Measures of cognitive function in persons with varying degrees of sleep-disordered breathing: the Sleep Heart Health Study

Epidemiologic literature suggests that persons with clinically diagnosed sleep apnoea frequently have impaired cognitive function, but whether milder degrees of sleep-disordered breathing (SDB) are associated with cognitive dysfunction in the general population is largely unknown. Approximately 1700 subjects free of clinically diagnosed SDB underwent at-home polysomnography (PSG) as part of the Sleep Heart Health Study (SHHS) and completed three cognitive function tests within 1-2 years of their PSG: the Delayed Word Recall Test (DWR), the WAIS-R Digit Symbol Subtest (DSS), and the Word Fluency test (WF). A respiratory disturbance index (RDI) was calculated as the number of apnoeas and hypopnoeas per hour of sleep. After adjustment for age, education, occupation, field centre, diabetes, hypertension, body-mass index, use of CNS medications, and alcohol drinking status, there was no consistent association between the RDI and any of the three cognitive function measures. There was no evidence of a dose-response relation between the RDI and cognitive function scores and the adjusted mean scores by quartiles of RDI never differed from one another by more than 5% for any of the tests. In this sample of free-living individuals with mostly mild to moderate levels of SDB, the degree of SDB appeared to be unrelated to three measures of cognitive performance.     

Sex Differences in Subjective and Actigraphic Sleep Measures: A Population-Based Study of Elderly Persons

Study Objectives:

To investigate and explain sex differences in subjective and actigraphic sleep parameters in community-dwelling elderly persons.

Design:

Cross-sectional study.

Setting:

The study was embedded in the Rotterdam Study, a population-based study.

Participants:

Nine hundred fifty-six participants aged 59 to 97 years.

Interventions:

N/A.

Measurements and Results:

Participants wore an actigraph and kept a sleep diary for an average of 6 consecutive nights. Subjective sleep quality was assessed with the Pittsburgh Sleep Quality Index. Unadjusted sex differences in sleep parameters were assessed with t tests. Women reported shorter total sleep time, a less favorable sleep-onset latency, lower sleep efficiency, and worse global sleep quality, as compared with men. When assessed with actigraphy, however, women were found to have longer and less-fragmented sleep than men. Sex differences in diary-reported sleep duration and other subjective sleep parameters were attenuated by adjustment for marital status, the use of sleep medication, and other covariates, but all sex differences remained significant in a multivariate-adjusted model. Sex differences in actigraphic sleep parameters were barely attenuated by multivariate adjustment, although the shorter actigraphically measured sleep duration in men was partly explained by their higher alcohol consumption. Some covariates (eg, sleep medication) had a different relationship with diary-reported or actigraphic total sleep time in men and women.

Conclusions:

If assessed by diary or interview, elderly women consistently reported shorter and poorer sleep than elderly men. In contrast, actigraphic sleep measures showed poorer sleep in men. These discrepancies are partly explained by determinants of sleep duration, such as sleep medication use and alcohol consumption.

Citation:

van den Berg JF; Miedema HME; Tulen JHM; Hofman A; Knuistingh Neven A; Tiemeier H. Sex differences in subjective and actigraphic sleep measures: a population-based study of elderly persons. SLEEP 2009;32(10):1367-1375.     

Sleep disorders in Taiwanese children with attention deficit/hyperactivity disorder

To assess obstructive sleep apnea syndrome (OSAS) and periodic limb movement disorder (PLMD) in children with attention deficit/hyperactivity disorder (ADHD) compared with a control group. The ADHD was diagnosed based on Diagnostic and Statistical Manual, version IV (DSM-IV) criteria on successively seen elementary school children aged 6-12 years referred to a psychiatric clinic for suspected ADHD. A standardized interview (Kiddie-SADS-E), parents and teacher questionnaires, neuropsychological testing, and nocturnal polysomnography were completed for each child. Eighty-eight children (77 boys) with ADHD and 27 controls were involved in the study. Fifty children with ADHD (56.8%) had an apnea-hypopnea index (AHI) >1 event h(-1) and 17 (19.3%) had an AHI >5 event h(-1). Nine children (10.2%) had a periodic limb movement index (PLMI) >5 events h(-1). There is one child with AHI >1 and none with a PLMI > 5 in the control group. In the test of variables of attention (TOVA), the response time was significantly worse in ADHD with sleep disorders than those without them. The child behavior checklist (CBCL) showed a significant difference between groups in the hyperactivity subscale. The diagnostic criteria for ADHD based on DSM-IV do not differentiate between children with or without sleep disorders. Evaluation of sleep disorders should be considered before starting drug treatment for ADHD.     

