title: Electroencephalogram spindle activity during dexmedetomidine sedation and physiological sleep.
abstract: BACKGROUND
  Dexmedetomidine, a selective alpha(2)-adrenoceptor agonist, induces a unique, sleep-like state of sedation. The objective of the present work was to study human electroencephalogram (EEG) sleep spindles during dexmedetomidine sedation and compare them with spindles during normal physiological sleep, to test the hypothesis that dexmedetomidine exerts its effects via normal sleep-promoting pathways.
  
  
  METHODS
  EEG was continuously recorded from a bipolar frontopolar-laterofrontal derivation with Entropy Module (GE Healthcare) during light and deep dexmedetomidine sedation (target-controlled infusions set at 0.5 and 3.2 ng/ml) in 11 healthy subjects, and during physiological sleep in 10 healthy control subjects. Sleep spindles were visually scored and quantitatively analyzed for density, duration, amplitude (band-pass filtering) and frequency content (matching pursuit approach), and compared between the two groups.
  
  
  RESULTS
  In visual analysis, EEG activity during dexmedetomidine sedation was similar to physiological stage 2 (S2) sleep with slight to moderate amount of slow-wave activity and abundant sleep spindle activity. In quantitative EEG analyses, sleep spindles were similar during dexmedetomidine sedation and normal sleep. No statistically significant differences were found in spindle density, amplitude or frequency content, but the spindles during dexmedetomidine sedation had longer duration (mean 1.11 s, SD 0.14 s) than spindles in normal sleep (mean 0.88 s, SD 0.14 s; P=0.0014).
  
  
  CONCLUSIONS
  Analysis of sleep spindles shows that dexmedetomidine produces a state closely resembling physiological S2 sleep in humans, which gives further support to earlier experimental evidence for activation of normal non-rapid eye movement sleep-promoting pathways by this sedative agent.
authors.affiliation: Department of Clinical Neurophysiology, Tampere University Hospital, Finland.
authors.forename: E
authors.initials: E
authors.lastname: Huupponen
authors.forename: A
authors.initials: A
authors.lastname: Maksimow
authors.forename: P
authors.initials: P
authors.lastname: Lapinlampi
authors.forename: M
authors.initials: M
authors.lastname: Särkelä
authors.forename: A
authors.initials: A
authors.lastname: Saastamoinen
authors.forename: A
authors.initials: A
authors.lastname: Snapir
authors.forename: H
authors.initials: H
authors.lastname: Scheinin
authors.forename: M
authors.initials: M
authors.lastname: Scheinin
authors.forename: P
authors.initials: P
authors.lastname: Meriläinen
authors.forename: S-L
authors.initials: SL
authors.lastname: Himanen
authors.forename: S
authors.initials: S
authors.lastname: Jääskeläinen
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D020927:Dexmedetomidine / Q000494:pharmacology*; D004569:Electroencephalography / Q000187:drug effects* / Q000379:methods; D006801:Humans; D006993:Hypnotics and Sedatives / Q000494:pharmacology*; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods; D012016:Reference Values; D012890:Sleep / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors
chemical_list: D006993:Hypnotics and Sedatives; D020927:Dexmedetomidine