Images: Identification and Effect of Periodic Limb Movements in End-Stage Renal Disease.

None: Sleep disorders are prevalent in patients with end-stage renal disease (ESRD). In those patients on nocturnal dialysis, it is important to perform objective sleep assessment during regular dialysis. We present the case of a man on continuous cycler peritoneal dialysis with disabling fatigue and moderate restless legs syndrome (RLS). Actigraphy demonstrated excessive nocturnal movement. Unattended home polysomnography, performed during his regular peritoneal dialysis, confirmed frequent nocturnal periodic limb movements with disturbed sleep. Treatment with low dose pramipexole led to improved RLS and marked improvement in his energy. Clinicians caring for patients with ESRD should have a low threshold for objective sleep assessment given that sleep disorders are common, disabling and eminently amenable to treatment.

Sleep and Limb Movement Characteristics of Children With Atopic Dermatitis Coincidentally Undergoing Clinical Polysomnography.

STUDY OBJECTIVES: Atopic dermatitis (AD) is a prevalent, chronic, itchy skin condition. Children undergoing polysomnography (PSG) may coincidentally have AD. Many children with AD have sleep disturbances. Our study aimed to characterize limb movements in children with AD and their effect on sleep. METHODS: A retrospective chart review was conducted for children who underwent comprehensive attended PSG and had AD. PSG sleep parameters were compared to published normative data. A subset of patients with markedly elevated total limb movements was further compared to a matched group of patients with a diagnosis of periodic limb movement disorder (PLMD) and no history of AD. RESULTS: There were 34 children with AD 6.36 ± 3.21 years (mean ± standard deviation), 50% female and with mild to moderate AD. There was increased wake after sleep onset (WASO = 46.0 ± 37.8 minutes), sleep onset latency (46.5 ± 53.0 minutes) and total limb movement index (13.9 ± 7.5 events/h) compared to normative values. Although our cohort was mostly mild AD, 7 of the 34 children with AD (20%) had a total limb movement index during sleep > 15 events/h. Increased total limb movements in PLMD versus patients with AD was most notable during stage N2 sleep (38 ± 17 versus 22 ± 7, P = .01, respectively). CONCLUSIONS: We found altered PSG parameters in children with AD, suggesting that clinicians should consider the diagnosis when affected children undergo PSG. Although our AD cohort was mild, we still determined a need to consider AD when diagnosing PLMD given the presence of elevated total limb movements in children with AD. CITATION: Treister AD, Stefek H, Grimaldi D, Rupani N, Zee P, Yob J, Sheldon S, Fishbein AB. Sleep and limb movement characteristics of children with atopic dermatitis coincidentally undergoing clinical polysomnography. J Clin Sleep Med. 2019;15(8):1107-1113.

Neurocognitive and behavioral significance of periodic limb movements during sleep in adolescents with attention-deficit/hyperactivity disorder.

Study Objectives: The purpose of this study is to examine the association of abnormal periodic limb movements during sleep (PLMS) with neurocognitive and behavioral outcomes in adolescents with attention-deficit/hyperactivity disorder (ADHD) from the general population. Methods: Four hundred twenty-one adolescents (17.0 ± 2.3 years, 53.9% male) from the Penn State Child Cohort, a random general population sample, underwent 9 hr polysomnography, clinical history, physical examination, neurocognitive evaluation, and completed the Child or Adult Behavioral Checklist (C/ABCL). The presence of ADHD was ascertained by parent- or self-report of receiving a diagnosis of ADHD. PLMS were defined as a PLM index (PLMI) of ≥5 events per hour of sleep. Results: Adolescents with ADHD (n = 98) had a significantly higher PLMI (5.4 ± 7.3) and prevalence of PLMS (35%) when compared with controls (3.4 ± 5.6, p = 0.006 and 21%, p = 0.004). Significant interactions between ADHD and PLMS showed that adolescents with both disorders (n = 35) were characterized by deficits in control interference, as measured by Stroop test, and elevated internalizing behaviors, as measured by C/ABCL. ADHD severity and externalizing behaviors were elevated in a dose-response manner across ADHD-alone (n = 63) and ADHD + PLMS groups. The association of ADHD with other neurocognitive functions did not vary as a function of PLMS. Conclusions: PLMS are significantly more frequent in adolescents with ADHD. Importantly, adolescents with both disorders not only have worse neurobehavioral functioning than adolescents with ADHD-alone but specifically presented with executive deficits and anxiety symptoms. These data suggest that PLMS may be a marker of more severe underlying neurobiological deficits in adolescents with ADHD and comorbid internalizing problems.

