Periodic limb movements during sleep are associated with poor health-related quality of life in patients with obstructive sleep apnea.

PURPOSE: The clinical significance of the comorbidity of periodic limb movements during sleep (PLMS) in sleep-disordered breathing remains unclear. This study aimed to determine whether or not the presence of PLMS is related to depressed mood and poor quality of life in subjects with obstructive sleep apnea (OSA). METHODS: We defined PLMS as a periodic leg movement index of > 15/h. Scores for the Medical Outcomes Study Short Form Health Survey and Beck Depression Inventory were assessed with multiple logistic or linear regression analyses. RESULTS: Of 1370 subjects with OSA, a prevalence of PLMS was 14.1%. Older age, men, and obesity were positively associated with PLMS. PLMS occurred in 17%, 15%, and 12% of mild, moderate, and severe subjects with OSA, respectively. Severe OSA was less likely to be associated with PLMS than mild OSA. PLMS negatively correlated with physical and mental component summary scores of the health survey but not with Beck Depression Inventory scores after controlling for confounding variables. PLMS were significantly associated with poor sleep architecture on polysomnography. However, the relationship between PLMS and disturbed sleep was no longer significant after adjusting for age. CONCLUSIONS: Health-related quality of life, including physical and mental health but not depressive symptoms, was worse in subjects with OSA and PLMS than in those without PLMS.

Prevalence of periodic limb movement in sleep in people with epilepsy: A semi-structured literature review.

OBJECTIVES: Epilepsy is a prevalent health problem worldwide in all ages, and it is essential to identify disease markers for diagnosis and treatment. Periodic limb movements in sleep (PLMS) are a common finding in polysomnography (PSG). Still, its clinical relevance in people with epilepsy (PWE) is unknown. The aim of this review was to compare PLMS frequency in PWE and controls. METHODS: A semi-structured literature review was conducted using PubMed in search of relevant studies in English on August 23, 2019, with the search terms "sleep," "epilepsy," or "seizure," and "polysomnography" in the title and/or abstract. The research was complemented with citation analysis and manual search using Google Scholar. Studies involved PWE and comparative controls using PSG with reported PLMS index (PLMI). RESULTS: Seven studies were identified. Only two showed a statistically significant difference in PLMI between cases and controls, and in another study, cases had uncontrolled seizures. In general, studies did not adjust for potential confounders including demographics, apnea-hypopnea index, or medication use. CONCLUSIONS: We found few studies exploring the prevalence of PLMS in PWE. In the majority, PLMI did not differ from controls. Further studies are warranted given the prevalence of sleep disturbances in epilepsy.

Contemporary Concise Review 2020: Sleep.

Obstructive sleep apnoea (OSA) now affects one-seventh of the world's population. Treatment of even mild OSA can improve daytime sleepiness and quality of life. Recent modifications to uvulopalatopharyngoplasty may make it a more widely applicable treatment option in selected patients with OSA. Diet and exercise have effects on sleep apnoea severity independent of weight loss. Insomnia has become increasingly common during the coronavirus disease 2019 (COVID-19) pandemic.

Effects of new PLM scoring rules on PLM rate in relation to sleep and resting wake for RLS and healthy controls.

PURPOSE: This study evaluates the differences in periodic leg movement (PLM) rates for Restless Legs Syndrome (RLS) and healthy controls when using the updated PLM scoring criteria developed by IRLSSG in 2016 versus the prior PLM scoring criteria developed by IRLSSG in 2006. Four major problems with the prior standards had been objectively identified, i.e. minimum inter-movement interval should be 10 not 5 s, non-PLM leg movements should end any preceding PLM sequence, a leg movement (LM) can be any length > 0.5 s, and a PLM should be a persisting movement not a couple or a series of closely spaced, very brief events. Each of these led to including, erroneously, various random leg movements as PLM. Correcting these problems was expected to increase specificity, reducing the number of PLM detected, particularly in situations producing relatively more random leg movements, e.g. wake vs. sleep and controls without PLMD vs. RLS patients. METHODS: This study evaluated the putative benefits of the updated, 2016-scoring criteria. The LMs from 42 RLS patients and 30 age- and gender-matched controls were scored for PLMS and PLMW from standard all-night PSG recordings using both 2006 and 2016 WASM criteria. RESULTS/CONCLUSION: The results confirmed that that the 2016 compared to the 2006 criteria generally decreased the PLM rates with particularly large decreases for the conditions with more random non-PLM events, e.g. wake times and normal healthy controls. This supported the view that the new criteria succeeded in increasing the specificity of PLM detection. Moreover, the changes in PLM rates were generally small for the conditions with relatively few random LM, e.g. RLS and sleep. Thus the bulk of existing PLMS research does not require reconsideration of results, with possible exception of special situations with relatively more random leg movements than periodic leg movements, e.g. wake, healthy normals and children.

