L-Dopa improves Restless Legs Syndrome and periodic limb movements in sleep but not Attention-Deficit-Hyperactivity Disorder in a double-blind trial in children

The management of sleep disturbances in children with attention-deficit/hyperactivity disorder (ADHD): an update of the literature

INTRODUCTION

Sleep disorders represent an important comorbidity in individuals with ADHD. While the links between ADHD and sleep disturbances have been extensively investigated, research on the management of sleep disorders in individuals with ADHD is relatively limited, albeit expanding.

AREAS COVERED

The authors searched PubMed, Medline, PsycInfo, Embase+Embase Classic, Web of Sciences databases, and clinicaltrials.gov up to 4 January 2024, for randomized controlled trials (RCTs) of any intervention for sleep disorders associated with ADHD. They retained 16 RCTs (eight on pharmacological and eight on non-pharmacological interventions), supporting behavioral intervention and melatonin, and nine ongoing RCTs registered on clinicaltrials.gov.

EXPERT OPINION

The pool of RCTs testing interventions for sleep disorders in individuals with ADHD is expanding. However, to inform clinical guidelines, there is a need for additional research in several areas, including 1) RCTs based on a precise phenotyping of sleep disorders; 2) pragmatic RCTs recruiting neurodevelopmental populations representative of those seen in clinical services; 3) trials testing alternative interventions (e.g. suvorexant or light therapy) or ways to deliver them (e.g. online); 4) sequential and longer-term RCTs; 5) studies testing the impact of sleep interventions on outcomes other than sleep; 6) and implementation of advanced evidence synthesis and precision medicine approaches.

Association among attention-deficit hyperactivity disorder, restless legs syndrome, and peripheral iron status: a two-sample Mendelian randomization study

Background

Epidemiological evidence indicates a high correlation and comorbidity between Attention Deficit Hyperactivity Disorder (ADHD) and Restless Legs Syndrome (RLS).

Objective

We aimed to investigate the causal relationship and shared genetic architecture between ADHD and RLS, as well as explore potential causal associations between both disorders and peripheral iron status.

Methods

We performed two-sample Mendelian randomization (MR) analyses using summary statistics from genome-wide meta-analyses of ADHD, RLS, and peripheral iron status (serum iron, ferritin, transferrin saturation, and total iron binding capacity). Additionally, we employed linkage disequilibrium score regression (LDSC) to assess genetic correlations between ADHD and RLS using genetic data.

Results

Our MR results supports a causal effect from ADHD (as exposure) to RLS (as outcome) (inverse variance weighted OR = 1.20, 95% CI: 1.08-1.34, p = 0.001). Conversely, we found no a causal association from RLS to ADHD (inverse variance weighted OR = 1.04, 95% CI: 0.99-1.09, p = 0.11). LDSC analysis did not detect a significant genetic correlation between RLS and ADHD (Rg = 0.3, SE = 0.16, p = 0.068). Furthermore, no evidence supported a causal relationship between peripheral iron deficiency and the RLS or ADHD onset. However, RLS may have been associated with a genetic predisposition to reduced serum ferritin levels (OR = 1.20, 95% CI: 1.00-1.04, p = 0.047).

Conclusion

This study suggests that ADHD is an independent risk factor for RLS, while RLS may confer a genetic predisposition to reduced serum ferritin levels.

Limitations

The GWAS summary data utilized originated from populations of European ancestry, limiting the generalizability of conclusions to other populations.

Clinical implications

The potential co-occurrence of RLS in individuals with ADHD should be considered during diagnosis and treatment. Moreover, iron supplementation may be beneficial for alleviating RLS symptoms.

Restless Legs Syndrome in Children and Adolescents

Children with psychiatric comorbidities frequently are referred for evaluation of sleep complaints. Common sleep symptoms can include difficulty falling asleep, frequent nocturnal awakening, restless sleep, and symptoms of restless legs syndrome (RLS). The understanding of the sleep condition in relation to the psychiatric comorbidity often is a challenge to the physician and often sleep disorders remain undiagnosed, untreated, or undertreated. Restless legs syndrome has been associated with psychiatric comorbidities and with certain medications, such as antidepressants, antihistamines, and antipsychotics. This article reviews the presentation of RLS and restless sleep, the association with psychiatric comorbidities, and treatment options.