Sleeping chILD: Neuroendocrine cell hyperplasia of infancy and polysomnography.

OBJECTIVES: Neuroendocrine cell hyperplasia of infancy (NEHI) is a children's interstitial and diffuse lung disease of unknown etiology that presents in infancy with characteristic findings of tachypnea, retractions, crackles, and hypoxemia. At the present, the mainstay of treatment is oxygen supplementation to normalize oxygen saturations and decrease work of breathing. There are characteristic pulmonary function, radiographic, and histologic findings, but polysomnography (PSG) data has not been reported. We sought to report PSG data and implications for management and treatment of NEHI patients. METHODS: A retrospective chart review was performed under a Colorado Institutional Review Board approved protocol for which consent was waived. Informatics for Integrating Biology and the Bedside was used to query the electronic medical record at Children's Hospital Colorado for patients with both a diagnosis of NEHI and a PSG. PSG was performed for clinical reasons. Routine sleep quality and respiratory parameters were recorded and analyzed. RESULTS: Of our 77 patients with NEHI, 14 (19%) children underwent PSG during the study period. Eight children met criteria for OSA and three met criteria for CSA. Ten patients had low oxygen saturations during a study, six had low sleep efficiency, and three had periodic limb movement disorder. CONCLUSIONS: Patients with NEHI may have sleep related breathing disorders that contribute to disrupted sleep, including obstructive and central sleep apnea, hypoxemia, decreased sleep efficiency, and increased periodic limb movement disorder. PSG should be considered as part of NEHI management, as it may lead to recognition of clinically significant sleep-disordered breathing.

Sleep Disorders and Their Management in Children With Ehlers-Danlos Syndrome Referred to Sleep Clinics.

STUDY OBJECTIVES: The nature of sleep disorders in children with Ehlers-Danlos syndrome (EDS) is unknown. We aimed to describe the type, the management, and the short-term outcome of sleep disorders in children with EDS referred to sleep clinics. METHODS: This is a retrospective review of medical records and polysomnography tests of children with EDS younger than 18 years who were referred to the sleep clinic. Demographic information and medical history were collected, and polysomnography tests were reviewed. Questionnaires completed during previous clinic visits, including the Pediatrics Sleep Questionnaire (PSQ), Epworth Sleepiness Scale (ESS), and Pediatric Quality of Life Inventory (PedsQL), were also evaluated. RESULTS: Sixty-five patients with EDS-hypermobility type were included. The mean age was 13.15 ± 3.9 years. There were 68% of patients who were female, and 91% of patients were Caucasian. The mean follow-up period was 1.14 ± 1.55 years. Common sleep diagnoses included insomnia (n = 14, 22%), obstructive sleep apnea (OSA) (n = 17, 26%), periodic limb movement disorder (PLMD) (n = 11, 17%), and hypersomnia (n = 10, 15%). In addition, 65% required pharmacologic treatment and 29% were referred to behavioral sleep medicine. For OSA, two patients required continuous positive airway pressure. A significant improvement was observed in the PSQ, ESS, and PedsQL scores during follow-up visits after treatment (n = 34; P = .0004, 0.03, and 0.01, respectively). CONCLUSIONS: There is a high prevalence of sleep disorders, including OSA, insomnia, PLMD, and hypersomnia in children with EDS referred to sleep clinics. Specific management can improve quality of life and questionnaire scores of this patient population. Our study emphasizes the importance of screening for sleep disorders in children with EDS.

Periodic limb movements during sleep in stroke/TIA: Prevalence, course, and cardiovascular burden.

