Enhanced conductive body heat loss during sleep increases slow-wave sleep and calms the heart.

Substantial evidence suggests that the circadian decline of core body temperature (CBT) triggers the initiation of human sleep, with CBT continuing to decrease during sleep. Although the connection between habitual sleep and CBT patterns is established, the impact of external body cooling on sleep remains poorly understood. The main aim of the present study is to show whether a decline in body temperatures during sleep can be related to an increase in slow wave sleep (N3). This three-center study on 72 individuals of varying age, sex, and BMI used an identical type of a high-heat capacity mattress as a reproducible, non-disturbing way of body cooling, accompanied by measurements of CBT and proximal back skin temperatures, heart rate and sleep (polysomnography). The main findings were an increase in nocturnal sleep stage N3 (7.5 ± 21.6 min/7.5 h, mean ± SD; p = 0.0038) and a decrease in heart rate (- 2.36 ± 1.08 bpm, mean ± SD; p < 0.0001); sleep stage REM did not change (p = 0.3564). Subjects with a greater degree of body cooling exhibited a significant increase in nocturnal N3 and a decrease in REM sleep, mainly in the second part of the night. In addition, these subjects showed a phase advance in the NREM-REM sleep cycle distribution of N3 and REM. Both effects were significantly associated with increased conductive inner heat transfer, indicated by an increased CBT- proximal back skin temperature -gradient, rather than with changes in CBT itself. Our findings reveal a previously far disregarded mechanism in sleep research that has potential therapeutic implications: Conductive body cooling during sleep is a reliable method for promoting N3 and reducing heart rate.

Sleep and sleep disorders during pregnancy and postpartum: The Life-ON study.

OBJECTIVE: to prospectively assess sleep and sleep disorders during pregnancy and postpartum in a large cohort of women. METHODS: multicenter prospective Life-ON study, recruiting consecutive pregnant women at a gestational age between 10 and 15 weeks, from the local gynecological departments. The study included home polysomnography performed between the 23rd and 25th week of pregnancy and sleep-related questionnaires at 9 points in time during pregnancy and 6 months postpartum. RESULTS: 439 pregnant women (mean age 33.7 ± 4.2 yrs) were enrolled. Poor quality of sleep was reported by 34% of women in the first trimester of pregnancy, by 46% of women in the third trimester, and by as many as 71% of women in the first month after delivery. A similar trend was seen for insomnia. Excessive daytime sleepiness peaked in the first trimester (30% of women), and decreased in the third trimester, to 22% of women. Prevalence of restless legs syndrome was 25%, with a peak in the third trimester of pregnancy. Polysomnographic data, available for 353 women, revealed that 24% of women slept less than 6 h, and 30.6% of women had a sleep efficiency below 80%. Sleep-disordered breathing (RDI≥5) had a prevalence of 4.2% and correlated positively with BMI. CONCLUSIONS: The Life-ON study provides the largest polysomnographic dataset coupled with longitudinal subjective assessments of sleep quality in pregnant women to date. Sleep disorders are highly frequent and distributed differently during pregnancy and postpartum. Routine assessment of sleep disturbances in the perinatal period is necessary to improve early detection and clinical management.

Optimal risk and diagnosis assessment strategies in perinatal depression: A machine learning approach from the life-ON study cohort.

This study aimed to assess the concordance of various psychometric scales in detecting Perinatal Depression (PND) risk and diagnosis. A cohort of 432 women was assessed at 10-15th and 23-25th gestational weeks, 33-40 days and 180-195 days after delivery using the Edinburgh Postnatal Depression Scale (EPDS), Visual Analogue Scale (VAS), Hamilton Depression Rating Scale (HDRS), Montgomery-Åsberg Depression Rating Scale (MADRS), and Mini International Neuropsychiatric Interview (MINI). Spearman's rank correlation coefficient was used to assess agreement across instruments, and multivariable classification models were developed to predict the values of a binary scale using the other scales. Moderate agreement was shown between the EPDS and VAS and between the HDRS and MADRS throughout the perinatal period. However, agreement between the EPDS and HDRS decreased postpartum. A well-performing model for the estimation of current depression risk (EPDS > 9) was obtained with the VAS and MADRS, and a less robust one for the estimation of current major depressive episode (MDE) diagnosis (MINI) with the VAS and HDRS. When the EPDS is not feasible, the VAS may be used for rapid and comprehensive postpartum screening with reliability. However, a thorough structured interview or clinical examination remains necessary to diagnose a MDE.

