Presynaptic Dopaminergic Imaging Characterizes Patients with REM Sleep Behavior Disorder Due to Synucleinopathy.

OBJECTIVE: To apply a machine learning analysis to clinical and presynaptic dopaminergic imaging data of patients with rapid eye movement (REM) sleep behavior disorder (RBD) to predict the development of Parkinson disease (PD) and dementia with Lewy bodies (DLB). METHODS: In this multicenter study of the International RBD study group, 173 patients (mean age 70.5 ± 6.3 years, 70.5% males) with polysomnography-confirmed RBD who eventually phenoconverted to overt alpha-synucleinopathy (RBD due to synucleinopathy) were enrolled, and underwent baseline presynaptic dopaminergic imaging and clinical assessment, including motor, cognitive, olfaction, and constipation evaluation. For comparison, 232 RBD non-phenoconvertor patients (67.6 ± 7.1 years, 78.4% males) and 160 controls (68.2 ± 7.2 years, 53.1% males) were enrolled. Imaging and clinical features were analyzed by machine learning to determine predictors of phenoconversion. RESULTS: Machine learning analysis showed that clinical data alone poorly predicted phenoconversion. Presynaptic dopaminergic imaging significantly improved the prediction, especially in combination with clinical data, with 77% sensitivity and 85% specificity in differentiating RBD due to synucleinopathy from non phenoconverted RBD patients, and 85% sensitivity and 86% specificity in discriminating PD-converters from DLB-converters. Quantification of presynaptic dopaminergic imaging showed that an empirical z-score cutoff of -1.0 at the most affected hemisphere putamen characterized RBD due to synucleinopathy patients, while a cutoff of -1.0 at the most affected hemisphere putamen/caudate ratio characterized PD-converters. INTERPRETATION: Clinical data alone poorly predicted phenoconversion in RBD due to synucleinopathy patients. Conversely, presynaptic dopaminergic imaging allows a good prediction of forthcoming phenoconversion diagnosis. This finding may be used in designing future disease-modifying trials. ANN NEUROL 2024;95:1178-1192.

Progression of clinical markers in prodromal Parkinson's disease and dementia with Lewy bodies: a multicentre study.

The neurodegenerative synucleinopathies, including Parkinson's disease and dementia with Lewy bodies, are characterized by a typically lengthy prodromal period of progressive subclinical motor and non-motor manifestations. Among these, idiopathic REM sleep behaviour disorder is a powerful early predictor of eventual phenoconversion, and therefore represents a critical opportunity to intervene with neuroprotective therapy. To inform the design of randomized trials, it is essential to study the natural progression of clinical markers during the prodromal stages of disease in order to establish optimal clinical end points. In this study, we combined prospective follow-up data from 28 centres of the International REM Sleep Behavior Disorder Study Group representing 12 countries. Polysomnogram-confirmed REM sleep behaviour disorder subjects were assessed for prodromal Parkinson's disease using the Movement Disorder Society criteria and underwent periodic structured sleep, motor, cognitive, autonomic and olfactory testing. We used linear mixed-effect modelling to estimate annual rates of clinical marker progression stratified by disease subtype, including prodromal Parkinson's disease and prodromal dementia with Lewy bodies. In addition, we calculated sample size requirements to demonstrate slowing of progression under different anticipated treatment effects. Overall, 1160 subjects were followed over an average of 3.3 ± 2.2 years. Among clinical variables assessed continuously, motor variables tended to progress faster and required the lowest sample sizes, ranging from 151 to 560 per group (at 50% drug efficacy and 2-year follow-up). By contrast, cognitive, olfactory and autonomic variables showed modest progression with higher variability, resulting in high sample sizes. The most efficient design was a time-to-event analysis using combined milestones of motor and cognitive decline, estimating 117 per group at 50% drug efficacy and 2-year trial duration. Finally, while phenoconverters showed overall greater progression than non-converters in motor, olfactory, cognitive and certain autonomic markers, the only robust difference in progression between Parkinson's disease and dementia with Lewy bodies phenoconverters was in cognitive testing. This large multicentre study demonstrates the evolution of motor and non-motor manifestations in prodromal synucleinopathy. These findings provide optimized clinical end points and sample size estimates to inform future neuroprotective trials.

Prodromal dementia with Lewy bodies in REM sleep behavior disorder: A multicenter study.

