SNCA 3'UTR genetic variants in patients with Parkinson's disease and REM sleep behavior disorder.

REM sleep behavior disorder (RBD) is an early marker of Parkinson's disease (PD); however, it is still unclear which patients with RBD will eventually develop PD. Single nucleotide polymorphisms (SNPs) in the 3'untranslated region (3'UTR) of alpha-synuclein (SNCA) have been associated with PD, but at present, no data is available about RBD. The 3'UTR hosts regulatory regions involved in gene expression control, such as microRNA binding sites. The aim of this study was to determine RBD specific genetic features associated to an increased risk of progression to PD, by sequencing of the SNCA-3'UTR in patients with "idiopathic" RBD (iRBD) and in patients with PD. We recruited 113 consecutive patients with a diagnosis of iRBD (56 patients) or PD (with or without RBD, 57 patients). Sequencing of SNCA-3'UTR was performed on genomic DNA extracted from peripheral blood samples. Bioinformatic analyses were carried out to predict the potential effect of the identified genetic variants on microRNA binding. We found three SNCA-3'UTR SNPs (rs356165, rs3857053, rs1045722) to be more frequent in PD patients than in iRBD patients (p = 0.014, 0.008, and 0.008, respectively). Four new or previously reported but not annotated specific genetic variants (KP876057, KP876056, NM_000345.3:c*860T>A, NM_000345.3:c*2320A>T) have been observed in the RBD population. The in silico approach highlighted that these variants could affect microRNA-mediated gene expression control. Our data show specific SNPs in the SNCA-3'UTR that may bear a risk for RBD to be associated with PD. Moreover, new genetic variants were identified in patients with iRBD.

Sleep continuity scale in Alzheimer's disease (SCADS): application in daily clinical practice in an Italian center for dementia.

Sleep disorders can occur in many neurodegenerative disorders; in a previous paper we constructed a scale investigating sleep discontinuity/fragmentation with the aim to obtain a rapidly and easily administered tool suitable for early identification and longitudinal monitoring of sleep disturbances in Alzheimer's disease (AD). We introduced this instrument in the daily clinical practice in a center for dementia; here we present the results of our experience. Two hundred and sixteen AD outpatients referred to the Alzheimer's Disease Assessment Unit at the IRCCS C. Mondino National Neurological Institute, Pavia, Italy, in the period October 2012 to March 2014 were administered the scale. The questionnaire global score was correlated with measures of cognitive, functional and behavioral impairment; a significant association was found with Mini-Mental State (p = 0.005), Activities of Daily Living (p = 0.01), Neuropsychiatric Inventory (p = 0.01) and Clinical Dementia Rating (p = 0.0005). The present data indicate that the previously validated questionnaire proves to be a suitable, rapid and easy to use tool in investigating sleep quality in AD in daily clinical practice. An early identification and longitudinal monitoring of sleep disturbances in AD may improve pharmacological and non-pharmacological interventions.

Interspecific variation in functional traits of oak seedlings (Quercus ilex, Quercus trojana, Quercus virgiliana) grown under artificial drought and fire conditions.

To face summer drought and wildfire in Mediterranean-type ecosystems, plants adopt different strategies that involve considerable rearrangements of biomass allocation and physiological activity. This paper analyses morphological and physiological traits in seedlings of three oak species (Quercus ilex, Quercus trojana and Quercus virgiliana) co-occurring under natural conditions. The aim of this study was to evaluate species-specific characteristics and the response of these oak seedlings to drought stress and fire treatment. Seedlings were kept in a growth chamber that mimicked natural environmental conditions. All three species showed a good degree of tolerance to drought and fire treatments. Differences in specific biomass allocation patterns and physiological traits resulted in phenotypic differences between species. In Q. ilex, drought tolerance depended upon adjustment of the allocation pattern. Q. trojana seedlings undergoing mild to severe drought presented a higher photosystem II (PSII) efficiency than control seedlings. Moreover, Q. trojana showed a very large root system, which corresponded to higher soil area exploitation, and bigger leaf midrib vascular bundles than the other two species. Morphological and physiological performances indicated Q. trojana as the most tolerant to drought and fire. These characteristics contribute to a high recruitment potential of Q. trojana seedlings, which might be the reason for the dominance of this species under natural conditions. Drought increase as a result of climate change is expected to favour Q. trojana, leading to an increase in its spatial distribution.