Focus on Multidisciplinary Aspects of Sleep Medicine.

Sleep is an essential biological requirement for human life, alongside food, water, and air [...].

Sleep fragmentation affects glymphatic system through the different expression of AQP4 in wild type and 5xFAD mouse models.

Alzheimer's disease (AD) is characterized by genetic and multifactorial risk factors. Many studies correlate AD to sleep disorders. In this study, we performed and validated a mouse model of AD and sleep fragmentation, which properly mimics a real condition of intermittent awakening. We noticed that sleep fragmentation induces a general acceleration of AD progression in 5xFAD mice, while in wild type mice it affects cognitive behaviors in particular learning and memory. Both these events may be correlated to aquaporin-4 (AQP4) modulation, a crucial player of the glymphatic system activity. In particular, sleep fragmentation differentially affects aquaporin-4 channel (AQP4) expression according to the stage of the disease, with an up-regulation in younger animals, while such change cannot be detected in older ones. Moreover, in wild type mice sleep fragmentation affects cognitive behaviors, in particular learning and memory, by compromising the glymphatic system through the decrease of AQP4. Nevertheless, an in-depth study is needed to better understand the mechanism by which AQP4 is modulated and whether it could be considered a risk factor for the disease development in wild type mice. If our hypotheses are going to be confirmed, AQP4 modulation may represent the convergence point between AD and sleep disorder pathogenic mechanisms.

Influence of chronotype on the incidence and severity of perinatal depression in the "Life-ON" study.

BACKGROUND: Perinatal depression (PND) is a severe complication of pregnancy, but there are no established risk factors predicting the disease. Evening chronotype has been associated with unhealthy lifestyle habits and adverse outcomes during pregnancy. In this study, we aimed to clarify whether chronotype can predict symptoms and/or occurrence of PND. METHODS: Two hundred ninety-nine women were followed-up from the first trimester of pregnancy until 6 months postpartum. Chronotype was assessed at baseline using the MEQ, while mood was repeatedly assessed by depression rating scales (EPDS, HDRS, MADRS). The influence of time and chronotype on EPDS, HDRS and MADRS, was estimated by constructing multilevel linear mixed regression models. A Cox proportional-hazard regression model was built to evaluate the association between chronotype and incidence of depression. RESULTS: Chronotype modulated PND symptom severity depending on time of assessment, with evening chronotypes having a higher risk for developing PND symptoms, as assessed by EPDS, at postpartum visits V4 (5-12 days) and V5 (19-26 days). These also had less healthy lifestyle habits and were more likely to suffer from gestational diabetes mellitus and undergo cesarean delivery as compared to other chronotypes. LIMITATIONS: Only a minority of women were classified as evening chronotypes. The long follow-up phase of the study led to missing data. CONCLUSIONS: Pregnant evening chronotypes show unhealthy lifestyle habits and sociodemographic characteristics commonly associated with a higher risk for PND. They also have a higher risk of developing PND symptoms in the first month after delivery. Chronotype should therefore be routinely assessed during pregnancy to identify women potentially at risk for developing PND.

Sustained remission from perinatal depression after bright light therapy: A pilot randomised, placebo-controlled trial.