INTRODUCTION: Isolated/idiopathic rapid eye movement sleep behavior disorder (iRBD) is a powerful early predictor of dementia with Lewy bodies (DLB) and Parkinson's disease (PD). This provides an opportunity to directly observe the evolution of prodromal DLB and to identify which cognitive variables are the strongest predictors of evolving dementia. METHODS: IRBD participants (n = 754) from 10 centers of the International RBD Study Group underwent annual neuropsychological assessment. Competing risk regression analysis determined optimal predictors of dementia. Linear mixed-effect models determined the annual progression of neuropsychological testing. RESULTS: Reduced attention and executive function, particularly performance on the Trail Making Test Part B, were the strongest identifiers of early DLB. In phenoconverters, the onset of cognitive decline began up to 10 years prior to phenoconversion. Changes in verbal memory best differentiated between DLB and PD subtypes. DISCUSSION: In iRBD, attention and executive dysfunction strongly predict dementia and begin declining several years prior to phenoconversion. HIGHLIGHTS: Cognitive decline in iRBD begins up to 10 years prior to phenoconversion. Attention and executive dysfunction are the strongest predictors of dementia in iRBD. Decline in episodic memory best distinguished dementia-first from parkinsonism-first phenoconversion.

Prognostic biomarkers in prodromal α-synucleinopathies: DAT binding and REM sleep without atonia.

BACKGROUND: Isolated rapid eye movement (REM) sleep behaviour disorder (iRBD) is a prodromal state of clinical α-synucleinopathies such as Parkinson's disease and Lewy body dementia. The lead-time until conversion is unknown. The most reliable marker of progression is reduced striatal dopamine transporter (DAT) binding, but low availability of imaging facilities limits general use. Our prospective observational study aimed to relate metrics of REM sleep without atonia (RWA)-a hallmark of RBD-to DAT-binding ratios in a large, homogeneous sample of patients with RBD to explore the utility of RWA as a marker of progression in prodromal α-synucleinopathies. METHODS: DAT single-photon emission CT (SPECT) and video polysomnography (vPSG) were performed in 221 consecutive patients with clinically suspected RBD. RESULTS: vPSG confirmed RBD in 176 patients (162 iRBD, 14 phenoconverted, 45 non-synucleinopathies). Specific DAT-binding ratios differed significantly between groups, but showed considerable overlap. Most RWA metrics correlated significantly with DAT-SPECT ratios (eg, Montreal tonic vs most-affected-region: r=-0.525; p<0.001). In patients taking serotonergic/noradrenergic antidepressants or dopaminergic substances or with recent alcohol abuse, correlations were weaker, suggesting a confounding influence, unlike other possible confounders such as beta-blocker use or comorbid sleep apnoea. CONCLUSIONS: In this large single-centre prospective observational study, we found evidence that DAT-binding ratios in patients with iRBD can be used to describe a continuum in the neurodegenerative process. Overlap with non-synucleinopathies and clinical α-synucleinopathies, however, precludes the use of DAT-binding ratios as a precise diagnostic marker. The parallel course of RWA metrics and DAT-binding ratios suggests in addition to existing data that RWA, part of the routine diagnostic workup in these patients, may represent a marker of progression. Based on our findings, we suggest ranges of RWA values to estimate whether patients are in an early, medium or advanced state within the prodromal phase of α-synucleinopathies, providing them with important information about time until possible conversion.

Treatment of isolated REM sleep behavior disorder using melatonin as a chronobiotic.

Melatonin is recommended as a first-line treatment in isolated REM sleep behavior disorder (iRBD), although no large patient group has been reported. To assess effects, time course and confounding factors in the treatment of patients with iRBD using melatonin, 209 consecutive patients were included in this single-center, observational cohort study. A total of 171 patients had taken melatonin according to our chronobiotic protocol (2 mg, ≥6 months, always-at-the-same-clock time, 10-11pm, corrected for chronotype), 13 had applied melatonin for about 1-3 months, and 25 underwent mixed treatments. In total, 1529 clinical evaluations were performed, including Clinical Global Impression (CGI) and a newly developed RBD symptom severity scale (Ikelos-RS), analyzed using linear mixed models. Validation of Ikelos-RS showed excellent inter-rater reliability (ρ = 0.9, P < .001), test-retest reliability (ρ = 0.9, P < .001) and convergent validity (ρ = 0.9, P < .001). With melatonin, RBD symptom severity gradually improved over the first 4 weeks of treatment (Ikelos-RS: 6.1 vs. 2.5; CGI Severity: 5.7 vs. 3.2) and remained stably improved (mean follow-up 4.2 ± 3.1years; range: 0.6-21.7years). Initial response was slowed to up to 3 months with melatonin-suppressing (betablockers) or REM sleep spoiling co-medication (antidepressants) and failed with inadequately timed melatonin intake. When melatonin was discontinued after 6 months, symptoms remained stably improved (mean follow-up after discontinuation of 4.9 ± 2.5years; range: 0.6-9.2). When administered only 1-3 months, RBD symptoms gradually returned. Without any melatonin, RBD symptoms persisted and did not wear off over time. Clock-timed, low-dose, long-term melatonin treatment in patients with iRBD appears to be associated with the improvement of symptoms. The outlasting improvement over years questions a pure symptomatic effect. Clock-time dependency challenges existing prescription guidelines for melatonin.

