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.

Production of Noble-Metal Nanohelices Based on Nonlinear Dynamics in Electrodeposition of Binary Copper Alloys.

Spatiotemporal pattern formation is dynamic self-organization widely observed in nature and drives various functions. Among these functions, chirality plays a central role. The relationship between dynamic self-organization and chirality has been an open question; therefore, the production of chiral nanomaterials by dynamic self-organization has not been achieved. Here, we show that the confinement of a two-dimensional spatiotemporal micropattern via the electrodeposition of a binary Cu alloy into a nanopore induces mirror symmetry breaking to produce a helical nanostructure of the noble-metal component although it is still not yet possible to control the handedness at this stage. This result suggests that spatiotemporal symmetry breaking functions as a mirror symmetry breaking if cylindrical pores are given as the boundary condition. This study can be a model system of how spatiotemporal symmetry breaking plays a role in mirror symmetry breaking, and it proposes a new approach to producing helical nanomaterials through dynamic self-organization.

Risk Factors for Phenoconversion in Rapid Eye Movement Sleep Behavior Disorder.

OBJECTIVE: This study was undertaken to follow up predictive factors for α-synuclein-related neurodegenerative diseases in a multicenter cohort of idiopathic/isolated rapid eye movement sleep behavior disorder (iRBD). METHODS: Patients with iRBD from 12 centers underwent a detailed assessment for potential environmental and lifestyle risk factors via a standardized questionnaire at baseline. Patients were then prospectively followed and received assessments for parkinsonism or dementia during follow-up. The cumulative incidence of parkinsonism or dementia was estimated with competing risk analysis. Cox regression analyses were used to evaluate the predictive value of environmental/lifestyle factors over a follow-up period of 11 years, adjusting for age, sex, and center. RESULTS: Of 319 patients who were free of parkinsonism or dementia, 281 provided follow-up information. After a mean follow-up of 5.8 years, 130 (46.3%) patients developed neurodegenerative disease. The overall phenoconversion rate was 24.2% after 3 years, 44.8% after 6 years, and 67.5% after 10 years. Patients with older age (adjusted hazard ratio [aHR] = 1.05) and nitrate derivative use (aHR = 2.18) were more likely to phenoconvert, whereas prior pesticide exposure (aHR = 0.21-0.64), rural living (aHR = 0.53), lipid-lowering medication use (aHR = 0.59), and respiratory medication use (aHR = 0.36) were associated with lower phenoconversion risk. Risk factors for those converting to primary dementia and parkinsonism were generally similar, with dementia-first converters having lower coffee intake and beta-blocker intake, and higher occurrence of family history of dementia. INTERPRETATION: Our findings elucidate the predictive values of environmental factors and comorbid conditions in identifying RBD patients at higher risk of phenoconversion. ANN NEUROL 2022;91:404-416.

Dopaminergic imaging and clinical predictors for phenoconversion of REM sleep behaviour disorder.

This is an international multicentre study aimed at evaluating the combined value of dopaminergic neuroimaging and clinical features in predicting future phenoconversion of idiopathic REM sleep behaviour (iRBD) subjects to overt synucleinopathy. Nine centres sent 123I-FP-CIT-SPECT data of 344 iRBD patients and 256 controls for centralized analysis. 123I-FP-CIT-SPECT images were semiquantified using DaTQUANTTM, obtaining putamen and caudate specific to non-displaceable binding ratios (SBRs). The following clinical variables were also analysed: (i) Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale, motor section score; (ii) Mini-Mental State Examination score; (iii) constipation; and (iv) hyposmia. Kaplan-Meier survival analysis was performed to estimate conversion risk. Hazard ratios for each variable were calculated with Cox regression. A generalized logistic regression model was applied to identify the best combination of risk factors. Bayesian classifier was used to identify the baseline features predicting phenoconversion to parkinsonism or dementia. After quality check of the data, 263 iRBD patients (67.6 ± 7.3 years, 229 males) and 243 control subjects (67.2 ± 10.1 years, 110 males) were analysed. Fifty-two (20%) patients developed a synucleinopathy after average follow-up of 2 years. The best combination of risk factors was putamen dopaminergic dysfunction of the most affected hemisphere on imaging, defined as the lower value between either putamina (P < 0.000001), constipation, (P < 0.000001) and age over 70 years (P = 0.0002). Combined features obtained from the generalized logistic regression achieved a hazard ratio of 5.71 (95% confidence interval 2.85-11.43). Bayesian classifier suggested that patients with higher Mini-Mental State Examination score and lower caudate SBR asymmetry were more likely to develop parkinsonism, while patients with the opposite pattern were more likely to develop dementia. This study shows that iRBD patients older than 70 with constipation and reduced nigro-putaminal dopaminergic function are at high risk of short-term phenoconversion to an overt synucleinopathy, providing an effective stratification approach for future neuroprotective trials. Moreover, we provide cut-off values for the significant predictors of phenoconversion to be used in single subjects.