A sleep continuity scale in Alzheimer's disease: validation and relationship with cognitive and functional deterioration.

Considering that disrupted sleep may be detrimental to daytime performance in people with dementia, we set out to construct a questionnaire able to identify sleep patterns potentially associated with clinical and functional disease variables in this population. Two subsets of items indicative of patterns of unstable sleep and of disordered rapid eye movement sleep (REM) were selected. The first included items investigating sleep continuity, with low sleep continuity markers considered indicative of high arousability; the second included items investigating the frequency and quality of dreams and the frequency of clinically identifiable REM sleep behaviour disorder episodes. The questionnaire was administered to 140 outpatients with a diagnosis of mild-to-moderate Alzheimer's disease. The Mini-Mental State Examination (MMSE), Activities of Daily Living (ADL), Instrumental Activities of Daily Living, Neuropsychiatric Inventory and Clinical Dementia Rating (CDR) were administered to quantify cognitive, functional and behavioural impairment. A subscale comprising items investigating sleep discontinuity/fragmentation and showing high internal consistency was constructed and found to correlate significantly with variables considered indexes of cognitive and functional deterioration in AD (MMSE, ADL and CDR). Conversely, it did not prove possible to obtain a subscale of dysfunctional REM phenomena. The use of a rapidly and easily administered sleep scale, like the one we constructed, appears to be suitable for early identification and longitudinal monitoring of sleep disturbances in AD.

Factors associated with treatment escalation among MS specialists and general neurologists: Results from an International cojoint study.

BACKGROUND: Previous studies in multiple sclerosis (MS) showed that therapeutic inertia (TI) affects 60-90% of neurologists and up to 25% of daily treatment decisions. The objective of this study was to determine the most common factors and attribute levels associated with decisions to treatment escalation in an international study in MS care. METHODS: 300 neurologists with MS expertise from 20 countries were invited to participate. Participants were presented with 12 pairs of simulated MS patient profiles described by 13 clinically relevant factors. We used disaggregated discrete choice experiments to estimate the weight of factors and attributes affecting physicians' decisions when considering treatment selection. Participants were asked to select the ideal candidate for treatment escalation from modest to higher-efficacy therapies. RESULTS: Overall, 229 neurologists completed the study (completion rate: 76.3%). The top 3 weighted factors associated with treatment escalation were: previous relapses (20%), baseline expanded disability status scale [EDSS] (18%), and MRI activity (13%). Patient demographics and desire for pregnancy had a modest influence (≤ 3%). We observed differences in the weight of factors associated with treatment escalation between MS specialists and non-MS specialists. CONCLUSIONS: Our results provide critical information on factors influencing neurologists' treatment decisions and should be applied to continuing medical education strategies.

Anodal transcranial direct current stimulation in chronic migraine and medication overuse headache: A pilot double-blind randomized sham-controlled trial.

OBJECTIVES: Little evidence is available on the role of transcranial direct current stimulation (tDCS) in patients affected by chronic migraine (CM) and medication overuse headache (MOH). We aim to investigate the effects of tDCS in patients with CM and MOH as well as its role on brain activity. METHODS: Twenty patients with CM and MOH were hospitalized for a 7-day detoxification treatment. Upon admission, patients were randomly assigned to anodal tDCS or sham stimulation delivered over the primary motor cortex contralateral to the prevalent migraine pain side every day for 5 days. Clinical data were recorded at baseline (T0), after 1 month (T2) and 6 months (T3). EEG recording was performed at T0, at the end of the tDCS/Sham treatment, and at T2. RESULTS: At T2 and T3, we found a significant reduction in monthly migraine days (p = 0.001), which were more pronounced in the tDCS group when compared to the sham group (p = 0.016). At T2, we found a significant increase of alpha rhythm in occipital leads, which was significantly higher in tDCS group when compared to sham group. CONCLUSIONS: tDCS showed adjuvant effects to detoxification in the management of patients with CM and MOH. The EEG recording showed a significant potentiation of alpha rhythm, which may represent a correlate of the underlying changes in cortico-thalamic connections. SIGNIFICANCE: This study suggests a possible role for tDCS in the treatment of CM and MOH. The observed clinical improvement is coupled with a potentiation of EEG alpha rhythm.