Clinical trials in REM sleep behavioural disorder: challenges and opportunities.

The rapid eye movement sleep behavioural disorder (RBD) population is an ideal study population for testing disease-modifying treatments for synucleinopathies, since RBD represents an early prodromal stage of synucleinopathy when neuropathology may be more responsive to treatment. While clonazepam and melatonin are most commonly used as symptomatic treatments for RBD, clinical trials of symptomatic treatments are also needed to identify evidence-based treatments. A comprehensive framework for both disease-modifying and symptomatic treatment trials in RBD is described, including potential treatments in the pipeline, cost-effective participant recruitment and selection, study design, outcomes and dissemination of results. For disease-modifying treatment clinical trials, the recommended primary outcome is phenoconversion to an overt synucleinopathy, and stratification features should be used to select a study population at high risk of phenoconversion, to enable more rapid clinical trials. For symptomatic treatment clinical trials, objective polysomnogram-based measurement of RBD-related movements and vocalisations should be the primary outcome measure, rather than subjective scales or diaries. Mobile technology to enable objective measurement of RBD episodes in the ambulatory setting, and advances in imaging, biofluid, tissue, and neurophysiological biomarkers of synucleinopathies, will enable more efficient clinical trials but are still in development. Increasing awareness of RBD among the general public and medical community coupled with timely diagnosis of these diseases will facilitate progress in the development of therapeutics for RBD and associated neurodegenerative disorders.

Risk and predictors of dementia and parkinsonism in idiopathic REM sleep behaviour disorder: a multicentre study.

Idiopathic REM sleep behaviour disorder (iRBD) is a powerful early sign of Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy. This provides an unprecedented opportunity to directly observe prodromal neurodegenerative states, and potentially intervene with neuroprotective therapy. For future neuroprotective trials, it is essential to accurately estimate phenoconversion rate and identify potential predictors of phenoconversion. This study assessed the neurodegenerative disease risk and predictors of neurodegeneration in a large multicentre cohort of iRBD. We combined prospective follow-up data from 24 centres of the International RBD Study Group. At baseline, patients with polysomnographically-confirmed iRBD without parkinsonism or dementia underwent sleep, motor, cognitive, autonomic and special sensory testing. Patients were then prospectively followed, during which risk of dementia and parkinsonsim were assessed. The risk of dementia and parkinsonism was estimated with Kaplan-Meier analysis. Predictors of phenoconversion were assessed with Cox proportional hazards analysis, adjusting for age, sex, and centre. Sample size estimates for disease-modifying trials were calculated using a time-to-event analysis. Overall, 1280 patients were recruited. The average age was 66.3 ± 8.4 and 82.5% were male. Average follow-up was 4.6 years (range = 1-19 years). The overall conversion rate from iRBD to an overt neurodegenerative syndrome was 6.3% per year, with 73.5% converting after 12-year follow-up. The rate of phenoconversion was significantly increased with abnormal quantitative motor testing [hazard ratio (HR) = 3.16], objective motor examination (HR = 3.03), olfactory deficit (HR = 2.62), mild cognitive impairment (HR = 1.91-2.37), erectile dysfunction (HR = 2.13), motor symptoms (HR = 2.11), an abnormal DAT scan (HR = 1.98), colour vision abnormalities (HR = 1.69), constipation (HR = 1.67), REM atonia loss (HR = 1.54), and age (HR = 1.54). There was no significant predictive value of sex, daytime somnolence, insomnia, restless legs syndrome, sleep apnoea, urinary dysfunction, orthostatic symptoms, depression, anxiety, or hyperechogenicity on substantia nigra ultrasound. Among predictive markers, only cognitive variables were different at baseline between those converting to primary dementia versus parkinsonism. Sample size estimates for definitive neuroprotective trials ranged from 142 to 366 patients per arm. This large multicentre study documents the high phenoconversion rate from iRBD to an overt neurodegenerative syndrome. Our findings provide estimates of the relative predictive value of prodromal markers, which can be used to stratify patients for neuroprotective trials.

