Changes in the symptom frequency of rapid eye movement sleep behavior disorder according to disease duration

Abstract

Background: This descriptive study was conducted to examine the changes in the symptom frequency in patients with rapid eye movement (REM) sleep behavior disorder (RBD) without medical intervention, in order to determine the association of RBD symptom frequency with disease duration. Methods: Data were collected from 70 consecutive RBD patients who visited the Sleep Clinic in Shiga University of Medical Science. RBD symptom frequencies at the first visit to the clinic were quantified based on the reports by the patients and their family members. For quality assurance, patients living alone or those with cognitive decline were excluded. Finally, 50 patients with family-confirmed symptom history were enrolled. The symptom frequencies were converted to a unit that reflects the estimated number of nights in a year affected by RBD (NAR). Using NAR, we observed the relation between RBD symptom frequency and the disease duration. Results: Of the 50 patients, 41 were male and 9 were female, consistent with the male-dominant nature of this disease. The mean age at RBD onset was 62.2 ± 9.1 years, and the mean disease duration at the time of visit was 6.0 ± 4.9 years. The median symptom frequency was 50 NAR, with a 1st quantile value of 24 NAR and a 3rd quantile value of 115 NAR. When RBD symptom frequency was plotted against disease duration, we found that the frequency was lowest in the first 2 years of RBD (median, 18; range, 2-29 NAR), and higher frequencies were found in 2-year bin groups from 2 to 8 years after RBD onset (median, 60; range,. Intriguingly, after 8 years of RBD, the frequency returned to a level comparable to that in the first 2 years of RBD (median, 50; range, 12-100 NAR). Conclusions: There was no association between RBD symptom frequency and disease duration. RBD clinical symptoms could be less prominent when neural damage becomes severe. Therefore, a natural decrease in RBD symptom frequency may be indicative of progression of neurodegeneration.

Minor hallucinations in isolated rapid eye movement sleep behavior disorder indicative of early phenoconversion: A preliminary study

“…Therefore, patients with RBD and MH can be considered a group in which neurodegeneration has progressed further compared to patients without MH. There were no significant differences in RBDSQ scores between the longer/shorter disease duration groups (RBD with/without MH), which is consistent with the findings that symptom frequency of RBD peaks after 2–8 years of disease duration, after which the frequency decreases 47 . Among the RBD without MH group (at baseline), one patient presented MH and was subsequently diagnosed with DLB during follow‐up (Table S3).…”

“…There were no significant differences in RBDSQ scores between the longer/ shorter disease duration groups (RBD with/without MH), which is consistent with the findings that symptom frequency of RBD peaks after 2-8 years of disease duration, after which the frequency decreases. 47 Among the RBD without MH group (at baseline), one patient presented MH and was subsequently diagnosed with DLB during follow-up (Table S3). From a different perspective, all five patients who progressed to phenoconversion presented with MH before 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

“…On the other hand, the RBDSQ-J score of our population was lower than in the previous report (53), and the average disease duration was rather long: ∼10 years after symptom emergence. The RBDSQ-J score may have been low due to the long disease duration of iRBD (77). According to a longitudinal observational study of patients with a long disease duration of iRBD, almost all subjects showed multiple features of neurodegeneration including autonomic dysfunction after a follow-up of at least 10 years (19).…”

Age of Diagnosis and Comorbid PLMD Predict Poor Response of REM Behavior Disorder to Clonazepam

“…Furthermore, a recent study in Japan has reported that there was no association between RBD symptom frequency and disease duration, implying that the clinical symptoms of RBD may not be affected by disease progression. 32 As another factor for poor treatment outcomes, we found the presence of comorbid PLMS and poor treatment outcomes. Periodic limb movement during sleep is a common comorbid problem in patients with RBD, 33,34 and these 2 disorders share a pathophysiology, including dysfunction of the central dopaminergic system.…”