OBJECTIVE: To define the prevalence, time course, and associated factors of periodic limb movements during sleep (PLMS) in patients with ischemic stroke or TIA. METHODS: Patients enrolled in the prospective Sleep-Disordered Breathing in Transient Ischemia Attack (TIA)/Ischemic Stroke and Continuous Positive Airway Pressure (CPAP) Treatment Efficacy (SAS-CARE) study underwent a double polysomnographic investigation in the acute and chronic phases after stroke/TIA, together with a MRI brain scan and a 24-hour blood pressure evaluation. The prevalence of PLMS in patients was compared with that in a matched sample of randomly selected healthy controls from the HypnoLaus cohort. One hundred sixty-nine recordings were performed in the acute phase and 191 after 3 months (210 recordings were obtained from the same 105 patients in both phases) and were compared to those of 162 controls. RESULTS: The mean number of PLMS per hour and the percentage of participants with a PLMS index >10 and >15 per hour were similar between patients and controls. PLMS remained stable from the acute to the chronic phase after stroke. Factors positively associated with PLMS were age, body mass index, and history of hypertension. Blood pressure over 24 hours and the burden of cerebrovascular damage were similar between the groups with PLMS and without PLMS. CONCLUSIONS: PLMS are equally frequent in patients with stroke/TIA and the general population. The absence of higher blood pressure values and of a greater vascular brain damage found in patients with PLMS compared to those without PLMS might be due to a greater use of antihypertensive medication among patients with PLMS, which corresponds to a higher prevalence of previous diagnosis of hypertension in these patients.

Sleep disturbances in veterans with chronic war-induced PTSD.

Post-traumatic stress disorder is related to a wide range of medical problems, with a majority of neurological, psychological, cardiovascular, respiratory, gastrointestinal disorders, diabetes, as well as sleep disorders. Although the majority of studies reveal the association between PTSD and sleep disturbances, there are few studies on the assessment of sleep disruption among veterans with PTSD. In this review, we attempt to study the sleep disorders including insomnia, nightmare, sleep-related breathing disorders, sleep-related movement disorders and parasomnias among veterans with chronic war-induced PTSD. It is an important area for further research among veterans with PTSD.

Association of low ferritin with PLM in the Wisconsin Sleep Cohort.

OBJECTIVE: The origins of periodic leg movements (PLMs), a strong correlate of restless legs syndrome (RLS), are uncertain. This study was performed to assess the relationship between PLMs and peripheral iron deficiency, as measured with ferritin levels corrected for inflammation. METHODS: We included a cross-sectional sample of a cohort study of 801 randomly selected people (n = 1008 assays, mean age 58.6 ± 0.3 years) from Wisconsin state employee agencies. A previously validated automatic detector was used to measure PLMs during sleep. The patients were categorized into RLS symptoms-positive and RLS symptoms-negative based on a mailed survey response and prior analysis. Analyses were performed using a linear model with PLM category above and below 15 PLM/h (periodic leg movement index, PLMI) as the dependent variable, and adjusting for known covariates, including previously associated single-nucleotide polymorphisms (SNPs) within BTBD9, TOX3/BC034767, MEIS1, MAP2K5/SKOR1, and PTPRD. Ferritin and C-reactive protein (CRP) levels were measured in serum, and ferritin levels corrected for inflammation using CRP levels. RESULTS: After controlling for cofactors, PLMI ≥ 15 was associated with low (≤50 ng/mL) ferritin levels (OR = 1.55, p = 0.020). The best model was found using quasi-least squares regression of ferritin as a function of PLMI, with an increase of 0.0034 PLM/h predicted by a decrease of 1 ng/mL ferritin (p = 0.00447). CONCLUSIONS: An association was found between low ferritin and greater PLMs in a general population of older adults, independent of genetic polymorphisms, suggesting a role of low iron stores in the expression of these phenotypes. Patients with high PLMI may require to be checked for iron deficiency.

Sleep fragmentation and periodic limb movements in children with monosymptomatic nocturnal enuresis and polyuria.