Cognitive Function and Sleep Related Breathing Disorders in a Healthy Elderly Population: the Synapse Study

Study Objectives:

Sleep related breathing disorders (SRBD) are risk factors for cognitive dysfunction in middle-aged subjects, but this association has not been observed in the elderly. We assess the impact of SRBD on cognitive performance in a large cohort of healthy elderly subjects.

Design:

Cross-sectional study examining the association between subjective memory test, neuropsychological battery testing and SRBD in the elderly.

Setting:

Community-based sample in home and research clinical settings.

Participants:

827 subjects, 58.5% women, aged 68 y at study entry, participated in the study. All were free of previously diagnosed SRBD, coronary heart disease, and neurological disorders, including stroke and dementia. Clinical interview, neurological assessment, polygraphy, and extensive cognitive testing were conducted for all participants.

Intervention:

N/A

Measurement and Results:

SRBD (apnea-hypopnea index [AHI] > 15 events/h) was diagnosed in 445 (53%) subjects, 167 (37%) of them with AHI > 30. Minimal daytime sleepiness was found in the group; 9.2% of the population had an Epworth Sleepiness Scale score > 10. No significant association was found between AHI, nocturnal hypoxemia, and cognitive scores. Comparison of mild vs severe cases showed a trend toward lower cognitive scores with AHI > 30, affecting delayed recall and Stroop test.

Conclusions:

The impact of undiagnosed SRBD on cognitive function appeared quite limited in a generally older healthy population, and only slightly affected severe cases. The implication of undiagnosed SRBD on the cognitive impairment in elderly subjects remains hypothetical and needs to be prospectively studied.

Clinical Trial Information:

Autonomic Nervous System Activity, Aging and Sleep Apnea/Hypopnea (SYNAPSE); Registration #{"type":"clinical-trial","attrs":{"text":"NCT 00766584","term_id":"NCT00766584"}}NCT 00766584 (This study is ongoing, but not recruiting participants.); URL - http://clinicaltrials.gov/ct2/show/{"type":"clinical-trial","attrs":{"text":"NCT00766584","term_id":"NCT00766584"}}NCT00766584?term=NCT+00766584&rank=1

Citation:

Sforza E; Roche F; Thomas-Anterion C; Kerleroux J; Beauchet O; Celle S; Maudoux D; Pichot V; Laurent B; Barthélémy JC. Cognitive function and sleep related breathing disorders in a healthy elderly population: the synapse study. SLEEP 2010;33(4):515-521     

Sleep Quality and Psychological Adjustment in Chronic Fatigue Syndrome

Without specific etiology or effective treatment, chronic fatigue syndrome (CFS) remains a contentious diagnosis. Individuals with CFS complain of fatigue and poor sleep—symptoms that are often attributed to psychological disturbance. To assess the nature and prevalence of sleep disturbance in CFS and to investigate the widely presumed presence of psychological maladjustment we examined sleep quality, sleep disorders, physical health, daytime sleepiness, fatigue, and psychological adjustment in three samples: individuals with CFS; a healthy control group; and individuals with a definite medical diagnosis: narcolepsy. Outcome measures included physiological evaluation (polysomnography), medical diagnosis, structured interview, and self-report measures. Results indicate that the CFS sample had a very high incidence (58%) of previously undiagnosed primary sleep disorder such as sleep apnea/hypopnea syndrome and restless legs/periodic limb movement disorder. They also had very high rates of self-reported insomnia and nonrestorative sleep. Narcolepsy and CFS participants were very similar on psychological adjustment: both these groups had more psychological maladjustment than did control group participants. Our data suggest that primary sleep disorders in individuals with CFS are underdiagnosed in primary care settings and that the psychological disturbances seen in CFS may well be the result of living with a chronic illness that is poorly recognized or understood.     

