Changes in cerebral and autonomic activity heralding periodic limb movements in sleep.
OBJECTIVE
Periodic limb movement disorder (PLMD) is frequently accompanied by awakenings or signs of EEG arousal. However, it is matter of debate whether EEG arousals trigger leg movements or both EEG arousal and leg movements are separate expressions of a common pathophysiological mechanism. Previous studies showed that cardiac and cerebral changes occur in association with periodic limb movements (PLMs), and that a combining increase in delta activity and in heart rate (HR) occurs before the onset of PLMs.


METHODS
This paper presents some preliminary data, obtained from a sample of 5 subjects with PLMD not associated to restless legs syndrome. To describe the temporal pattern of cardiac and EEG activities changes concomitant with PLMs in NREM sleep we used time frequency analysis technique.


RESULTS
PLM onset is heralded by a significant activation of HR and delta activity power, beginning 4.25 and 3 s respectively before PLMs onset, with PLMs onset and arousal onset falling together.


CONCLUSIONS
Delta and HR variations herald PLMs and activation of fast EEG frequencies. Such a stereotyped pattern is common in PLMs and in spontaneous or stimuli-induced arousals. Moreover a similar pattern seems to encompass the CAP phenomenon. The whole of these phenomena can be linked to the activity of a common brainstem system, which receives peripheral inputs, regulating the vascular, cardiac and respiratory activities and synchronizing them to cortical oscillations of EEG.
Ferrillo
Franco
F
Center for Sleep Medicine, DISMR, Department of Motor Sciences, University of Genova, Ospedale S. Martino, Largo R. Benzi 10, I-16132 Genoa, Italy. franco.ferrillo@unige.it
Beelke
Manolo
M
Canovaro
Paola
P
Watanabe
Tsuyoshi
T
Aricò
Debora
D
Rizzo
Pierpaolo
P
Garbarino
Sergio
S
Nobili
Lino
L
De Carli
Fabrizio
F
D000328:Adult; D000368:Aged; D001341:Autonomic Nervous System / Q000503:physiopathology*; D001921:Brain / Q000503:physiopathology*; D004569:Electroencephalography; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007866:Leg / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D020189:Nocturnal Myoclonus Syndrome / Q000503:physiopathology*; D017286:Polysomnography; D012894:Sleep Stages / Q000502:physiology