BACKGROUND: Children with nocturnal enuresis (NE) have been found to have sleep fragmentation and a high incidence of periodic limb movements in sleep (PLMS). This study explored the association of monosymptomatic NE and polyuria in relation to fluid intake, bladder volume, number of wet nights, and number of nights with polyuria to the frequency of PLMS and cortical arousals during sleep. MATERIALS AND METHODS: Thirty children with monosymptomatic NE and polyuria were enrolled in the study. Enuretic parameters were determined by diaries, forced drinking, uroflow, and ultrasound examination. All subjects participated in one polysomnographic study. The number of cortical arousals and PLMS were compared with those recorded in a former pilot study which included only children with refractory NE. RESULTS: Of the 30 children who participated in the study, the mean age was 10.43 ± 3.08 (range 6-16) years, and 23 were boys. The PLMS index was positively associated with the arousal index and the awakening index (p < 0.001). No significant association between the sleep and the enuretic parameters was found. Children with refractory NE showed a significantly higher PLMS index (p < 0.001). CONCLUSIONS: We found that PLMS and cortical arousals in sleep were increased in children with monosymptomatic NE and polyuria, without a significant association with the enuretic parameters. These observations suggest the presence of a comorbid mechanism driven by a common, independent pacemaker. We hypothesize the autonomic system, its sympathetic branch, and the dopaminergic system as candidates for this pacemaker.

Periodic leg movements during sleep in children scheduled for adenotonsillectomy: frequency, persistence, and impact.

OBJECTIVE: The aim of this study was to assess the frequency and potential clinical impact of periodic leg movements during sleep (PLMS), with or without arousals, as recorded incidentally from children before and after adenotonsillectomy (AT). METHODS: Children scheduled for AT for any clinical indications who participated in the Washtenaw County Adenotonsillectomy Cohort II were studied at enrollment and again 6 months thereafter. Assessments included laboratory-based polysomnography, a Multiple Sleep Latency Test (MSLT), parent-completed behavioral rating scales, neuropsychological testing, and psychiatric evaluation. RESULTS: Participants included 144 children (81 boys) aged 3-12 years. Children generally showed mild to moderate obstructive sleep apnea (median respiratory disturbance index 4.5 (Q1 = 2.0, Q3 = 9.5)) at baseline, and 15 subjects (10%) had at least five periodic leg movements per hour of sleep (PLMI ≥ 5). After surgery, 21 (15%) of n = 137 subjects who had follow-up studies showed PLMI ≥ 5 (p = 0.0067). Improvements were noted after surgery in the respiratory disturbance index; insomnia symptoms; sleepiness symptoms; mean sleep latencies; hyperactive behavior; memory, learning, attention, and executive functioning on NEPSY assessments; and frequency of attention-deficit/hyperactivity disorder (DSM-IV criteria). However, PLMI ≥ 5 failed to show associations with worse morbidity in these domains at baseline or follow-up. New appearance of PLMI ≥ 5 after surgery failed to predict worsening of these morbidities (all p > 0.05), with only one exception (NEPSY) where the magnitude of association was nonetheless negligible. Similar findings emerged for periodic leg movements with arousals (PLMAI ≥ 1). CONCLUSION: PLMS, with and without arousals, become more common after AT in children. However, results in this setting did not suggest substantial clinical impact.

Time structure of leg movement activity during sleep in untreated Parkinson disease and effects of dopaminergic treatment.

OBJECTIVES: To evaluate the specific time structure of periodic leg movements during sleep (PLMS) in untreated Parkinson disease (PD) patients by means of an advanced analysis; and to evaluate the effects of treatment on this activity, in a cross-sectional comparison and in a prospective follow-up study, in a subgroup of previously untreated patients. METHODS: Forty-four consecutive PD patients were enrolled in the study; 19 had not yet started any drug therapy for PD (PDnother); 10 out of these patients were re-evaluated after an average time lag of 19.6months from baseline. The remaining 25 patients (PDther) were taking l-dopa and/or dopamine agonists. Eighteen age-matched normal controls were also included. All subjects underwent a polysomnographic recording and the time structure of their sleep leg movement activity was analyzed by means of the periodicity index and other advanced measures. RESULTS: Both PD groups tended to show increased PLMS and decreased isolated limb movement activity with respect to controls. PLMS index >15/h was found in 26.3% of PDnother patients, 24.0% of PDther subjects, and in 16.7% of controls; none of the three PDnother patients who had PLMS index >15/h at baseline sustained this level at follow-up, nor did the other seven patients. The intermovement interval distribution showed a clear peak at 10-40s in the PDnother group; a suppression of this peak was observed after the introduction of dopaminergic treatment in the subgroup of 10 PDnother patients. Both groups of PD patients showed a progressively decreasing number of PLMS through the night; an almost complete abolition of PLMS was seen in the first 2h of sleep after the introduction of dopaminergic drug therapy. CONCLUSION: Our data do not seem to support the hypothesis that PLMS are particularly frequent in PD but seem to indicate an interaction between PD pathophysiology and genetic predisposition for PLMS, producing a slightly increased number of patients with this sleep motor phenomenon when compared to controls.

