Periodic Limb Movement Index Research Articles

Risk of resistant hypertension associated with restless legs syndrome and periodic limb movements during sleep: A study on 673 treated hypertensive individuals

Given the limited data available in the literature, the aim of this study was to examine the risk of resistant hypertension (RHT) associated with restless legs syndrome (RLS) and periodic limb movements during sleep (PMLS) in a large sample of treated hypertensive individuals. Demographic and polysomnographic data from 673 treated hypertensive individuals recruited from the research database of the sleep laboratory were analysed. After exclusion of the main causes of pseudo-resistance and secondary hypertension, RHT status was defined by the presence of an uncontrolled hypertension despite treatment with at least three antihypertensive agents (including a diuretic) from different classes in correct combination and at the highest tolerated doses or by the presence of controlled hypertension requiring the use of at least four antihypertensive agents. Logistic regression analyses were conducted to examine the risk of RHT associated with RLS and PMLS in treated hypertensive individuals. After adjustment for major confounding factors associated with RHT, multivariate logistic regression analysis revealed that frequent RLS (≥ 2 episodes/week) combined to PLMS index ≥ 26/hour [OR 2.25 (95% CI 1.37–3.69)] was significant risk factors of RHT in treated hypertensive individuals. In treated hypertensive individuals, frequent RLS combined to PLMS index ≥ 26/hour is associated with higher risk of RHT which suggests that this pathology may be a secondary cause of RHT (such as obstructive sleep apnea syndrome and insomnia with short sleep duration) justifying the establishment of effective treatment in order to avoid the negative consequences associated with the occurrence of resistance to antihypertensive agents.

Prevalence and correlates of periodic limb movements in OSA and the effect of CPAP therapy.

We sought to assess the prevalence, correlates, and consequences of periodic limb movements of sleep (PLMS) in persons with obstructive sleep apnea (OSA) and the effect (worsening or improvement) of continuous positive airway pressure (CPAP) therapy on PLMS in a large prospective multicenter randomized controlled trial. We performed retrospective analyses of data from the Apnea Positive Pressure Long-term Efficacy Study, a prospective multicenter randomized controlled trial. A total of 1,105 persons with OSA enrolled in this study underwent a polysomnographic investigation at baseline, another one for CPAP titration, and another study 6 months after randomization to either active CPAP or sham CPAP. Of all participants, 19.7% had PLM index (PLMI) ≥10/hour, 14.8% had PLMI ≥15/hour, 12.1% had PLMI ≥20/hour, 9.3% had PLMI ≥25/hour, and 7.5% had PLMI ≥30/hour. The odds of having a PLMI ≥10 were higher in older participants (odds ratio [OR] 1.03, p < 0.001), men (OR 1.63. p = 0.007), those using antidepressants (OR 1.48. p = 0.048), and those with higher caffeine use (OR 1.01, p = 0.04). After controlling for OSA and depression, PLMS were associated with increased sleep latency, reduced sleep efficiency, and reduced total sleep time. No significant relationships were noted between PLMS frequency and subjective sleepiness (Epworth Sleepiness Scale score) or objective sleepiness (Maintenance of Wakefulness Test). There was no differential effect of CPAP in comparison to sham CPAP on PLMS after 6 months of therapy. PLMS are common in patients with OSA and are associated with a significant reduction in sleep quality over and above that conferred by OSA. Treatment with CPAP does not affect the severity of PLMS.

Clinical characteristics of sleep disorders in patients with vestibular migraine.

To study and analyze the sleep quality and sleep structure of patients with vestibular migraine (VM). In this cross-sectional case-control study, the Pittsburgh Sleep Quality Index (PSQI) questionnaire and polysomnography (PSG) were used to compare the clinical characteristics of sleep disorders in 49 patients with VM, 52 patients with migraine, and 54 controls. The VM, migraine, and control groups did not significantly differ in terms of age or sex. Compared with the migraine and control groups, the VM group had a higher incidence of poor sleep quality (χ2 = 36.618, p < 0.01) and greater severity of poor sleep quality (p < 0.01). Furthermore, the VM group showed reduced sleep efficiency (p < 0.01) and reduced proportions of REM and slow wave (N3) sleep (p≤ 0.01). Conversely, sleep latency (p = 0.01) and REM latency (p= 0.04) were prolonged, and proportions of light sleep phases (N1, p< 0.05, and N2, p< 0.01) and the micro-arousal index (p = 0.03) were increased. The migraine group had significantly higher apnea hypopnea (AHI) and periodic leg movement (PLMI) indices than the VM group. We report an effect of VM on sleep structure and an association with migraine. Similar to migraine, VM affects the sleep regulation centers and causes structural sleep disorders.