Predicting Medication Use in an Elderly Hypertensive Sample: Revisiting the Established Populations for Epidemiologic Studies of the Elderly Study

Though some research has begun to examine specific factors related to race that should be targeted in the design of interventions to improve medication adherence, there remains an underreporting of factors that contribute to the use of hypertensive medications by race.Methods:This study examined medication use reported by a sample of elderly, controlled and uncontrolled hypertensive patients from the North Carolina Established Populations for the Epidemiologic Studies of the Elderly (NC EPESE) study.Results:In the adjusted final multivariable models of medication use over time in both Caucasian and African-American women, those with higher BMI were more likely to report taking their medication over time; satisfaction with their medical care was predictive among Caucasian women and receiving treatment from a minority physician was predictive among African-American women.Conclusion:Focusing on individual-level characteristics and the different issues that may underlie specific ethnic groups, healthcare provider characteristics in particular may help to develop more precisely targeted interventions to improve a full range of healthcare services that are often needed by elderly hypertensive patients.     

Periodic limb movement disorder of sleep in children

To characterize periodic limb movement disorder (PLMD) in a cohort of prepubertal children we examined sleep-related identifiable differences between children with PLMD and attention-deficit/hyperactivity disorder (ADHD), PLMD alone, and age-matched controls. Children were selected from a chart review of all children referred to a pediatric sleep medicine center and from a community survey of 5-7-year-old-children. Polysomnography (PSG) and parental report data from all children identified as having periodic limb movement index (PLMI) >5 were reviewed and compared with a cohort of age-matched controls. A total of 8.4% of children in the clinic-referred sample, and 11.9% of the children recruited from the community had PLMI >5. Of those, 44.4% were identified as having ADHD. Children with PLMD had significantly lower percentage of rapid eye movement (REM) than control children (P < 0.001). Children in the PLMD/ADHD group had a significantly greater number of arousals associated with PLM (PLMa) than children with PLMD only (P < 0.05). While a relationship between ADHD and PLMD was observed, it was weaker than previous reports (Chervin, R. D. et al. Sleep, 2002; 25: 213; Chervin, R. D. and Archbold, K. H. Sleep, 2001; 24: 313; Picchietti et al. J. Child Neurol., 1999; 13: 588; Picchietti et al. Mov. Disord., 1999; 14: 1000; Picchietti and Walters Sleep, 1999; 22: 297). Children in the PLMD/ADHD group were more likely to have PLMas than were children with PLMD only. We postulate that rather than a direct relationship between ADHD and PLMD, this link may be mediated by the presence of reduced REM sleep and more importantly by the sleep fragmentation associated with PLM-induced arousals.     

Longitudinal Evaluation of Sleep-Disordered Breathing and Sleep Symptoms with Change in Quality of Life: The Sleep Heart Health Study (SHHS)

Study Objectives:

Findings from population studies evaluating the progression and incidence of sleep disordered breathing have shown evidence of a longitudinal increase in the severity of sleep disordered breathing. The present study evaluates the association among changes in sleep disordered breathing, sleep symptoms, and quality of life over time.

Design:

Prospective cohort study. Data were from the Sleep Heart Health Study.

Setting:

Multicenter study.

Participants:

Three thousand seventy-eight subjects aged 40 years and older from the baseline and follow-up examination cycles were included.

Measurements:

The primary outcomes were changes in the Physical Component Summary and Mental Component Summary scales obtained from the Medical Outcomes Study Short-Form Health Survey. The primary exposure was change in the respiratory disturbance index obtained from unattended overnight polysomnograms performed approximately 5 years apart. Other covariates included measures of excessive daytime sleepiness and difficulty initiating and maintaining sleep.

Results:

Mean respiratory disturbance index increased from 8.1 ± 11 SD at baseline to 10.9 ± 14 (P < 0.0001) at follow-up. The mean Physical Component Summary and Mental Component Summary scores were 48.5 and 54.1 at baseline and 46.3 and 54.8 at follow-up. No associations between change in respiratory disturbance index and changes in Physical Component Summary or Mental Component Summary scores were seen. However, worsening of difficulty initiating and maintaining sleep and excessive daytime sleepiness were significantly associated with lower quality of life.

Conclusions:

A slight increase in severity of sleep disordered breathing was seen over 5 years; this was not associated with worsening of quality of life. However, subjective symptoms of quality of sleep and daytime sleepiness were associated with declining quality of life.