OBJECTIVE: Perinatal depression (PND) is a severe complication of pregnancy, affecting both mothers and newborns. Bright light therapy (BLT) has only been tested in a few studies for treating either antenatal or postnatal depression. We conducted a pilot trial to investigate the efficacy and safety of BLT for PND occurring at any time across the perinatal period. METHODS: A single-blind RCT was carried out in women with an EPDS >12 from the 2nd gestational trimester until 9 months postpartum. Participants received either 30-minutes morning BLT (10'000 lux) or dim red light (DRL, 19 lux) for 6 weeks. RESULTS: Twenty-two women were randomised to BLT (n = 11) or DRL (n = 11). Among those receiving BLT, 73% achieved remission (improvement ≥50%, EPDS score ≤ 12), in contrast to 27% in the DRL group (p = 0.04). A significant influence of time on EPDS score and group-time interaction emerged, with a greater reduction in the BLT-group across the follow-up period. No women in either group reported major side effects. CONCLUSION: Morning BLT induced a significant remission from PND as compared to DRL and this effect was maintained across the perinatal period. BLT showed an excellent safety profile and was well-tolerated, thus representing a valid therapeutic strategy in this vulnerable perinatal population.

Sleep Deprivation During Memory Consolidation, but Not Before Memory Retrieval, Widens Threat Generalization to New Stimuli.

Past aversive experiences shape our ability to deal with future dangers, through the encoding of implicit and explicit memory traces and through the ability to generalize defensive reactions to new stimuli resembling learned threats. Numerous evidence demonstrate that sleep is important for the consolidation of memories related to threatening events. However, there is a lack of studies examining the effects of sleep deprivation on the retrieval of consolidated threat memories, and previous studies on the role of sleep in threat generalization have produced mixed results. To address these issues, here we adopted a differential threat conditioning and a delayed (second half of the night) sleep deprivation during the first or the seventh night after learning. We found no effects of sleep deprivation on either implicit or explicit threat memories, regardless of its occurrence timing. Conversely, implicit but not explicit responses to novel cues similar to a learned threat displayed a widened generalization pattern, but only if sleep deprivation took place during the first night after conditioning and not if it occurred during the seventh night after conditioning. Therefore, we propose that sleeping after exposure to danger may support optimal implicit discrimination processes to evaluate new signals in the future and that even a brief period of sleeplessness may widen threat generalization to new stimuli, which is a hallmark of several threat-related disorders.

Clinical characteristics of a large cohort of patients with narcolepsy candidate for pitolisant: a cross-sectional study from the Italian PASS Wakix® Cohort.

INTRODUCTION: Narcolepsy is a chronic and rare hypersomnia of central origin characterized by excessive daytime sleepiness and a complex array of symptoms as well as by several medical comorbidities. With growing pharmacological options, polytherapy may increase the possibility of a patient-centered management of narcolepsy symptoms. The aims of our study are to describe a large cohort of Italian patients with narcolepsy who were candidates for pitolisant treatment and to compare patients' subgroups based on current drug prescription (drug-naïve patients in whom pitolisant was the first-choice treatment, switching to pitolisant from other monotherapy treatments, and adding on in polytherapy). METHODS: We conducted a cross-sectional survey based on Italian data from the inclusion visits of the Post Authorization Safety Study of pitolisant, a 5-year observational, multicenter, international study. RESULTS: One hundred ninety-one patients were enrolled (76.4% with narcolepsy type 1 and 23.6% with narcolepsy type 2). Most patients (63.4%) presented at least one comorbidity, mainly cardiovascular and psychiatric. Pitolisant was prescribed as an add-on treatment in 120/191 patients (62.8%), as switch from other therapies in 42/191 (22.0%), and as a first-line treatment in 29/191 (15.2%). Drug-naive patients presented more severe sleepiness, lower functional status, and a higher incidence of depressive symptoms. CONCLUSION: Our study presents the picture of a large cohort of Italian patients with narcolepsy who were prescribed with pitolisant, suggesting that polytherapy is highly frequent to tailor a patient-centered approach.