Lack of Association between Periodic Limb Movements during Sleep and Neuroimaging Signatures of Cerebral Small Vessel Disease in Stroke-Free Community-Dwelling Older Adults. The Atahualpa Project

Evidence of the relationship between periodic limb movements during sleep (PLMS) and cerebral small vessel disease (cSVD) is limited and inconsistent. Here, we aimed to assess the independent association between PLMS and the different neuroimaging signatures of cSVD. Atahualpa residents aged more than or equal to 60 years enrolled in the Atahualpa Project undergoing polysomnography and MRI with time intervals less than or equal to 6 months were included. MRI readings focused on white matter hyperintensities (WMH) of presumed vascular origin, deep cerebral microbleeds (CMB), silent lacunar infarcts (LI), and more than 10 enlarged basal ganglia-perivascular spaces (BG-PVS). Data from single-night polysomnograms were interpreted according to recommendations of the American Academy of Sleep Medicine. Associations between the PLMS index and neuroimaging signatures of cSVD (as dependent variables) were assessed by means of logistic regression models, adjusted for relevant confounders. A total of 146 individuals (mean age: 71.4 ± 7.5 years; 64% women) were included. A PLMS index more than or equal to 15 per hour were noted in 48 (33%) participants. Moderate-to-severe WMH were present in 33 individuals (23%), deep CMB in 9 (6%), silent LI in 16 (11%), and more than 10 BG-PVS in 44 (30%). In univariate analyses, silent LI (P = .035) and the presence of more than 10 enlarged BG-PVS (P = .034) were significantly higher among participants with a PLMS index more than or equal to 15 per hour. However, fully-adjusted multivariate models showed no significant association between PLMS index more than or equal to 15 per hour and any of the neuroimaging signatures of cSVD. This study shows no independent association between the PLMS index and neuroimaging signatures of cSVD in stroke-free community-dwelling older adults.

Comorbidities in children with elevated periodic leg movement index

Comorbidities in children with elevated periodic leg movement index

Sleep spindles, K-complexes, limb movements and sleep stage proportions may be biomarkers for amnestic mild cognitive impairment and Alzheimer's disease.

Sleep disturbances are common in Alzheimer's disease (AD) and mild cognitive impairment (MCI) patients. Non-rapid eye movement stage 3 (N3), rapid eye movement stage (REM), spindle density, and K-complex (KC) density are decreased in MCI and AD patients. Periodic limb movements in sleep (PLMS) are increased in other neurodegenerative diseases. We aimed to distinguish amnestic mild cognitive impairment (aMCI) patients from the overall population of MCI patients by comparing the N3 and REM proportions, the morphological characteristics of spindles and KCs and the periodic limb movement index (PLMI) among control, aMCI and AD subjects. In 92 subjects (30 controls, 32 aMCI and 30 AD), sleep stages, spindles, KCs and PLMS were recorded during the second of two nights of polysomnography (PSG). We compared the above parameters among the three groups. AD and aMCI subjects had lower proportions of N3 and REM, poorer spindle and KC activities and more frequent PLMS than controls. These alterations were associated with decreased Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) scores. We determined cut-off values for distinguishing aMCI and AD using logistic regression and receiver operating characteristic (ROC) analyses. AD and aMCI patients have abnormal sleep stage proportions, spindles, KCs and PLMS. The combination of the above alterations may distinguish aMCI and AD patients from controls with high specificity and sensitivity.

Robust, ECG-based detection of Sleep-disordered breathing in large population-based cohorts.

