Sleep Behavior Disorder Screening Questionnaire Research Articles

Validation of the REM sleep behavior disorder screening questionnaire in the Czech population

BackgroundIdiopathic rapid eye movement sleep behavior disorder (iRBD) affects 1–2% of people over 60 years of age and presents a high risk of developing a neurodegenerative disorder from the group of synucleinopathies, such as Parkinson’s disease, dementia with Lewy bodies and multiple system atrophy. Therefore, screening tools are needed. In 2007, the rapid eye movement sleep behavior disorder screening questionnaire (RBD-SQ) was developed and has been translated into several languages. The aim of study was to assess the validity and reliability of the Czech version of the RBD-SQ in a mixed population of sleep clinic patients, supplemented by healthy volunteers and RBD patients.MethodsParticipants included 81 iRBD patients, 205 patients with other sleep disorders (obstructive sleep apnea, insomnia, restless legs syndrome and periodic limb movement disorder, other parasomnias, or central hypersomnias including narcolepsy) and 20 healthy volunteers.ResultsThe mean RBD-SQ score in the iRBD patients was 9.4 ± 2.8 points, and in the non-RBD group it was 4.5 ± 3.0 (P < 0.0001). Receiver -operator analysis yielded an area under the curve of 0.864, suggesting good diagnostic performance of the scale. When using a cut-off value for positivity of 5 points, sensitivity was 0.89 and specificity was 0.62.ConclusionsThe Czech version of the RBD-SQ is a sensitive tool for screening for iRBD patients and helps to identify subjects for complete clinical workup.

Mild cognitive impairment in de novo Parkinson's disease: A neuromelanin MRI study in locus coeruleus.

We aimed to investigate neuromelanin-sensitive magnetic resonance imaging (NM-MRI) features in the locus coeruleus of de novo Parkinson's disease patients with different cognitive states and to determine whether these features are associated with cognitive impairment. Three groups of subjects were recruited in this study, including patients with de novo PD with mild cognitive impairment (n = 23), patients with de novo PD without cognitive impairment (n = 48), and control subjects (n = 32). All subjects underwent clinical evaluations, as well as MRI scanning. The contrast-to-noise ratio of the locus coeruleus in the neuromelanin-sensitive MRI images and cortical thickness were measured. The contrast-to-noise ratio of the locus coeruleus in PD patients with mild cognitive impairment was significantly lower than that of controls (P = 0.016). The contrast-to-noise ratio of the locus coeruleus for PD patients without cognitive impairment was intermediate between that of controls and PD patients with mild cognitive impairment. Furthermore, multiple linear regression analysis showed that the contrast-to-noise ratio of the locus coeruleus was negatively associated with performance on the Trail Making Test B in all PD patients, controlling for age, sex, years of education, the Unified Parkinson's Disease Rating Scale motor scores from right upper limb, Geriatric Depression Rating Scales scores, Rapid Eye Movement Sleep Behavior Disorder Screening Questionnaire scores, and cortical thickness. Dysfunction of the locus coeruleus neurons may partly contribute to the decline in executive function in early de novo PD. In the future, the locus coeruleus-norepinephrine system might be targeted for early-intervention strategies in PD patients. © 2019 International Parkinson and Movement Disorder Society.

Rapid eye movement behavior disorder in drug-naïve patients with Parkinson’s disease

