A community-based study of risk factors for probable rapid eye movement sleep behavior disorder

ObjectivesTo cross-sectionally explore the potential risk factors for rapid eye movement (REM) sleep behavior disorder (RBD) in a community cohort in Shanghai.MethodsBased on the validated RBD screening questionnaire (RBDSQ), we identified individuals with probable RBD (pRBD) in 3635 community-dwelling residents (≥50 years old) from an urban community of Shanghai. Potential risk factors of pRBD, including age, sex, smoking, socioeconomic status, obesity, consumption of tea (surrogate for caffeine intake) and alcohol, medications and chronic disease status, were assessed via questionnaire. We used logistic regression to investigate the associations between these studied factors and pRBD after adjusting for age, sex and other studied factors.ResultsBased on the RBDSQ score ≥5, 2.70% (3.28% in men and 2.41% in women) participants were considered as pRBD. We found that lower education, presence of head injury, atrial fibrillation, hyperlipidemia, constipation, olfactory disturbance, and imbalance, use of alcoholic beverage, selective serotonin reuptake inhibitor, and benzodiazepine were associated with higher likelihood of having pRBD (P < 0.05 for all). In contrast, male sex, use of coffee or tea, smoking and other factors were not significantly association with altered risk of having pRBD. We did not find significant interaction between sex, age and these factors, in relation to pRBD risk.ConclusionsIn this community-based study of older adults, we identified several potential risk factors for concurrent pRBD, including environmental factors and vascular risk factors.     

Comparison between an automatic and a visual scoring method of the chin muscle tone during rapid eye movement sleep

ObjectiveTo compare two different methods, one visual and the other automatic, for the quantification of rapid eye movement (REM) sleep without atonia (RSWA) in the diagnosis of REM sleep behavior disorder (RBD).MethodsSeventy-four RBD patients (mean age, 62.14 ± 9.67 years) and 75 normal controls (mean age, 61.04 ± 12.13 years) underwent one night video-polysomnographic recording. The chin electromyogram (EMG) during REM sleep was analyzed by means of a previously published visual method quantifying the percentage of 30 s epochs scored as tonic (abnormal, ⩾30%) and that of 2 s mini-epochs containing phasic EMG events (abnormal, ⩾15%). For the computer quantitative analysis we used the automatic scoring algorithm known as the atonia index (abnormal, <0.8). The percentage correct classification, sensitivity, specificity, and Cohen kappa were calculated.ResultsThe atonia index correctly classified 82.6% of subjects, similar to the percentage of correct classifications with individual components of the visual analysis (83.2% each for tonic and phasic), and the combined visual parameters (85.9%). The sensitivity and specificity of automatic analysis (84% and 81%) was similar to the combined visual analysis (89% and 83%). The correlation coefficient between the automatic atonia index and the percentage of visual tonic EMG was high (r = −0.886, P < 0.00001), with moderately high correlation with the percentage of phasic EMG (r = −0.690, P < 0.00001). The agreement between atonia index and the visual parameters (individual or combined) was approximately 85% with Cohen’s kappa, ranging from 0.638 to 0.693.ConclusionSensitivity, specificity, and correct classifications were high with both methods. Moreover, there was general agreement between methods, with Cohen’s kappa values in the ‘good’ range. Given the considerable practical advantages of automatic quantification of REM atonia, automatic quantification may be a useful alternative to visual scoring methods in otherwise uncomplicated polysomnograms.     

Investigating rapid eye movement sleep without atonia in Parkinson's disease using the rapid eye movement sleep behavior disorder screening questionnaire