Correlation between HLA-DQB1*06:02 and narcolepsy with and without cataplexy: approving a safe and sensitive genetic test in four major ethnic groups. A systematic meta-analysis.

STUDY OBJECTIVES: we performed a meta-analysis to assess the usefulness of HLA testing for Narcolepsy diagnosis in four major ethnical groups: Asians, Afro-Americans, Amerindians and Caucasians. METHODS: PubMed, EMBASE, Web of Science, Scopus and Cochrane databases were searched for articles in English and French published before October 2017 on HLA class II alleles in Narcolepsy. We included case-control studies, cross-sectional and retrospective cohort studies with patients diagnosed following the International classifications of sleep disorders (1990-2012) and ethnically matched controls. Following PRISMA guidelines, two investigators independently extracted data according to the inclusion criteria listed in PROSPERO CRD42017058677. A third researcher was consulted for discrepancies. We extracted and pooled adjusted OR using random-effect models. We verified the strength of the association between HLA-DQB1*06:02 and the worldwide distribution of Narcolepsy type 1 (NT1) and type 2 (NT2); furthermore, we pooled the OR measuring the association between HLA-DQB1*06:02 and NT1, NT2 and hypersomniacs. RESULTS: We identified 511 titles. Of these, 12 case-control studies were included, for a total of 2077 NT1 patients, 235 NT2 patients, 161 hypersomniacs and 7802 controls. In the population-stratified analysis, HLA-DQB1*06:02 conferred an increased risk for NT1 (OR: 24.1, IC: 14.6-39.5, p < 0.001) and NT2 (OR: 3.9; IC: 2.2-6.8, p < 0.001). For NT1 the pooled estimated positive Likelihood Ratio (LR+) was 5.94 (IC: 3.71-9.51) and the negative Likelihood Ratio (LR-) was 0.23 (IC: 0.16-0.33); for NT2 LR+ was 3.35 (IC: 2.08-5.38) and LR- 0.72 (IC: 0.63-0.81). Moreover, for hypersomniacs LR+ was 1.436 (IC 0.668-3.089) and LR- 0.903 (IC 0.714-1.142). CONCLUSIONS: Our data support the preponderant role of HLA-DQB1*06:02 in susceptibility to NT1/NT2 across all ethnicities. HLA-DQB1*06:02 negativity should make clinicians cautious in excluding other diagnoses.

Transcription factors PRE3 and WOX11 are involved in the formation of new lateral roots from secondary growth taproot in A. thaliana.

The spatial deployment of lateral roots determines the ability of a plant to interact with the surrounding environment for nutrition and anchorage. This paper shows that besides the pericycle, the vascular cambium becomes active in Arabidopsis thaliana taproot at a later stage of development and is also able to form new lateral roots. To demonstrate the above, we implemented a two-step approach in which the first step leads to development of a secondary structure in A. thaliana taproot, and the second applies a mechanical stress on the vascular cambium to initiate formation of a new lateral root primordium. GUS staining showed PRE3, DR5 and WOX11 signals in the cambial zone of the root during new lateral root formation. An advanced level of wood formation, characterized by the presence of medullar rays, was achieved. Preliminary investigations suggest the involvement of auxin and two transcription factors (PRE3/ATBS1/bHLH135/TMO7 and WOX11) in the transition of some vascular cambium initials from a role as producers of xylem/phloem mother cells to founder cells of a new lateral root primordium.

Sleep disorders in Parkinson's disease: facts and new perspectives.

Awareness of the clinical and pathophysiological importance of sleep disorders in Parkinson's disease (PD) has been growing in recent years. Sleep disorders are now regarded as important among non-motor symptoms in PD and as a significant variable of PD-related quality of life. Furthermore, some sleep disorders, namely REM behaviour disorder (RBD), has been hypothesised to herald PD by years. Subjective reports of disrupted nocturnal sleep and daytime sleepiness appear to be supported by descriptions of several sleep alterations at nocturnal polysomnographic investigation and Multiple Sleep Latency Test findings. Sleep alterations in PD are to be viewed from the multifactorial perspective of a framework of reciprocally interacting factors: pathophysiology of the disease itself, sleep-related motor symptoms, dopaminergic treatments, ageing, depression, restless legs, periodic limb movements (PMLs) and sleep-disordered breathing. Ad hoc questionnaires and scales such as the Parkinson's Disease Sleep Scale and the Short and Practical (SCOPA) Sleep Scale are now available for the evaluation of disordered sleep in PD patients and have been proved to be useful for preliminary screening of sleep disorders in PD. However in a few cases a video-polysomnography (V-PSG) is needed in order to confirm a diagnosis of sleep disorder in PD, particularly in diagnosing RBD. As for treatment of sleep disorders, combined pharmacological and non-pharmacological protocols appear to be particularly suitable in their treatment in PD.