Twenty Years After: Another Case Report of Melatonin Effects on REM Sleep Behavior Disorder, Using Serial Dopamine Transporter Imaging.

INTRODUCTION: REM sleep behavior disorder (RBD) is considered a prodromal phase of α-synucleinopathy like Parkinson disease (PD). PD is characterized by a progressive decline of dopamine (DA) in the striatum. Here we report the surprising increase in DA transporter density over successive years in an RBD patient treated with melatonin. CASE PRESENTATION: A then 72-year-old man was clinically suspected to suffer from PD in 2011. DA transporter scintigraphy (DaTSCAN) revealed reduced DA transporter density, and the patient was diagnosed with developing PD. Because of outacting dreams every night (speaking, yelling, kicking, pushing) he was referred to our clinic. Video-assisted polysomnography (PSG) confirmed the diagnosis of RBD in 2012. Management and Outcome: Melatonin treatment (2 mg slow release/day; 30 min prior to habitual bedtime; always at the same clock time) was initiated after PSG and continued. After 6 months of gradual improvement, clinical signs of RBD were absent. Control PSG in 2014 confirmed normalized REM sleep with atonia. Furthermore, no clinical sign of neurodegeneration occurred ever since. Additional DaTSCANs were performed in 2013 and 2015. Whereas the 2011 scan prior to melatonin treatment bore clear signs of PD, the 2013 scan was considered borderline and the 2015 scan without any sign of PD. DISCUSSION: To the best of our knowledge, DA transporter density increase over time has never been reported in a single subject, neither healthy aged individuals nor patients suffering from RBD or PD. We interpret these results as a possible neuroprotective role for melatonin in synucleinopathy.

Night-time activity forecast by season and weather in a longitudinal design - natural light effects on three years' rest-activity cycles in nursing home residents with dementia.

Backround: Night-time agitation is a frequent symptom of dementia. It often causes nursing home admission and has been linked to circadian rhythm disturbances. A positive influence of light interventions on night-time agitation was shown in several studies. The aim of our study was to investigate whether there is a long-term association between regional weather data (as indicator for daylight availability) and 24-hour variations of motor activity. METHODS: Motor activity of 20 elderly nursing home residents living with dementia was analyzed using recordings of continuously worn wrist activity monitors over a three-year period. The average recording duration was 479 ± 206 days per participant (mean ± SD). Regional cloud amount and day length data from the local weather station (latitude: 52°56'N) were included in the analysis to investigate their effects on several activity variables. RESULTS: Nocturnal rest, here defined as the five consecutive hours with the least motor activity during 24 hours (L5), was the most predictable activity variable per participant. There was a significant interaction of night-time activity with day length and cloud amount (F 1,1174 = 4.39; p = 0.036). Night-time activity was higher on cloudy short days than on clear short days (p = 0.007), and it was also higher on cloudy short days than on cloudy long days (p = 0.032). CONCLUSIONS: The need for sufficient zeitgeber (time cue) strength during winter time, especially when days are short and skies are cloudy, is crucial for elderly people living with dementia. Activity forecast by season and weather might be a valuable approach to anticipate adequately complementary use of electrical light and thereby foster lower night-time activity.

Blue-Enriched Morning Light as a Countermeasure to Light at the Wrong Time: Effects on Cognition, Sleepiness, Sleep, and Circadian Phase.

Light during the day and darkness at night are crucial factors for proper entrainment of the human circadian system to the solar 24-h day. However, modern life and work styles have led to much more time spent indoors, often with lower daytime and higher evening/nighttime light intensity from electrical lighting than outdoors. Whether this has long-term consequences for human health is being currently investigated. We tested if bright blue-enriched morning light over several days could counteract the detrimental effects of inadequate daytime and evening lighting. In a seminaturalistic, within-between subject study design, 18 young participants were exposed to different lighting conditions on 3 evenings (blue-enriched, bright orange, or dim light), after exposure to 2 lighting conditions (mixed blue-enriched light and control light, for 3 days each) in the mornings. Subjective sleepiness, reaction times, salivary melatonin concentrations, and nighttime sleep were assessed. Exposure to the blue-enriched morning lighting showed acute wake-promoting effects and faster reaction times than with control lighting. Some of these effects persisted until the evening, and performance improved over several days. The magnitude of circadian phase shifts induced by combinations of 3 different evening and 2 morning lighting conditions were significantly smaller with the blue-enriched morning light. During the night, participants had longer total sleep times after orange light exposure than after blue light exposure in the evening. Our results indicate that bright blue-enriched morning light stabilizes circadian phase, and it could be an effective counterstrategy for poor lighting during the day and also light exposure at the wrong time, such as in the late evening.