Brain Perfusion Single-Photon Emission Computed Tomography Using an Easy Z-Score Imaging System Predicts Progression to Neurodegenerative Dementia in Rapid Eye Movement Sleep Behavior Disorder.

INTRODUCTION: Longitudinal studies have reported that patients with idiopathic rapid eye movement sleep behavior disorder (IRBD) have an increased risk of developing synucleinopathies, such as Parkinson's disease and dementia with Lewy bodies (DLB). Clinical trials of disease-modifying therapies for IRBD patients require suitable biomarkers that can predict the short-term onset of neurodegenerative dementia. METHODS: We retrospectively examined if easy Z-score imaging system-specific volume-of-interest analysis (SVA) using brain perfusion single-photon emission computed tomography (SPECT) imaging or the cingulate island sign score can predict the short-term development of neurodegenerative dementia in 30 patients with IRBD. RESULTS: Ten patients (33.3%) who exceeded the thresholds for three indicators (severity, extent, and ratio) were included in an SVA-positive group, while 20 (66.7%) were included in an SVA-negative group. Nine (30.0%) IRBD patients had phenoconversion, of which eight had DLB and one had Parkinson's disease with dementia. In Kaplan-Meier analysis, patients in the SVA-positive group converted to neurodegenerative dementia in a significantly shorter period of time compared to patients in the SVA-negative group. CONCLUSIONS: These data suggest that SVA-positive IRBD patients have an increased short-term risk of developing neurodegenerative dementia.

Sudden onset of sleep caused by hypothalamic infarction: a case report.

BACKGROUND: Hypothalamic lesions, such as tumors and demyelinating diseases, reportedly cause abnormal sleepiness. However, stroke involving the hypothalamus has rarely been described. Here, we report a patient with infarction restricted to the hypothalamus who presented with sudden onset of sleep. CASE PRESENTATION: A 42-year-old woman with a history of migraine without aura presented with irresistible sleepiness and developed several episodes of sudden onset of sleep. Neurological examinations were unremarkable except for partial left Horner syndrome. Brain magnetic resonance imaging (MRI) revealed a high-intensity lesion restricted to the left hypothalamus on diffusion-weighted and fluid-attenuated inversion recovery MRI images. Cerebrospinal fluid (CSF) orexin-A levels obtained on hospital day 3 after her sleepiness had resolved were normal (337 pg/mL; normal > 200 pg/mL). Serum anti-nuclear and anti-aquaporin 4 (AQP4) antibodies and CSF myelin basic protein and oligoclonal band were negative. A small hypothalamic infarction was suspected, and the patient was treated with intravenous edaravone and argatroban, as well as oral clopidogrel. Three months later, there had been no clinical relapse, and the hypothalamic lesion had almost disappeared on follow-up MRI. No new lesion suggestive of demyelinating disease or tumor was observed. CONCLUSION: Hypothalamic stroke should be considered a cause of sudden onset of sleep.

A variant at 9q34.11 is associated with HLA-DQB1*06:02 negative essential hypersomnia.

Essential hypersomnia (EHS) is a lifelong disorder characterized by excessive daytime sleepiness without cataplexy. EHS is associated with human leukocyte antigen (HLA)-DQB1*06:02, similar to narcolepsy with cataplexy (narcolepsy). Previous studies suggest that DQB1*06:02-positive and -negative EHS are different in terms of their clinical features and follow different pathological pathways. DQB1*06:02-positive EHS and narcolepsy share the same susceptibility genes. In the present study, we report a genome-wide association study with replication for DQB1*06:02-negative EHS (408 patients and 2247 healthy controls, all Japanese). One single-nucleotide polymorphism, rs10988217, which is located 15-kb upstream of carnitine O-acetyltransferase (CRAT), was significantly associated with DQB1*06:02-negative EHS (P = 7.5 × 10-9, odds ratio = 2.63). The risk allele of the disease-associated SNP was correlated with higher expression levels of CRAT in various tissues and cell types, including brain tissue. In addition, the risk allele was associated with levels of succinylcarnitine (P = 1.4 × 10-18) in human blood. The leading SNP in this region was the same in associations with both DQB1*06:02-negative EHS and succinylcarnitine levels. The results suggest that DQB1*06:02-negative EHS may be associated with an underlying dysfunction in energy metabolic pathways.