The current study aimed to investigate the occurrence and clinical associations of rapid eye movement (REM) behavior disorder (RBD) in early-stage Parkinson’s disease (PD) from a cohort of Chinese patients. 158 treatment-naive PD patients in total were enrolled in the study. Each patient was categorized as PD with or without RBD according to the Rapid Eye Movement Sleep Behavior Disorder Screening Questionnaire (RBDSQ). Of 158 patients, 31 PD patients (19.62%) reported RBD. PD patients with RBD showed higher Non-Motor Symptoms Scale (NMSS) score, higher Hamilton Depression Rating Scale (HAMD) score, higher Hamilton Anxiety Rating Scale (HAMA) score, higher Fatigue Severity Scale (FSS) score, higher PD Sleep Scale 2nd version (PDSS-2) score, lower Montreal Cognitive Assessment (MOCA) score and higher scores for the cognitions and communication domains from the PD Questionnaire-39 (PDQ-39). The stepwise binary logistic regression analysis showed that higher HAMA score (OR = 1.089, 95% CI = 1.010–1.174, P = 0.026), higher motor symptoms at night domain score from the PDSS-2 (OR = 1.389, 95% CI = 1.128–1.711, P = 0.002) and lower MOCA score (OR = 0.864, 95% CI = 0.757–0.986, P = 0.030) were correlated with RBD. This study found that RBD is not rare (19.62%) in Chinese drug-naïve PD patients and RBD has a great effect on quality of life. RBD in PD is related to cognitive dysfunction, anxiety and sleep disturbances.

Baseline symptoms and basal forebrain volume predict future psychosis in early Parkinson disease.

Determining baseline predictors of future psychosis in Parkinson disease (PD) may identify those at risk for more rapidly progressive disease, i.e., a more malignant PD subtype. This cohort study evaluated 423 patients with newly diagnosed PD collected as part of the Parkinson's Progression Markers Initiative. Psychotic symptoms were assessed with the Movement Disorders Society-Unified Parkinson Disease Rating Scale item 1.2, which assesses hallucinations and psychosis over the past week. At baseline, participants completed the Scales for Outcomes in Parkinson's Disease-Autonomic, the REM Sleep Behavior Disorder (RBD) Screening Questionnaire, and the Epworth Sleepiness Scale. Cholinergic nucleus 4 (Ch4) density was calculated for 228 participants with PD and 101 healthy controls. Multivariate logistic regression adjusted for age and sex found that greater autonomic symptoms (p = 0.002), RBD (p = 0.021), and excessive daytime sleepiness (EDS) (p = 0.003) at baseline were associated with increased risk of reporting psychotic symptoms on ≥2 occasions. Having 2 or 3 of these baseline symptoms was associated with lower Ch4 density (p = 0.007). In a logistic regression model adjusted for age and sex, higher Ch4 gray matter density was associated with lower risk of reporting psychotic symptoms on ≥2 occasions (odds ratio 0.96 [for an increase in density of 1 unit], p = 0.03). This study confirms that RBD, EDS, and greater autonomic symptom burden are associated with greater risk of future psychotic symptoms in PD. Reduced Ch4 density at baseline is associated with future psychotic symptoms and a greater burden of RBD, EDS, and autonomic symptoms.

Dopamine reuptake transporter-single-photon emission computed tomography and transcranial sonography as imaging markers of prediagnostic Parkinson's disease.

The objective of this study was to examine whether prediagnostic features of Parkinson's disease (PD) were associated with changes in dopamine reuptake transporter-single-photon emission computed tomography and transcranial sonography. Prediagnostic features of PD (risk estimates, University of Pennsylvania Smell Identification Test, Rapid Eye Movement Sleep Behavior Disorder Screening Questionnaire, and finger-tapping scores) were assessed in a large cohort of older U.K. residents. A total of 46 participants were included in analyses of prediagnostic features and MDS-UPDRS scores with the striatal binding ratio on dopamine reuptake transporter-single-photon emission computed tomography and nigral hyperechogenicity on transcranial sonography. The striatal binding ratio was associated with PD risk estimates (P = .040), University of Pennsylvania Smell Identification Test (P = .002), Rapid Eye Movement Sleep Behavior Disorder Screening Questionnaire scores (P = .024), tapping speed (P = .024), and MDS-UPDRS motor scores (P = .009). Remotely collected assessments explained 26% of variation in the striatal binding ratio. The inclusion of MDS-UPDRS motor scores did not explain additional variance. The size of the nigral echogenic area on transcranial sonography was associated with risk estimates (P < .001) and MDS-UPDRS scores (P = .03) only. The dopamine reuptake transporter-single-photon emission computed tomography results correlated with motor and nonmotor features of prediagnostic PD, supporting its potential use as a marker in the prodromal phase of PD. Transcranial sonography results also correlated with risk scores and motor signs. © 2018 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Clinical features of Parkinson\u2019s disease with and without rapid eye movement sleep behavior disorder