Body Schema Self-Awareness and Related Dream Content Modifications in Amputees Due to Cancer.

PURPOSE: the evaluation of body image perception, pain coping strategies, and dream content, together with phantom limb and telescoping phenomena in patients with sarcoma who underwent surgery for limb amputation. MATERIAL AND METHODS: consecutive outpatients were evaluated at T0 (within 3 weeks after surgery) and T1 (4-6 months after surgery) as follows: demographic and clinical data collection; the Groningen Questionnaire Problems after Arm Amputation; the West Haven-Yale Multidimensional Pain Inventory; the Body Image Concern Inventory, a clinical trial to identify telescoping; and a weekly diary of dreams. Dream contents were coded according to the Hall and Van de Castle coding system. RESULTS: Twenty patients completed the study (15 males and 5 females, mean age: 53.9 ± 24.6, education: 7.8 ± 3.4). All subjects experienced phantom limb and 35% of them experienced telescoping soon after surgery, and 25% still after 4-6 months. Both at T0 and T1, that half of the subjects reported dreams about still having their missing limbs. At T1 the patients' perceptions of being able to deal with problems were lower, and pain and its interference in everyday life were higher yet associated with significant engagement in everyday activities and an overall good mood. The dream content analysis highlighted that males were less worried about health problems soon after amputation, and women showed more initial difficulties that seemed to be resolved after 4-6 months after surgery. CONCLUSIONS: The dream content analysis may improve clinicians' ability to support their patients during their therapeutic course.

Developments in the assessment of non-motor disease progression in amyotrophic lateral sclerosis.

INTRODUCTION: The burden of non-motor symptoms is a major determinant of quality of life and outcome in amyotrophic lateral sclerosis (ALS) and has profound negative effect also on caregivers. AREAS COVERED: Non-motor symptoms in ALS include cognitive impairment, neurobehavioral symptoms, depression and anxiety, suicidal ideation, pain, disordered sleep, fatigue, weight loss and reduced appetite, and autonomic dysfunctions. This review summarizes the measures used for the assessment of non-motor symptoms and their properties and recaps the frequency and progression of these symptoms along the course of ALS. EXPERT OPINION: Non-motor symptoms in ALS represent a major component of the disease and span over several domains. These symptoms require a high level of medical attention and should be checked at each visit using ad hoc questionnaires and proactively treated. Several instruments assessing non-motor symptoms have been used in ALS. Specific screening questionnaires for non-motor symptoms can be used for monitoring patients during telehealth visits and for remote surveillance through sensors and apps installed on smartphones. Novel trials for non-motor symptoms treatment specifically designed for ALS are necessary to increase and refine the therapeutic armamentarium. Finally, scales assessing the most frequent and burdensome non-motor symptoms should be included in clinical trials.

Assessing REM Sleep Behaviour Disorder: From Machine Learning Classification to the Definition of a Continuous Dissociation Index.

Objectives: Rapid Eye Movement Sleep Behaviour Disorder (RBD) is regarded as a prodrome of neurodegeneration, with a high conversion rate to α-synucleinopathies such as Parkinson's Disease (PD). The clinical diagnosis of RBD co-exists with evidence of REM Sleep Without Atonia (RSWA), a parasomnia that features loss of physiological muscular atonia during REM sleep. The objectives of this study are to implement an automatic detection of RSWA from polysomnographic traces, and to propose a continuous index (the Dissociation Index) to assess the level of dissociation between REM sleep stage and atonia. This is performed using Euclidean distance in proper vector spaces. Each subject is assigned a dissociation degree based on their distance from a reference, encompassing healthy subjects and clinically diagnosed RBD patients at the two extremes. Methods: Machine Learning models were employed to perform automatic identification of patients with RSWA through clinical polysomnographic scores, together with variables derived from electromyography. Proper distance metrics are proposed and tested to achieve a dissociation measure. Results: The method proved efficient in classifying RSWA vs. not-RSWA subjects, achieving an overall accuracy, sensitivity and precision of 87%, 93% and 87.5%, respectively. On its part, the Dissociation Index proved to be promising in measuring the impairment level of patients. Conclusions: The proposed method moves a step forward in the direction of automatically identifying REM sleep disorders and evaluating the impairment degree. We believe that this index may be correlated with the patients' neurodegeneration process; this assumption will undergo a robust clinical validation process involving healthy, RSWA, RBD and PD subjects.