Excessive fragmentary myoclonus in Machado-Joseph disease.

OBJECTIVE: Machado-Joseph disease (MJD) is a neurodegenerative disease which usually presents several clinical findings including cerebellar ataxia and other extracerebellar features, such as Parkinsonism, dystonia, peripheral neuropathy, and lower motor neuron disease. Some data have demonstrated a high frequency of sleep disorders in these patients, including excessive daytime sleepiness (EDS), insomnia, obstructive sleep apnea (OSA), rapid eye movement (REM) sleep behavior disorder (RBD), and restless legs syndrome (RLS). Herein, we aimed to describe the high frequency of excessive fragmentary myoclonus (EFM) in MJD. MATERIALS AND METHODS: We recruited 44 patients with MJD and 44 healthy controls. All participants underwent an all-night polysomnography (PSG). EFM was evaluated and defined in accordance to the criteria of the American Academy of Sleep Medicine. RESULTS: Half of the MJD patients (n = 22) had EFM diagnosed through PSG, though no healthy control participant presented this finding (P < .0001). In the MJD group, older participants and men had a higher frequency of EFM. There was no correlation between EFM and the following data: body mass index (BMI), apnea-hypopnea index (AHI), EDS, loss of atonia during REM sleep, periodic limb movements during sleep (PLMS), RLS, RBD, ataxia severity, the number of cytosine-adenine-guanine trinucleotide (CAG) repeats, disease duration, sleep efficiency, sleep fragmentation, and sleep stage percentages between patients with or without EFM. CONCLUSION: EFM is highly prevalent in patients with MJD. Our study demonstrates that EFM must be included in the clinical spectrum of sleep disorders in MJD patients.

Sleep disorders in Charcot-Marie-Tooth disease type 1.

INTRODUCTION: Obstructive sleep apnoea (OSA) and restless legs syndrome (RLS) have been reported in Charcot-Marie-Tooth disease (CMT) type 1A and axonal subtypes of CMT, respectively. The aim of this case-control study was to investigate both prevalence and severity of OSA, RLS and periodic limb movements in sleep (PLMS) in adult patients with genetically proven CMT1. PATIENTS AND METHODS: 61 patients with CMT1 and 61 insomnic control subjects were matched for age, sex, and Body Mass Index. Neurological disability in patients with CMT was assessed using the Functional Disability Scale (FDS). RLS diagnosis was based on a screening questionnaire and structured clinical interviews. All participants underwent overnight polysomnography. RESULTS: OSA was present in 37.7% of patients with CMT1 and 4.9% of controls (p<0.0001). The mean Apnoea Hypoponea Index (AHI) was significantly higher in patients with CMT1 than in control individuals (9.1/h vs 1.2/h). RLS was present in 40.9% of patients with CMT1 and in 16.4% of controls (p<0.001). In the CMT1 group, OSA was significantly more common in men and RLS in women. The AHI correlated with both age and the FDS score, the latter being a significant independent predictor of OSA. PLMS were found in 41.0% of patients with CMT1, but were not correlated with measures of sleep quality. CONCLUSIONS: In addition to known risk factors, CMT may predispose to OSA. RLS is highly prevalent not only in axonal subtypes of CMT but also in primarily demyelinating subforms of CMT. PLMS are common in CMT1, but do not significantly impair sleep quality.

Daytime leg pain after overnight continuous positive airway pressure titration.

We report a case that showed transitional, severe emergent periodic limb movements during sleep (PLMS) in the first continuous positive airway pressure (CPAP) titration night and mild PLMS in the 3rd and 20th nights of CPAP titration in a 56-year-old woman after she was found to have severe obstructive sleep apnea (OSA). Severe PLMS in the initial CPAP night unexpectedly resulted in acute leg muscle soreness in the second morning. The case suggests that CPAP therapy in patients who suffer from severe OSA may provide a unique opportunity to look into the pathological mechanism of PLMS.