Up to 5% of adults in Western countries have undiagnosed sleep-disordered breathing (SDB). Studies have shown that electrocardiogram (ECG)-based algorithms can identify SDB and may provide alternative screening. Most studies, however, have limited generalizability as they have been conducted using the apnea-ECG database, a small sample database that lacks complex SDB cases. Here, we developed a fully automatic, data-driven algorithm that classifies apnea and hypopnea events based on the ECG using almost 10 000 polysomnographic sleep recordings from two large population-based samples, the Sleep Heart Health Study (SHHS) and the Multi-Ethnic Study of Atherosclerosis (MESA), which contain subjects with a broad range of sleep and cardiovascular diseases (CVDs) to ensure heterogeneity. Performances on average were sensitivity(Se)=68.7%, precision(Pr)=69.1%, score(F1)=66.6% per subject, and accuracy of correctly classifying apnea-hypopnea index (AHI) severity score was Acc=84.9%. Target AHI and predicted AHI were highly correlated (R2 = 0.828) across subjects, indicating validity in predicting SDB severity. Our algorithm proved to be statistically robust between databases, between different periodic leg movement index (PLMI) severity groups, and for subjects with previous CVD incidents. Further, our algorithm achieved the state-of-the-art performance of Se=87.8%, Sp=91.1%, Acc=89.9% using independent comparisons and Se=90.7%, Sp=95.7%, Acc=93.8% using a transfer learning comparison on the apnea-ECG database. Our robust and automatic algorithm constitutes a minimally intrusive and inexpensive screening system for the detection of SDB events using the ECG to alleviate the current problems and costs associated with diagnosing SDB cases and to provide a system capable of identifying undiagnosed SDB cases.

A Systematic Literature Review of the Burden of Ischemic Priapism in Patients with Sickle Cell Disease

INTRODUCTION: Ischemic or low-flow priapism is a serious condition characterized by a persistent, painful erection that lasts at least 4 hours or is unrelated to sexual stimulation. Both stuttering (repeated short episodes) and fulminant (long-lasting) priapism are prevalent in men and boys with sickle cell disease (SCD). Approximately 40% of patients with SCD will experience priapism during their lifetime. The objective of this study was to conduct a systematic literature review (SLR) to identify published studies reporting the burden associated with priapism in patients with SCD. METHODS: MEDLINE, Embase, Cochrane CENTRAL/CDSR and 14 congresses were searched from May 9-16, 2019. Results were screened against predefined criteria by two independent researchers. Studies assessing the clinical, humanistic, or economic burden of human patients with SCD and priapism (N≥15) were included. Outcomes of interest included priapism-related symptoms, treatment-related complications, quality of life (QoL), and economic burden. RESULTS: The literature search identified 1236 articles; 62 full-text studies were reviewed in detail and 34 studies were included in the analysis. Most studies were retrospective observational (21), others were prospective (7 observational, 6 interventional). Study size varied widely (range: 15-10,788 patients). Of 27 studies that reported mean or median patient age, the age statistic for patients with SCD and priapism ranged from 10 to 32. Overall, 19 studies reported at least one aspect of clinical burden. Thirteen reported the rate of erectile dysfunction or impotence, ranging from 0% to 56%. Eight reported treatment-related complications, including perceived penile scarring/deformity (19.4%) and small intrapenile hematoma (13.3%). Nineteen studies reported QoL outcomes. Eight reported physical outcomes, including a negative impact of SCD-related priapism on sleep quality and worse scores on periodic limb movement and apnea hypopnea indices. Seven reported measures of sexual function, including low rates of satisfactory sexual intercourse. One study reported a diminished Sexual Health Inventory for Men score in patients with active priapism, and another found a statistically significant relationship between stuttering priapism and premature ejaculation. Three studies reported measures of mental function, one of which outlined increased cognitive fatigue and impaired emotional functioning among children with priapism and another reported that 36% of patients had substantial to very extreme worry regarding episodes of priapism. Use of validated measures for QoL were limited: 3 studies assessed patients with the International Index of Erectile Function (IIEF) and 1 with the Priapism Impact Profile (PIP). No studies measuring the burden to caregivers of pediatric patients with priapism were identified. Eight studies reported the economic burden of priapism in patients with SCD, including rates of emergency department visits (4 studies: 56.5% sought hospital treatment - 26/46; 49.8% admission to the hospital out of emergency department visits - 5371/10,788; 50.4% admitted at the emergency department - 930/1844; 26% vs. 11% readmission vs no readmission - p &amp;lt;0.001) and hospital length of stay (4 studies: mean 3.38 days; mean 3.8 days; median 2 days; median 5 days in patients who received an exchange transfusion as a treatment for priapism.). Three studies reported direct treatment costs, ranging from a mean of $4496 (2015 USD) for patients who did not undergo penile operations to a mean of $19,670 (2013 USD) total adjusted hospital costs for patients receiving both transfusions and urologic procedures. CONCLUSIONS: This SLR identified 34 studies reporting the burden of priapism in patients with SCD. No RCTs were identified. The use of comprehensive or validated measures of humanistic burden was limited. Manifestations of priapism are wide-ranging, including painful treatment-related complications, impaired sleep, and diminished physical, mental and sexual function. Patients with priapism and SCD are more likely to visit the emergency department and experience longer hospital stays compared to SCD patients without priapism. Together, the evidence identified in this SLR indicates that priapism not only can result in erectile dysfunction, but can impair multiple dimensions of a patient's physical and mental health. Disclosures Nellesen: Analysis Group, Inc.: Consultancy. Lucas:Analysis Group, Inc.: Consultancy. Liu:Analysis Group, Inc.: Consultancy. Bhor:Novartis: Employment, Equity Ownership. Paulose:Novartis Pharmaceuticals Corporation: Employment.

