Dauvilliers, Yves

Abstract Isolated/idiopathic rapid-eye-movement (REM)-Sleep Behavior Disorder (iRBD) is characterized by dream enactment behaviors associated with loss of REM atonia. iRBD is in most cases a prodromal synucleinopathy, and emerging evidence suggests associations between RBD and other neurological and psychiatric conditions. In this study, we performed pathway-based polygenic risk score (PRS) and rare variant burden analyses to examine these potential associations. Pathway-specific PRS were constructed from genome-wide association study summary statistics of five neurodegenerative and seven psychiatric traits across 10 biologically relevant pathway categories, including a total of 279 pathways, in 1,573 iRBD cases and 16,022 controls from the International RBD Study Group and UK Biobank. Rare variant burden tests were performed in 1,264 iRBD cases and 2,581 controls. We identified multiple potential pathways indicating shared polygenic risk between RBD and both neurodegenerative and psychiatric disorders. Lewy body diseases and post-traumatic stress disorder had the most shared polygenic risk pathways in neurological and psychiatric disorders, respectively. Two pathways, the serotonin transport pathway and the chaperone-mediated autophagy pathway, showed the strongest association with iRBD, and gene-based rare variants analyses revealed five genes associated with iRBD: GBA1 , PLEKHM1 , LRP2 , P2RX1 , and HAP1. Subsequent analysis of these genes in Parkinson’s disease and dementia with Lewy bodies replicated several associations. Together, these findings provide novel insights into the shared genetic architecture underlying iRBD, neurodegenerative disorders, and psychiatric traits, with implications for early identification and mechanistic understanding.

Abstract Two recent studies suggested that the APOE ε4 haplotype was associated with increased α-synuclein pathology in cell and mouse models. Genetic variants in the SNCA region have strong association with Parkinson’s disease (PD), dementia with Lewy bodies (DLB) and idiopathic REM sleep behaviour disorder (iRBD), while APOE is a genetic risk determinant for only DLB. To determine if genetic-level interactions between SNCA and APOE exists that can explain the protein-level association, we investigated the genotypic interaction of APOE and SNCA in cohorts of PD, DLB and iRBD. We analysed genome-wide association study (GWAS) data from 5229 PD patients and 5480 controls, 2610 DLB patients and 1920 controls, and 1055 iRBD patients and 3667 controls. We used logistic regression interaction models across all three cohorts independently between the (i) top GWAS signals of SNCA single nucleotide polymorphisms (SNPs) and APOE haplotypes and (ii) SNP×SNP and three-way SNP interaction across the entire coding region plus 200 kb flanking each gene. No significant interactions were found to be associated with any of the synucleinopathies after correction for multiple testing. Our results do not support a role for genetic interactions between APOE and SNCA across PD, DLB and iRBD. Since the tested genetic variants affect the expression and function of these proteins, it is likely that any interactions between them do not affect the risk of PD, DLB and iRBD.

BACKGROUND: People with narcolepsy are at increased risk for hypertension and cardiovascular disease; excessive sodium intake is linked to both. METHODS: We studied patients with narcolepsy and office systolic blood pressures (BPs) of 130 to 155 mm Hg taking twice-nightly high-sodium oxybate for ≥6 weeks who switched to low-sodium oxybate at the same dosage. The primary end point was the change from baseline in mean 24-hour ambulatory systolic BP at the end of treatment (≈6 weeks after switching). Secondary and exploratory end points included changes in diastolic BP, office BP, and 24-hour sodium excretion. RESULTS: Patients (n=43) had a mean age of 45 years, were 65% female, 33% on antihypertensives, with baseline mean (SD) office BP of 138.0/85.2 (5.7/6.6). Mean (SD) total high- and low-sodium oxybate dosages of 8.0 (1.1) and 8.1 (1.1) g/night, respectively, represented 1456.5 (206.2) and 117.8 (16.3) mg of sodium. The median 24-hour urinary sodium was 4278 mg/d at baseline and 2703 mg/d at the end of treatment (median change, 1288 mg/d). Mean (SE) 24-hour ambulatory systolic BPs at baseline and study end were 132.3 (1.8) and 128.2 (1.8) mm Hg (least-squares mean change, −4.1 [95% CI, −6.9 to −1.4] mm Hg; 1-sided P =0.0019). BP changes by narcolepsy subtype, sex, body mass index, baseline office BP, and baseline antihypertensive use were consistent with the overall effect size. CONCLUSIONS: People with narcolepsy switching from high- to low-sodium oxybate showed substantially reduced daily medication-related sodium intake and significant 24-hour BP reductions. These results demonstrate the importance of reducing pharmaceutical sodium content in this elevated cardiovascular risk patient population. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT05869773.