Establishment and characteristics of a hamster lung adenocarcinoma in vivo and in vitro.

Several cell lines designated HLAC were derived from primary lung carcinomas induced in Syrian hamsters by polonium-210 or benzo[a]pyrene. Primary tumor nodules were initially transplanted into cheek pouches, and the tumors that grew were passed into tissue culture and into the cheek pouches of other hamsters for continued in vivo passage. By serial passage and cloning, cell lines were isolated with plating efficiencies of 20-50% in vitro and 10-25% when cultured directly from solid tumors. These cells formed adenocarcinomas in vivo. The radiosensitivities in vitro of HLAC-4 and HLAC-14 varied; observed D0 (the inverse of the slope of the exponential portion of the survival curve) values were 80 and 155 rads, respectively; n (the dose at which the exponential portion of the survival curve extrapolates to 100% survival) values were approximately 1.8. Survival curves obtained following in situ irradiation of 4- to 5-mm3 HLAC-4 tumors showed a D0 of 80 rads and an n of 7. Morphology and growth characteristics of two HLAC cell lines in vivo and in vitro were described.

Differentiation of normal and cultured preneoplastic tracheal epithelial cells in rats: importance of epithelial mesenchymal interactions.

Changes in the dependence on mesenchymal tissues for survival and differentiation in inbred F344 female rats were investigated in tracheal epithelial cells exposed to 7, 12-dimethylbenz[a]anthracene (DMBA) and 12-O-tetradecanoylphorbol 13-acetate (TPA). Fresh suspensions of normal tracheal epithelium or cultured preneoplastic cells were inoculated into isolated organ segments (trachea, esophagus, bladder, or small intestine) or into Dacron containers that were then implanted subdermally into isogenic recipients. At various times after cell inoculation and implantation, tissues were removed for histologic evaluation. Normal cells inoculated into frozen-thawed trachea, esophagus, bladder, and intestine yielded a regular mucociliary epithelium. Normal cell inocula did not, however, survive in tracheae previously heated (100 degrees C), fixed in ethanol, or digested with collagenase; nor did normal cells survive in Dacron containers unless tracheal fibroblasts plus epithelial cells were inoculated together. DMBA- and TPA-exposed cell populations with increased growth capacity in vitro survived and differentiated on all of the above substrates. Our observations were consistent with those of other investigators in that normal cell survival and differentiation depend to some extent on interaction with extracellular material(s) present in various organs. The essential elements were not supplied by subdermal fibroblasts alone. For survival and differentiation in vivo, preneoplastic cells appeared to have less stringent substrate requirements than did normal cells. Application of the described techniques to the study of changes occurring early in the development of neoplastic disease is discussed.

Epithelial focus assay for early detection of carcinogen-altered cells in various organs of rats exposed in situ to N-nitrosoheptamethyleneimine.

The purpose of these studies was to determine a) whether epithelial cells with altered in vitro growth capacity occur not only after topical application of 7-12-dimethylbenz [a]-anthracene but also after systemic administration of a carcinogenic nitrosamine, and b) whether such cells can be isolated from tissues other than tracheal mucosa. AT 3 and 20 weeks following intragastric administration of 150, 300, or 600 mg N-nitrosohepatamethyleneimine (NHMI)/kg, cells were harvested from tracheas, esophagi, and lungs (target tissues for NHMI) of inbred F344 rats and seeded into culture dishes. Normal cells from nonexposed organs produced no proliferative epithelial foci (EF). Of those tracheas sampled 3 weeks following exposure to 150 and 300 mg/kg 10 and 20%, respectively, contained one or more EF that could be subcultured. Of these tracheas harvested 3 weeks post exposure to 600 mg/kg or 20 weeks post exposure to 150-600 mg/kg, 80-100% contained EF that could be subcultured. Twenty weeks after 600 mg NHMI/kg, the incidence of tracheas harboring cell populations with neoplastic potential (agarose-positive EF) was 80%, whereas the tracheal tumor incidence determined at 24 months was only 29%. Epithelial focus-forming units with various abnormal in vitro growth potentials were also detected in esophagi and lungs of NHMI-exposed rats.