Rapid eye movement (REM) sleep behavior disorder (RBD) is frequently observed in patients with Parkinson's disease (PD). Accurate diagnosis is essential for managing this condition. Furthermore, the emergence of idiopathic RBD in later life can represent a premotor feature, heralding the development of PD. Reliable, accurate methods for identifying RBD may offer a window for early intervention. This study sought to identify whether the RBD screening questionnaire (RBDSQ) and three questionnaires focused on dream enactment were able to correctly identify patients with REM without atonia (RWA), the neurophysiological hallmark of RBD. Forty‐six patients with PD underwent neurological and sleep assessment in addition to completing the RBDSQ, the RBD single question (RBD1Q), and the Mayo Sleep Questionnaire (MSQ). The REM atonia index was derived for all participants as an objective measure of RWA. Patients identified to be RBD positive on the RBDSQ did not show increased RWA on polysomnography (80% sensitivity and 55% specificity). However, patients positive for RBD on questionnaires specific to dream enactment correctly identified higher degrees of RWA and improved the diagnostic accuracy of these questionnaires. This study suggests that the RBDSQ does not accurately identify RWA, essential for diagnosing RBD in PD. Furthermore, the results suggest that self‐report measures of RBD need to focus questions on dream enactment behavior to better identify RWA and RBD. Further studies are needed to develop accurate determination and quantification of RWA in RBD to improve management of patients with PD in the future. © 2014 International Parkinson and Movement Disorder Society     

Disturbance of rapid eye movement sleep in spinocerebellar ataxia type 2.

Five genetically confirmed spinocerebellar ataxia type 2 (SCA2) patients were admitted to our sleep laboratory for two all-night video-polysomnographies. A standard montage was used, including electroencephalography, vertical and horizontal electrooculography, electromyography of mental, submental, and tibialis anterior muscles, and respiratory monitoring. Four of five SCA2 patients had insufficient muscle atonia during rapid eye movement (REM) sleep. All patients exhibited myoclonic jerks during REM sleep, while elaborated behavior was not observed in the video. Abnormal motor control during sleep with periodic leg movements and REM sleep without atonia occurs frequently in SCA2. This finding may reflect a dysfunction of dopaminergic and/or brainstem and cerebellar outflow pathways.     

发作性睡病36例临床分析

目的探讨发作性睡病的临床特征、诊断、治疗及预后。方法对36例发作性睡病患者进行睡眠脑电图监测,结合临床表现进行诊断,采用哌醋甲酯、氯酯醒、氯丙米嗪治疗,并进行随访。结果36例患者均有过度或发作性的不可抑制的白天睡眠,30例有夜间睡眠紊乱,25例伴猝倒,9例伴睡眠瘫痪,10例出现睡眠幻觉。睡眠脑电图监测显示36例患者平均睡眠潜伏期<5 min,有2次或2次以上直接进入快速眼动相睡眠。随访29例,其中20例采用哌醋甲酯治疗,17例白天过度睡眠得到改善;8例采用氯酯醒或合并氯丙米嗪治疗,5例症状改善;大多数患者出现不同程度的心理和学习问题。结论发作性睡病是慢性神经系统疾病,应根据其典型的临床表现及睡眠脑电监测结果作出早期诊断,对患者应给予长期的药物治疗、心理治疗和教育,以提高患者的生活质量。     

A case series and systematic review of rapid eye movement sleep behavior disorder outcome after deep brain stimulation in Parkinson's disease

REM-sleep behavior disorder (RBD) is a parasomnia and a common sleep disorder in Parkinson's disease (PD). While deep brain stimulation (DBS) is an established treatment for advanced PD with beneficial effects on cardinal PD motor symptoms, the data on the impact of DBS on RBD are limited and often controversial.We reviewed published articles that reported on RBD in the context of DBS surgery via systematic PubMed search. We identified 75 studies and included 12 studies, involving a total of 320 subjects, in our review. Results in respect to EMG activity outcome after subthalamic stimulation are inconsistent. We found no study that reported on RBD outcome after pallidal DBS and no DBS study quantified complex behavior during REM sleep.We also added data on RBD outcome after subthalamic (N = 4 patients) or pallidal (N = 3 patients) DBS from patients with PD with RBD, obtained as part of a prospective DBS study in our centre. Our case series showed an increase of complex behavior during REM (CB-REM) after surgery, independent of DBS target. Conversely, we found a trend towards increasing REM sleep without atonia (RSWA) in subthalamic-stimulated patients and a trend towards decreased RSWA in pallidal stimulated patients.We conclude that CB-REM and RSWA might represent two distinct elements in RBD and should be assessed separately, especially in studies that report on RBD outcome after treatment interventions. Further, larger, prospective, controlled studies in different DBS targets, reporting separately on the different RBD modalities, are needed.     

