Accuracy of Rating Scales and Clinical Measures for Screening of Rapid Eye Movement Sleep Behavior Disorder and for Predicting Conversion to Parkinson’s Disease and Other Synucleinopathies

Abstract

Rapid eye movement (REM) sleep behavior disorder (RBD) is characterized by repeated episodes of REM sleep-related vocalizations and/or complex motor behaviors. Definite diagnosis of RBD is based on history and polysomnography, both of which are less accessible due to the lack of trained specialists and high cost. While RBD may be associated with disorders like narcolepsy, focal brain lesions, and encephalitis, idiopathic RBD (iRBD) may convert to Parkinson’s disease (PD) and other synucleinopathies in more than 80% of patients and it is to date the most specific clinical prodromal marker of PD. Identification of individuals at high risk for development of PD is becoming one of the most important topics for current PD-related research as well as for future treatment trials targeting prodromal PD. Furthermore, concomitant clinical symptoms, such as subtle motor impairment, hyposmia, autonomic dysfunction, or cognitive difficulties, in subjects with iRBD may herald its phenoconversion to clinically manifest parkinsonism. The assessment of these motor and non-motor symptoms in iRBD may increase the sensitivity and specificity in identifying prodromal PD subjects. This review evaluates the diagnostic accuracy of individual rating scales and validated single items for screening of RBD and the role and accuracy of available clinical, electrophysiological, imaging, and tissue biomarkers in predicting the phenoconversion from iRBD to clinically manifest synucleinopathies.

Hypomethylation of SNCA in Idiopathic REM Sleep Behavior Disorder Associated With Phenoconversion

“…Biomarkers capable of predicting the phenoconversion from iRBD to clinical synucleinopathies are of great importance. Previous studies have indicated that the rate of phenoconversion was significantly increased in patients with motor dysfunction, olfactory deficits, mild cognitive impairment, erectile dysfunction, abnormal dopamine transporters scan, color vision abnormalities, and other factors 27,28 . In our study, the methylation level at CpG 17 was able to predict early phenoconversion.…”

Resting Heart Rate Variability Is Associated With Subsequent Orthostatic Hypotension: Comparison Between Healthy Older People and Patients With Rapid Eye Movement Sleep Behavior Disorder

“…The cognitive functions of the subjects were evaluated using the Mini-Mental State Examination (MMSE), which is a screening tool for dementia with a cut-off score of 23/24 (maximum score of 30) (50). The participants were asked to answer the REM sleep behavior disorder screening questionnaire (RBDSQ), which consists of 13 questions (maximum possible score = 13), to assess RBD symptoms such as nocturnal movements, injuries, and motor behavior during the night (51,52). In this study, the Japanese version of the RBDSQ (RBDSQ-J) was used (53).…”

The neuropsychological assessment battery (NAB) is a valuable tool for evaluating neuropsychological outcome after aneurysmatic subarachnoid hemorrhage

“…It consists of 13 tasks and evaluates multiple domains of cognitive function (visuospatial abilities, attention, concentration, language, shortterm and working memory). It can be administered within 15 min and has been used to screen patients with a wide range of conditions including aSAH [19][20][21][22]. The maximum score is 30 points and using a cutoff of 25 points is suggested to detect mild cognitive impairment; therefore, in the current study a MoCA score of 25 or less was categorized as impaired.…”