Restless Legs Syndrome and Restless Sleep Disorder in Children

Restless legs syndrome (RLS) affects 2% of children presenting with symptoms of insomnia, restless sleep, decreased quality of life, and effects on cognition and behavior. The International RLS Study Group and the American Academy of Sleep Medicine have published guidelines for the diagnosis and treatment of RLS in children. Restless sleep disorder has been recently identified in children and presents with frequent movements during sleep and daytime symptoms with polysomnography findings of at least 5 large muscle movements at night. Treatment options for both disorders include iron supplementation, either oral or intravenous with improvement in nighttime and daytime symptoms.

A Systematic Review of Sleep and Circadian Rhythms in Children with Attention Deficit Hyperactivity Disorder

OBJECTIVE

Children and adults with ADHD often report sleep disturbances that may form part of the etiology and/or symptomatology of ADHD. We review the evidence for sleep changes in children with ADHD.

METHODS

Systematic review with narrative synthesis assessing sleep and circadian function in children aged 5 to 13 years old with a diagnosis of ADHD.

RESULTS

148 studies were included for review, incorporating data from 42,353 children. We found that sleep disturbances in ADHD are common and that they may worsen behavioral outcomes; moreover, sleep interventions may improve ADHD symptoms, and pharmacotherapy for ADHD may impact sleep.

CONCLUSION

Sleep disturbance may represent a clinically important feature of ADHD in children, which might be therapeutically targeted in a useful way. There are a number of important gaps in the literature. We set out a manifesto for future research in the area of sleep, circadian rhythms, and ADHD.

Assessment of intellectual impairment, health-related quality of life, and behavioral phenotype in patients with neurotransmitter related disorders: Data from the iNTD registry

Inherited disorders of neurotransmitter metabolism are a group of rare diseases, which are caused by impaired synthesis, transport, or degradation of neurotransmitters or cofactors and result in various degrees of delayed or impaired psychomotor development. To assess the effect of neurotransmitter deficiencies on intelligence, quality of life, and behavior, the data of 148 patients in the registry of the International Working Group on Neurotransmitter Related Disorders (iNTD) was evaluated using results from standardized age-adjusted tests and questionnaires. Patients with a primary disorder of monoamine metabolism had lower IQ scores (mean IQ 58, range 40-100) within the range of cognitive impairment (<70) compared to patients with a BH₄ deficiency (mean IQ 84, range 40-129). Short attention span and distractibility were most frequently mentioned by parents, while patients reported most frequently anxiety and distractibility when asked for behavioral traits. In individuals with succinic semialdehyde dehydrogenase deficiency, self-stimulatory behaviors were commonly reported by parents, whereas in patients with dopamine transporter deficiency, DNAJC12 deficiency, and monoamine oxidase A deficiency, self-injurious or mutilating behaviors have commonly been observed. Phobic fears were increased in patients with 6-pyruvoyltetrahydropterin synthase deficiency, while individuals with sepiapterin reductase deficiency frequently experienced communication and sleep difficulties. Patients with BH₄ deficiencies achieved significantly higher quality of life as compared to other groups. This analysis of the iNTD registry data highlights: (a) difference in IQ and subdomains of quality of life between BH₄ deficiencies and primary neurotransmitter-related disorders and (b) previously underreported behavioral traits.

Non-mental diseases associated with ADHD across the lifespan: Fidgety Philipp and Pippi Longstocking at risk of multimorbidity?

Several non-mental diseases seem to be associated with an increased risk of ADHD and ADHD seems to be associated with increased risk for non-mental diseases. The underlying trajectories leading to such brain-body co-occurrences are often unclear - are there direct causal relationships from one disorder to the other, or does the sharing of genetic and/or environmental risk factors lead to their occurring together more frequently or both? Our goal with this narrative review was to provide a conceptual synthesis of the associations between ADHD and non-mental disease across the lifespan. We discuss potential shared pathologic mechanisms, genetic background and treatments in co-occurring diseases. For those co-occurrences for which published studies with sufficient sample sizes exist, meta-analyses have been published by others and we discuss those in detail. We conclude that non-mental diseases are common in ADHD and vice versa and add to the disease burden of the patient across the lifespan. Insufficient attention to such co-occurring conditions may result in missed diagnoses and suboptimal treatment in the affected individuals.