The prevalence, course and clinical correlates of migraine in Parkinson's disease: A multicentre case-controlled study.

Background Previous studies have reported a lower migraine prevalence in Parkinson's disease (PD) patients and improvements in migraine headaches after PD onset, but the clinical association of migraines with PD is unclear. Methods We analysed headache and migraine prevalence and clinical correlates in 436 PD patients (mean age, 69.3 ± 7.8 years) and 401 age- and sex-matched controls (mean age, 69.2 ± 8.6 years) in a case-controlled, multicentre study. Migraines were diagnosed by a questionnaire developed according to the International Classification of Headache Disorders, second edition. We evaluated changes in headache intensity, frequency and severity over several years around the onset of PD among PD patients with headaches or migraines, and over the past several years among control subjects with headaches or migraines. Results PD patients had lower lifetime (9.6% vs. 18.0%) and 1-year (6.7% vs. 11.0%) migraine prevalences than controls. However, lifetime (38.5% vs. 38.9%) and 1-year (26.1% vs. 26.2%) headache prevalence did not differ between PD patients and controls. After adjusting for gender, timing of the evaluation of headache changes, and recall period, PD patients with headaches or migraines exhibited a pronounced reduction in the intensity, frequency and overall severity of their headaches and migraines after the onset of PD compared with controls with headaches or migraines. PD patients with migraines exhibited a higher rate of depression and higher Pittsburgh Sleep Quality Index and PD sleep scale-2 scores than those without headaches. Conclusion While overall headache and migraine severity reduced after PD onset, the presence of migraines was associated with sleep disturbances and depression in PD patients.

New susceptibility variants to narcolepsy identified in HLA class II region.

Narcolepsy, a sleep disorder characterized by excessive daytime sleepiness, cataplexy and rapid eye movement sleep abnormalities, is tightly associated with human leukocyte antigen HLA-DQB1*06:02. DQB1*06:02 is common in the general population (10-30%); therefore, additional genetic factors are needed for the development of narcolepsy. In the present study, HLA-DQB1 in 664 Japanese narcoleptic subjects and 3131 Japanese control subjects was examined to determine whether HLA-DQB1 alleles located in trans of DQB1*06:02 are associated with narcolepsy. The strongest association was with DQB1*06:01 (P = 1.4 × 10(-10), odds ratio, OR = 0.39), as reported in previous studies. Additional predisposing effects of DQB1*03:02 were also found (P = 2.5 × 10(-9), OR = 1.97). A comparison between DQB1*06:02 heterozygous cases and controls revealed dominant protective effects of DQB1*06:01 and DQB1*05:01. In addition, a single-nucleotide polymorphism-based conditional analysis controlling for the effect of HLA-DQB1 was performed to determine whether there were other independent HLA associations outside of HLA-DQB1. This analysis revealed associations at HLA-DPB1 in the HLA class II region (rs3117242, P = 4.1 × 10(-5), OR = 2.45; DPB1*05:01, P = 8.1 × 10(-3), OR = 1.39). These results indicate that complex HLA class II associations contribute to the genetic predisposition to narcolepsy.

Impact of sleep-related symptoms on clinical motor subtypes and disability in Parkinson's disease: a multicentre cross-sectional study.