BackgroundRapid eye movement sleep behavior disorder (RBD) and Parkinson’s disease (PD) are two distinct clinical diseases but they share some common pathological and anatomical characteristics. This study aims to confirm the clinical features of RBD in Chinese PD patients.MethodsOne hundred fifty PD patients were enrolled from the Parkinson`s disease and Movement Disorders Center in Department of Neurology, Shanghai General Hospital from January 2013 to August 2014. This study examined PD patients with or without RBD as determined by the REM Sleep Behavior Disorder Screening Questionnaire (RBDSQ), assessed motor subtype by Unified PD Rating Scale (UPDRS) III at “on” state, and compared the sub-scale scores representing tremor, rigidity, appendicular and axial. Investigators also assessed the Hamilton Anxiety Scale (HAMA), Hamilton Depression Scale (HAMD), Mini-Mental State Examination (MMSE), Clinical Dementia Rating (CDR), and Parkinson’s disease Sleep Scale (PDSS).ResultsOne hundred fourty one PD patients entered the final study. 30 (21.28%) PD patients had probable RBD (pRBD) diagnosed with a RBDSQ score of 6 or above. There were no significant differences for age, including age of PD onset and PD duration, gender, smoking status, alcohol or coffee use, presence of anosmia or freezing, UPDRS III, and H-Y stages between the pRBD+ and pRBD− groups. pRBD+ group had lower MMSE scores, higher PDSS scores, and pRBD+ PD patients had more prominent proportion in anxiety, depression, constipation, hallucination and a greater prevalence of orthostatic hypotension.ConclusionpRBD+ PD patients exhibited greater changes in non-motor symptoms. However, there was no increase in motor deficits.

The REM sleep behavior disorder screening questionnaire: Validation study of a korean version (RBDQ-KR)

The REM sleep behavior disorder screening questionnaire: Validation study of a korean version (RBDQ-KR)

Is there a common motor dysregulation in sleepwalking and REM sleep behaviour disorder?

This study sought to determine if there is any overlap between the two major non-rapid eye movement and rapid eye movement parasomnias, i.e. sleepwalking/sleep terrors and rapid eye movement sleep behaviour disorder. We assessed adult patients with sleepwalking/sleep terrors using rapid eye movement sleep behaviour disorder screening questionnaires and determined if they had enhanced muscle tone during rapid eye movement sleep. Conversely, we assessed rapid eye movement sleep behaviour disorder patients using the Paris Arousal Disorders Severity Scale and determined if they had more N3 awakenings. The 251 participants included 64 patients with rapid eye movement sleep behaviour disorder (29 with idiopathic rapid eye movement sleep behaviour disorder and 35 with rapid eye movement sleep behaviour disorder associated with Parkinson's disease), 62 patients with sleepwalking/sleep terrors, 66 old healthy controls (age-matched with the rapid eye movement sleep behaviour disorder group) and 59 young healthy controls (age-matched with the sleepwalking/sleep terrors group). They completed the rapid eye movement sleep behaviour disorder screening questionnaire, rapid eye movement sleep behaviour disorder single question and Paris Arousal Disorders Severity Scale. In addition, all the participants underwent a video-polysomnography. The sleepwalking/sleep terrors patients scored positive on rapid eye movement sleep behaviour disorder scales and had a higher percentage of 'any' phasic rapid eye movement sleep without atonia when compared with controls; however, these patients did not have higher tonic rapid eye movement sleep without atonia or complex behaviours during rapid eye movement sleep. Patients with rapid eye movement sleep behaviour disorder had moderately elevated scores on the Paris Arousal Disorders Severity Scale but did not exhibit more N3 arousals (suggestive of non-rapid eye movement parasomnia) than the control group. These results indicate that dream-enacting behaviours (assessed by rapid eye movement sleep behaviour disorder screening questionnaires) are commonly reported by sleepwalking/sleep terrors patients, thus decreasing the questionnaire's specificity. Furthermore, sleepwalking/sleep terrors patients have excessive twitching during rapid eye movement sleep, which may result either from a higher dreaming activity in rapid eye movement sleep or from a more generalised non-rapid eye movement/rapid eye movement motor dyscontrol during sleep.