Amphetamine Promotes Cortical Up State in Part Via Dopamine Receptors

Cortical neurons oscillate between Up and Down states during slow wave sleep and general anesthesia. Recent studies show that Up/Down oscillations also occur during quiet wakefulness. Arousal eliminates Down states and transforms Up/Down oscillations to a persistent Up state. Further evidence suggests that Up/Down oscillations are crucial to memory consolidation, whereas their transition to a persistent Up state is essential for arousal and attention. We have shown that D-amphetamine promotes cortical Up state, and the effect depends on activation of central α_1A adrenergic receptors. Here, we report that dopamine also plays a role in D-amphetamine’s effect. Thus, using local-field-potential recording in the prefrontal cortex in chloral hydrate-anesthetized rats, we showed that the Up-state promoting effect of D-amphetamine was attenuated by antagonists at either D1 or D2-like dopamine receptors. The effect was also partially mimicked by co-activation of D1 and D2-like receptors. These results are consistent with the fact that D-amphetamine increases the release of both norepinephrine and dopamine. They are also in agreement with studies showing that dopamine promotes wakefulness and mediates D-amphetamine-induced emergence from general anesthesia. The effect of D-amphetamine was not mimicked, however, by activation of either D1 or D2-like receptors alone, indicating an interdependence between D1 and D2-like receptors. The dopamine/norepinephrine precursor L-DOPA also failed to promote the Up state. While more studies are needed to understand the difference between L-DOPA and D-amphetamine, our finding may provide an explanation for why L-DOPA lacks significant psychostimulant properties and is ineffective in treating attention-deficit/hyperactivity disorder.

[Pharmacotherapy of sleep disturbances in pre-school and elementary school children]

Sleep disturbance in pre-school and elementary school children is a common clinical situation. These disturbances may require pharmacotherapeutic approaches in certain cases. Major forms of sleep disturbances in children and data on known pharmacotherapeutic means of their treatment are considered.

Pediatric Restless Legs Syndrome

Early-onset restless legs syndrome has a relatively high prevalence in pediatrics, is highly familial, and is often preceded by a diagnosis of periodic limb movement disorder or childhood insomnia. Diagnostic criteria are derived but not equal to those of the adult syndrome and are adapted according to children's age and linguistic competence. Diagnosis requires parents or caregivers to participate; video-polysomnographic nocturnal recording, although not mandatory, may help confirm dubious cases. The syndrome severely impacts children's sleep and cognitive-behavioral abilities. Iron supplementation is currently the most used and viable therapeutic option.

Restless Legs Syndrome in Children and Adolescents

Children with psychiatric comorbidities frequently are referred for evaluation of sleep complaints. Common sleep symptoms can include difficulty falling asleep, frequent nocturnal awakening, restless sleep, and symptoms of restless legs syndrome (RLS). The understanding of the sleep condition in relation to the psychiatric comorbidity often is a challenge to the physician and often sleep disorders remain undiagnosed, untreated, or undertreated. Restless legs syndrome has been associated with psychiatric comorbidities and with certain medications, such as antidepressants, antihistamines, and antipsychotics. This article reviews the presentation of RLS and restless sleep, the association with psychiatric comorbidities, and treatment options.

[Pharmacotherapy of sleep disturbances in pre-school and elementary school children]

Sleep disturbance in pre-school and elementary school children is a common clinical situation. These disturbances may require pharmacotherapeutic approaches in certain cases. Major forms of sleep disturbances in children and data on known pharmacotherapeutic means of their corrections are considered.