OBJECTIVES: To investigate the impact of sleep disturbances on Parkinson's disease (PD) clinical motor subtypes and disease-related disability in a multicentre setting. METHODS: We report a cross-sectional relationship between sleep-related symptoms and clinical motor subtypes (tremor dominant (TD); intermediate; postural instability and gait disturbances (PIGDs)) identified in a multicentre study, including 436 patients with PD and 401 age-matched controls. PD-related sleep problems (PD-SP), excessive daytime sleepiness (EDS) and probable REM sleep behaviour disorder (pRBD) were evaluated using the PD sleep scale (PDSS)-2, Epworth Sleepiness Scale (ESS) and RBD screening questionnaire-Japanese version (RBDSQ-J), respectively. RESULTS: PD-SP (PDSS-2 ≥18; 35.1% vs 7.0%), EDS (ESS ≥10; 37.8% vs 15.5%) and pRBD (RBDSQ-J ≥5; 35.1% vs 7.7%) were more common in patients with PD than in controls. The prevalence of restless legs syndrome did not differ between patients with PD and controls (3.4% vs 2.7%). After adjusting for age, sex, disease duration and Movement Disorder Society-Unified PD Rating Scale (MDS-UPDRS) part III score, the PIGD group had higher PDSS-2 and ESS scores than the TD group. The RBDSQ-J scores did not differ among the TD, intermediate and PIGD groups. A stepwise regression model predicting the MDS-UPDRS part II score identified the Hoehn and Yahr stage, followed by the number of sleep-related symptoms (PD-SP, EDS and pRBD), disease duration, MDS-UPDRS part III score, PIGD subtype, depression and MDS-UPDRS part IV score as significant predictors. CONCLUSION: Our study found a significant relationship between sleep disturbances and clinical motor subtypes. An increased number of sleep-related symptoms had an impact on disease-related disability.

Risk factors for neurodegeneration in idiopathic rapid eye movement sleep behavior disorder: a multicenter study.

OBJECTIVE: To assess whether risk factors for Parkinson disease and dementia with Lewy bodies increase rate of defined neurodegenerative disease in idiopathic rapid eye movement (REM) sleep behavior disorder (RBD). METHODS: Twelve centers administered a detailed questionnaire assessing risk factors for neurodegenerative synucleinopathy to patients with idiopathic RBD. Variables included demographics, lifestyle factors, pesticide exposures, occupation, comorbid conditions, medication use, family history, and autonomic/motor symptoms. After 4 years of follow-up, patients were assessed for dementia or parkinsonism. Disease risk was assessed with Kaplan-Meier analysis, and epidemiologic variables were compared between convertors and those still idiopathic using logistic regression. RESULTS: Of 305 patients, follow-up information was available for 279, of whom 93 (33.3%) developed defined neurodegenerative disease. Disease risk was 25% at 3 years and 41% after 5 years. Patients who converted were older (difference = 4.5 years, p < 0.001), with similar sex distribution. Neither caffeine, smoking, nor alcohol exposure predicted conversion. Although occupation was similar between groups, those who converted had a lower likelihood of pesticide exposure (occupational insecticide = 2.3% vs 9.0%). Convertors were more likely to report family history of dementia (odds ratio [OR] = 2.09), without significant differences in Parkinson disease or sleep disorders. Medication exposures and medical history were similar between groups. Autonomic and motor symptoms were more common among those who converted. Risk factors for primary dementia and parkinsonism were generally similar, except for a notably higher clonazepam use in dementia convertors (OR = 2.6). INTERPRETATION: Patients with idiopathic RBD are at very high risk of neurodegenerative synucleinopathy. Risk factor profiles between convertors and nonconvertors have both important commonalities and differences.

A polymorphism in CCR1/CCR3 is associated with narcolepsy.

Etiology of narcolepsy-cataplexy involves multiple genetic and environmental factors. While the human leukocyte antigen (HLA)-DRB1*15:01-DQB1*06:02 haplotype is strongly associated with narcolepsy, it is not sufficient for disease development. To identify additional, non-HLA susceptibility genes, we conducted a genome-wide association study (GWAS) using Japanese samples. An initial sample set comprising 409 cases and 1562 controls was used for the GWAS of 525,196 single nucleotide polymorphisms (SNPs) located outside the HLA region. An independent sample set comprising 240 cases and 869 controls was then genotyped at 37 SNPs identified in the GWAS. We found that narcolepsy was associated with a SNP in the promoter region of chemokine (C-C motif) receptor 1 (CCR1) (rs3181077, P=1.6×10(-5), odds ratio [OR]=1.86). This rs3181077 association was replicated with the independent sample set (P=0.032, OR=1.36). We measured mRNA levels of candidate genes in peripheral blood samples of 38 cases and 37 controls. CCR1 and CCR3 mRNA levels were significantly lower in patients than in healthy controls, and CCR1 mRNA levels were associated with rs3181077 genotypes. In vitro chemotaxis assays were also performed to measure monocyte migration. We observed that monocytes from carriers of the rs3181077 risk allele had lower migration indices with a CCR1 ligand. CCR1 and CCR3 are newly discovered susceptibility genes for narcolepsy. These results highlight the potential role of CCR genes in narcolepsy and support the hypothesis that patients with narcolepsy have impaired immune function.