Determinants of Nocturnal Cardiovascular Variability and Heart Rate Arousal Response in Restless Legs Syndrome (RLS)/Periodic Limb Movements (PLMS).

Recent studies have suggested that restless legs syndrome is associated with an increased prevalence of cardiovascular diseases mediated by sympathetic activation occurring during periodic limb movements. The aim of this study was to establish which factors affect the degree of sympathetic activation during the basal condition and during periodic limb movements that may contribute to increased vascular risk. Fifty untreated restless legs syndrome patients aged 62.6 ± 11.1 y, free of cardiovascular diseases, were examined. Heart rate variability was calculated during wakefulness and all sleep stages, during periods with and without periodic limb movements. Heart rate changes before and after periodic limb movement onset were analyzed to assess the arousal response to periodic limb movements. Both analyses took into account the effects of age, gender, periodic limb movement duration, periodic limb movement index, periodic limb movement interval and periodicity, and magnitude of muscular activity (electromyogram power). Compared to periods without periodic limb movements, a significant increase in sympathetic activity occurred in periods with periodic limb movements, independent of age, sex and periodic limb movement characteristics. Data obtained from the cardiac arousal response to periodic limb movements showed that electromyogram power is the factor affecting sympathetic tonus. These results suggest that other factors, such as electromyogram power and individual susceptibility, should be considered in the assessment of the vascular risk related to restless legs syndrome.

Comorbidities in children with elevated periodic limb movement index during sleep

Little is known about comorbidities in children who have elevated periodic limb movement index (PLMI) during overnight polysomnogram (PSG). The aim of this study is to identify comorbidities in children with elevated PLMI (PLMI > 5) versus children with PLMI < 5 presenting to a pediatric sleep center. This study was a retrospective review of all clinically indicated PSGs obtained consecutively from 3/2017-3/2019 at Seattle Children's Sleep Disorders Center. Data collected included demographics, clinical presentation, medications, medical history, family history specifically for restless legs syndrome (RLS), ferritin levels, and PSG metrics. Characteristics between those with (cases) elevated PLMI (AASM criteria) and without (controls) were summarized. We identified 148 subjects with elevated PLMI (67% male, mean age 7.95 years, range 1-20), yielding a PLMI > 5 prevalence of 5%. There were 188 controls included (58% male, mean age 8.0 years, range 1-19). Neither sex (chi-square = 2.8, NS) nor age (Mann-Whitney U = 1339.5, NS) differed between groups. Case subjects had a higher prevalence of RLS, snoring, insomnia, mood disorders, behavioral problems, morning headaches, chronic kidney disease, epilepsy, and chronic heart disease. Similarly, the use of antidepressants, antipsychotics, antiseizure medication, and other medications was statistically more frequent in children with elevated PLMS. The prevalence of PLMI > 5 was 5% and the prevalence of periodic limb movement disorder (PLMD) was 0.3% in children referred to polysomnography. Ferritin levels did not differ. We identified the prevalence of PLMD in a sleep medicine-referred population. We have also identified comorbidities and medications associated with elevated PLMI in children.No clinical trial.