The face of Dental Sleep Medicine in the 21st century

It becomes increasingly clear that some sleep disorders have important diagnostic and/or management links to the dental domain, hence the emergence of the discipline ‘Dental Sleep Medicine’. In this review, the following topics are discussed: 1. the reciprocal associations between oro‐facial pain and sleep; 2. the associations between sleep bruxism and other sleep‐related disorders; 3. the role of the dentist in the assessment and management of sleep bruxism; and 4. the dental management of obstructive sleep apnoea. From these topics' descriptions, it becomes clear that the role of the dentist in the recognition and management of sleep‐related oro‐facial pain, sleep bruxism and obstructive sleep apnoea is large and important. Since many dental sleep disorders can have severe consequences for the individual's general health and well‐being, it is imperative that dentists are not only willing to take on that role, but are also able to do so. This requires more attention for Dental Sleep Medicine in the dental curricula worldwide, as well as better postgraduate training of dentists who are interested in specialising in this intriguing domain. This review contributes to increasing the dental researcher's, teacher's and care professional's insight into the discipline ‘Dental Sleep Medicine’ as it has taken shape in the 21st century, to the benefit of all patients suffering from dental sleep disorders.

Actigraphic Sleep Pattern of Preschoolers With ADHD

Objective: To assess the features of sleep in preschoolers with ADHD by means of questionnaire and actigraphy. Method: Twenty-five ADHD and 21 age-matched typically developing (TD) preschool children underwent the Child Behavior Checklist (CBCL) for ages 1½ to 5 and Pre-School-Age Psychiatric Assessment interview. Sleep was assessed by means of a modified Sleep Disturbance Scale for Children and wrist actigraphy for at least 5 days. Results: Children with ADHD, compared with TD, showed higher scores in CBCL Withdrawal (58.83 vs. 51.15, p < .0001), Attention Problems (69.88 vs. 51.54, p < .0001), and Aggressive Behavior (59.46 vs. 51.08, p < .0001) dimensions; they also showed increased actigraphic nocturnal activity (activity index 31.57 vs. 25.74, p < .05); and night-to-night variability for sleep minutes (56.44 vs. 32.79, p < .01), mean wake episodes (1.34 vs. 0.98, p < .05), mean activity (2.64 vs. 1.71, p < .05), and activity index (5.15 vs. 3.77, p < .05). Conclusion: This pilot study in preschoolers with ADHD showed increased motor activity during sleep and night-to-night variability for sleep duration and motor activity.

Association Between Restless Legs Syndrome and Adult ADHD in a German Community-Based Sample

OBJECTIVE

Previous research in clinical samples indicated a significant association between ADHD and restless legs syndrome (RLS). The present study examined the association between adult ADHD and RLS in the German population.

METHOD

Self-rating instruments to assess RLS, childhood ADHD, and adult ADHD were administered to a community-based sample ( N = 1,632). In addition, current depression and anxiety, sleep disturbances, weight, and height were assessed by self-report.

RESULTS

Adult ADHD was associated with statistically significant increases in the odds of meeting diagnostic criteria for RLS even when adjusting for potential confounding variables such as weight (odds ratio [OR] = 3.18, 95% confidence interval [CI] = [1.29, 7.63], p< .001). However, the association did not hold true after adjusting for the presence of sleep disturbances (OR = 2.02, 95% CI = [0.82, 4.96], p = .13).

CONCLUSION

The findings suggest a strong link between RLS and adult ADHD symptoms. Clinicians should be aware of RLS among adult ADHD patients, especially as there might be a negative interactive effect.

Pharmacological Management of Restless Legs Syndrome and Periodic Limb Movement Disorder in Children

Restless legs syndrome (RLS) and periodic limb movement disorder (PLMD) are under-recognized sleep disorders in children and adolescents. Several recent epidemiological studies have shown that RLS and PLMD are common in the pediatric population, and if left untreated, may lead to cardiovascular and neurocognitive consequences. Therefore, early diagnosis and intervention may help preventing long-term consequences. The management of RLS and PLMD in children involves both non-pharmacologic and pharmacologic approaches. Although there is emerging literature supporting medical therapy in children with RLS and PLMD, the overall experiences with these medications remain limited. Most children and adolescents with RLS and PLMD have low iron storage; therefore, iron therapy should be considered as the first line of treatment in children. Currently, there is no FDA-approved medication for RLS and PLMD in children. There is increasing evidence on the effectiveness of dopaminergic medications in children but the data are quite limited. Other medications such as α2δ-1 ligands, benzodiazepine, and clonidine are frequently used, but have not been adequately investigated in children. Further studies are needed to evaluate the safety and efficacy of pharmacologic therapy for RLS and PLMD in children.