Parkinson's disease and sleep/wake disturbances.

Sleep disturbances are a common non-motor feature in patients with Parkinson's disease (PD). Early diagnosis and appropriate management are imperative for enhancing patient quality of life. Sleep disturbances can be caused by multiple factors in addition to age-related changes in sleep, such as nocturnal motor symptoms (rigidity, resting tremor, akinesia, tardive dyskinesia, and the "wearing off" phenomenon), non-motor symptoms (pain, hallucination, and psychosis), nocturia, and medication. Disease-related pathology involving the brainstem and changes in the neurotransmitter systems (norepinephrine, serotonin, and acetylcholine) responsible for regulating sleep structure and the sleep/wake cycle play a role in emerging excessive daytime sleepiness and sleep disturbances. Additionally, screening for sleep apnea syndrome, rapid eye movement sleep behavior disorder, and restless legs syndrome is clinically important. Questionnaire-based assessment utilizing the PD Sleep Scale-2 is useful for screening PD-related nocturnal symptoms. In this review, we focus on the current understanding and management of sleep disturbances in PD.

Sleep apnoea headache in obstructive sleep apnoea syndrome patients presenting with morning headache: comparison of the ICHD-2 and ICHD-3 beta criteria.

BACKGROUND: Morning headache is associated with obstructive sleep apnoea syndrome (OSAS); however, OSAS patients present with various characteristics of morning headache, and they often do not fulfil the International Classification of Headache Disorders (ICHD)-2 criteria for "sleep apnoea headache". The aims of this study were to assess the new ICHD-3 beta criteria for sleep apnoea headache in OSAS patients and to evaluate the differences with the ICHD-2. METHODS: We conducted a cross-sectional survey regarding morning and sleep apnoea headaches that included 235 OSAS outpatients receiving continuous positive airway pressure (CPAP) treatment. The presence of morning headache was evaluated by reviewing the medical records before administration of CPAP treatment. RESULTS: Of all of the OSAS patients, 48 (20.4%) reported morning headaches. Of the 48 patients with morning headaches, 29 (60.4%) and 39 (81.3%) fulfilled the ICHD-2 and ICHD-3 beta criteria for sleep apnoea headache, respectively. The increased frequency of individuals who qualified for diagnosis was likely attributable to the extension of headache duration from 30 min to 4 h. The severity of OSAS was not associated with the presence of sleep apnoea headache. CONCLUSIONS: The utilisation of ICHD-3 beta criteria is clinically useful for diagnosing sleep apnoea headache in patients with OSAS. Applying the ICHD-3 beta criteria was of clinical significance when considering the marked response of these headaches to CPAP therapy. The cause of sleep apnoea headache remains to be elucidated.

[Sleep related movement disorders].

Sleep related movement disorders (SRMD) are characterized by simple, stereotyped movements occur during sleep, with the exception of restless legs syndrome (RLS). RLS has the following essential features; an urge to move the legs usually accompanied by uncomfortable sensation in the legs, improvement of symptoms after movement (non-stereotypical movements, such as walking and stretching, to reduce symptoms), and symptoms occur or worsen during periods of rest and in the evening and night. However, RLS is closely associated with periodic limb movement, which shows typical stererotyped limb movements. In the International Classification of Sleep Disorders, 3rd edition, sleep disturbances or daytime symptoms are prerequiste for a diagnosis of SRMD. We here review diagnosis and treatment of SRMD.

Reduced cardiac 123I-MIBG uptake is a robust biomarker of Lewy body disease in isolated rapid eye movement sleep behaviour disorder.