Sleep manifestations, sleep architecture in children with Eosinophilic esophagitis presenting to a sleep clinic

Study objectivesTo describe sleep manifestations, polysomnographic (PSG) findings, and specific sleep disorders in children with Eosinophilic Esophagitis (EoE). MethodsThis retrospective study included children with EoE who were referred to sleep clinics. Clinical manifestations, PSG variables, and diagnosis of sleep disorders were analyzed. Sleep architecture of patients with EoE was compared to control subjects. ResultsIn sum, 81 children with EoE met the criteria for entry into the analysis with a mean age of 10.1 ± 4.4 years. Of those, 46 children (57%) presented in the sleep clinic with active EoE symptoms, while 35 (43%) children did not have active EoE symptoms at presentation. Several sleep complaints were common in children with EoE, including snoring (62, 76.5%), restless sleep (54, 66.6%), legs jerking or leg discomfort (35, 43.2%) and daytime sleepiness (47, 58.0%). Comparing sleep architecture with controls, children with EoE had significantly higher NREM2 (P= < 0.001), lower NREM3 (P= < 0.001), lower rapid eye movement (REM) (P = 0.017), increased periodic leg movements (PLM) index (P= < 0.001) and increased arousal index (P = 0.007). There were no significant differences in the sleep efficiency between the EoE and control subjects. Common sleep diagnoses included obstructive sleep apnea (OSA, 30, 37.0%) and periodic limb movements disorder (PLMD, 20, 24.6%). Of note, we found a much higher percentage of PLMD in active EoE compared to inactive EoE (P = 0.004). ConclusionsChildren with EoE have frequent sleep complaints and several sleep disorders identified from the sleep study, including sleep-disordered breathing and PLMD. Analysis of sleep architecture demonstrates significant sleep fragmentation as evidenced by decreased slow-wave sleep and REM sleep and increased arousal index.

African ethnicity is associated with a higher prevalence of diabetes in obstructive sleep apnea patients: results of a retrospective analysis.

Obstructive sleep apnea (OSA) syndrome is a well-recognized independent risk factor for cardiovascular disease and its prevalence is increasing. OSA symptomology, polysomnographic features, and comorbidities are heterogeneous among patients. Ethnicity is thought to influence OSA phenotypes, but extensive knowledge of OSA ethnic patterns is lacking. The primary aim of the present study was to compare comorbidities in Caucasian and African OSA. Secondary aims were to observe OSA symptomatology, polysomnographic characteristics, and CPAP adherence in these two ethnic groups. In this retrospective study, 1717 patients suffering from moderate/severe OSA were included between 2013 and 2017. Data on demographics, symptomatology, comorbidities, polysomnographic characteristics, and CPAP adherence were collected. Data were analyzed to identify potential differences between Caucasians and Africans. Despite healthier lifestyles and lower BMI, a higher prevalence of diabetes but less cardiac comorbidities and dyslipidemia was observed in the African population. Younger African patients (< 56years) suffered more from cognitive impairment than Caucasians and both younger and older Africans complained more of nighttime choking than Caucasians. In analysis of polysomnographic data, Africans had higher apnea-hypopnea index (AHI) in REM sleep, lower supine AHI, lower desaturation time, and lower periodic leg movements index. Compared with Caucasians, African OSA showed a particular comorbidity profile. There are younger patients who exhibit more diabetes but less cardiac comorbidities than the Caucasians. African diabetics should be more promptly referred for OSA testing. Moreover, as they suffer more often from choking and cognitive impairment, OSA treatment could positively impact their quality of life.

Individual periodic limb movements with arousal are temporally associated with nonsustained ventricular tachycardia: a case-crossover analysis.