The Clinical Importance of Periodic Leg Movements in Sleep

OPINION STATEMENT

Periodic leg movements during sleep (PLMS) are commonly found in patients with restless leg syndrome (RLS), but they may occur in other sleep disorders and several medical conditions. Their prevalence increases with age, but they can also be observed in children. During the last decades, very active research has been devoted to determine and understand the pathophysiology, associated events, and clinical significance of PLMS. This chapter tries to sum up the most relevant PLMS-related findings, focusing on the relationship between PLMS and the cardiovascular system, in order to understand the clinical implication of this complex motor phenomenon. PLMS have been associated with sympathetic overactivity, namely surges in nocturnal blood pressure and heart rate, without modification in global autonomic balance. Also, PLMS have been related to inflammatory cellular pathways, with elevated level of inflammatory markers, which are associated with cardiovascular risk. The PLMS-related modulation of the autonomic system and of inflammation may increase cardiovascular and cerebrovascular risk in subjects with frequent PLMS. Moreover, also, comorbidities associated with PLMS may play a synergic role in worsening the cardiovascular risk and the consequent mortality and morbidity. Furthermore, little is known about pathophysiological correlates in children with PLMS and their chronic implication on the cardiovascular and cerebrovascular systems. A few studies have suggested that treating PLMS with dopaminergic drugs may reduce their associated sympathetic overactivity and modify disease progression. Definitely, further research is needed to assess the clinical impact of PLMS, associated or not with RLS, and above all the long-term impact of treating PLMS on cardiovascular risk, morbidity, and mortality.

L-DOPA therapy interferes with urine catecholamine analysis in children with suspected neuroblastoma: a case series

Neuroblastoma is the most common solid extracranial malignancy diagnosed in childhood. Clinical presentation is variable, and metastatic disease is common at diagnosis. Analyses of urinary catecholamines and their metabolites are commonly requested as a first-line investigation when clinical suspicion exists. Levodopa (L-Dopa) therapy is utilized as a treatment for a number of disorders in childhood, including Dopa-responsive dystonia. Neuroblastoma may mimic some of the clinical features of this disorder. L-Dopa can interfere with analysis of urinary catecholamines and their metabolites and complicate the interpretation of results. We present the cases of three children who were prescribed L-dopa at the time of analysis of urinary catecholamines and metabolites as a screen for neuroblastoma, but who did not have the disease. Comparison of their results with those from cases with true neuroblastoma reveal that it is impossible to reliably distinguish true neuroblastoma from L-Dopa therapy using these tests. We recommend that patients should be off L-dopa therapy, if possible when these tests are performed. These cases illustrate the importance of providing clinical details and drug history to the laboratory in order to avoid diagnostic confusion.

Sleep Problems in Children with Attention Deficit/Hyperactivity Disorder: Current Status of Knowledge and Appropriate Management

Attention deficit hyperactivity disorder (ADHD) affects approximately 5 % of children and adolescents, and sleep problems are common in these patients. There is growing evidence informing the significant importance of sleep problems in youth with ADHD. The sleep problems in children with ADHD include specific sleep disorders and sleep disturbances due to comorbid psychiatric disorders or ADHD medications. The specific sleep disorders of ADHD children include behaviorally based insomnia, sleep-disordered breathing, and restless legs syndrome/periodic limb movement disorder. Current practices on the management of sleep problems for ADHD children are based mostly on expert consensus, whereas more evidence-based literature can be found only recently. Assessment of the sleep conditions in ADHD children before initiation of pharmacotherapy is the currently recommended guideline, and good sleep hygiene can be considered as the first-line treatment option. In addition to modifying the dose regimens, formulation, or alternative stimulants when sleep problems are encountered in ADHD children, atomoxetine, once daily guanfacine extended release, and melatonin are potential choices for ADHD children with more severe sleep problems. In this review, we aimed to provide the most updated information, preferably based on meta-analyses, systemic review, and randomized controlled trials published in the latest 3 years, in order to be clinically useful for practitioners and clinicians.