The prodromal phase of leucine-rich repeat kinase 2-associated Parkinson disease: Clinical and imaging Studies.

Asymptomatic, nonmanifesting carriers of leucine-rich repeat kinase 2 mutations are at increased risk of developing PD. Clinical and neuroimaging features may be associated with gene carriage and/or may demarcate individuals at greater risk for phenoconversion to PD. To investigate clinical and dopamine transporter single-photon emission computed tomography imaging characteristics of leucine-rich repeat kinase 2 asymptomatic carriers. A total of 342 carriers' and 259 noncarriers' relatives of G2019S leucine-rich repeat kinase 2/PD patients and 39 carriers' and 31 noncarriers' relatives of R1441G leucine-rich repeat kinase 2/PD patients were evaluated. Motor and nonmotor symptoms were assessed using specific scales and questionnaires. Neuroimaging quantitative data were obtained in 81 carriers and compared with 41 noncarriers. G2019S carriers scored higher in motor scores and had lower radioligand uptake compared to noncarriers, but no differences in nonmotor symptoms scores were observed. R1441G carriers scored higher in motor scores, had lower radioligand uptake, and had higher scores in depression, dysautonomia, and Rapid Eye Movements Sleep Behavior Disorder Screening Questionnaire scores, but had better cognition scores than noncarriers. Among G2019S carriers, a group with "mild motor signs" was identified, and was significantly older, with worse olfaction and lower radioligand uptake. G2019S and R1441G carriers differ from their noncarriers' relatives in higher motor scores and slightly lower radioligand uptake. Nonmotor symptoms were mild, and different nonmotor profiles were observed in G2019S carriers compared to R1441G carriers. A group of G2019S carriers with known prodromal features was identified. Longitudinal studies are required to determine whether such individuals are at short-term risk of developing overt parkinsonism. © 2017 International Parkinson and Movement Disorder Society.

Diagnostic accuracy of REM sleep behaviour disorder screening questionnaire: a meta-analysis.

A screening tool can greatly facilitate the identification of individuals with rapid eye movement (REM) sleep behaviour disorder (RBD). Currently, the REM sleep behaviour disorder screening questionnaire (RBDSQ) is widely used, but its diagnostic accuracy has varied across previous studies. The aim of the present study was to systematically assess the diagnostic performance of the RBDSQ. We comprehensively searched for studies that evaluated the diagnostic performance of the RBDSQ. A bivariate mixed-effects model was used to summarize the diagnostic accuracy of the RBDSQ. Subgroup analyses were performed according to the study design and the different populations included in the studies. Ten studies were included. Using a cutoff value of 5, the pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 0.91 (95% CI 0.85-0.95), 0.77 (95% CI 0.66-0.85), 4.00 (95% CI 2.60-6.10), 0.12 (95% CI 0.07-0.19), and 34 (95% CI 16-71), respectively. A subgroup analysis revealed that the RBDSQ had excellent diagnostic accuracy for RBD screening in the general population. However, its performance in specific patient populations, especially patients with Parkinson's disease, was less satisfactory. In conclusion, the RBDSQ is an effective diagnostic screening tool for RBD in the general population, but its performance in subjects with specific neurological disorders requires more comprehensive assessments.