Citation:

Silva GE; An MW; Goodwin JL; Shahar E; Redline S; Resnick H; Baldwin CM; Quan SF. Longitudinal evaluation of sleep-disordered breathing and sleep symptoms with change in quality of life: the Sleep Heart Health Study (SHHS). SLEEP 2009;32(8):1049-1057.     

孤独症儿童睡眠障碍对照研究

目的比较孤独症儿童与正常儿童睡眠障碍发生情况。方法对140例确诊的孤独症儿童和82例正常儿童,用自编睡眠及一般情况问卷进行调查。结果在140名孤独症儿童中,共有102名儿童目前或既往存在睡眠障碍,其中,男孩85人,女孩17人,孤独症儿童睡眠障碍的终生患病率为72.86%,男孩终生患病率(72.03%)和女孩终生患病率(77.27%)差异无统计学意义(χ2=1.912,P=0.384)。在82名正常儿童中,共有14名儿童目前或既往存在睡眠障碍,其中,男孩10人,女孩4人,正常儿童睡眠障碍的终生患病率为17.07%,男孩终生患病率(16.67%)和女孩终生患病率(18.19%)差异无统计学意义(χ2=0.080,P=0.117)。孤独症儿童的睡眠障碍发病率明显高于正常儿童,差异无统计学意义(χ2=32.407,P=0.000)。结论孤独症儿童睡眠障碍发生多于正常儿童,睡眠障碍是孤独症儿童主要症状之一。     

The neuroscience of human relationships: Attachment and the developing social brain

This article explores the background of Elsa Gindler, in the early part of the twentieth century in Berlin, and whom she influenced in the 1930s and later, both in body psychotherapy and in other disciplines. It particularly explores the connection with Wilhelm Reich and Gindler's indirect influence on the development of his Vegetotherapy.     

Sleep disordered breathing in pregnancy: A review of the pathophysiology of adverse pregnancy outcomes

Sleep disordered breathing (SDB) is a common obesity‐related co‐morbidity with strong associations to cardiometabolic disease. The risk of SDB is increased during pregnancy, particularly among obese pregnant women. Accumulating evidence suggests that an association exists between maternal SDB and the development of adverse pregnancy outcomes, particularly gestational diabetes and hypertensive disorders of pregnancy. Intermittent hypoxia, a central characteristic of SDB, has been shown in animal and clinical studies to dysregulate several biological pathways. This includes the promotion of oxidative stress, increased inflammation, activation of the hypothalamic‐pituitary‐adrenal axis, increased sympathetic activity and impaired glucose and insulin metabolism. This review considers how, during pregnancy, these pathophysiological processes are plausible mechanisms through which SDB may contribute to an increased risk of adverse outcomes, for the mother and perhaps also the offspring. However, a lack of robust evidence specific to the pregnant population, including limited evaluation of the placental function in affected pregnancies, limits our ability to draw definite conclusions on mechanisms contributing to adverse pregnancy outcomes and, indeed, the strength of association between SDB and certain pregnancy complications.     

The Risk of Osteoporotic Fractures According to the FRAX Model in Korean Patients with Rheumatoid Arthritis

The aim of the current study is to identify patients without osteoporosis who met the criteria of the fracture risk assessment tool (FRAX) of the National Osteoporosis Foundation (NOF) only. The incidence of fractures was investigated in patients who met only the FRAX criteria of the NOF and patients who presented osteoporosis. Five hundred and forty five patients with rheumatoid arthritis who visited a single center were recruited in Korea. In the follow-up period of median 30 months, the new onset of fractures was investigated. Of 223 patients who have no osteoporosis, 39 (17.4%) satisfied the FRAX criteria for pharmacological intervention. During the follow-up period, 2 new onset fractures occurred in patients who met only the FRAX criteria and 22 new onset fractures did in patients with osteoporosis by bone mineral density. The incidence rate for new onset fractures of patients who met only the FRAX criteria was with 295.93 per 10,000 person-years higher than in the general population with 114.99 per 10,000 person-years. Patients who met the FRAX criteria of the NOF only need pharmacological intervention because their numbers of incidence for new onset fractures are similar to those of patients with osteoporosis by BMD.