Headache and ADHD in Pediatric Age: Possible Physiopathological Links

Primary headache and attention-deficit/hyperactivity disorder (ADHD) are common disorders in children and adolescences, frequently associated to severe cognitive, emotional, and behavioral impairments. They both are a disabling condition with consequences on family and child's quality of life. Literature data on their association are contrasting. Dopaminergic system dysfunction, brain iron deficiency, and sleep disturbance should be considered to better understand headache and ADHD overlap. In this review, we analyze the complex association between these two diseases and the potential impact on child neurodevelopment.

Psychiatric disorders and sleep issues

Sleep issues are common in people with psychiatric disorders, and the interaction is complex. Sleep disorders, particularly insomnia, can precede and predispose to psychiatric disorders, can be comorbid with and exacerbate psychiatric disorders, and can occur as part of psychiatric disorders. Sleep disorders can mimic psychiatric disorders or result from medication given for psychiatric disorders. Impairment of sleep and of mental health may be different manifestations of the same underlying neurobiological processes. For the primary care physician, key tools include recognition of potential sleep effects of psychiatric medications and familiarity with treatment approaches for insomnia in depression and anxiety.

Associations of sleep disturbance with ADHD: implications for treatment

Attention-deficit/hyperactivity disorder (ADHD) is commonly associated with disordered or disturbed sleep. The relationships of ADHD with sleep problems, psychiatric comorbidities and medications are complex and multidirectional. Evidence from published studies comparing sleep in individuals with ADHD with typically developing controls is most concordant for associations of ADHD with: hypopnea/apnea and peripheral limb movements in sleep or nocturnal motricity in polysomnographic studies; increased sleep onset latency and shorter sleep time in actigraphic studies; and bedtime resistance, difficulty with morning awakenings, sleep onset difficulties, sleep-disordered breathing, night awakenings and daytime sleepiness in subjective studies. ADHD is also frequently coincident with sleep disorders (obstructive sleep apnea, peripheral limb movement disorder, restless legs syndrome and circadian-rhythm sleep disorders). Psychostimulant medications are associated with disrupted or disturbed sleep, but also ‘paradoxically’ calm some patients with ADHD for sleep by alleviating their symptoms. Long-acting formulations may have insufficient duration of action, leading to symptom rebound at bedtime. Current guidelines recommend assessment of sleep disturbance during evaluation of ADHD, and before initiation of pharmacotherapy, with healthy sleep practices the first-line option for addressing sleep problems. This review aims to provide a comprehensive overview of the relationships between ADHD and sleep, and presents a conceptual model of the modes of interaction: ADHD may cause sleep problems as an intrinsic feature of the disorder; sleep problems may cause or mimic ADHD; ADHD and sleep problems may interact, with reciprocal causation and possible involvement of comorbidity; and ADHD and sleep problems may share a common underlying neurological etiology.

Prevalence of restless legs syndrome and sleep problems in Korean children and adolescents with attention deficit hyperactivity disorder: a single institution study

Purpose

Attention deficit hyperactivity disorder (ADHD) is a common disorder in school-aged children. Patients with restless legs syndrome (RLS) often present with ADHD symptoms and vice versa. This study was the first to attempt to identify the prevalence of RLS and sleep problems in children with ADHD in Korea.

Methods

Patients diagnosed with ADHD were asked to complete a sleep questionnaire. The sleep questionnaire included items to help identify the presence of four typical symptoms that are used as diagnostic criteria for RLS.

Results

A total of 56 patients, including 51 boys and 5 girls (mean age, 10.7 years old) participated. Of these, 24 complained of pain, discomfort, or an unpleasant sensation in the legs. Based on the RLS diagnostic criteria, 2 patients were diagnosed with definite RLS and 4 with probable RLS. There were no significant differences in age, medication dosage, or neuropsychological test scores between the patients with and without RLS symptoms.