Clinical variables and biomarkers in prediction of cognitive impairment in patients with newly diagnosed Parkinson's disease: a cohort study

Parkinson's disease is associated with an increased incidence of cognitive impairment and dementia. Predicting who is at risk of cognitive decline early in the disease course has implications for clinical prognosis and for stratification of participants in clinical trials. We assessed the use of clinical information and biomarkers as predictive factors for cognitive decline in patients with newly diagnosed Parkinson's disease. The Parkinson's Progression Markers Initiative (PPMI) study is a cohort study in patients with newly diagnosed Parkinson's disease. We evaluated cognitive performance (Montreal Cognitive Assessment [MoCA] scores), demographic and clinical data, APOE status, and biomarkers (CSF and dopamine transporter [DAT] imaging results). Using change in MoCA scores over 2 years, MoCA scores at 2 years' follow-up, and a diagnosis of cognitive impairment (combined mild cognitive impairment or dementia) at 2 years as outcome measures, we assessed the predictive values of baseline clinical variables and separate or combined additions of APOE status, DAT imaging, and CSF biomarkers. We did univariate and multivariate linear analyses with MoCA change scores between baseline and 2 years, and with MoCA scores at 2 years as dependent variables, using backwards linear regression analysis. Additionally, we constructed a prediction model for diagnosis of cognitive impairment using logistic regression analysis. 390 patients with Parkinson's disease recruited between July 1, 2010, and May 31, 2013, and for whom data on MoCA scores at baseline and 2 years were available. In multivariate analyses, baseline age, University of Pennsylvania Smell Inventory Test (UPSIT) scores, CSF amyloid - (Aβ42) to t-tau ratio, and APOE status were associated with change in MoCA scores over time. Baseline age, MoCA and UPSIT scores, and CSF Aβ42 to t-tau ratio were associated with MoCA score at 2 years (using a backwards p-removal threshold of 0·1). Accuracy of prediction of cognitive impairment using age alone (area under the curve 0·68, 95% CI 0·60-0·76) significantly improved by addition of clinical scores (UPSIT, Rapid Eye Movement Sleep Behaviour Disorder Screening Questionnaire [RBDSQ], Geriatric Depression Scale, and Movement Disorder Society Unified Parkinson's Disease Rating Scale motor scores; 0·76, 0·68-0·83), CSF variables (0·74, 0·68-0·81), or DAT imaging results (0·76, 0·68-0·83). In combination, the five variables showing the most significant associations with cognitive impairment (age, UPSIT, RBDSQ, CSF Aβ42, and caudate uptake on DAT imaging) allowed prediction of cognitive impairment at 2 years (0·80, 0·74-0·87; p=0·0003 compared to age alone). In newly diagnosed Parkinson's disease, the occurrence of cognitive impairment at 2 year follow-up can be predicted with good accuracy using a model combining information on age, non-motor assessments, DAT imaging, and CSF biomarkers. None.

National validation and proposed revision of REM sleep behavior disorder screening questionnaire (RBDSQ).

We validated the Italian version of the rapid eye movement sleep behavior disorder (RBD) screening questionnaire (RBDSQ) and calculated its cut-off value for discriminating RBD group from other sleep disorders and healthy controls (HC). 380 patients with sleep disorders and 101 HC were enrolled. RBDSQ achieved an acceptable Cronbach's α value of 0.787 and item 10 was the only one with a very low item-total biserial correlation (0.141). At ROC analysis, we obtained an AUC of 0.888, denoting a good performance of the RBDSQ total score for predicting the RBD status. The optimal cut-off value was 8 and it achieved good values of both sensitivity and specificity (0.842 and 0.780, respectively). Due to the poor performance of item 10 in our sample, we analyzed the RBDSQ without this item (called "revised RBDSQ"). We obtained a good Cronbach's α of 0.802. When evaluating the performance of the revised score in predicting the RBD status, we obtained an increased value of AUC (0.899). The optimal cut-off value was still 8 (sensitivity=0.829; specificity=0.820). The Italian version of RBDSQ is a sensitive tool for the identification of RBD patients. An improvement of the instrument could be obtained by removing item 10 and define a higher cut-off value of 8. The "revised RBDSQ" represents a reliable screening questionnaire for primary care physicians and neurologists and its employment may facilitate the choice of subjects that should undergo a PSG that confirms the diagnosis of RBD, thus avoiding polysomnographic exams when not needed.