Retrospective Analysis of Risk Factors for Periodic Limb Movements in a Large Cohort of Insomnia and Chronic Fatigue Patients.

INTRODUCTION: Although the pathophysiology of periodic limb movements in sleep (PLMS) is not well understood, there is increasing belief that management of PLMS can modulate humans' general health. The aim of this study is to investigate the associations between risk factors including the use of antidepressants, hypnotics, and antihistamines as well as of caffeine, alcohol, and nicotine and the occurrence of PLMS and periodic limb movement disorder (PLMD). METHODS: Patients with either chronic fatigue or insomnia who underwent polysomnography as standardized clinical assessment were included in a retrospective study. Associations were calculated between substance use and sleep variables. RESULTS: Tricyclic antidepressants and serotonin and norepinephrine reuptake inhibitor (SNRI) are significantly associated with higher rates of PLMS. Additionally, SNRI is significantly positive associated with PLMD, as also seen for selective serotonin reuptake inhibitors (SSRI). The most frequently used SSRI escitalopram was significantly positively associated with PLMS and PLMD. A significantly negative association was found between paroxetine and PLMS. Benzodiazepines are negatively associated with PLMS and PLMD. Sedative antidepressants, antihistamines, and substance use are not associated with PLMS nor PLMD in this study. DISCUSSION: This retrospective study adds supportive evidence to the association of drug classes with PLMS and PLMD. These findings may impact on clinical management of patients with a combined anxiety or mood disorder in need for these drug classes on the one hand and a significant sleep architecture disturbance through PLMS, potentially contributing to daytime symptoms, on the other hand.

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

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

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.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: This study shows no independent association between the PLMS index and neuroimaging signatures of cSVD in stroke-free community-dwelling older adults.

Level of sleep disorders among patients with chronic obstructive pulmonary disease.

OBJECTIVE: To measure the level of sleep disorders among patients with chronic obstructive pulmonary disease, and to see if there was any difference in terms of demographic variables and socioeconomic status. METHODS: The cross-sectional descriptive observational study was conducted from March to June 2017, and data was collected through purposive sampling from different tertiary health care centres of Faisalabad, Pakistan. Sleep-50-Urdu scale was used to measure sleep disorders among patients with chronic obstructive pulmonary disease. SPSS 21 was used for data analysis. RESULTS: Of the 140 respondents 70(50%) each were males and females with an overall mean age of 48.64±17.39 years. The patients had significantly high level of narcolepsy (p<0.05), but those from high socioeconomic status had relatively lower level of narcolepsy (p<0.05). Male patients and people from lower socioeconomic status also suffered from sleep apnoea and insomnia along with chronic obstructive pulmonary disease (p<0.05). CONCLUSIONS: Narcolepsy along with sleep apnoea and insomnia were significantly more prevalent among chronic obstructive pulmonary disease patients from lower socioeconomic status.

Periodic limb movements during sleep are associated with cardiovascular diseases: A systematic review and meta-analysis.