Decreased phasic EMG activity during rapid eye movement sleep in treatment‐naïve Parkinson's disease: Effects of treatment with levodopa and progression of illness

Rapid eye movement (REM) sleep behavior disorder (RBD) is frequently associated with Parkinson's disease (PD) and may anticipate its diagnosis by several years. We assessed the presence of motor dyscontrol during REM sleep in treatment‐naïve PD patients and investigated the putative effect of levodopa (L ‐dopa) treatment on motor activity. Overnight sleep studies were performed on 15 previously untreated PD patients and 14 controls at baseline, again after a 3‐ to 9‐month treatment period with a low dose of L ‐dopa, and 2 to 5 days after treatment discontinuation (in 8 patients). No differences in sleep parameters were observed across groups or treatment conditions. None of the patients met criteria for RBD at baseline, whereas 5 patients were symptomatic at the time of the second sleep study. A quantitative analysis of electromyographic (EMG) activity during REM sleep showed a lower phasic twitching activity in untreated PD than in controls. However, an increase in both phasic twitching and tonic activity was found after treatment with L ‐dopa. Discontinuation of treatment resulted in a return to pretreatment values of phasic but not of tonic EMG activity. Thus, the increase in phasic activity seems to depend on the effects of L ‐dopa, whereas the increase in tonic EMG activity during REM sleep might be caused by other factors such as the progression of disease. Potential implications for the understanding of the relationship between RBD and PD are discussed. © 2002 Movement Disorder Society     

早期帕金森病患者快速眼动睡眠期行为障碍研究

目的探讨早期帕金森病患者快速眼动睡眠期行为障碍发生情况,以及帕金森病运动症状、非运动症状和快速眼动睡眠期行为障碍特点。方法共60例原发性帕金森病患者,采用统一帕金森病评价量表第二和第三部分(UPDRSⅡ和UPDRSⅢ)以及Hoehn-Yahr分期评价帕金森病非运动症状和运动症状,蒙特利尔认知评价量表评价认知功能,汉密尔顿焦虑量表和汉密尔顿抑郁量表评价焦虑和抑郁症状;中文版快速眼动睡眠期行为障碍筛查量表判断是否伴快速眼动睡眠期行为障碍,Epworth嗜睡量表(ESS)评价白天过度嗜睡程度;多导睡眠图监测睡眠障碍特征,包括下颌位相性肌电活动密度和快速眼动睡眠期肌肉失弛缓。结果 60例帕金森病患者中42例(70%)伴快速眼动睡眠期行为障碍(PD+RBD组),多导睡眠图监测其异常行为主要表现为上肢伸展抓握、肢体震颤抽搐、发笑、喊叫和怒骂等非暴力动作,仅2例出现暴力击打、蹬踢等异常行为。PD+RBD组患者年龄(P=0.024)、病程8年比例(P=0.000)、UPDRSⅡ(P=0.005)和UPDRSⅢ(P=0.001)评分、Hoehn-Yahr分期2级比例(P=0.007)、焦虑障碍(P=0.044)和抑郁障碍(P=0.001)比例,以及下颌位相性肌电活动密度(P=0.000)和快速眼动睡眠期肌肉失弛缓比例(P=0.000)均高于对照组,其中,PD+RBD组有16例(38.10%)快速眼动睡眠期行为障碍症状早于帕金森样症状5.20(3.91,6.51)年。结论年龄大、病程长、运动症状和非运动症状严重的帕金森病患者易伴发快速眼动睡眠期行为障碍,快速眼动睡眠期行为障碍可能是帕金森病的早期表现。多导睡眠图监测对早期帕金森病伴快速眼动睡眠期行为障碍的诊断有重要参考价值。     