Retinal nerve fiber layer thinning: a window into rapid eye movement sleep behavior disorders in Parkinson’s disease

Retinal nerve fiber layer (RNFL) thinning occurs in Parkinson's disease (PD) and other neurodegenerative diseases. Idiopathic RBD (iRBD) is a well-established prodromal hallmark of synucleinopathies and occurs secondary to many neurodegenerative diseases, including PD. The aim of this study is to determine whether or not retinal structures are altered with the onset of rapid eye movement (REM) sleep behavior disorders (RBD). In all, a total of 63 patients with PD, 14 patients with idiopathic RBD, and 26 sex- and age-matched healthy controls were enrolled and underwent optical coherence tomography measurements (HD-OCT (Zeiss) ) for the average and every quadrant of RNFL thickness. The REM Sleep Behavior Disorder Screening Questionnaire (RBDSQ) was used to classify PD patients with clinically probable RBD (PD+pRBD) or without probable RBD (PD-pRBD). Patients with iRBD were identified by polysomnography. For patients with RBD (idiopathic or secondary to PD), we found a significant decrease in RNFL thickness compared with groups without RBD (PD-pRBD and healthy controls) (all p<0.05). Average RNFL thickness in patients with iRBD is significantly thinner than in healthy controls (p<0.05). In PD, the average RNFL thickness was dramatically thinner in the PD+pRBD group than the PD-pRBD group (p<0.005). Compared with healthy controls, RNFL thickness was slightly thinner in the drug-naive PD group but not the PD group with drug treatment. Multiple linear regression analysis showed that RBDSQ score was negatively associated with average and inferior RNFL variation in PD (all p<0.005). The findings show that RNFL was slightly but significantly thinner in idiopathic RBD. In PD, RNFL thickness may vary depending on the presence of RBD.

Screening tools for clinical characteristics of probable REM sleep behavior disorder in patients with Parkinson's disease.

IntroductionThe REM sleep behavior disorder (RBD) screening questionnaire (RBDSQ) has been used as a screening tool for RBD. We investigated the clinical characteristics of probable RBD (pRBD) using the RBDSQ in patients with Parkinson's disease (PD).MethodsSeventy patients with PD (age: 69.2 ± 8.9 years old, 31 males and 49 females, length of PD morbidity: 7.4 ± 6.4 years, Hoehn and Yahr: 2.7 ± 0.8) underwent examination including the RBDSQ and Mini-Mental State Examination (MMSE) in both 2011 and 2013. We assessed the changes and characteristics of pRBD associated with PD during the two year interval.ResultsNineteen patients (27.1%) in 2011 and 27 patients (38.6%) in 2013 were diagnosed as having pRBD because they scored 6 or higher on the RBDSQ. During the 2 year interval, twelve patients showed persistent pRBD, 15 developed pRBD, and 7 showed improved pRBD. In 2013, PD patients with pRBD took higher amounts of levodopa equivalents and scored lower on the MMSE than those without pRBD. Also, more PD patients with pRBD had dementia than those without pRBD. Similarly, more patients with persistent and developed pRBD had dementia than those without.ConclusionWe found that RBD symptoms might fluctuate during the clinical course of PD, and RBD symptoms might temporarily affect cognitive impairment.

Paired neurophysiological and clinical approach to brainstem assessment in Parkinson’s Disease