Both periodic limb movements during sleep (PLMS) and arousals are associated with sympathetic nervous system activation and may be arrhythmogenic. We hypothesize a temporal relationship exists between individual PLMS, particularly with arousal, and nonsustained ventricular tachycardia (NSVT) events. A bidirectional time-stratified case-crossover design was used to assess temporal associations between PLMS and NSVT during sleep in 49 Osteoporotic Fractures in Men Sleep Study participants with NSVT in a community-based cohort (n = 2,911). Sleep time was divided into approximate 30-min segments. For each NSVT (n = 141), we selected a preceding 30-s hazard period and three randomly chosen 30-s control periods from sleep within the same segment and evaluated for PLMS, respiratory events, minimum saturation, and arousals. Odds ratios and 95% confidence intervals-OR (95% CI)-were determined by conditional logistic regression; covariates included EEG arousals, minimum saturation, and respiratory events in the same hazard/control period. Participants with NSVT were 79.5 ± 6.2 years with a PLMS index of 32.1 (IQR: 10.1, 61.4) and apnea-hypopnea index of 17.1 (IQR: 9.4, 26.1). PLMS without arousal were not significantly associated with NSVT (OR = 0.80, 95% CI: 0.41-1.59). PLMS with arousal were associated with NSVT in unadjusted analyses (OR = 2.50, 95% CI: 1.11-5.65) and after adjustment (OR = 2.31, 95% CI: 1.02-5.25). Arousals associated with PLMS were associated with NSVT in unadjusted (OR = 2.84, 95% CI: 1.23-6.56) and adjusted analyses (OR = 2.61, 95% CI: 1.13-6.05). PLMS with (but not without) arousals are temporally associated with a greater than twofold higher odds of subsequent NSVT episodes. PLMS-related arousals may be physiologically important ventricular arrhythmia triggers. ClinicalTrials.gov, NCT00070681.

Association Between Periodic Limb Movements in Sleep and Cerebrovascular Changes in Children With Sickle Cell Disease.

Periodic limb movements (PLMs) have been associated with increased risk of stroke, but there is currently scarce research exploring this relationship in the setting of sickle cell disease (SCD). The aim of this study was to explore whether increased PLMs in children with SCD are associated with increased risk of cerebrovascular disease and to determine if there are any clinical or laboratory differences between children with SCD with elevated periodic limb movement index (PLMI) versus those with normal PLMI. This study is a comprehensive review of medical records of 129 children with SCD (aged ≤ 18 years) who had undergone polysomnography for evaluation of sleep-disordered breathing. Elevated PLMI (PLMI > 5 events/h) was present in 42% (54/129) of children with SCD. Children with elevated PLMI were found to have higher percentage of hemoglobin S, lower total iron, higher arousal index and tendency toward elevated transcranial Doppler velocity (P = .063, odds ratio = 3.9, 95% CI 0.93-16.22). While association between elevated PLMI and isolated cerebrovascular stenosis (P = .050, odds ratio 5.6, 95% CI 1.0-31.10) trended toward significance, there was significantly greater proportion of children with elevated PLMI who had cerebrovascular stenosis with Moyamoya disease (P = .046) as demonstrated by magnetic resonance imaging (MRI). The prevalence of elevated PLMI in children with SCD was higher than in previously published data. Elevated PLMI was significantly associated with greater rates of cerebrovascular disease as detected by MRI.

Prevalence and neurophysiological correlates of sleep disordered breathing in pediatric type 1 narcolepsy