Impulse control disorder and rapid eye movement sleep behavior disorder in Parkinson's disease

IntroductionThe relationship between ICD and RBD is still not yet understood and the results from the current literature are contradictory in PD. We aimed to explore the association between rapid eye movement (REM) sleep behavior disorder (RBD) and impulse control disorder in Parkinson's disease.MethodsNinety-eight non-demented patients with Parkinson's disease underwent one night of video-polysomnography recording. The diagnosis of RBD was established according to clinical and polysomnographic criteria. Impulse control disorders were determined by a gold standard, semi-structured diagnostic interview.ResultsHalf of the patients (n = 49) reported clinical history of RBD while polysomnographic diagnosis of RBD was confirmed in 31.6% of the patients (n = 31). At least one impulse control disorder was identified in 21.4% of patients, 22.6% with RBD and 20.9% without. Logistic regression controlling for potential confounders indicated that both clinical RBD (OR = 0.34, 95% CI = 0.07–1.48, P = 0.15) and polysomnographic confirmed RBD diagnoses (OR = 0.1.28, 95% CI = 0.31–5.33, P = 0.34) were not associated with impulse control disorder.ConclusionIn Parkinson's disease, REM Sleep Behavior Disorder is not associated with impulse control disorder. The results of our study do not support the notion that PSG-confirmed RBD and ICD share a common pathophysiology.     

Surface EMG activity during REM sleep in Parkinson's disease correlates with disease severity

ObjectivesOver 40% of individuals with Parkinson's disease (PD) have rapid eye movement sleep behavior disorder (RBD). This is associated with excessive sustained (tonic) or intermittent (phasic) muscle activity instead of the muscle atonia normally seen during REM sleep. We examined characteristics of manually-quantitated surface EMG activity in PD to ascertain whether the extent of muscle activity during REM sleep is associated with specific clinical features and measures of disease severity.MethodsIn a convenience sample of outpatients with idiopathic PD, REM sleep behavior disorder was diagnosed based on clinical history and polysomnogram, and severity was measured using the RBD sleep questionnaire. Surface EMG activity in the mentalis, extensor muscle group of the forearms, and anterior tibialis was manually quantitated. Percentage of REM time with excessive tonic or phasic muscle activity was calculated and compared across PD and RBD characteristics.ResultsAmong 65 patients, 31 had confirmed RBD. In univariate analyses, higher amounts of surface EMG activity were associated with longer PD disease duration (srho = 0.34; p = 0.006) and greater disease severity (p < 0.001). In a multivariate regression model, surface EMG activity was significantly associated with RBD severity (p < 0.001) after adjustment for age, PD disease duration, PD severity and co-morbid sleep abnormalities.ConclusionSurface EMG activity during REM sleep was associated with severity of both PD and RBD. This measure may be useful as a PD biomarker and, if confirmed, may aid in determining which PD patients warrant treatment for their dream enactment to reduce risk of injury.     

Semantic priming effect during REM-sleep inertia in patients with narcolepsy

Patients with narcolepsy-cataplexy (NC) present excessive daytime sleepiness (EDS), cataplexy and an altered architecture of nocturnal sleep, with frequent episodes of REM-sleep at sleep onset (SOREM-sleep). This altered organization of nocturnal sleep may be accompanied by some differences in the functioning of the cognitive processes involved in the access, organization and consolidation of information during sleep. This study attempts to ascertain whether the activation of semantic memory during REM-sleep, as measured using a technique of semantic priming (namely, the facilitation of the activation of strongly-related rather than weakly-related and, overall, unrelated pairs of prime-target words) is different in NC patients compared to normal subjects. A lexical decision task (LDT) was carried out twice in wakefulness (at 10a.m. and after a 24h interval) and twice in the period of sleep inertia following awakening from SOREM and 4th-cycle REM-sleep on 12 NC patients and from 1st- and 4th-cycle REM-sleep on 12 matched controls. Reaction time (RT) to target words, taken as a measure of the semantic priming effect, proved to be longer (a) in NC patients than in control subjects; (b) in the period of REM-sleep inertia than in wakefulness; (c) in the first rather than the second session; and (d) for unrelated compared to weakly-related and, overall, strongly-related prime-target pairs. RT in post-REM-sleep sessions was less impaired, compared to waking sessions, and less dependent on the associative strength of prime-target pairs in NC patients than in normal subjects. Finally, RT of NC patients, although longer than that of normal subjects in waking sessions, significantly improved in the second session, as a consequence of either the amount of exercise or the consolidation advantage provided by REM-sleep for the procedural components of the task. The whole picture suggests a greater effectiveness of the activation of semantic memory during (SO)REM-sleep in NC patients rather than in normal subjects, and overall for the organization of new and unexpected relationships (such as those between unrelated pairs) between items of information.     