Background Recent research has highlighted the role of brainstem (BS) structures in the early spread of Parkinson’s Disease (PD) pathological process. Vestibular Evoked Myogenic Potentials (VEMPs) corresponding to the Vestibulo-Ocular (VOR), Vestibulo-Masseteric (VMR) and Vestibulo-Collic (VCR) reflexes can provide information on BS function. Aims: to test the aforesaid set of VEMPs in a cohort of PD patients and healthy controls and to correlate it with presence of symptoms ascribable to BS dysfunction. Methods 19 PD patients (age 66.9 ± 5.4 years; 12 males; mean disease duration 6.16 ± 3.54 years) and 15 age and sex matched controls underwent bilateral recording of VOR, VMR and VCR from inferior oblique, masseter and sternocleidomastoid active muscles, respectively. PD patients were additionally administered a series of clinical scales used for evaluation of brainstem-integrated activities, namely sleep disorders (Epworth Sleepiness Scale, Parkinson’s Disease Sleep Scale and REM Sleep Behavior Disorder-Screening Questionnaire or RBD-SQ), postural instability (MiniBESTest) and depression (Geriatric Depression Scale). Groups’ comparisons were performed with χ 2 test and Mann–Whitney U-test; Sperman’s rho test was used for correlation analysis. Results VEMPs were significantly impaired in patients compared to controls, absence being the main pattern of alteration. When the set of the 3-VEMP battery was analyzed, both number of altered reflexes ( p = 0.017) and severity of alteration ( p = 0.001) were significantly higher in patients than controls. As for each single VEMP, only the VOR and the VMR were significantly altered (VOR: p = 0.022; VMR: p = 0.005; VCR: p = 0.056). Clinical scales revealed the presence of some degree of depression in 36.8% of patients, sleep disturbances in 68.4%, REM sleep disorder in 26.3% and postural instability in 36.8% of PD patients. A significant correlation with VEMP alterations was found only for high scores on RBD-SQ ( ρ = 0.554; p = 0.014). Conclusions Combined assessment of VOR, VMR and VCR was able to detect BS dysfunction in a rostro-caudal extension in PD. This may prove interesting in the perspective of identifying neurophysiological markers of BS dysfunction in early stages of the disease.

Effect of a Leucine-rich Repeat Kinase 2 Variant on Motor and Non-motor Symptoms in Chinese Parkinson's Disease Patients.

The G2385R variant of the leucine-rich repeat kinase 2 (LRRK2) is strongly associated with Parkinson’s disease (PD) in Asian populations. However, it is still unclear whether the clinical phenotype of PD patients with the G2385R variant can be distinguished from that of patients with idiopathic PD. In this study, we investigated motor and non-motor symptoms of LRRK2 G2385R variant carriers in a Chinese population. We genotyped 1031 Chinese PD patients for the G2385R variant of the LRRK2 gene, and examined the demographic and clinical characteristics of LRRK2 G2385R variant carrier and non-carrier PD patients. LRRK2 G2385R variant carriers were more likely to present the postural instability and gait difficulty dominant (PIGD) phenotype. This variant was also significantly associated with motor fluctuations and the levodopa equivalent dose (LED). G2385R variant carriers had higher REM sleep behavior disorder (RBD) screening questionnaire (RBDSQ) score and more RBD symptoms compared with non-carriers. We concluded that the G2385R variant could be a risk factor for the PIGD phenotype, motor fluctuations, LED values and RBD symptoms.

The utility of a Korean version of the REM sleep behavior disorder screening questionnaire in patients with obstructive sleep apnea

PurposeTo explore the utility of a Korean version of the rapid eye movement sleep behavior disorder screening questionnaire (RBDSQ-K) to discriminate patients with idiopathic REM sleep behavior disorder (iRBD) from patients with obstructive sleep apnea (OSA) and healthy subjects. MethodsParticipants with iRBD (n=47) and OSA (n=213) were diagnosed by polysomnography. In healthy subjects (n=58), RBD was excluded by medical history without polysomnography. Receiver operating characteristic curve analysis was used to identify the optimal cutoff value of the RBDSQ-K for iRBD. ResultsRBDSQ-K score was higher in iRBD subjects than in OSA subjects and healthy subjects (both p<0.001). The optimal cutoff was 6.5 to distinguish iRBD subjects from OSA subjects and 4.5 to distinguish iRBD subjects from healthy subjects. The corresponding sensitivity and specificity was high for detecting iRBD from OSA and healthy subjects. The percentages of individuals with RBDSQ-K scores ≥5 and ≥7 were higher in OSA subjects with daytime sleepiness (36.1% and 13.8%, respectively) than in OSA subjects without daytime sleepiness (12.0% and 3.1%, respectively). Apnea–hypopnea index had no influence on RBDSQ-K score. Cronbach's alpha for the RBDSQ-K was 0.768, indicating a high degree of internal consistency. ConclusionsThe RBDSQ-K had acceptable sensitivity and specificity for screening persons with probable RBD from healthy subjects and OSA subjects when the cutoff score was 4.5 and 6.5 points, respectively. However, attention must be paid to the possibility of false positives when using this scale, especially in OSA subjects with daytime sleepiness.

