title: Leg movements during wakefulness in restless legs syndrome: time structure and relationships with periodic leg movements during sleep.
abstract: OBJECTIVE
  Approximately one third of patients with restless legs syndrome (RLS) also show periodic leg movements (PLM) during relaxed wake fulness (PLMW). In contrast with the large amount of data published on periodic leg movements during sleep (PLMS), PLMW have received less attention from the scientific community. The objective of this study was to evaluate the correlations/differences of time-structure and response to a dopamine-agonist between PLMW and PLMS in patients with RLS.
  
  
  METHODS
  Ninety idiopathic RLS patients and 28 controls were recruited. Subjects underwent clinical and neurophysiological evaluation, hematological screening, and one or two consecutive full-night polysomnographic studies. A subset of patients received 0.25mg of pramipexole or placebo before the second recording. Polysomnographic recordings were scored and LM activity was analyzed during sleep and during the epochs of wakefulness occurring during the first recording hour.
  
  
  RESULTS
  RLS patients had higher LM activity during wakefulness than controls, but with a similar periodicity. Even if correlated, the ability of the PLMW index to predict the PLMS index decreased with increasing LM activity. Intermovement intervals during wakefulness showed one peak only at approximately 4s, gradually decreasing with increasing interval in both patients and controls. The effect of pramipexole was very limited and involved the small periodic portion of LM activity during wakefulness.
  
  
  CONCLUSIONS
  PLMW index and PLMS index were correlated; however, the magnitude of this correlation was not sufficient to suggest that PLMW can be good predictors of PLMS. Short-interval LM activity during wakefulness and sleep might be linked to the severity of sleep disruption in RLS patients and the differences between their features obtained during wakefulness or sleep might be relevant for the diagnosis of sleep disturbances in RLS.
authors.affiliation: Sleep Research Centre, Department of Neurology I.C., Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Troina, Italy. rferri@oasi.en.it
authors.forename: Raffaele
authors.initials: R
authors.lastname: Ferri
authors.forename: Mauro
authors.initials: M
authors.lastname: Manconi
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Plazzi
authors.forename: Oliviero
authors.initials: O
authors.lastname: Bruni
authors.forename: Filomena I I
authors.initials: FI
authors.lastname: Cosentino
authors.forename: Luigi
authors.initials: L
authors.lastname: Ferini-Strambi
authors.forename: Marco
authors.initials: M
authors.lastname: Zucconi
mesh_terms: D052160:Benzothiazoles / Q000627:therapeutic use; D016022:Case-Control Studies; D018491:Dopamine Agonists / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007866:Leg / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000187:drug effects / Q000502:physiology*; D020189:Nocturnal Myoclonus Syndrome / Q000503:physiopathology; D017286:Polysomnography; D000077487:Pramipexole; D012148:Restless Legs Syndrome / Q000188:drug therapy / Q000503:physiopathology*; D012890:Sleep / Q000187:drug effects / Q000502:physiology; D013997:Time Factors; D014851:Wakefulness / Q000502:physiology*
chemical_list: D052160:Benzothiazoles; D018491:Dopamine Agonists; D000077487:Pramipexole