Krüppel-like factor 9 is a circadian transcription factor in human epidermis that controls proliferation of keratinocytes.

Circadian clocks govern a wide range of cellular and physiological functions in various organisms. Recent evidence suggests distinct functions of local clocks in peripheral mammalian tissues such as immune responses and cell cycle control. However, studying circadian action in peripheral tissues has been limited so far to mouse models, leaving the implication for human systems widely elusive. In particular, circadian rhythms in human skin, which is naturally exposed to strong daytime-dependent changes in the environment, have not been investigated to date on a molecular level. Here, we present a comprehensive analysis of circadian gene expression in human epidermis. Whole-genome microarray analysis of suction-blister epidermis obtained throughout the day revealed a functional circadian clock in epidermal keratinocytes with hundreds of transcripts regulated in a daytime-dependent manner. Among those, we identified a circadian transcription factor, Krüppel-like factor 9 (Klf9), that is substantially up-regulated in a cortisol and differentiation-state-dependent manner. Gain- and loss-of-function experiments showed strong antiproliferative effects of Klf9. Putative Klf9 target genes include proliferation/differentiation markers that also show circadian expression in vivo, suggesting that Klf9 affects keratinocyte proliferation/differentiation by controlling the expression of target genes in a daytime-dependent manner.

Impaired sleep quality and sleep duration in smokers-results from the German Multicenter Study on Nicotine Dependence.

Cigarette smoking is a severe health burden being related to a number of chronic diseases. Frequently, smokers report about sleep problems. Sleep disturbance, in turn, has been demonstrated to be involved in the pathophysiology of several disorders related to smoking and may be relevant for the pathophysiology of nicotine dependence. Therefore, determining the frequency of sleep disturbance in otherwise healthy smokers and its association with degree of nicotine dependence is highly relevant. In a population-based case-control study, 1071 smokers and 1243 non-smokers without lifetime Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Axis I disorder were investigated. Sleep quality (SQ) of participants was determined by the Pittsburgh Sleep Quality Index. As possible confounders, age, sex and level of education and income, as well as depressiveness, anxiety, attention deficit hyperactivity, alcohol drinking behaviour and perceived stress, were included into multiple regression analyses. Significantly more smokers than non-smokers (28.1% versus 19.1%; P < 0.0001) demonstrated a disturbed global SQ. After controlling for the confounders, impaired scores in the component scores of sleep latency, sleep duration and global SQ were found significantly more often in smokers than non-smokers. Consistently, higher degrees of nicotine dependence and intensity of smoking were associated with shorter sleep duration. This study demonstrates for the first time an elevated prevalence of sleep disturbance in smokers compared with non-smokers in a population without lifetime history of psychiatric disorders even after controlling for potentially relevant risk factors. It appears likely that smoking is a behaviourally modifiable risk factor for the occurrence of impaired SQ and short sleep duration.

Out of the lab and into the bathroom: evening short-term exposure to conventional light suppresses melatonin and increases alertness perception.

Life in 24-h society relies on the use of artificial light at night that might disrupt synchronization of the endogenous circadian timing system to the solar day. This could have a negative impact on sleep-wake patterns and psychiatric symptoms. The aim of the study was to investigate the influence of evening light emitted by domestic and work place lamps in a naturalistic setting on melatonin levels and alertness in humans. Healthy subjects (6 male, 3 female, 22-33 years) were exposed to constant dim light (<10 lx) for six evenings from 7:00 p.m. to midnight. On evenings 2 through 6, 1 h before habitual bedtime, they were also exposed to light emitted by 5 different conventional lamps for 30 min. Exposure to yellow light did not alter the increase of melatonin in saliva compared to dim light baseline during (38 ± 27 pg/mL vs. 39 ± 23 pg/mL) and after light exposure (39 ± 22 pg/mL vs. 44 ± 26 pg/mL). In contrast, lighting conditions including blue components reduced melatonin increase significantly both during (office daylight white: 25 ± 16 pg/mL, bathroom daylight white: 24 ± 10 pg/mL, Planon warm white: 26 ± 14 pg/mL, hall daylight white: 22 ± 14 pg/mL) and after light exposure (office daylight white: 25 ± 15 pg/mL, bathroom daylight white: 23 ± 9 pg/mL, Planon warm white: 24 ± 13 pg/mL, hall daylight white: 22 ± 26 pg/mL). Subjective alertness was significantly increased after exposure to three of the lighting conditions which included blue spectral components in their spectra. Evening exposure to conventional lamps in an everyday setting influences melatonin excretion and alertness perception within 30 min.