Cardiac 123I-MIBG scintigraphy is used to assess the function of postganglionic presynaptic cardiac sympathetic nerve endings. 123I-MIBG cardiac uptake is markedly reduced in patients with isolated rapid eye movement sleep behaviour disorder, similar to Parkinson's disease and dementia with Lewy bodies. As a result, it can be used as an early biomarker of isolated rapid eye movement sleep behaviour disorder. Most patients with isolated rapid eye movement sleep behaviour disorder develop synucleinopathies: Parkinson's disease, dementia with Lewy bodies or multiple system atrophy. We aimed to investigate whether cardiac postganglionic denervation is present in patients with isolated rapid eye movement sleep behaviour disorder, as well as its possible usefulness as a marker for Lewy body disease status. This retrospective cohort study examined 306 patients (236 men and 70 women; mean age: 68.2 years; age range: 43-87 years) with polysomnography-confirmed isolated rapid eye movement sleep behaviour disorder who were followed for 1-3 months and underwent 123I-MIBG scintigraphy. We retrospectively analysed data from 306 patients with polysomnography-confirmed isolated rapid eye movement sleep behaviour disorder, and their longitudinal outcomes were documented at two centres. Among isolated rapid eye movement sleep behaviour disorder patients, reduced 123I-MIBG uptake was observed in the early and delayed images in 84.4 and 93.4% of patients, respectively, whereas 88.6% of the patients had a high washout rate. This large Japanese two-cohort study (n = 306) found that 91 patients (29.7%) developed an overt synucleinopathy (51 Parkinson's disease, 35 dementia with Lewy bodies, 4 multiple system atrophy, and 1 cerebellar ataxia) during a mean follow-up duration of 4.72 ± 3.94 years, with a conversion risk of 14.5% at 3 years, 25.4% at 5 years, 41.4% at 8 years and 52.5% at 10 years. On the other hand, among patients with heart-to-mediastinum ratio < 2.2 in the delayed images (n = 286), 85 (29.7%) developed Parkinson's disease or dementia with Lewy bodies during a mean follow-up duration of 4.71 ± 3.94 years, with a conversion risk of 14.5% at 3 years, 25.6% at 5 years, 42.0% at 8 years and 51.0% at 10 years. Among the 33 patients who underwent repeat 123I-MIBG scintigraphy, there was a progressive decline in uptake over the next 4.2 years, with patients exhibiting reduced uptake progressing to Parkinson's disease or dementia with Lewy bodies. In contrast, patients without decreased 123I-MIBG uptake progressed to multiple system atrophy. Reduced cardiac 123I-MIBG uptake was detected in over 90% of isolated rapid eye movement sleep behaviour disorder patients, with progression to Parkinson's disease or dementia with Lewy bodies, rather than multiple system atrophy, over time. Reduced 123I-MIBG uptake is a robust maker for Lewy body disease among isolated rapid eye movement sleep behaviour disorder patients.

Dream-enacting behaviour is associated with impaired sleep and severe headache-related disability in migraine patients.

BACKGROUND: Sleep disorders, nightmares and visual hallucinations have been reported in migraine patients, which may suggest the involvement of rapid eye movement (REM) sleep regulation in migraine. However, the relationship between migraine and REM sleep behaviour disorder (RBD) remains unclear. METHODS: To investigate the clinical correlates of dream-enacting behaviours (DEB) in migraine patients, we assessed episodic migraine patients ( N = 161, mean age 33.1 years) and headache-free control subjects ( N = 140, mean age 33.1 years) under 50 years of age in a cross-sectional, case-control study. The Japanese version of the RBD screening questionnaire was used, and subjects scoring 5 or higher were defined as having DEB. RESULTS: A significantly increased frequency of DEB was observed in migraine patients compared to controls (24.2% vs. 14.3%). Migraine patients with DEB presented higher scores on the Migraine Disability Assessment and Pittsburgh Sleep Quality Index and an increased rate of smoking compared to those without DEB. Duration of migraine and headache frequency and intensity were not different between migraine patients with or without DEB. CONCLUSION: DEB was associated with impaired sleep and severe headache-related disability in migraine patients and may reflect brainstem dysfunction and increased brain excitability in migraine patients.

Probable rapid eye movement sleep behavior disorder, nocturnal disturbances and quality of life in patients with Parkinson's disease: a case-controlled study using the rapid eye movement sleep behavior disorder screening questionnaire.

