effect (OR, 2.85 [95%CI, 1.58-5.13]). Music listeners were at increased risk for frequent nightmares (OR, 2.02 [95% CI, 1.22-3.45]). Frequent use of all technologies except for music and mobile telephones was significantly associated with greater cognitive difficulty in shutting off. Frequent television viewers were almost four times more likely to report higher sleepwalking frequency (OR, 3.70 [95% CI, 1.89-7.27]).

CONCLUSIONS

Frequent weekday technology use at bedtime was associated with significant adverse effects on multiple sleep parameters. If confirmed in other samples and longitudinally, improving sleep hygiene through better management of technology could enhance the health and well-being of adolescent populations.

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

There has been no previous side-by-side comparison of the diagnostic criteria for restless legs syndrome (RLS) (Willis-Ekbom disease) and growing pains. In our review, we explore this comparison emphasizing overlaps and disconnects, summarize recent literature exploring the relationship between the 2 entities, and make suggestions for future research. There is considerable overlap in the diagnostic criteria for childhood RLS and growing pains. The literature also indicates that RLS and growing pains more commonly occur together than one would expect based on chance alone, and the family histories of RLS and growing pains often are overlapping. Leg rubbing to obtain relief from leg discomfort is common to both disorders, though walking to obtain relief seems unique to RLS. Childhood RLS also has been reported to be painful in up to 45% of cases. The development of standard diagnostic criteria is necessary to move forward in the field of growing pains research. A quantitative and validated rating scale for growing pains severity already exists. Because of the clinical and genetic similarity between RLS and growing pains, studies that parallel those previously performed in RLS patients are recommended for growing pains patients. For example, a genome wide association study in growing pains patients of all possible genes with particular attention to those identified as related to RLS and a therapeutic trial of medications known to be effective in RLS would be welcome. Abnormalities in vitamin D metabolism also may be common to both disorders.

Early childhood-onset restless legs syndrome: symptoms and effect of oral iron treatment

AIM

To describe symptoms of restless legs syndrome (RLS) in early childhood and the effect of oral iron treatment.

METHODS

A study population comprising 22 children, 15 males and seven females referred for paediatric evaluation because of sleep disturbances. Presence of RLS was evaluated using the International RLS Study Group consensus criteria of RLS. In case of ferritin level below 50 ng/mL, oral iron treatment was initiated. Fourteen were examined by polysomnography as well, and periodic limb movement index during sleep (PLMSI) was calculated. Relief of symptoms was recorded by the parents and correlated with ferritin levels and PLMSI.

RESULTS

Median age at onset of symptoms was 7.5 months (0-40 months). The most striking single symptom was awakening after 1-3 h of sleep followed by screaming, crying, kicking or hitting the legs. Oral iron supplementation had a positive ferritin-concentration-dependent clinical effect. A relation between high PLMSI and low ferritin levels was demonstrated.

CONCLUSION

Symptoms of RLS may start as early as the first year of life, are accompanied by low ferritin levels and a high PLMSI and can be ameliorated by iron supplementation. An increased awareness and knowledge of RLS in early childhood are warranted.

Increased RLS prevalence in children and adolescents with migraine: a case-control study

BACKGROUND

Previous studies have reported an increased frequency of restless legs syndrome (RLS) in adult migraine patients. Until now, the frequency of RLS in pediatric patients has not been investigated. We set out to assess the frequency of RLS in children and adolescents with migraine compared to headache-free controls.

METHODS

We investigated 111 consecutive patients with a sole diagnosis of migraine with or without aura presenting to the Headache Unit at the Department of Child and Adolescent Psychiatry and 73 headache-free controls for the presence of RLS using a semistructured interview. In addition, we assessed the level of daytime sleepiness by means of the Epworth sleepiness scale (ESS). A second group of headache-free controls was screened for the presence of RLS using an online questionnaire.

RESULTS

The frequency of RLS in migraine patients was significantly higher than in controls (22% vs. 5% (p < 0.001) and 8% (p < 0.001)).

DISCUSSION

This is the first study suggesting an association between RLS and migraine in the pediatric population. Future studies are needed to determine the extent of sleep disruption in children and adolescents with migraine and comorbid RLS.

Psychiatric comorbidity in children and adolescents with restless legs syndrome: a retrospective study

OBJECTIVE

Children and adolescents with restless legs syndrome (RLS) are commonly diagnosed with comorbid attention deficit hyperactivity disorder and behavioral disturbances. Uncertainty exists over the significance of other co-occurring psychiatric disorders and their pharmacologic management in children with RLS. The purpose of this study was to determine the prevalence and nature of psychiatric disorders in children with RLS and to describe the use of psychotropic medications in our study cohort.