Periodic limb movements during sleep present with repetitive movements, typically in the lower limbs, during sleep. Periodic limb movements during sleep have been proposed to be associated with increased risk of heart diseases. The aim of this study was to examine the co-morbidity rates of heart disease, including acute myocardial infarction, coronary artery disease and cardiovascular disease, in subjects with or without periodic limb movements during sleep through a meta-analysis. An electronic review of PubMed, Embase, ScienceDirect, Cochrane Library, ProQuest, Web of Science, ClinicalKey and ClinicalTrials.gov was performed. Clinical studies, case-controlled trials and cohort studies were all included in the search. Case reports or series, and non-clinical studies were excluded. A meta-analysis of the results of six studies comparing the prevalence of coronary artery disease/acute myocardial infarction/cardiovascular disease in subjects with/without periodic limb movements during sleep was performed. There were significantly higher co-morbidity rates of coronary artery disease (odds ratio = 1.568, 95% confidence interval: 1.187-2.073, p = 0.002) and cardiovascular disease (odds ratio = 1.279, 95% confidence interval: 1.095-1.494, p = 0.002), but not acute myocardial infarction (odds ratio = 1.272, 95% confidence interval = 0.942-1.718, p = 0.117), in the periodic limb movements during sleep group than in the non-periodic limb movements during sleep group. This meta-analysis highlights the importance of a significantly high prevalence of coronary artery disease and cardiovascular disease in subjects with periodic limb movements during sleep. Further studies should be focused on the potential pathophysiology, and whether treatment for periodic limb movements during sleep can improve the outcome of heart disease.

Cerebrovascular Accident Risk in a Population with Periodic Limb Movements of Sleep: A Preliminary Meta-Analysis.

BACKGROUND AND PURPOSE: Periodic limb movements of sleep (PLMS) are usually comorbid with hypertension, tachycardia, and coronary arterial diseases, which are also risk factors for cerebrovascular accidents (CVA). However, evidence about the relationship between CVA and PLMS is still weak. The aim of this study was to investigate (1) the prevalence of CVA in patients with PLMS, and (2) the severity of PLMS in patients with or without CVA through a meta-analysis. METHODS: The electronic databases of PubMed, Embase, ScienceDirect, ClinicalKey, Cochrane Library, ProQuest, Web of Science, and ClinicalTrials.gov were searched. The inclusion criteria were (1) articles investigating comorbidity between PLMS and CVA, and (2) clinical trials in humans. RESULTS: This meta-analysis included (1) 9,823 patients with PLMS and 9,416 controls from 5 studies to analyze the prevalence of CVA in PLMS, and (2) 158 patients with PLMS with CVA and 88 PLMS controls without CVA from 3 studies to analyze the severity of PLMS with and without CVA. The results showed (1) significantly higher comorbidity rates of CVA in the patients with PLMS than in the controls without PLMS (OR 1.267, p = 0.019), and (2) higher PLM index in the patients with CVA than in the controls (Hedges' g = 0.860, p = 0.001; means difference: 4.435, p = 0.016). CONCLUSIONS: The results revealed (1) a worse severity of PLMS in the patients with CVA, and (2) increased prevalence of CVA in the patients with PLMS. Based on our results, the patients had a higher prevalence of CVA within 8 years of a diagnosis of PLMS compared to those without PLMS by about 1.3-fold. Whether (1) patients with PLMS receiving treatment have a similar incidence of stroke to those without PLMS, and (2) secondary stroke prevention can lower the severity of PLMS or whether those with severe PLMS have a higher risk of stroke is still inconclusive. Future studies investigating the prevalence of CVA in patients with PLMS should use a follow-up period of over 8 years.

ICI-RS 2015-Is a better understanding of sleep the key in managing nocturia?

AIMS: Nocturia, or waking up at night to void, is a highly prevalent and bothersome lower urinary tract symptom. However, the applied treatment modalities do not improve symptoms in about half of the patients. The aim of this report is to generate new ideas for future nocturia research, with special emphasis on the role of sleep physiology and sleep disorders. METHODS: The following is a report of the presentations and subsequent discussion of the Nocturia Think Tank session at the annual meeting of the International Consultation on Incontinence Research Society (ICI-RS), which took place in September 2015 in Bristol. General information about the organization of the ICI-RS meeting can be found on the website "www.ici-rs.org." An overview of challenges within the existing evidence, future research ideas, and results of research with regard to nocturia and sleep were presented. RESULTS AND CONCLUSION: In order to optimize the management of nocturia and nocturnal polyuria (NP), future research has to focus on the development of unambiguous terminology regarding nocturia and NP, the role of renal function profiles and simplified frequency volume charts as guidance of individualized therapy and the role of sleep disorders such as periodic limb movements during sleep and habitual voiding as a response to awakening. Neurourol. Urodynam. 37:2048-2052, 2018. © 2016 Wiley Periodicals, Inc.

Sleep-Related Leg Movements in Patients with Transient Ischemic Attack and Controls.