Restless legs syndrome (RLS) is a frequent sleep-related sensorimotor disorder defined by an urge to move the legs in the evening while resting. Severe RLS symptoms can negatively impact sleep, mood, and quality of life. Periodic leg movements during sleep and wakefulness are found in 60% to 80% of patients with RLS. The pathophysiology of RLS and periodic leg movement is still poorly understood and involves brain iron deficiency, dopamine dysregulation, and genetic predisposition. Over the past decades, several cross-sectional and longitudinal studies have reported an association between RLS, cardiovascular disease, and hypertension although the magnitude, direction, and underlying mechanisms of these associations remain inconclusive. Periodic leg movements during sleep are concomitant with an increase in blood pressure and heart rate, which may affect the physiological nocturnal blood pressure dip and, therefore, lead to an increased incidence of cardiovascular disease. Insomnia and sleep deprivation linked to sensory discomfort could also increase the sympathetic tone and contribute to an increase in cardiovascular risk. Comorbidities and associated sleep disorders may also synergically increase cardiovascular risk. This narrative review details the current knowledge of RLS, a still underdiagnosed and poorly recognized disorder, and examines the epidemiological relationship between RLS, cardiovascular disease and hypertension, potential mechanisms underlying this association, and strategies to reduce the risk of cardiovascular disease in patients with moderate-to-severe RLS. Greater multidisciplinary collaborations between cardiologists and sleep specialists are needed to better identify, understand, and manage patients with sleep disorders, including those with RLS.

Atrial fibrillation (AF) is the most prevalent sustained cardiac arrhythmia, with its incidence rising due to aging populations, obesity, and advancements in diagnostic modalities. The interplay between sleep disorders and AF is increasingly recognized, with obstructive sleep apnea (OSA) serving as a well-established risk factor. However, emerging evidence implicates additional sleep disturbances—including central sleep apnea, insomnia, and restless legs syndrome—in AF pathogenesis and progression. Despite compelling observational data, interventional studies evaluating the impact of sleep disorder treatment on AF outcomes have yielded mixed results. Although continuous positive airway pressure therapy in patients with OSA mitigates AF recurrence, randomized controlled trials have yet to confirm a definitive causal benefit. This review synthesizes epidemiological, mechanistic, and interventional data linking sleep disorders to AF.

ObjectiveThis study assessed the relationship between speech and language impairment and outcome in a multicenter cohort of isolated/idiopathic rapid eye movement (REM) sleep behavior disorder (iRBD).MethodsPatients with iRBD from 7 centers speaking Czech, English, German, French, and Italian languages underwent a detailed speech assessment at baseline. Story‐tale narratives were transcribed and linguistically annotated using fully automated methods based on automatic speech recognition and natural language processing algorithms, leading to the 3 distinctive linguistic and 2 acoustic patterns of language deterioration and associated composite indexes of their overall severity. Patients were then prospectively followed and received assessments for parkinsonism or dementia during follow‐up. The Cox proportional hazard was performed to evaluate the predictive value of language patterns for phenoconversion over a follow‐up period of 5 years.ResultsOf 180 patients free of parkinsonism or dementia, 156 provided follow‐up information. After a mean follow‐up of 2.7 years, 42 (26.9%) patients developed neurodegenerative disease. Patients with higher severity of linguistic abnormalities (hazard ratio [HR = 2.35]) and acoustic abnormalities (HR = 1.92) were more likely to develop a defined neurodegenerative disease, with converters having lower content richness (HR = 1.74), slower articulation rate (HR = 1.58), and prolonged pauses (HR = 1.46). Dementia‐first (n = 16) and parkinsonism‐first with mild cognitive impairment (n = 9) converters had higher severity of linguistic abnormalities than parkinsonism‐first with normal cognition converters (n = 17).InterpretationAutomated language analysis might provide a predictor of phenoconversion from iRBD into synucleinopathy subtypes with cognitive impairment, and thus can be used to stratify patients for neuroprotective trials. ANN NEUROL 2024;95:530–543

AbstractSynucleinopathies‐related disorders such as Lewy body dementia (LBD) and isolated/idiopathic REM sleep behavior disorder (iRBD) have been associated with neuroinflammation. In this study, we examined whether the human leukocyte antigen (HLA) locus plays a role in iRBD and LBD. In iRBD, HLA‐DRB1*11:01 was the only allele passing FDR correction (OR = 1.57, 95% CI = 1.27–1.93, p = 2.70e‐05). We also discovered associations between iRBD and HLA‐DRB1 70D (OR = 1.26, 95%CI = 1.12–1.41, p = 8.76e‐05), 70Q (OR = 0.81, 95%CI = 0.72–0.91, p = 3.65e‐04) and 71R (OR = 1.21, 95%CI = 1.08–1.35, p = 1.35e‐03). Position 71 (pomnibus = 0.00102) and 70 (pomnibus = 0.00125) were associated with iRBD. Our results suggest that the HLA locus may have different roles across synucleinopathies.