X-radiation-induced transformation in a C3H mouse embryo-derived cell line.

Reproducible X-ray-induced oncogenic transformation has been demonstrated in an established cell line of mouse embryo fibroblasts. Cells derived from transformed foci formed malignant tumors when injected into syngeneic hosts. An exponential increase in the number of transformants per viable cell occurred with doses of up to 400 rads of X-radiation. The transformation frequency in exponentially growing cultures remained constant at 2.3 x 10(-3) following doses of 400 to 1500 rads. There was little change in survival following X-ray doses up to 300 rads. Doses greater than 300 rads were associated with an exponential decline in survival; the Do for the survival curve was 175 rads. Transformation frequency varied with changes in the number of viable cells seeded per dish. There was about a 10-fold decline in the transformation frequency when the number of cells was increased from 400 to 1000 viable cells/100-mm Petri dish. Below this density range there was little change in transformation frequency. The presence of lethally preir-radiated cells was not associated with an enhancement of transformation in irradiated cells or with the induction of transformation in unirradiated cell cultures. Amphotericin B (Fungizone) inhibited the appearance of transformants when added to the culture medium within 2 to 3 weeks after initiation of the experiment.

Specific patterns of laryngeal electromyography during wakefulness are associated to sleep disordered breathing and nocturnal stridor in multiple system atrophy.

BACKGROUND: Nocturnal stridor and respiratory abnormalities are important features of multiple system atrophy (MSA) with relevance to patient survival, and they are detected and evaluated mainly through video-polysomnography (video-PSG). Diurnal laryngoscopy seems to yield abnormal findings only in the presence of significant vocal cord (VC) dysfunction. AIM: To assess whether specific electrophysiological patterns of diurnal EMG of VC muscles may indicate nocturnal stridor or respiratory dysfunctions in MSA patients. MATERIALS AND METHODS: Seventeen patients with probable MSA were examined. A full-night video-PSG to collect standard breathing parameters (apnea/hypopnea index, mean HbSAO2, oxygen desaturation index, total sleep time with HbSaO2 below 90%) was performed in all the patients. Laryngoscopy and EMG investigation of adductor (thyroarytenoid-TA) and abductor (posterior cricoarytenoid-PCA) muscles of the VCs were also performed. RESULTS: Both the laryngeal EMG abnormalities (based on MUAP analysis and kinesiologic EMG investigation of VC muscles) and the laryngoscopic alterations correlated with video-PSG respiratory abnormalities. Specific patterns of EMG findings were consistently found in MSA subjects with nocturnal stridor detected at PSG. In particular, the following EMG findings were related to the severity of breathing abnormalities and the presence of stridor on video-PSG: neurogenic pattern on MUAP analysis of the PCA, paradoxical activation of the TA during inspiration and tonic EMG activity of the TA during quiet breathing. CONCLUSIONS: Electromyographic/kinesiologic investigation of VC muscles during wakefulness provides additional information on the pathophysiology of the respiratory abnormalities in MSA patients that could be useful for guiding the choice of the best appropriate treatment and care.

Hallucinations and sleep-wake cycle in PD: a 24-hour continuous polysomnographic study.

Twenty-four-hour ambulatory polysomnography was performed in 20 patients with PD who were having visual hallucinations (12 men and 8 women, mean age 70 +/- 6 years). Visual hallucinations were clearly related to daytime NREM sleep or nocturnal REM sleep in 33% of the instances. The data reinforce the hypothesis that neural mechanisms implicated in generating sleep and, in particular, in dream imagery play a role in the occurrence of visual hallucinations in PD.

Heterotopic tracheal transplants: techniques and applications.

Heterotopic tracheal transplants, placed subcutaneously in syngeneic rats have been extensively used in our laboratory. The objective of these experiments was to study the toxic and/or carcinogenic effect of several compounds on the respiratory tract mucosa. This was attained by exposing the transplants to an intraluminal pettet containing the toxicant or carcinogen mixed with an adequate matrix (gelatin, beeswax, stearyl alcohol, silastic, etc.). By varying the concentration of the test chemicals, it is possible to study dose-response relationships, and by changing the pellet matrix, the effects of release rate (dose rate) can be analyzed. Several end points can be studied, such as histological changes in the mucociliary epithelium, changes in mucus secretion, tumor induction and changes in the in vitro behavior of the epithelial cells after in vivo exposure. In addition, by de-epithelializing the tracheal transplants and reseeding them with another cell population, e.g., from previously treated cell cultures or from human specimens and transplanting them subcutaneously in nude mice, completely new vistas on the effect of chemicals can be opened.