帕金森病合并快速眼球运动睡眠行为障碍患者的客观睡眠结构及认知功能

目的 评价帕金森病合并快速眼球运动睡眠行为障碍(RBD)患者的睡眠结构及认知功能,并探讨其睡眠结构与认知功能之间的相关性.方法 本研究为横断面研究,以在我院睡眠中心进行睡眠监测的39例帕金森病合并RBD患者作为病例组,并以年龄、性别相匹配的21例原发性快速眼球运动睡眠行为障碍(iRBD)患者及37例不合并RBD的帕金森病患者作为对照组.所有患者均行整夜睡眠监测以定量睡眠相关参数,并且于监测当天使用蒙特利尔(MoCA)评估量表评估其认知功能.采用多重线性回归分析量表得分与睡眠结构之间的相关性.结果 (1)帕金森病合并RBD患者的睡眠效率(60.9％±16.9％)、总睡眠时间[(329.7±96.5)min]、非快速眼动睡眠2期时间[(127.6±67.6) min]及快速眼动睡眠期时间[(45.3 ±33.2) min]较iRBD组的相应值[77.8％±16.9％以及(397.1 ±88.9)、(188.0±94.7)、(70.6 ±25.9) min]比较明显减少(均P＜0.05),较不合并RBD的PD组的相应值[61.3％±21.7％以及(324.9 ±134.6)、(132.6 ±65.6)、(47.1±31.9)min]减少,但差异均无统计学意义.3组的睡眠潜伏期、快速眼球运动睡眠潜伏期、非快速眼球运动睡眠1期,慢波睡眠比例、氧减指数、呼吸暂停低通气指数及周期性肢体运动指数比较差异均无统计学意义.(2)帕金森病合并RBD患者认知功能最差,其中视空间与执行功能得分[(3.8±1.1)分]较iRBD组[(4.4±0.7)分]比较差异有统计学意义(F=3.426,P＜0.05).(3)多重线性回归显示帕金森病合并RBD患者的RBD病程、睡眠效率和非快速眼动睡眠2期与视空间与执行功能得分有相关性.结论 帕金森病合并RBD患者的睡眠效率、总睡眠、非快速眼动睡眠2期及快速眼动睡眠期时间和认知功能均明显下降,认知功能的改变与睡眠结构的变化可能存在相关性.     

First rapid eye movement sleep periods and sleep-onset rapid eye movement periods in sleep-stage sequencing of hypersomnias

ObjectivesDiscrimination between narcolepsy, idiopathic hypersomnia, and behavior-induced inadequate sleep syndrome (BIISS) is based on clinical features and on specific nocturnal polysomnography (NPSG) and multiple sleep latency test (MSLT) results. However, previous studies have cast doubt on the specificity and sensitivity of these diagnostic tools.MethodsEleven variables of the NPSG were analyzed in 101 patients who were retrospectively diagnosed with narcolepsy with cataplexy (N + C) (n = 24), narcolepsy without cataplexy (N−C) (n = 38), idiopathic hypersomnia with long sleep period (IHL) (n = 21), and BIISS (n = 18).ResultsFifteen out of 24 N + C and 8 out of 38 N−C entered the first rapid eye movement (REM) sleep period (FREMP) from sleep stage 1 (N1) or wake (W), though this sleep-stage sequence did not arise in the other patient groups. FREMP stage sequence was a function of REM sleep latency (REML) for both N + C and N−C groups. FREMP stage sequence was not associated with mean sleep latency (MSL) in N + C but was associated in N−C, which implies heterogeneity within the N−C group. REML also was a useful discriminator. Depending on the cutoff period, REML had a sensitivity and specificity of up to 85.5% and 97.4%, respectively.ConclusionsThe FREMP stage sequence may be a useful tool in the diagnosis of narcolepsy, particularly in conjunction with sleep-stage sequence analysis of sleep-onset REM periods (SOREMPs) in the MSLT; it also may provide a helpful intermediate phenotype in the clarification of heterogeneity in the N−C diagnostic group. However, larger prospective studies are necessary to confirm these findings.     

