title: Is there a polysomnographic signature of augmentation in restless legs syndrome?
abstract: OBJECTIVE
  Augmentation of restless legs syndrome (RLS) is a potentially severe side-effect of dopaminergic treatment. Data on objective motor characteristics in augmentation are scarce. The aim of this study was to investigate in detail different variables of leg movements (LM) in untreated, treated, and augmented RLS patients.
  
  
  METHODS
  Forty-five patients with idiopathic RLS [15 untreated, 15 treated (non-augmented), 15 augmented] underwent RLS severity assessment, one night of video-polysomnography with extended electromyographic montage, and a suggested immobilization test (SIT).
  
  
  RESULTS
  Standard LM parameters as well as periodicity index (PI) and muscle recruitment pattern did not differ between the three groups. The ultradian distribution of periodic leg movements (PLM) in sleep during the night revealed significant differences only during the second hour of sleep (P <0.05). However, augmented patients scored highest on RLS severity scales (P <0.05) and were the only group with a substantial number of PLM during the SIT.
  
  
  CONCLUSIONS
  This study demonstrates that polysomnography is of limited usefulness for the diagnosis and evaluation of RLS augmentation. In contrast, the SIT showed borderline differences in PLM, and differences on subjective scales were marked. According to these results, augmentation of RLS is a phenomenon that predominantly manifests in wakefulness.
authors.affiliation: Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Mitterling
authors.affiliation: Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Birgit
authors.initials: B
authors.lastname: Frauscher
authors.affiliation: Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Tina
authors.initials: T
authors.lastname: Falkenstetter
authors.affiliation: Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Viola
authors.initials: V
authors.lastname: Gschliesser
authors.affiliation: Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Laura
authors.initials: L
authors.lastname: Ehrmann
authors.affiliation: Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: David
authors.initials: D
authors.lastname: Gabelia
authors.affiliation: Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Brandauer
authors.affiliation: Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Werner
authors.initials: W
authors.lastname: Poewe
authors.affiliation: Department of Neurology, Innsbruck Medical University, Innsbruck, Austria. Electronic address: birgit.ho@i-med.ac.at.
authors.forename: Birgit
authors.initials: B
authors.lastname: Högl
mesh_terms: D000328:Adult; D000368:Aged; D015259:Dopamine Agents / Q000009:adverse effects; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D012148:Restless Legs Syndrome / Q000139:chemically induced / Q000175:diagnosis* / Q000503:physiopathology; D014851:Wakefulness / Q000502:physiology; D055815:Young Adult
chemical_list: D015259:Dopamine Agents
keywords: Circadian; Electromyography (EMG); Movement disorders; Muscle; Periodicity; Recruitment; Restless legs syndrome therapy; Sleep