ObjectiveThis multilanguage study used simple speech recording and high‐end pattern analysis to provide sensitive and reliable noninvasive biomarkers of prodromal versus manifest α‐synucleinopathy in patients with idiopathic rapid eye movement sleep behavior disorder (iRBD) and early‐stage Parkinson disease (PD).MethodsWe performed a multicenter study across the Czech, English, German, French, and Italian languages at 7 centers in Europe and North America. A total of 448 participants (337 males), including 150 with iRBD (mean duration of iRBD across language groups 0.5–3.4 years), 149 with PD (mean duration of disease across language groups 1.7–2.5 years), and 149 healthy controls were recorded; 350 of the participants completed the 12‐month follow‐up. We developed a fully automated acoustic quantitative assessment approach for the 7 distinctive patterns of hypokinetic dysarthria.ResultsNo differences in language that impacted clinical parkinsonian phenotypes were found. Compared with the controls, we found significant abnormalities of an overall acoustic speech severity measure via composite dysarthria index for both iRBD (p = 0.002) and PD (p < 0.001). However, only PD (p < 0.001) was perceptually distinct in a blinded subjective analysis. We found significant group differences between PD and controls for monopitch (p < 0.001), prolonged pauses (p < 0.001), and imprecise consonants (p = 0.03); only monopitch was able to differentiate iRBD patients from controls (p = 0.004). At the 12‐month follow‐up, a slight progression of overall acoustic speech impairment was noted for the iRBD (p = 0.04) and PD (p = 0.03) groups.InterpretationAutomated speech analysis might provide a useful additional biomarker of parkinsonism for the assessment of disease progression and therapeutic interventions. ANN NEUROL 2021;90:62–75

Objective Rapid eye movement sleep behavior disorder (RBD) is a prodromal synucleinopathy, as >80% will eventually convert to overt synucleinopathy. We performed an in‐depth analysis of the SNCA locus to identify RBD‐specific risk variants. Methods Full sequencing and genotyping of SNCA was performed in isolated/idiopathic RBD (iRBD, n = 1,076), Parkinson disease (PD, n = 1,013), dementia with Lewy bodies (DLB, n = 415), and control subjects (n = 6,155). The iRBD cases were diagnosed with RBD prior to neurodegeneration, although some have since converted. A replication cohort from 23andMe of PD patients with probable RBD (pRBD) was also analyzed (n = 1,782 cases; n = 131,250 controls). Adjusted logistic regression models and meta‐analyses were performed. Effects on conversion rate were analyzed in 432 RBD patients with available data using Kaplan–Meier survival analysis. Results A 5′‐region SNCA variant (rs10005233) was associated with iRBD (odds ratio [OR] = 1.43, p = 1.1E‐08), which was replicated in pRBD. This variant is in linkage disequilibrium (LD) with other 5′ risk variants across the different synucleinopathies. An independent iRBD‐specific suggestive association (rs11732740) was detected at the 3′ of SNCA (OR = 1.32, p = 4.7E‐04, not statistically significant after Bonferroni correction). Homozygous carriers of both iRBD‐specific SNPs were at highly increased risk for iRBD (OR = 5.74, p = 2E‐06). The known top PD‐associated variant (3′ variant rs356182) had an opposite direction of effect in iRBD compared to PD. Interpretation There is a distinct pattern of association at the SNCA locus in RBD as compared to PD, with an opposite direction of effect at the 3′ of SNCA . Several 5′ SNCA variants are associated with iRBD and with pRBD in overt synucleinopathies. ANN NEUROL 2020;87:584–598

There is increasing awareness that sleep disorders may be associated with increased perioperative risk. The Society of Anesthesia and Sleep Medicine created the Narcolepsy Perioperative Task Force: (1) to investigate the current state of knowledge of the perioperative risk for patients with narcolepsy, (2) to determine the viability of developing perioperative guidelines for the management of patients with narcolepsy, and (3) to delineate future research goals and clinically relevant outcomes. The Narcolepsy Perioperative Task Force established that there is evidence for increased perioperative risk in patients with narcolepsy; however, this evidence is sparse and based on case reviews, case series, and retrospective reviews. Mechanistically, there are a number of potential mechanisms by which patients with narcolepsy could be at increased risk for perioperative complications. These include aggravation of the disease itself, dysautonomia, narcolepsy-related medications, anesthesia interactions, and withdrawal of narcolepsy-related medications. At this time, there is inadequate research to develop an expert consensus or guidelines for the perioperative management of patients with narcolepsy. The paucity of available literature highlights the critical need to determine if patients with narcolepsy are at an increased perioperative risk and to establish appropriate research protocols and clearly delineated patient-centered outcomes. There is a real need for collaborative research among sleep medicine specialists, surgeons, anesthesiologists, and perioperative providers. This future research will become the foundation for the development of guidelines, or at a minimum, a better understanding how to optimize the perioperative care of patients with narcolepsy.