Graphical Abstract

相似文献   

Population-based Analysis for Risk of Suicide Death in Elderly Patients after Osteoporotic Fracture: a Nested Case-Control Study

BackgroundThe purpose of study was to investigate the incidence rate of suicide in elderly patients with osteoporotic fractures in a nested case-control model and to analyze the change in the risk of suicide death over time after each osteoporotic fracture.MethodsWe used the National Health Insurance Service-Senior cohort of South Korea. Suicide cases and controls were matched based on sex and age at the index date. Controls were randomly selected at a 1:5 ratio from the set of individuals who were at risk of becoming a case at the time when suicide cases were selected. Conditional logistic regression analysis was performed to evaluate the association between each type of osteoporotic fracture and the risk of suicide death.ResultsThree thousand seventy suicide cases and 15,350 controls were identified. Patients with hip fracture showed an increased risk of suicide death within 1 year of fracture (adjusted odds ratio [aOR] = 2.64; 95% confidence interval [CI], 1.57–4.46; P < 0.001) compared to controls. However, the increased risk of suicide death in patients with hip fracture lasted up to 2 years (aOR = 1.59; 95% CI, 1.04–2.41; P = 0.031). Spine fracture increased the risk of suicide deaths for all observation periods. There was no evidence that humerus fracture increased the risk of suicide death during the observational period. Radius fracture increased only the risk of suicide death within 2 years of fracture (aOR = 1.43; 95% CI, 0.74–2.77; P = 0.282).ConclusionThere were noticeable differences in both degree and duration of increased suicide risks depending on the type of osteoporotic fracture. Mental stress and suicide risk in elderly patients after osteoporotic fracture should be assessed differently depending on the types of fracture.     

Sleepiness is not the inverse of alertness: evidence from four sleep disorder patient groups

The constructs “sleepiness” and “alertness” are often assumed to be reciprocal states of consciousness. This distinction is of increasing concern in relation to psychomotor performance tasks such as driving. We developed two separate subjective scales of alertness to complement existing sleepiness scales. Subjective sleepiness and alertness were compared in four groups of sleep-disordered patients. In a 175-patient cohort [25 narcoleptics and 50 each with sleep apnea, insomnia and periodic leg movement disorder (PLMD)], the Epworth Sleepiness Scale (ESS) was used to measure sleepiness while the Toronto Hospital Alertness Test (THAT) and ZOGIM Alertness Scale (ZOGIM-A) were used to measure alertness. Significant differences existed for sleepiness scores, with narcoleptics scoring highest on the ESS, followed by sleep apnea, with similar ESS scores for insomnia and PLMD. By contrast, alertness scores on both the THAT and ZOGIM-A did not differ significantly between the four groups. Sleepiness scores show a correlation of close to nil to alertness scores for the combined sleep disorder patient cohort, with the exception of insomnia patients, where a modest but significant inverse relationship was noted between sleepiness and alertness. Subjective states of impaired alertness and excessive sleepiness are independent constructs in the evaluation of sleep-disordered patients. The specific primary sleep disorder diagnosis may play a relevant role in mitigating this interrelationship.     

Sleep architecture as correlate and predictor of symptoms and impairment in inter‐episode bipolar disorder: taking on the challenge of medication effects

This study was designed to clarify the association between inter‐episode bipolar disorder (BD) and sleep architecture. Participants completed a baseline symptom and sleep assessment and, 3 months later, an assessment of symptoms and impairment. The effects of psychiatric medications on sleep architecture were also considered. Participants included 22 adults with BD I or II (inter‐episode) and 22 non‐psychiatric controls. The sleep assessment was conducted at the Sleep and Psychological Disorders Laboratory at the University of California, Berkeley. Follow‐up assessments 3 months later were conducted over the phone. Results indicate that, at the sleep assessment, BD participants exhibited greater rapid eye movement sleep (REM) density than control participants with no other group differences in sleep architecture. Sleep architecture was not correlated with concurrent mood symptoms in either group. In the BD group, duration of the first REM period and slow‐wave sleep (SWS) amount were positively correlated with manic symptoms and impairment at 3 months, while REM density was positively correlated with depressive symptoms and impairment at 3 months. The amount of Stage 2 sleep was negatively correlated with manic symptoms and impairment at 3 months. In contrast, for the control group, REM density was negatively correlated with impairment at 3 months. SWS and Stage 2 sleep were not correlated with symptoms or impairment. Study findings suggest that inter‐episode REM sleep, SWS and Stage 2 sleep are correlated with future manic and depressive symptoms and impairment in BD. This is consistent with the proposition that sleep architecture may be a mechanism of illness maintenance in BD.     