End-of-Life in Oncologic Patients' Dream Content.

Both non-rapid eye movements and rapid eye movements sleep facilitate the strengthening of newly encoded memory traces, and dream content reflects this process. Numerous studies evaluated the impact of diseases on dream content, with particular reference to cancer, and reported the presence of issues related to death, negative emotions, pain and illness. This study investigates death and illness experiences in 13 consecutive patients with sarcoma compared to paired controls, early after diagnosis, evaluating dream contents, fear of death, mood and anxiety, distress, and severity of disease perception (perceived and communicated). Ten patients and 10 controls completed the study. Dream contents were significantly different between patients and normative data (DreamSat) and patients and controls (higher presence of negative emotions, low familiar settings and characters and no success involving the dreamer). Illness and death were present in 57% of patients' dreams (0% among controls), but no differences emerged between patients and controls in regard to anxiety and depression, distress and fear of death, even if the severity of illness was correctly perceived. The appearance of emotional elements in dreams and the absence of conscious verbalization of distress and/or depressive or anxious symptoms by patients could be ascribed to the time required for mnestic elaboration (construction/elaboration phase) during sleep.

Diagnosing REM sleep behavior disorder in Parkinson's disease without a gold standard: a latent-class model study.

STUDY OBJECTIVES: To ascertain whether current diagnostic criteria for REM sleep behavior disorder (RBD) are appropriate in patients with Parkinson's disease (PD) consulting a movement disorder center, to evaluate the accuracy of REM sleep without atonia (RSWA) thresholds and determine the value of screening questionnaires to discriminate PD patients with RBD. METHODS: One hundred twenty-eight consecutive PD patients (M = 80; mean age: 65.6 ± 8.3 years) underwent screening questionnaires, followed by a sleep-focused interview and a full-night video-polysomnography (vPSG). Without a gold standard, latent class models (LCMs) were applied to create an unobserved ("latent") variable. Sensitivity analysis was performed using RSWA cutoff derived from two visual scoring methods. Finally, we assessed the respective diagnostic performance of each diagnostic criterion for RBD and of the screening questionnaires. RESULTS: According to the best LCM-derived model, patients having either "history" or "video" with RSWA or alternatively showing both "history" and "video" without RSWA were classified as having RBD. Using both SINBAR and Montreal scoring methods, RSWA criterion showed the highest sensitivity while concomitant history of RBD and vPSG-documented behaviors, regardless to presence of RSWA, displayed the highest specificity. Currently recommended diagnostic threshold of RSWA was found to be optimal in our large cohort of PD patients. Both the RBD screening questionnaire (RBDSQ) and the RBD single question (RBD1Q) showed poor sensitivity and specificity. CONCLUSIONS: Results of the best LCM for diagnosis of RBD in PD were consistent with the current diagnostic criteria. Moreover, RBD might be considered in those PD patients with both history and vPSG-documented dream enactment behaviors, but with RSWA values within the normal range.

Polysomnographic features of pregnancy: A systematic review.