Validation of the rapid eye movement sleep behavior disorder screening questionnaire in China

We validated the Chinese version of the rapid eye movement sleep behavior disorder (RBD) screening questionnaire (RBDSQ) and calculated its cut-off value for idiopathic or symptomatic sleep behavior disorders (iRBD or sRBD) in Chinese people. Patients with RBD (n=63) and controls (n=165) were enrolled. After all subjects had completed a structured interview, the Chinese version of the RBDSQ and the video polysomnography test, we evaluated the reliability, areas under the curves and the best cut-off values of the RBDSQ and investigated the utility of RBDSQ for iRBD and sRBD in China. We found that Cronbach’s alpha was 0.769 and the test-retest reliability was 0.916. RBDSQ scores in iRBD and sRBD patients were similar and higher than those in controls. A total of five points represented the best cut-off value for detecting all RBD patients. In Parkinson’s disease, a total score of six points represented the best cut-off value for detecting sRBD. There was no statistically significant difference in total RBDSQ score between iRBD and sRBD, or male and female patients. There was no significant correlation between the RBDSQ score and duration or severity of RBD symptoms. The Chinese version of the RBDSQ had high sensitivity, specificity and reliability and could be used as a tool for screening RBD patients in China.

Longitudinal assessment of probable rapid eye movement sleep behaviour disorder in Parkinson's disease.

Rapid eye movement (REM) sleep behaviour disorder (RBD) is frequently present in patients with Parkinson's disease (PD) and may have prognostic implications. There are few longitudinal studies of RBD in patients with PD. Our aim was to investigate whether RBD was a persistent feature in a follow-up study of 107 patients with PD. After a mean follow-up time of 3 years, 96 patients were available for reassessment. Probable RBD (pRBD) was diagnosed by the REM sleep behaviour disorder screening questionnaire. At follow-up, pRBD was found in 49% of the patients, versus 38% at baseline. The pRBD status remained unchanged in three-quarters of the patients, whilst 17% had new pRBD symptoms. Disease duration was longer in the pRBD group, 9.4 vs. 7.6 years (P = 0.02). Probable RBD is a persistent feature in PD and probably increases over time.

Validity of the Japanese version of the REM Sleep Behavior Disorder (RBD) Screening Questionnaire for detecting probable RBD in the general population.

In order to evaluate the validity of the REM Sleep Behavior Disorder (RBD) Screening Questionnaire (RBDSQ) as a screening tool for RBD in a general population setting, we conducted a validation study using residents of a rural community. We sent questionnaires that included the RBDSQ to 2631 eligible adult residents in the town of Daisen, Japan. Of those residents, 1572 participants (59.7%) gave complete answers to the RBDSQ. Among them, 179 participants (11.4%) scored ≥5 points on the questionnaire; an additional 149 participants scoring ≤4 points were randomly selected for further telephone interview. Based on obtained results, nine participants (0.57%) were judged as having probable RBD. Receiver-operator curve analysis revealed that a total score of 6 points on the RBDSQ represented the best cut-off value for detecting probable RBD (sensitivity: 100%; specificity: 73.0%). Analysis based on the item response theory revealed that items 1, 4, 6-1, 7, and 8 had lower difficulty than the remaining items, suggesting that these items are more essential in the screening for probable RBD. The present study revealed that a score of 6 points on the RBDSQ could be used as a cut-off value for the screening of probable RBD in the general population. Evaluation of the distribution of positive items might be helpful for identifying the intensity of a person's RBD symptoms.