Conclusion

Approximately 42.9% of patients with ADHD presented with RLS symptoms and 7.1% of these were diagnosed with RLS. Patients with ADHD also experienced various other sleep disorders. Thus, appropriate assessment and treatment for sleep disorders in patients with ADHD is essential.

Headache and attention deficit and hyperactivity disorder in children: common condition with complex relation and disabling consequences

The aim of this review was to analyze literature data on the complex association between headache and attention deficit and hyperactivity disorder (ADHD) in children, in order to explore its possible consequences on child neurological development. Headache and ADHD are two common conditions in the pediatric population. They both are disabling diseases that impact the child's quality of life and are associated with severe cognitive, emotional, and behavioral impairments. To assess and analyze literature data about the association of ADHD and headache in children and possible physiopathogenesis relationships, we searched for the following terms: headache, migraine, tension-type headache, ADHD, and children (MESH or text words). We found different studies that assess the clinical, epidemiological, and physiopathogenetic overlap between these two diseases, with contrasting results and unresolved questions. Structural and functional abnormalities in brain networks have been found to be central in both headache and ADHD pathophysiology. It will be crucial to gain a better understanding of how subcortical-cortical and corticocortical network development is altered during the onset of the disorders.

Sleep problems and their effect in ADHD

Sleep problems are common in attention-deficit/hyperactivity disorder (ADHD) to the extent that they mimic or exacerbate daytime symptoms expression. In this review, we advocate the need for a better understanding of sleep alterations in youths with ADHD and their impact on neurobehavioral functions including learning, memory and emotional regulation. An in-depth exploration of existing data showed that although extensively studied, the actual nature of sleep problems in ADHD and their effects on daytime behavior are still less well understood. Important issues, among which developmental changes in sleep architecture and role of subtle sleep electroencephalogram signatures, are generally neglected. Future research of sleep effects on behavior in ADHD would benefit from considering developmental aspects and links between brain activation patterns during sleep and wake.

To sleep or not to sleep: a systematic review of the literature of pharmacological treatments of insomnia in children and adolescents with attention-deficit/hyperactivity disorder

OBJECTIVE

This systematic review assessed current evidence on sleep medication for attention-deficit/hyperactivity disorder (ADHD) patients, to establish appropriate guidance for clinicians faced with prescribing such medications.

METHODS

Five articles (based on four pharmacological compounds) out of a total 337 were identified as evidence to guide pharmacological treatment of ADHD-related sleep disorders. Data regarding participant characteristics, measures of ADHD diagnosis, measures of sleep, and outcome data were extracted.

RESULTS

Zolpidem and L-theanine both displayed a poor response in reducing sleep latency and increasing total sleep time, however L-theanine did produce an increase in sleep efficiency. Zolpidem produced high levels of side effects, leading to the largest dropout rate of all five studies. Clonidine reduced insomnia; and melatonin also exhibited a positive response, with reduced sleep latency, higher total sleep time, and higher sleep efficiency.

CONCLUSIONS

There is a relative paucity of evidence for the pharmacological treatment of ADHD-related sleep disorders; therefore, further research should be conducted to replicate these findings and obtain reliable results.

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.

Assessment and management of sleep problems in youths with attention-deficit/hyperactivity disorder

OBJECTIVE

To provide evidence- or consensus-based recommendations concerning the assessment and management of sleep problems in youths with attention-deficit/hyperactivity disorder (ADHD).

METHOD

PubMed, Ovid, EMBASE, and Web of Knowledge were searched through October 31, 2012. When no evidence was available, consensus of the authors was achieved. The evidence-level of the recommendations on the management of sleep disturbances was based on the Scottish Intercollegiate Guidelines Network (SIGN) system.

RESULTS

A total of 139 original articles on sleep and childhood ADHD were retrieved, including 22 on treatment of sleep disturbances. This review focuses on behaviorally based insomnia, circadian rhythm disorder, sleep-disordered breathing, restless legs syndrome/periodic limb movement disorder, and sleep disturbances due to comorbid psychiatric disorders or ADHD medications. Healthy sleep practices are recommended as the foundation of management strategies. Behavioral interventions should be considered as first-line treatment of insomnia, although further evidence from randomized controlled trials (RCTs) is needed to prove their efficacy in ADHD. Among pharmacological treatments, RCTs support the use of melatonin to reduce sleep-onset delay, whereas there is more limited evidence for other medications.