Difference in severity of sleep apnea in patients with rapid eye movement sleep behavior disorder with or without parkinsonism

ObjectiveRapid eye movement sleep behavior disorder (RBD) is a common sleep disturbance in patients with neurodegenerative disorders. We aimed to compare sleep parameters among the different types of RBD patients.MethodsA total of 122 patients with dream enactment behavior were screened. Of these, 92 patients who were diagnosed with RBD by polysomnography were included in this study. Enrolled patients with RBD were classified into four groups based on the following diagnoses: idiopathic RBD (iRBD); RBD with Parkinson disease (PD-RBD); multiple system atrophy (MSA) with RBD (MSA-RBD); and dementia with Lewy bodies (DLB) with RBD (DLB-RBD). Various clinical and polysomnographic parameters were compared.ResultsAmong the 92 patients with RBD, 35 had iRBD, 25 had PD-RBD, 17 had MSA-RBD, and 15 had DLB-RBD. The mean apnea−hypopnea index of atypical parkinsonism with RBD (AP-RBD) group was 16.2 ± 17.7 events/h (MSA-RBD, 14.0 ± 16.6; DLB-RBD, 18.8 ± 19.1), which was significantly higher than the other groups (p < 0.05). The proportion of patients with 100% supine sleep in the AP-RBD group (44%) was higher than that in the iRBD group (14%; p = 0.030). The proportion of OSA with 100% supine sleep position was significantly higher in the MSA-RBD and DLB-RBD groups than in the iRBD group (p = 0.042 and p = 0.029, respectively).ConclusionOur study demonstrated that patients in the MSA-RBD and DLB-RBD groups had a tendency to sleeping in the supine position and a higher vulnerability to OSA compared to other RBD groups. Further cohort studies are needed to evaluate the influence of these factors on the development of parkinsonism.     

Structural and functional brain alterations in patients with idiopathic rapid eye movement sleep behavior disorder

ObjectiveTo investigate structural and functional alterations in patients with idiopathic rapid eye movement (REM) sleep behavior disorder (iRBD) compared with healthy controls.MethodsTwenty-seven patients with polysomnography-confirmed iRBD and 33 healthy subjects were recruited. All subjects underwent a 3-tesla structural and resting-state functional magnetic resonance imaging (fMRI) examination. Voxel-based morphometry (VBM) analysis was performed to assess grey matter alterations between groups. The amplitude of low-frequency fluctuations (ALFF) was calculated and then compared to measure differences in spontaneous brain activity. Correlations were performed to explore associations between imaging metrics and clinical characteristics in iRBD patients.ResultsCompared with healthy controls, patients with iRBD had decreased grey matter volume in the frontal, temporal, parietal, occipital cortices as well as increased grey matter volume in cerebellum posterior lobe, putamen, and thalamus. Patients with iRBD also exhibited increased ALFF values in the right parahippocampal gyrus. Olfaction correlated with ALFF value changes in occipital cortices.ConclusionsPatients with iRBD had widespread decreases of grey matter volume. Increases of grey matter volume in cerebellum, putamen, and thalamus may suggest a compensatory effect, while the altered ALFF values in parahippocampal gyrus and occipital cortices may play a role in the underlying process of neurodegeneration in this disorder.