Impaired cortical and autonomic arousal during sleep in multiple system atrophy.
OBJECTIVE
Periodic limb movements during sleep (PLMS) in Restless Legs Syndrome (RLS) are associated with arousals and stereotyped EEG and heart rate (HR) changes. We investigated PLMS-related EEG and HR variations in multiple system atrophy (MSA) in order to detect possible abnormalities in cortical and autonomic arousal responses.


METHODS
Ten patients with MSA were contrasted against ten patients with primary RLS. Cortical (EEG) and autonomic (HR) variations associated with PLMS during NREM sleep were analysed by means of Fast Fourier Transform and HR analysis. In addition, we analysed the cyclic alternating pattern (CAP) during sleep, CAP representing a measure of the spontaneous arousal oscillations during NREM sleep.


RESULTS
PLMS in RLS were associated with tachycardia and spectral EEG variations, beginning about 2s before the onset of PLMS, and peaking 1-4s after. The HR and spectral EEG variations were strikingly reduced or absent in MSA. MSA patients also had significantly lower CAP rate compared to RLS patients.


CONCLUSIONS
Blunted HR and EEG spectral changes adjacent to PLMS indicated impaired cortical and autonomic arousal responses during sleep in MSA patients.


CONCLUSIONS
PLMS, when present, may represent a useful means to study the arousal responses during sleep.
Vetrugno
Roberto
R
Department of Neurological Sciences, University of Bologna, Via Ugo Foscolo 7, 40123 Bologna, Italy. vetrugno@neuro.unibo.it
D'Angelo
Roberto
R
Cortelli
Pietro
P
Plazzi
Giuseppe
G
Vignatelli
Luca
L
Montagna
Pasquale
P
D000368:Aged; D002540:Cerebral Cortex / Q000503:physiopathology*; D004569:Electroencephalography; D005260:Female; D005583:Fourier Analysis; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000150:complications* / Q000473:pathology; D010507:Periodicity; D012148:Restless Legs Syndrome / Q000209:etiology*; D012890:Sleep / Q000502:physiology*; D018709:Statistics, Nonparametric