Seasonality of human sleep: Polysomnographic data of a neuropsychiatric sleep clinic.

While short-term effects of artificial light on human sleep are increasingly being studied, reports on long-term effects induced by season are scarce. Assessments of subjective sleep length over the year suggest a substantially longer sleep period during winter. Our retrospective study aimed to investigate seasonal variation in objective sleep measures in a cohort of patients living in an urban environment. In 2019, three-night polysomnography was performed on 292 patients with neuropsychiatric sleep disturbances. Measures of the diagnostic second nights were averaged per month and analyzed over the year. Patients were advised to sleep "as usual" including timing, except alarm clocks were not allowed. Exclusion criteria: administration of psychotropic agents known to influence sleep (N = 96), REM-sleep latency > 120 min (N = 5), technical failure (N = 3). Included were 188 patients: [46.6 ± 15.9 years (mean ± SD); range 17-81 years; 52% female]; most common sleep-related diagnoses: insomnia (N = 108), depression (N = 59) and sleep-related breathing disorders (N = 52). Analyses showed: 1. total sleep time (TST) longer during winter than summer (up to 60 min; not significant); 2. REM-sleep latency shorter during autumn than spring (about 25 min, p = 0.010); 3. REM-sleep longer during winter than spring (about 30 min, p = 0.009, 5% of TST, p = 0.011); 4. slow-wave-sleep stable winter to summer (about 60-70 min) with 30-50 min shorter during autumn (only significant as % of TST, 10% decrease, p = 0.017). Data suggest seasonal variation in sleep architecture even when living in an urban environment in patients with disturbed sleep. If replicated in a healthy population, this would provide first evidence for a need to adjust sleep habits to season.

Ikelos-RWA. Validation of an Automatic Tool to Quantify REM Sleep Without Atonia.

Study Objectives. To present and evaluate an automatic scoring algorithm for quantification of REM-sleep without atonia (RWA) in patients with REM-sleep behaviour disorder (RBD) based on a generally accepted, well-validated visual scoring method, ("Montreal" phasic and tonic) and a recently developed, concise scoring method (Ikelos-RWA). Methods. Video-polysomnographies of 20 RBD patients (68.2 ± 7.2 years) and 20 control patients with periodic limb movement disorder (65.9 ± 6.7 years) were retrospectively analysed. RWA was estimated from chin electromyogram during REM-sleep. Visual and automated RWA scorings were correlated, and agreement (a) and Cohen's Kappa (k) calculated for 1735 minutes of REM-sleep of the RBD patients. Discrimination performance was evaluated with receiver operating characteristic (ROC) analysis. The algorithm was then applied on the polysomnographies of a cohort of 232 RBD patients (total analysed REM-sleep: 17,219 minutes) and evaluated, while correlating the different output parameters. Results. Visual and computer-derived RWA scorings correlated significantly (tonic Montreal: rTM = 0.77; phasic Montreal: rPM = 0.78; Ikelos-RWA: rI = 0.97; all p < 0.001) and showed good to excellent Kappa coefficients (kTM = 0.71; kPM = 0.79; kI = 0.77). The ROC analysis showed high sensitivities (95%-100%) and specificities (84%-95%) at the optimal operation points, with area under the curve (AUC) of 0.98, indicating high discriminating capacity. The automatic RWA scorings of 232 patients correlated significantly (rTM{I} = 0.95; rPM{I} = 0.91, p < 0.0001). Conclusions. The presented algorithm is an easy-to-use and valid tool for automatic RWA scoring in patients with RBD and may prove effective for general use being publicly available.

Sleep and circadian rhythms in α-synucleinopathies-Perspectives for disease modification.