CONCLUSION

Growing empirical evidence is informing assessment/management strategies of sleep problems in youths with ADHD. However, further RCTs are warranted to support current recommendations.

Pediatric sleep pharmacology

This article reviews common sleep disorders in children and pharmacologic options for them. Discussions of pediatric sleep pharmacology typically focus on treatment of insomnia. Although insomnia is a major concern in this population, other conditions of concern in children are presented, such as narcolepsy, parasomnias, restless legs syndrome, and sleep apnea.

A novel locus for restless legs syndrome on chromosome 13q

BACKGROUND

Restless legs syndrome (RLS) is a sensorimotor disorder in which affected individuals suffer from uncomfortable sensations and an urge to move their lower limbs; it occurs mainly in resting situations during the evening or at night. Multiple chromosomal loci have been mapped for RLS through family-based linkage analysis, and genome-wide association studies but causative mutations have not been identified yet.

METHOD

We identified an RLS family from the eastern part of central Turkey which has 10 patients suffering from this syndrome. Whole genome linkage analysis was performed in family members who consented for study (9 affected and 2 unaffected).

RESULTS

A theoretical maximum logarithm of the odds score of 3.29 was identified at chromosome 13q32.3-33.2. This result shows strong genetic linkage to this locus.

CONCLUSIONS

We demonstrated a genetic linkage at chromosome 13 in a RLS family. Further investigation in this linkage area may reveal a causative gene leading to RLS phenotype and may illuminate the pathogenesis of this disease. This study supports the genetic heterogeneity in the pathogenesis of this syndrome.

Pediatric periodic limb movement disorder: sleep symptom and polysomnographic correlates compared to obstructive sleep apnea

STUDY OBJECTIVES

Although periodic limb movements in sleep (PLMS) have been described in multiple pediatric publications, periodic limb movement disorder (PLMD) has not. The aims of this study were to describe the prevalence, sleep-related correlates, and polysomnographic correlates of PLMD in a large pediatric case series, and compare these to pediatric obstructive sleep apnea (OSA).

METHODS

All PLMD cases (defined by International Classification of Sleep Disorders, 2nd edition criteria + respiratory disturbance index [RDI] < 3) and OSA cases (defined by RDI ≥ 3 + PLMS < 5), from a single pediatric sleep practice, over a 2-year time span, were included. Chart, questionnaire, and polysomnographic data were compiled. Of 468 referred children, 66 PLMD cases were identified (14%).

RESULTS

The PLMD cases, mean age 8.1 years (range 1-17), were clinically characterized by frequent sleep onset and maintenance problems, difficulty awakening, restless sleep, leg pain/discomfort at night, and parasomnias. Compared to 90 OSA children, those with PLMD had a history of significantly more sleep onset and maintenance problems, leg pain/discomfort at night, parasomnias, getting out of bed at night, and family history of restless legs syndrome. Polysomnographically, PLMD cases had more awakenings, stage 1 sleep, stage shifts, and spontaneous arousals.

CONCLUSIONS

These data indicate that pediatric PLMD has important clinical and polysomnographic correlates. In addition, PLMD has many characteristics that are different from pediatric OSA, suggesting that PLMD is a distinct pediatric sleep disorder, of which clinicians should be aware.

Comorbidity and confounding factors in attention-deficit/hyperactivity disorder and sleep disorders in children

Sleep problems are commonly reported in children with attention-deficit/hyperactivity disorder (ADHD) symptoms. Research data regarding the complex and reciprocal relationship between ADHD and sleep disturbances has now accumulated. This paper is focused on the types of sleep problems that are associated with ADHD symptomatology, and attempts to untangle confounding factors and overlapping symptoms. The goal is also to present an updated overview of the pathophysiology of and treatment strategies for sleep problems in children with ADHD. The review also points out that future research will be needed to clarify further the other psychiatric comorbidities and side effects of medication in order to improve treatment outcomes and prevent misdiagnosis in clinical practice.