Studies of neoplastic development in respiratory tract epithelium.

The dynamics of neoplastic development in conducting airways were studied in an animal model using morphologic and tissue culture techniques. Evidence for the regression of many metaplastic-dysplastic lesions, including advanced "preneoplastic" lesions, was provided. This regression of lesions is not synonymous with reversion of the neoplastic process. The number of "carcinogen-altered" cells and the number of cells with neoplastic potential continued to increase as a function of time after carcinogen exposure. With the cell culture methods developed for these studies, it is possible to analyze qualitatively and quantitatively the progression of the neoplastic process as it takes place in vivo and to detect and enumerate the progenitor cells of later-appearing cancers. The investigations also provide strong evidence suggesting that carcinogen-exposed organs contain many more cells with neoplastic potential. This expression may, however, be sharply enhanced when permissive or promoting conditions prevail. The investigations open up new avenues to develop means for detection of preneoplastic cell populations and for therapeutic intervention during early phases of the neoplastic disease process.

[Genetical aspects in cerebrovascular disease]. / Aspectos genéticos en la enfermedad cerebrovascular.

INTRODUCTION: Stroke is a pathophysiological heterogeneous syndrome with numerous genetic influences. DEVELOPMENT: Previous populational studies had demonstrated the familial correlation. The parental history of stroke has been associated with stroke in the descendant with a significant relative risk of 2. A study of mono- and dizygotic twins found a fivefold risk of stroke among monozygotic compared with dizygotic. Other modifiable and non-modifiable risk factors are involve in cerebrovascular disease. Recently, the gene that codifies the angiotensin converting enzyme has been determine. An insertion/deletion polymorphism of was associated with increased levels of angiotensin converting enzyme. ApoE4 and high levels of homocysteine has been reported as a risk factors for cerebral infarction. Apoptotic mechanisms have recently been discovered in rats models of ischemia. Caspases inhibitors have shown a reduction of 40% in the cerebral infarction area. CONCLUSION: The purpose of this work is to analyze the genetic factors that constitute an influence in stroke.

Environmental risk factors for REM sleep behavior disorder: a multicenter case-control study.

OBJECTIVE: Idiopathic REM sleep behavior disorder is a parasomnia characterized by dream enactment and is commonly a prediagnostic sign of parkinsonism and dementia. Since risk factors have not been defined, we initiated a multicenter case-control study to assess environmental and lifestyle risk factors for REM sleep behavior disorder. METHODS: Cases were patients with idiopathic REM sleep behavior disorder who were free of dementia and parkinsonism, recruited from 13 International REM Sleep Behavior Disorder Study Group centers. Controls were matched according to age and sex. Potential environmental and lifestyle risk factors were assessed via standardized questionnaire. Unconditional logistic regression adjusting for age, sex, and center was conducted to investigate the environmental factors. RESULTS: A total of 694 participants (347 patients, 347 controls) were recruited. Among cases, mean age was 67.7 ± 9.6 years and 81.0% were male. Cases were more likely to smoke (ever smokers = 64.0% vs 55.5%, adjusted odds ratio [OR] = 1.43, p = 0.028). Caffeine and alcohol use were not different between cases and controls. Cases were more likely to report previous head injury (19.3% vs 12.7%, OR = 1.59, p = 0.037). Cases had fewer years of formal schooling (11.1 ± 4.4 years vs 12.7 ± 4.3, p < 0.001), and were more likely to report having worked as farmers (19.7% vs 12.5% OR = 1.67, p = 0.022) with borderline increase in welding (17.8% vs 12.1%, OR = 1.53, p = 0.063). Previous occupational pesticide exposure was more prevalent in cases than controls (11.8% vs 6.1%, OR = 2.16, p = 0.008). CONCLUSIONS: Smoking, head injury, pesticide exposure, and farming are potential risk factors for idiopathic REM sleep behavior disorder.