Symptoms of sleep disturbances are common among pregnant women and generally worsen across gestation. Pregnancy-related sleep disorders are not only associated with a poor quality of life of the affected mothers, but also with adverse perinatal outcomes, including perinatal depression, gestational diabetes, preeclampsia, and preterm birth. The current knowledge about the impact of sleep disorders during pregnancy largely derives from the results of sleep surveys conducted in various populations. However, the number of studies examining changes in objective sleep variables during pregnancy via polysomnography has progressively increased in recent years. Here we systematically reviewed the polysomnographic studies available in the literature with the aim to describe the sleep pattern and to identify possible markers of sleep disruption in pregnant women. Based on our analysis, subjective worsening of sleep quality across gestation is related to objective changes in sleep macrostructure, which become particularly evident in the third trimester. Pregnancy per se does not represent an independent risk factor for developing major polysomnography-assessed sleep disorders in otherwise healthy women. However, in women presenting predisposing factors, such as obesity or hypertension, physiological changes occurring during pregnancy may contribute to the onset of pathological conditions, especially sleep-disordered breathing, which must be carefully considered.

Sleep and REM sleep behaviour disorder in Parkinson's disease with impulse control disorder.

INTRODUCTION: Because the association between rapid eye movement sleep behaviour disorder (RBD) and impulse control disorders (ICDs) in Parkinson's disease (PD) has been debated, we assessed the sleep characteristics and the frequency of RBD using video-polysomnography (v-PSG) in patients with PD with versus without ICDs. METHODS: Eighty non-demented patients with PD consecutively identified during routine evaluation at three movement disorders centres were enrolled in a case-control study. Forty patients (22 men; mean age: 62.6±9.7 years, Hoehn & Yahr: 2.1±0.6) with one or more current ICDs were age-matched and sex-matched with 40 patients with no history of ICDs (22 men, mean age: 64.9±7.8 years, Hoehn & Yahr: 2.2±0.6). They underwent a detailed sleep interview followed by a full-night in-lab v-PSG. Sleep was scored blindly to ICDs condition and RBD diagnosis included a clinical complaint of enacted dreams and/or documented behaviour during rapid eye movement (REM) sleep, with the presence of quantified REM sleep without atonia (RSWA). RESULTS: Patients with ICDs had a higher arousal index and higher RSWA than those without ICDs (51.9%±28.2%vs 32.2±27.1%, p=0.004). In addition, RBD was more frequent in the ICD group (85%vs53%, p=0.0001). RBD was still associated with ICDs in a multivariate regression analysis including age of onset, PD duration and severity, treatment duration, levodopa-equivalent and dopamine agonist-equivalent daily doses and antidepressant use (OR: 4.9 (95% CI 1.3 to 18.5), p=0.02). CONCLUSIONS: This large, controlled series of patients with PD with ICDs assessed by v-PSG confirms the association between ICDs and RBD. Increased surveillance of symptoms of ICDs should be recommended in patients with PD with RBD.

Sleep on a high heat capacity mattress increases conductive body heat loss and slow wave sleep.

Environmental temperature can strongly affect sleep. The habitual sleep phase is usually located between evening decline and morning rise of the circadian rhythm of core body temperature (CBT). However, the thermophysiological mechanisms promoting or disturbing sleep are not yet fully understood. The purpose of this study was to examine the effects of a high heat capacity mattress (HHCM) on CBT, skin temperatures and sleep in comparison to a conventional low heat capacity mattress (LHCM). Based on the higher heat capacity of HHCM an increase in conductive body heat loss enhances the nocturnal decline in CBT can be expected. Based on previous findings this may then be accompanied by an increase in slow wave sleep (SWS). The mattresses were studied in a randomized single-blind crossover design in fifteen healthy young men (Age: 26.9±2.1yr, BMI: 22.2±0.4kg/m2) by overnight in laboratory standard video-polysomnography in a temperature stabilized setting. CBT, room temperature, and skin and mattress surface temperatures were continuously recorded in order to get information about inner and outer body heat flow. Additionally, subjective sleep quality was estimated by visual analogue scale. In comparison to LHCM sleep on HHCM exhibited a selective increase in SWS (16%, p<0.05), increased subjective sleep quality and sleep stability [reduced cyclic alternating pattern (CAP) rate; 5.3%, p<0.01]. Additionally, analyses of the sleep stages showed in the second part of the night a significant increase in SWS and a decrease in REMS. In addition, HHCM induced a greater reduction in CBT (maximally by -0.28°C), reduced the increase in proximal skin temperatures on the back (PROBA; maximally by -0.98°C), and delayed the increase in mattress surface temperature (maximal difference LHCM-HHCM: 6.12°C). Thus, the CBT reduction can be explained by an increase in conductive heat loss to the mattress via proximal back skin regions. Regression analysis identified PROBA as the critical variable to predict inner conductive heat transfer from core to shell and SWS. In conclusion, the study expands the previous findings that a steeper nocturnal decline in CBT increases SWS and subjective sleep quality, whereas inner conductive heat transfer could be identified as the crucial thermophysiological variable, and not CBT.