The global north is facing an unprecedented rise in the prevalence of neurodegenerative diseases. The increasing incidence of Parkinson's disease is being referred to as a pandemic. The reason for the enormous increase is only partly understood. Lifestyle factors are known to play a role, but they alone cannot account for the surge. One factor that-although being recognized as important-has not been explored in detail so far is the influence of circadian rhythms. Sleep and circadian rhythm disruption are known as key factors in neurodegeneration, and their occurrence during early disease stages suggests a causal role in the pathogenesis. Isolated rapid eye movement (REM) sleep behavior disorder (iRBD) has been identified as a prodromal state of α-synucleinopathies, such as Parkinson's disease, Lewy body dementia, and multiple system atrophy offering a window for insights into the early development of these diseases. Even though REM sleep is the sleep state most pronounced, driven and modulated by the circadian timing system, specific circadian abnormalities have not been described in iRBD. Novel experimental and clinical approaches exploiting the molecular circuitry underlying circadian timekeeping hold promise to disentangle some of the pathophysiologic mechanisms of α-synucleinopathies. In this review, we summarize current knowledge on sleep and circadian rhythm disruptions in α-synucleinopathies with an emphasis on molecular aspects and therapeutic potentials. These insights might contribute to our understanding of the pathogenesis of neurodegenerative diseases and may allow therapeutic interventions addressing the disturbed circadian system at the early stage of disease.

Long-Term Safety and Tolerability of Daridorexant in Patients with Insomnia Disorder.

BACKGROUND AND OBJECTIVE: Daridorexant is a dual orexin receptor antagonist for the treatment of insomnia. In two phase III, 12-week studies in patients with insomnia disorder, daridorexant improved sleep and daytime functioning while maintaining a favorable safety profile. The objective of this 40-week extension study was to assess the long-term safety and tolerability of daridorexant. METHODS: Adults with insomnia disorder who completed the 12-week studies were invited to enroll in this double-blind extension study. Patients originally randomised to daridorexant (10 mg/25 mg/50 mg) remained on their respective treatments; patients randomised to placebo were re-randomised to daridorexant 25 mg or placebo. The 40-week treatment period was followed by a 7-day placebo run-out. The primary objective was to assess safety/tolerability. Exploratory objectives were to evaluate the efficacy of daridorexant on sleep (self-reported total sleep time) and daytime functioning (Insomnia Daytime Symptoms and Impacts Questionnaire). RESULTS: In total, 804 patients were enrolled in the study, of whom 801 received at least one dose of the study treatment and 550 patients (68.4%) completed the study. Overall incidence of treatment-emergent adverse events was similar across groups (35-40%). Daridorexant did not induce next-morning sleepiness and no withdrawal-related symptoms or rebound were observed after treatment discontinuation. Improvements in sleep and daytime functioning were maintained through to the end of the study and were most pronounced with daridorexant 50 mg. Daridorexant 50 mg, compared with placebo, increased self-reported total sleep time by a least-squares mean of 20.4 (95% confidence interval [CI] 4.2, 36.5), 15.8 (95% CI - 0.8, 32.5) and 17.8 (95% CI - 0.4, 35.9) minutes and decreased (i.e., improved) Insomnia Daytime Symptoms and Impacts Questionnaire total scores by a least-squares mean of - 9.3 (95% CI - 15.1, - 3.6), - 9.5 (95% CI - 15.4, - 3.5) and - 9.1 (95% CI - 15.6, - 2.7), at weeks 12, 24 and 36 of the extension study, respectively. CONCLUSIONS: Treatment with daridorexant, for up to 12 months, was generally safe and well tolerated. Exploratory efficacy analyses suggest that the sustained improvements in sleep and daytime functioning with daridorexant 50 mg support its use for long-term treatment of insomnia disorder, without concerns of new safety signals. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov (NCT03679884) [first posted: 21 September, 2018], https://clinicaltrials.gov/ct2/show/NCT03679884 .

Insomnia disorder is the long-term inability to fall asleep or stay asleep with a significant impact on daily life. Left inadequately treated, this disorder may increase the risk of other health problems. For patients with insomnia disorder who require a sleep medication, many drugs are not recommended for long-term use and there is an unmet need for one that can be used safely and effectively over the long term. Daridorexant is a new insomnia treatment that was approved for adults following positive results in two 12-week clinical studies. Both studies showed that, in patients with insomnia disorder, daridorexant improved night-time sleep and patients' ability to function during the day, while avoiding major safety concerns. Patients who completed these two studies could continue into a 40-week extension study enabling the safety and tolerability of daridorexant to be investigated for up to 1 year. Treatment remained double blind for the entire 1-year period. The extension study showed that daridorexant, at all doses studied (10 mg, 25 mg, 50 mg), continued to be generally safe and well tolerated. Patients showed no signs of tolerance, physical dependence, rebound nor any excessive daytime sleepiness. Exploratory efficacy analyses suggest that improved night-time and daytime symptoms of insomnia were sustained, in particular with the highest approved dose, 50 mg, and there were no signs that the benefits of the drug were wearing off at the end of the 1 year. These results support the use of daridorexant 50 mg for the long-term treatment of insomnia disorder in adults.