BACKGROUND: Increasing evidence provides a clear association between rapid eye movement sleep behavior disorders (RBD) and Parkinson's disease (PD), but the clinical features that determine the co-morbidity of RBD and PD are not yet fully understood. METHODS: We evaluated the characteristics of nocturnal disturbances and other motor and non-motor features related to RBD in patients with PD and the impact of RBD on their quality of life. Probable RBD (pRBD) was evaluated using the Japanese version of the RBD screening questionnaire (RBDSQ-J). RESULTS: A significantly higher frequency of pRBD was observed in PD patients than in the controls (RBDSQ-J ≥ 5 or ≥ 6: 29.0% vs. 8.6%; 17.2% vs. 2.2%, respectively). After excluding restless legs syndrome and snorers in the PD patients, the pRBD group (RBDSQ-J≥5) showed higher scores compared with the non-pRBD group on the Parkinson's disease sleep scale-2 (PDSS-2) total and three-domain scores. Early morning dystonia was more frequent in the pRBD group. The Parkinson's Disease Questionnaire (PDQ-39) domain scores for cognition and emotional well-being were higher in the patients with pRBD than in the patients without pRBD. There were no differences between these two groups with respect to the clinical subtype, disease severity or motor function. When using a cut-off of RBDSQ-J = 6, a similar trend was observed for the PDSS-2 and PDQ-39 scores. Patients with PD and pRBD had frequent sleep onset insomnia, distressing dreams and hallucinations. The stepwise linear regression analysis showed that the PDSS-2 domain "motor symptoms at night", particularly the PDSS sub-item 6 "distressing dreams", was the only predictor of RBDSQ-J in PD. CONCLUSION: Our results indicate a significant impact of RBD co-morbidity on night-time disturbances and quality of life in PD, particularly on cognition and emotional well-being. RBDSQ may be a useful tool for not only screening RBD in PD patients but also predicting diffuse and complex clinical PD phenotypes associated with RBD, cognitive impairment and hallucinations.

Montreal Cognitive Assessment Predicts the Short-Term Risk of Lewy Body Disease in Isolated REM Sleep Behavior Disorder with Reduced MIBG Scintigraphy.

Background: Long-term follow-up of isolated rapid eye movement (REM) sleep behavior disorder (IRBD) patients reveals a high risk of α-synucleinopathies. Objective: We explored the early clinical predictive factors of phenoconversion from IRBD to Parkinson's disease (PD) or dementia with Lewy bodies (DLB). Methods: We assessed baseline office-based cognitive test scores (Montreal Cognitive Assessment [MoCA-J], Mini-Mental State Examination [MMSE], and Frontal Assessment Battery [FAB]), motor function, and olfactory function in 36 consecutive polysomnography (PSG)-confirmed IRBD patients with reduced metaiodobenzylguanidine (MIBG) accumulation. PD or DLB was confirmed by medical chart review retrospectively. Results: Of 36 IRBD patients, 19 (n = 19, 52.8%) with abnormal MoCA-J score (< 26) had significantly lower scores in trail making B, phonetic verbal fluency sub-items in the executive domain, and in delayed recall in the memory domain. In total, 12 (33.3%) patients developed PD or DLB; seven of 12 patients (58.3%) developed DLB at a mean follow-up period of 6.8 years. In the normal MoCA-J group (n = 17, 47.2%), two patients developed PD, but none developed dementia. Furthermore, in the abnormal MoCA-J group, seven patients developed DLB and three developed PD without dementia. The phenoconverter group had significantly lower scores in delayed recall in the memory domain compared to the disease-free group. Cox hazard analysis showed that MoCA-J was superior to MMSE. Conclusions: Among IRBD patients with reduced cardiac MIBG accumulation, MoCA-J score of <26 (Mild Cognitive Impairment-Lewy body) and a low sub-item score for delayed recall predicted short-term progression to probable DLB.

A single-question screen for rapid eye movement sleep behavior disorder: a multicenter validation study.

BACKGROUND: Idiopathic rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia that is an important risk factor for Parkinson's disease (PD) and Lewy body dementia. Its prevalence is unknown. One barrier to determining prevalence is that current screening tools are too long for large-scale epidemiologic surveys. Therefore, we designed the REM Sleep Behavior Disorder Single-Question Screen (RBD1Q), a screening question for dream enactment with a simple yes/no response. METHODS: Four hundred and eighty-four sleep-clinic-based participants (242 idiopathic RBD patients and 242 controls) completed the screen during a multicenter case-control study. All participants underwent a polysomnogram to define gold-standard diagnosis according to standard criteria. RESULTS: We found a sensitivity of 93.8% and a specificity of 87.2%. Sensitivity and specificity were similar in healthy volunteers, compared to controls or patients with other sleep diagnoses. CONCLUSIONS: A single-question screen for RBD may reliably detect disease, with psychometric properties favorably comparable to those reported for longer questionnaires.