A polysomnographic study in parkinsonian patients treated with intestinal levodopa infusion.

Sleep disorders are very common in advanced Parkinson's disease (PD) and have a significant negative impact on the quality of life of patients. Questionnaire-based studies suggest that sleep quality might improve following levodopa-carbidopa intestinal gel (LCIG) infusion. The objective of this study was to evaluate the impact of LCIG infusion and subsequent oral medication changes on polysomnography (PSG) and sleep symptoms in advanced PD patients. Eleven PD patients underwent PSG at baseline and after 3.8 ± 1.2 months of LCIG treatment. LCIG infusion therapy was halted during PSG. Patients were assessed with the Unified-PD-rating-Scale and completed the PD-Sleep-Scale-version-2 (PDSS-2), the Epworth Sleepiness Scale and the RBD single question. Subjective sleep quality improved in all patients. PSG showed a reduction of the number of awakenings in sleep, a trend towards a lower apnea-hypopnea index and no change in sleep latency, total sleep time and sleep efficiency. There was a positive correlation between the number of awakenings and PDSS-2 scores for "difficulty staying asleep", "muscle cramps of arms or legs" and "urge to move arms or legs". Motor complications and activities of daily living improved with LCIG. Subjective sleep quality improved significantly and the PSG study showed a less fragmented sleep pattern in advanced PD patients treated with LCIG infusion.

Comparison Between Automatic and Visual Scorings of REM Sleep Without Atonia for the Diagnosis of REM Sleep Behavior Disorder in Parkinson Disease.

Study Objectives: To compare three different methods, two visual and one automatic, for the quantification of rapid eye movement (REM) sleep without atonia (RSWA) in the diagnosis of REM sleep behavior disorder (RBD) in Parkinson's disease (PD) patients. Methods: Sixty-two consecutive patients with idiopathic PD underwent video-polysomnographic recording and showed more than 5 minutes of REM sleep. The electromyogram during REM sleep was analyzed by means of two visual methods (Montréal and SINBAR) and one automatic analysis (REM Atonia Index or RAI). RBD was diagnosed according to standard criteria and a series of diagnostic accuracy measures were calculated for each method, as well as the agreement between them. Results: RBD was diagnosed in 59.7% of patients. The accuracy (85.5%), receiver operating characteristic (ROC) area (0.833) and Cohen's K coefficient (0.688) obtained with RAI were similar to those of the visual parameters. Visual tonic parameters, alone or in combination with phasic activity, showed high values of accuracy (93.5-95.2%), ROC area (0.92-0.94), and Cohen's K (0.862-0.933). Similarly, the agreement between the two visual methods was very high, and the agreement between each visual methods and RAI was substantial. Visual phasic measures alone performed worse than all the other measures. Conclusion: The diagnostic accuracy of RSWA obtained with both visual and automatic methods was high and there was a general agreement between methods. RAI may be used as the first line method to detect RSWA in the diagnosis of RBD in PD, together with the visual inspection of video-recorded behaviors, while the visual analysis of RSWA might be used in doubtful cases.