Post-Illumination Pupil Response as a Biomarker for Cognition in α-Synucleinopathies.

Neurodegenerative processes in the brain are reflected by structural retinal changes. As a possible biomarker of cognitive state in prodromal α-synucleinopathies, we compared melanopsin-mediated post-illumination pupil response (PIPR) with cognition (CERAD-plus) in 69 patients with isolated REM-sleep behavior disorder. PIPR was significantly correlated with cognitive domains, especially executive functioning (r = 0.417, p < 0.001), which was more pronounced in patients with lower dopamine-transporter density, suggesting advanced neurodegenerative state (n = 26; r = 0.575, p = 0.002). Patients with mild neurocognitive disorder (n = 10) had significantly reduced PIPR (smaller melanopsin-mediated response) compared to those without (p = 0.001). Thus, PIPR may be a functional-possibly monitoring-marker for impaired cognitive state in (prodromal) α-synucleinopathies.

Inter-layer and inter-subject variability of diurnal gene expression in human skin.

The skin is the largest human organ with a circadian clock that regulates its function. Although circadian rhythms in specific functions are known, rhythms in the proximal clock output, gene expression, in human skin have not been thoroughly explored. This work reports 24 h gene expression rhythms in two skin layers, epidermis and dermis, in a cohort of young, healthy adults, who maintained natural, regular sleep-wake schedules. 10% of the expressed genes showed such diurnal rhythms at the population level, of which only a third differed between the two layers. Amplitude and phases of diurnal gene expression varied more across subjects than layers, with amplitude being more variable than phases. Expression amplitudes in the epidermis were larger and more subject-variable, while they were smaller and more consistent in the dermis. Core clock gene expression was similar across layers at the population-level, but were heterogeneous in their variability across subjects. We also identified small sets of biomarkers for internal clock phase in each layer, which consisted of layer-specific non-core clock genes. This work provides a valuable resource to advance our understanding of human skin and presents a novel methodology to quantify sources of variability in human circadian rhythms.

Expression of pancreatitis-associated protein after traumatic brain injury: a mechanism potentially contributing to neuroprotection in human brain.

Neuronal cell death after severe traumatic brain injury (TBI) is caused by a complex interplay of pathological mechanisms including excitotoxicity, oxidative stress, mitochondrial dysfunction, extensive neuroinflammation, and ischemia-reperfusion injury. Pancreatitis-associated protein I (PAP I/reg2) was reported to be a survival factor for peripheral neurons, particularly sensory and motor neurons. In rat brains, by experimental TBI as well as by kainic acid induced brain seizure, PAP I and PAP III were found to be up-regulated in central neurons. In this study, we performed immunohistochemical staining in postmortem human brain from patients who died after severe TBI to demonstrate PAP expression on protein level in cerebellar Purkinje cells, pyramidal and granular neurons in cerebral cortex, and cortical neurons in the fore- and mid-brain. In primary cultures of rat brain cortical, hippocampal, and cerebellar neurons, we found neuroprotective effects for PAP I on H(2)O(2)-induced oxidative stress. Moreover, serum K(+)-deprivation induces apoptotic cell death in 55% of cerebellar granule neurons (CGN), whereas upon treatment with PAP I only 32% of CGN are apoptotic. Using Western blot analyses, we compared protein phosphorylation in neuronal signaling pathways activated by PAP I versus Interleukin-6 (IL-6). We found a rapid activation of Akt-kinase phosphorylation by PAP I with a peak at 15 min, whereas IL-6 induces Akt-phosphorylation lasting longer than 30 min. Phosphorylation of MAP-42/44 kinases is stimulated in a comparable fashion. Both, IL-6 and PAP I increase phosphorylation of NFκB for activation of gene transcription, whereas only IL-6 recruits STAT3 phosphorylation, indicating that STAT3 is not a target of PAP I transcription activation in brain neurons. Application of the Akt-inhibitor Wortmanin reveals only a partial inhibition of PAP I-dependent protection of CGN from H(2)O(2)-induced oxidative stress. Based on our findings, we suggest that PAP I is a long lasting neurotrophic signal for central neurons. The neuroprotective effects parallel those that have been described for effects of PAP I in ciliary neurotrophic factor (CNTF)-mediated survival of sensory and motor neurons. PAP I may act in autocrine and/or paracrine fashion and thus may contribute to endogenous protective mechanisms relevant under harmful conditions like oxidative stress, brain injury, or neurodegeneration.