Study objectivesTo investigate the prevalence and neurophysiological correlates of obstructive sleep disordered breathing (OSA) in type 1 narcolepsy (NT1) children and adolescents. MethodsThirty-eight, drug-naïve, NT1 children and adolescents and 21 age- and sex-balanced clinical controls underwent nocturnal polysomnography (PSG) and multiple sleep latency test (MSLT). According to the rules for pediatric population, an obstructive apnea-hypopnea index (Obstructive AHI) ≥ 1 (comprising obstructive and mixed events), defined comorbid OSA. ResultsNT1 children showed higher prevalence of overweight/obesity and severe nocturnal sleep disruption (lower sleep efficiency, and increased N1 sleep stage percentage) coupled with higher motor activity (periodic limb movement index [PLMi] and REM atonia index) compared to clinical controls. Sleep-related respiratory variables did not differ between NT1 and clinical controls (OSA prevalence of 13.2% and 4.8%, respectively). NT1 children with OSA were younger and showed lower N2 sleep stage percentage and higher PLMi than NT1 children without comorbid OSA. Overweight/obesity was not associated with OSA in NT1. ConclusionsDespite higher body mass index (BMI), OSA prevalence did not differ between children with NT1 and clinical controls. OSA in pediatric NT1 patients is a rare and mild comorbidity, further contributing to nocturnal sleep disruption without effects on daytime sleepiness.

Different diagnostic criteria for periodic leg movements in patients with obstructive sleep apnea after continuous positive airway pressure titration.

ObjectivePeriodic leg movement in sleep (PLMS) is common among patients with obstructive sleep apnea (OSA). The PLMS frequency changes after continuous positive airway pressure (CPAP) titration. This study investigated the effects of two PLMS diagnostic criteria on PLMS prevalence and the restless leg syndrome (RLS) detection rate in patients with OSA before and after CPAP titration.MethodsThis retrospective study included patients with OSA who received polysomnography (PSG) and successful CPAP titration from December 2012 to December 2014. Their clinical variables and sleep parameters were evaluated using the PLMS diagnostic criteria: PLMS index (PLMI) ≥5 and ≥15. PLMS prevalence and the RLS detection rate were analyzed according to the PLMI before and after CPAP.ResultsIn patients with OSA with a PLMI of ≥5 and ≥15 after PSG with CPAP titration, the PLMS prevalence was 20.1% (76/378) and 4.5% (17/378), respectively, which revealed CPAP titration increased PLMI. Moreover, in terms of PLMI ≥5 and ≥15, PSG with CPAP titration led to significantly higher PLMS prevalence than PSG alone (20.1% vs 7.1% and 4.5% vs 0.8%, respectively; both P<0.001). PLMI ≥5 also demonstrated a higher RLS detection rate than PLMI ≥15 did (69.2% vs 15.4%; P=0.016).ConclusionIn patients with OSA, CPAP titration increases PLMS prevalence and the PLMI regardless of whether PLMI is ≥5 or ≥15. The use of the current diagnostic criteria, PLMI ≥15, for PLMS may lead to underestimation of PLMS prevalence and the RLS detection rate in patients with OSA.

Actigraphic detection of periodic limb movements: development and validation of a potential device-independent algorithm. A proof of concept study.

We propose a unique device-independent approach to analyze long-term actigraphy signals that can accurately quantify the severity of periodic limb movements in sleep (PLMS). We analyzed 6-8 hr of bilateral ankle actigraphy data for 166 consecutively consenting patients who simultaneously underwent routine clinical polysomnography. Using the proposed algorithm, we extracted 14 time and frequency features to identify PLMS. These features were then used to train a Naïve-Bayes learning tool which permitted classification of mild vs. severe PLMS (i.e. periodic limb movements [PLM] index less than vs. greater than 15 per hr), as well as classification for four PLM severities (i.e. PLM index < 15, between 15 and 29.9, between 30 and 49.9, and ≥50 movements per hour). Using the proposed signal analysis technique, coupled with a leave-one-out cross-validation method, we obtained a classification accuracy of 89.6%, a sensitivity of 87.9%, and a specificity of 94.1% when classifying a PLM index less than vs. greater than 15 per hr. For the multiclass classification for the four PLM severities, we obtained a classification accuracy of 85.8%, with a sensitivity of 97.6%, and a specificity of 84.8%. Our approach to analyzing long-term actigraphy data provides a method that can be used as a screening tool to detect PLMS using actigraphy devices from various manufacturers and will facilitate detection of PLMS in an ambulatory setting.