BACKGROUND: Periodic leg movements during sleep (PLMS) have been associated with an increased risk for cardiovascular diseases and there is a high prevalence of PLMS found in patients with obstructive sleep apnea syndrome (OSAS). We evaluated patients with transient ischemic attack (TIA) for PLMS and respiratory related leg movements (RRLM), versus a control group without TIA. METHODS: Twenty-five patients with TIA and 34 patients with no vascular diagnosis were referred for polysomnography. Diagnosis of PLMS was made if the periodic leg movement index (PLMI) was ≥5 and clinical significant as PLMI ≥15. RESULTS: There was no significant difference in PLMI ≥5 and ≥15 between patients with and without TIA. In the absence of OSAS, 2 out of 5 TIA patients (40%) had a PLMI ≥15 compared to 1 of the 19 patients without TIA (5%; p = 0.037). There was no increase in RRLMs when OSAS was present. CONCLUSIONS: TIA patients did not have higher PLMI compared to controls, and in the presence of OSAS, there was no increase in RRLMs compared to patients without TIA. In selective patients, PLMS could be associated with cardiovascular diseases, since PLMS was clinically more often found in the TIA group without OSAS.

Basal sympathetic predominance in periodic limb movements in sleep after continuous positive airway pressure.

PURPOSE: This study investigated the basal autonomic regulation in patients with obstructive sleep apnea (OSA) showing periodic limb movements in sleep (PLMS) emerging after therapy with continuous positive airway pressure (CPAP). METHODS: Data of patients with OSA undergoing a first polysomnography for diagnosis and a second polysomnography for therapy with CPAP were reviewed. Patients with OSA showing PLMS on the first polysomnography were excluded. By using heart rate variability analysis, epochs without any sleep events and continuous effects from the second polysomnography were retrospectively analyzed. RESULTS: Of 125 eligible patients, 30 with PLMS after therapy with CPAP (PLMS group) and 30 not showing PLMS on both polysomnography (non-PLMS group) were randomly selected for the analysis. No significant differences in the demographic characteristics and variables of polysomnographies were identified between the groups. Although one trend of low root mean square of successive differences (RMSSD) between intervals of adjacent normal heart beats (NN intervals) in the PLMS group was observed, patients in the PLMS group had significantly low normalized high-frequency (n-HF) and high-frequency (HF) values, but high normalized low frequency (n-LF) and high ratio of LF to HF (LF/HF ratio). After adjustment for confounding variables, PLMS on the second polysomnography was significantly associated with RMSSD (ß = - 6.7587, p = 0.0338), n-LF (ß = 0.0907, p = 0.0148), n-HF (ß = - 0.0895, p = 0.0163), log LF/HF ratio (ß = 0.4923, p = 0.0090), and log HF (ß = - 0.6134, p = 0.0199). CONCLUSIONS: Patients with OSA showing PLMS emerging after therapy with CPAP may have a basal sympathetic predominance with potential negative cardiovascular effects.

Validation of a non-contact screening device for the combination of sleep-disordered breathing and periodic limb movements in sleep.

PURPOSE: Recent studies found that the non-contact screening device SleepMinder (ResMed Sensor Technologies, Dublin, Ireland) detects sleep-disordered breathing (SDB) with high diagnostic accuracy in cohorts suspected of this disorder. However, it was reported that in patients with periodic limb movement in sleep (PLMS), this non-contact device overestimates the apnea-hypopnea index (AHI). We aimed to overcome this limitation by introducing the novel sleep disorder index (SDI) which is sum of the AHI and the period limb movement index (PLMI). METHODS: Between January 2011 and December 2013, we studied a mixed cohort of 57 patients (31 OSA, 19 PLMS). The easy-to-use non-contact device emits a very weak electromagnetic radiation and detects body movement by measuring the Doppler effect. We interpreted the device-generated movement index as the SDI and validated the diagnostic accuracy against simultaneous application of the gold-standard polysomnography (PSG). RESULTS: We found that the SDI of the non-contact device correlated well with the sum of AHI and PLMI derived from PSG (r = 0.79, p = 0.01). For PSG-derived SDI cutoff ≥ 15/h, we obtained a sensitivity of 92.2% and a specificity of 95.8%. Positive likelihood ratio was 23.3 and negative likelihood ratio 0.03. CONCLUSIONS: The studied non-contact screening device detects accurately the combination of the sleep disorders SDB and/or PLM. However, further testing is required in order to specify the nature of the underlying sleep disorder. At the current stage of algorithm development, the clinical strength is that the studied non-contact device can be used as a rule-out screening device for SDB and PLM.

