Diagnosis of REM sleep behavior disorder by video-polysomnographic study: is one night enough?
OBJECTIVE
Clinical features of RBD were typically episodic with limited data on the night-to-night reliability of the diagnostic video-PSGs. We aimed to assess on whether a single night study was adequate.


METHODS
Retrospective review.


METHODS
Sleep laboratory.


METHODS
55 RBD patients with at least 2 consecutive video-PSGs.


METHODS
N/A.


METHODS
We analyzed 2 consecutive video-PSGs using REM-related EMG activity (REMREEA), REM sleep without atonia (RSWA), and video analysis of motor events.


RESULTS
A weak first night effect with increased REM sleep latency, increased stage 1 sleep, and increased arousal index were found. No differences were found in phasic and tonic EMG activity scores between night 1 and night 2. The presence of OSAS, use of CPAP, and clonazepam treatment did not affect the night-to-night variability and diagnostic accuracy. The kappas were 0.64, 0.51, and 0.31 between night 1 and night 2 for 10% REMREEA, RSWA, and video analysis respectively. Over 80% of patients could be diagnosed by various criteria in the first night, but the diagnostic ability could be enhanced to nearly 95% when combining PSG with video analysis. While both of the EMG criteria as well as the combination criteria had good reliability, video-analysis had poorer night-to-night reliability.


CONCLUSIONS
A single night of video-PSG was adequate in the diagnosis of RBD in most clinical patients and the combination of PSG and video analysis could enhance the detection rate further. Our findings have important resource implications.
Zhang
Jihui
J
Department of Psychiatry, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong, SAR.
Lam
Siu Ping
SP
Ho
Crover Kwok Wah
CK
Li
Albert Martin
AM
Tsoh
Joshua
J
Mok
Vincent
V
Wing
Yun Kwok
YK
D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography / Q000706:statistics & numerical data*; D020187:REM Sleep Behavior Disorder / Q000175:diagnosis*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014741:Video Recording