Quantification of electromyographic activity during REM sleep in multiple muscles in REM sleep behavior disorder.
OBJECTIVE
The aim of our study was to determine which muscle or combination of muscles (either axial or limb muscles, lower or upper limb muscles, or proximal or distal limb muscles) provides the highest rates of rapid eye movement (REM) sleep phasic electromyographic (EMG) activity seen in patients with REM sleep behavior disorder (RBD).


METHODS
Two university hospital sleep disorders centers.


METHODS
Seventeen patients with idiopathic RBD (n = 8) and RBD secondary to Parkinson disease (n = 9).


METHODS
Not applicable.


RESULTS
Patients underwent polysomnography, including EMG recording of 13 different muscles. Phasic EMG activity in REM sleep was quantified for each muscle separately. A mean of 1459.6 +/- 613.8 three-second REM sleep mini-epochs were scored per patient. Mean percentages of phasic EMG activity were mentalis (42 +/- 19), flexor digitorum superficialis (29 +/- 13), extensor digitorum brevis (23 +/- 12), abductor pollicis brevis (22 +/- 11), sternocleidomastoid (22 +/- 12), deltoid (19 +/- 11), biceps brachii (19 +/- 11), gastrocnemius (18 +/- 9), tibialis anterior (right, 17 +/- 12; left, 16 +/- 10), rectus femoris (left, 11 +/- 6; right, 9 +/- 6), and thoraco-lumbar paraspinal muscles (6 +/- 5). The mentalis muscle provided significantly higher rates of excessive phasic EMG activity than all other muscles but only detected 55% of all the mini-epochs with phasic EMG activity. Simultaneous recording of the mentalis, flexor digitorum superficialis, and extensor digitorum brevis muscles detected 82% of all mini-epochs containing phasic EMG activity. This combination provided higher rates of EMG activity than any other 3-muscle combination. Excessive phasic EMG activity was more frequent in distal than in proximal muscles, both in upper and lower limbs.


CONCLUSIONS
Simultaneous recording of the mentalis, flexor digitorum superficialis, and extensor digitorum brevis muscles provided the highest rates of REM sleep phasic EMG activity in subjects with RBD.
Innsbruck Medical University, Department of Neurology, Innsbruck, Austria.
Birgit
B
Frauscher
Alex
A
Iranzo
Birgit
B
Högl
Jordi
J
Casanova-Molla
Manel
M
Salamero
Viola
V
Gschliesser
Eduardo
E
Tolosa
Werner
W
Poewe
Joan
J
Santamaria
D000368:Aged; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008432:Mathematical Computing; D008875:Middle Aged; D009129:Muscle Tonus / Q000502:physiology; D018482:Muscle, Skeletal / Q000503:physiopathology*; D010300:Parkinson Disease / Q000503:physiopathology; D017286:Polysomnography; D020187:REM Sleep Behavior Disorder / Q000175:diagnosis / Q000503:physiopathology*; D012815:Signal Processing, Computer-Assisted; D012984:Software