Sleep-related movement disorders and disturbances of motor control.

PURPOSE OF REVIEW: Review of the literature pertaining to clinical presentation, classification, epidemiology, pathophysiology, diagnosis, and treatment of sleep-related movement disorders and disturbances of motor control. RECENT FINDINGS: Sleep-related movement disorders and disturbances of motor control are typically characterized by positive motor symptoms and are often associated with sleep disturbances and consequent daytime symptoms (e.g. fatigue, sleepiness). They often represent the first or main manifestation of underlying disorders of the central nervous system, which require specific work-up and treatment. Diverse and often combined cause factors have been identified. Although recent data provide some evidence regarding abnormal activation and/or disinhibition of motor circuits during sleep, for the majority of these disorders the pathogenetic mechanisms remain speculative. The differential diagnosis is sometimes difficult and misdiagnoses are not infrequent. The diagnosis is based on clinical and video-polysomnographic findings. Treatment of sleep-related motor disturbances with few exceptions (e.g. restless legs/limbs syndrome) are based mainly on anecdotal reports or small series. SUMMARY: More state-of-the-art studies on the cause, pathophysiology, and treatment of sleep-related movement disorders and disturbances of motor control are needed.

Prevalence and determinants of periodic limb movements in the general population.

OBJECTIVE: Periodic limb movements during sleep (PLMS) are sleep phenomena characterized by periodic episodes of repetitive stereotyped limb movements. The aim of this study was to describe the prevalence and determinants of PLMS in a middle to older aged general population. METHODS: Data from 2,162 subjects (51.2% women, mean age = 58.4 ± 11.1 years) participating in a population-based study (HypnoLaus, Lausanne, Switzerland) were collected. Assessments included laboratory tests, sociodemographic data, personal and treatment history, and full polysomnography at home. PLMS index (PLMSI) was determined, and PLMSI > 15/h was considered as significant. RESULTS: Prevalence of PLMSI > 15/h was 28.6% (31.3% in men, 26% in women). Compared to subjects with PLMSI ≤ 15/h, subjects with PLMSI > 15/h were older (p < 0.001), were predominantly males (p = 0.007), had a higher proportion of restless legs syndrome (RLS; p < 0.001), had a higher body mass index (p = 0.001), and had a lower mean glomerular filtration rate (p < 0.001). Subjects with PLMSI > 15/h also had a higher prevalence of diabetes, hypertension, and beta-blocker or hypnotic treatments. The prevalence of antidepressant use was higher, but not statistically significant (p = 0.07). Single nucleotide polymorphisms (SNPs) within BTBD9 (rs3923809), TOX3 (rs3104788), and MEIS1 (rs2300478) genes were significantly associated with PLSMI > 15/h. Conversely, mean hemoglobin and ferritin levels were similar in both groups. In the multivariate analysis, age, male gender, antidepressant intake, RLS, and rs3923809, rs3104788, and rs2300478 SNPs were independently associated with PLMSI > 15/h. INTERPRETATION: PLMS are highly prevalent in our middle-aged European population. Age, male gender, RLS, antidepressant treatment, and specific BTBD9, TOX3, and MEIS1 SNP distribution are independent predictors of PLMSI > 15/h.

Restless legs syndrome and periodic leg movements in patients with movement disorders: Specific considerations.

Restless legs syndrome is a frequent neurological disorder with potentially serious and highly distressing treatment complications. The role and potential implications of periodic leg movements during sleep range from being a genetic risk marker for restless legs syndrome to being a cardiovascular risk factor. The diagnosis of restless legs syndrome in patients with daytime movement disorders is challenging and restless legs syndrome needs to be differentiated from other sleep-related movement disorders. This article provides an update on the diagnosis of restless legs syndrome as an independent disorder and the role of periodic leg movements and reviews the association of restless legs syndrome with Parkinson's disease and other movement disorders. © 2017 International Parkinson and Movement Disorder Society.

Advanced signal analysis for the detection of periodic limb movements from bilateral ankle actigraphy.