METHODS

The electronic medical records of children younger than 18 years of age who had been diagnosed with RLS between January 1, 2003, and December 31, 2009, were reviewed. Only those patients whose findings were consistent with the 2003 NIH workshop diagnostic criteria for probable or definite restless legs syndrome were included in this study. The medical records were cross-referenced for encounters with a child psychiatrist or psychologist. Likewise, only psychiatric diagnoses whose medical records explicitly reflected DSM-IV diagnostic criteria for psychiatric disorder(s) were included. Demographic data, serum ferritin, psychotropic medications, and in some cases, the results of pharmacogenomic testing were included in the data analysis in an ad hoc fashion.

RESULTS

We found 374/922 patients who met diagnostic criteria for childhood onset RLS. The mean age of the subjects was 10.6 years (range 0 to 18) and the male to female ratio was approximately 1:1. Overall, 239/374 (64%) patients with RLS had one or more comorbid psychiatric disorders. Attention deficit hyperactivity disorder was found in 94/374 (25%) patients, mood disturbances were found in 109/374 (29.1%) patients, anxiety disorders in 43/374 (11.5%) patients, and behavioral disturbances in 40/374 (10.9%) patients. Attention deficit hyperactivity disorder and disruptive behavior disorders were more common in males (OR = 1.94 for both), whereas mood disturbances and anxiety disorders were more common in females (OR = 1.6 and 1.26, respectively). Mean serum ferritin levels derived from all patients without any psychiatric disorder were compared to all patients with one or more psychiatric disorder. No differences were found. The number of new psychotropic medication trials increased significantly with increase in patient age. Stimulants and antidepressant medications were the most commonly prescribed agents. As a part of clinical care, 15 of these patients underwent pharmacogenomic testing. Metabolic abnormalities were predicted by genotyping in 12/15 (80%) patients.

CONCLUSION

Comorbid psychiatric conditions occurred in two-thirds of children with RLS, underscoring the need for multidisciplinary management of this condition. An important relationship might exist between psychotropic medication, and possibly pharmacogenomic factors, in children and adolescents with symptoms of restless legs syndrome. These findings are consistent and build on those reported in the adult literature.

Growing pains: twin family study evidence for genetic susceptibility and a genetic relationship with restless legs syndrome

BACKGROUND

Growing pains (GP) is a prevalent familial childhood disorder of unknown aetiology. Familial occurrence of GP, and individual and familial association of GP with restless legs syndrome (RLS) has been reported.

METHODS

We applied a twin family design to search for evidence of genetic susceptibility to GP, and for a genetic relationship between GP and RLS. The parents of 1843 twin pairs aged 3-16 years were administered a questionnaire, which identified 88 pairs with at least one twin individual fulfilling criteria for GP. Standard questionnaires for history of GP and RLS were completed for these twin pairs, their siblings and parents.

RESULTS

Twenty-five of 34 monozygotic (MZ) pairs were concordant for GP, compared with 12 of the 54 dizygotic (DZ) pairs. The casewise concordance was 0.85 and 0.36 for MZ and DZ pairs, respectively (p < 0.001). The lifetime GP prevalence for relatives of twins with GP was 51% for non-twin siblings, 47% for parents. Twenty-three percent of twin individuals with GP met RLS criteria compared with 8% of twin individuals without GP (p = 0.03). Of the twins with GP concordance, 19% met RLS criteria compared with 2% of twins with GP discordance (p = 0.01). In two MZ pairs, one had GP and the other RLS. The lifetime prevalence of RLS was 40% for mothers, and 24% for fathers and 18% for non-twin siblings.

CONCLUSION

This first twin family study of GP provides evidence for a genetic aetiology and for a genetic relationship to RLS.

Restless legs syndrome: a comprehensive overview on its epidemiology, risk factors, and treatment

PURPOSES

Restless legs syndrome (RLS) is underdiagnosed and poorly understood by clinicians and the general public alike; accordingly, a broad literature review with information most relevant to general practice is needed to help dispel misconceptions and improve level of care.

METHODS

Specifically, this review comprehensively provides an epidemiological analysis of RLS and examines the risk factors and treatment options for RLS by compiling the findings of past RLS studies. These RLS studies were identified through a retrospective PubMed search. The epidemiological analysis was conducted by calculating a weighted mean average of all the relevant general population RLS prevalence studies, separated into geographical/racial categories.

RESULTS

A comprehensive analysis of RLS epidemiological studies finds the prevalence rate of RLS to be 5-15% in the general population with 2.5% of adults having symptoms severe enough to require medical intervention. Some of the risk factors for RLS include female gender, pregnancy, low iron levels, lower socioeconomic status, poor health, elderly age, comorbidity with Parkinson's disease, positive family history of RLS, and comorbidity with psychiatric disorders. A wide array of treatment options exist for RLS including pharmacological and nonpharmacologic interventions.

CONCLUSIONS

Clinicians' understanding of RLS enigma has recently improved due to the increased intensity of RLS research over the past decade. This review summarizes the current findings in the RLS field as well as providing guidelines for future RLS-related research.