单侧入路后凸成形术治疗胸腰椎压缩骨折47例

目的分析总结经单侧入路椎体后凸成形术(percutaneous kyphoplasty PKP)治疗骨质疏松性椎体压缩骨折的临床疗效及安全性。方法回顾分析自2011年6月~2013年5月,成都体育学院附属体育医院经单侧入路PKP术治疗并获得不少于1年随访的47例共60椎体骨质疏松性椎体压缩骨折病例,经术前、术后1天、术后1月、12月的定期随访,观察患者手术前后VAS评分变化、椎体平均高度、局部Cobb角改善及近远期并发症的发生情况。结果所有患者均顺利完成手术,手术时间(57±26)min,骨水泥注入量(2.9±1.4)ml,术前术后1天、术后1月、12月时VAS评分均较术前明显降低(P0.05),术后椎体平均高度及局部Cobb角较术前均有显著恢复(P0.05),骨水泥渗漏至椎体前方2例,椎间隙5例,无一例进入椎管内,术后一例患者出现右侧股静脉血栓,经过溶栓抗凝治疗12天后右侧股静脉血栓消失,无1例患者出现肺栓塞。结论经单侧椎弓根途径穿刺骨水泥过椎体中线注射治疗骨质疏松性椎体压缩骨折可取得满意的临床效果,且具有手术时间短、放射暴露次数少等优点。     

Predicting incident dementia and mild cognitive impairment in older women with nonparametric analysis of circadian activity rhythms in the Study of Osteoporotic Fractures

Study ObjectivesDisrupted daily rhythms are associated with mild cognitive impairment (MCI) and dementia. The specific nature of how rhythms and cognition are related, however, is unknown. We hypothesized characteristics from a nonparametric estimate of circadian rest-activity rhythm patterns would be associated to the development of MCI or dementia.MethodsWrist actigraphy from 1232 cognitively healthy, community-dwelling women (mean age 82.6 years) from the Study of Osteoporotic Fractures was used to estimate rest-activity patterns, including intradaily variability (IV), interdaily stability (IS), most active 10-hour period (M10), least active 5-hour period (L5), and relative amplitude (RA). Logistic regression examined associations of these predictors with 5-year incidence of MCI or dementia. Models were adjusted for potential confounders.ResultsWomen with earlier sleep/wake times had higher risk of dementia, but not MCI, (early vs. average L5 midpoint: OR, 1.66; 95% CI, 1.08–2.55) as did women with smaller day/night activity differentials (low vs. high RA: OR, 1.96; 95% CI, 1.14–3.35). IV, IS, and M10 were not associated with MCI or dementia.ConclusionThe timing and difference in day/night amplitude, but not variability of activity, may be useful as predictors of dementia.     

Review of the Relationship of Restless Legs Syndrome and Periodic Limb Movements in Sleep to Hypertension,Heart Disease,and Stroke

Evidence is reviewed documenting an intimate relationship among restless legs syndrome (RLS) / periodic limb movements in sleep (PLMS) and hypertension and cardiovascular and cerebrovascular disease. Sympathetic overactivity is associated with RLS/PLMS, as manifested by increased pulse rate and blood pressure coincident with PLMS. Causality is far from definitive. Mechanisms are explored as to how RLS/PLMS may lead to high blood pressure, heart disease, and stroke: (a) the sympathetic hyperactivity associated with RLS/PLMS may lead to daytime hypertension that in turn leads to heart disease and stroke; (b) in the absence of daytime hypertension, this sympathetic hyperactivity may predispose to heart disease and stroke either directly or indirectly via atherosclerotic plaque formation and rupture; and (c) comorbidities associated with RLS/PLMS, such as renal failure, diabetes, iron deficiency, and insomnia, may predispose to heart disease and stroke. One theoretical cause for sympathetic hyperactivity is insufficient A11 diencephalospinal dopaminergic neuron inhibition of sympathetic preganglionic neurons residing in the intermediolateral cell columns of the spinal cord. We cannot exclude the possibility that peripheral vascular, cardiovascular, and cerebrovascular disease may also contribute to RLS/PLMS, and mechanisms for these possibilities are also discussed.

Citation:

Walters AS; Rye DB. Review of the relationship of restless legs syndrome and periodic limb movements in sleep to hypertension, heart disease, and stroke. SLEEP 2009;32(5):589-597.