Risk of resistant hypertension associated with restless legs syndrome and periodic limb movements during sleep: a study on 673 treated hypertensive individuals

ObjectiveGiven the limited data available in the literature, the aim of this study was to examine the risk of resistant hypertension (RHT) associated with restless legs syndrome (RLS) and periodic limb movements during sleep (PLMS) in a large sample of treated hypertensive individuals. MethodsDemographic and polysomnographic (PSG) data from 673 treated hypertensive individuals recruited from the research database of the sleep laboratory of Erasme Hospital were analysed. After exclusion of the main causes of pseudo-resistance and secondary hypertension, RHT status was defined by the presence of an uncontrolled hypertension despite treatment with at least three antihypertensive agents (including a diuretic) from different classes in correct combination and at the highest tolerated doses or by the presence of controlled hypertension requiring the use of at least four antihypertensive agents. Logistic regression analyses were conducted to examine the risk of RHT associated with RLS and PLMS in treated hypertensive individuals. ResultsAfter adjustment for major confounding factors associated with RHT, multivariate logistic regression analysis revealed that frequent RLS (≥2 episodes/week) combined with PLMS index ≥26/h [odds ratio (OR) 2.20; 95% confidence interval (CI) 1.35–3.61, p = 0.021] was a significant risk factor of RHT in treated hypertensive individuals. ConclusionIn treated hypertensive individuals, frequent RLS combined with PLMS index ≥26/h is associated with higher risk of RHT which suggests that this pathology may be a secondary cause of RHT (eg, obstructive sleep apnoea syndrome and insomnia with short sleep duration) justifying the establishment of effective treatments in this particular subpopulation.

It twitches without kicking – An association between fragmentary myoclonus and arousal?

ObjectiveFragmentary myoclonus (FM) is a polysomnographic motor phenomenon of unknown clinical relevance. This study investigates FM prevalence, gender differences, sleep stage distribution and association with clinical factors using recently introduced advanced FM scoring criteria. MethodsWe analyzed polysomnographic recordings of 178 patients of a mixed sleep-disorder patient cohort. FM indices (FMI) of newly introduced 25 μV (FMI25) and standard 50 μV (FMI50) amplitude cut-offs were calculated. ResultsFMI25 and FMI50 were higher in men compared to women. FMI were higher during wakefulness and lower during S3 compared to all other sleep stages, with stronger effects in men compared to women. FMI25 was correlated with higher age, lower mean oxygen saturation, lower sleep efficiency, higher periodic limb movement (PLM) index, shorter sleep period time and higher arousal index. Linear regression showed that age predicted higher FMI25 in both males and females. Additionally, higher arousal index predicted higher FMI25 in women only. FMI were not associated with the presence of sleep-related breathing disorders. ConclusionsWe suggest FM represents a ubiquitous motor phenomenon occurring spontaneously during relaxed wakefulness and sleep, primarily in men and with advanced age. SignificanceIn women, particularly FMI25 may be a surrogate marker for more frequent arousals and sleep fragmentation.

Relationship between periodic limb movement and seizure recurrence in genetic generalized epilepsy

BackgroundAlthough periodic limb movements are prevalent among patients with epilepsy, the exact relationship between these movements and epilepsy remains elusive.ObjectiveThe aim of this work was to study the periodic limb movements among patients with genetic generalized epilepsy in relation to different clinical characteristics and seizure recurrence.MethodsSixty individuals participated in this study: 30 of them were newly diagnosed with genetic generalized epilepsy and 30 were healthy individuals. Sleep quality was assessed using the Pittsburgh Sleep Quality Index questionnaire, and a standard polysomnographic study was conducted to all subjects. All patients then received sodium valproate in therapeutic doses and were followed up for 6 months. Electroencephalogram (EEG) was done after the follow-up period and seizure recurrence was assessed. Accordingly, patients were classified into three groups according to clinical seizure recurrence and follow-up EEG findings. Periodic limb movement index and frequency were compared among the patients’ groups and were correlated with different clinical characteristics.ResultsPeriodic limb movement index was highest among the group who were not controlled, followed by the partially controlled, then the controlled group. The difference between the three groups was statistically significant.ConclusionPeriodic limb movement index was positively correlated with seizure recurrence and can be used as a predictor of seizure outcome.Trial registrationThe trial registration number (TRN) on clinicaltrials.gov is NCT03587506, and the date of registration is July 16, 2018.