Actigraphy can assist in the detection of periodic limb movements in sleep. Although several actigraphs have been previously reported to accurately detect periodic limb movements, many are no longer available; of the existing actigraphs, most sample too infrequently to accurately detect periodic limb movements. The purpose of this study was to use advanced signal analysis to validate a readily available actigraph that has the capability of sampling at relatively high frequencies. We simultaneously recorded polysomnography and bilateral ankle actigraphy in 96 consecutive patients presenting to our sleep laboratory. After pre-processing and conditioning, the bilateral ankle actigraphy signals were then analysed for 14 simple time, frequency and morphology-based features. These features reduced the signal dimensionality and aided in better representation of the periodic limb movement activity in the actigraph signals. These features were then processed by a Naïve-Bayes binary classifier for distinguishing between normal and abnormal periodic limb movement indices. We trained the Naïve-Bayes classifier using a training set, and subsequently tested its classification accuracy using a testing set. From our experiments, using a periodic limb movement index cut-off of 5, we found that the Naïve-Bayes classifier had a correct classification rate of 78.9%, with a sensitivity of 80.3% and a specificity of 73.7%. The algorithm developed in this study has the potential of facilitating identification of periodic limb movements across a wide spectrum of patient populations via the use of bilateral ankle actigraphy.

REM sleep behavior disorder and periodic leg movements during sleep in ALS.

OBJECTIVE: To assess sleep characteristics and the occurrence of abnormal muscle activity during sleep, such as REM sleep without atonia (RSWA), REM sleep behavior disorder (RBD), and periodic leg movements during sleep (PLMS), in patients with amyotrophic lateral sclerosis (ALS). METHODS: A total of 41 patients with ALS and 26 healthy subjects were submitted to clinical interview and overnight video-polysomnography. RESULTS: A total of 22 patients with ALS (53.6%) reported poor sleep quality. Polysomnographic studies showed that patients with ALS had reduced total sleep time, increased wakefulness after sleep onset, shortened REM and slow-wave sleep, and decreased sleep efficiency, compared to controls. Polysomnographic abnormalities were not different in patients reporting good or poor sleep and were not correlated to clinical and demographic variables. The PLMS index was significantly higher in patients with ALS than in healthy subjects, and 22 patients (53.6%) showed a PLMS index > 15/h, vs 4 (15.4%) controls (P < 0.001). Finally, two patients with ALS (4.9%) had RBD, and two more patients presented RSWA (4.9%), whereas no controls showed abnormalities of REM sleep. CONCLUSION: Patients with ALS frequently present abnormalities of sleep that can be documented both at the clinical interview and at the polysomnographic evaluation, including insomnia, fragmented sleep, and increased PLMS. Moreover, abnormalities of REM sleep can be found in some of these patients.

Post-stroke restless leg syndrome and periodic limb movements in sleep.

OBJECTIVES: Primary restless leg syndrome (RLS) and periodic limb movements in sleep (PLMS) frequently co-exist, obscuring the boundaries between the two conditions. In such instances, a study of secondary cases with focal lesions such as post-stroke RLS and PLMS (psRLS and psPLMS, respectively) can be helpful in identifying characteristics of the individual conditions. MATERIALS AND METHODS: Patients who had suffered strokes and who subsequently developed psRLS or psPLMS were recruited. To determine the overall features of psRLS/PLMS, historical cases were selected from the literature. All cases with either psRLS or psPLMS alone were further analyzed to elucidate the distinctive pathomechanisms of the two conditions. RESULTS: Six patients with either psRLS or psPLMS were recruited from our hospital; two patients had both conditions contemporaneously. The literature contains details on 30 cases of psRLS or psPLMS. The causative lesion was most frequently located in the pons. We found that psRLS was more often bilateral, and usually detected later in time. Lesions in both the pontine base and tegmentum (together) were associated with unilateral psPLMS, whereas lesions in the corona radiata and adjacent basal ganglia were associated with bilateral RLS. Lesions confined to the corona radiata resulted in either unilateral or bilateral RLS. CONCLUSIONS: The observed differences in the clinical and radiological features of psRLS and psPLMS suggest that the pathophysiologies of the two conditions are distinct. Further research is needed to understand the pathophysiologies of primary RLS and PLMS.