title: Enhanced frontoparietal synchronized activation during the wake-sleep transition in patients with primary insomnia.
abstract: BACKGROUND
  Cognitive and brain hyperactivation have been associated with trouble falling asleep and sleep misperception in patients with primary insomnia (PI). Activation and synchronization/temporal coupling in frontal and frontoparietal regions involved in executive control and endogenous attention might be implicated in these symptoms.
  
  
  METHODS
  Standard polysomnography (PSG) and electroencephalogram (EEG) were recorded in 10 unmedicated young patients (age 19-34 yr) with PI with no other sleep/medical condition, and in 10 matched control subjects. Absolute power, temporal coupling, and topographic source distribution (variable resolution electromagnetic tomography or VARETA) were obtained for all time spent in waking, Stage 1 and Stage 2 of the wake-sleep transition period (WSTP), and the first 3 consecutive min of N3. Subjective sleep quality and continuity were evaluated.
  
  
  RESULTS
  In comparison with control subjects, patients with PI exhibited significantly higher frontal beta power and current density, and beta and gamma frontoparietal temporal coupling during waking and Stage 1.
  
  
  CONCLUSIONS
  These findings suggest that frontal deactivation and disengagement of brain regions involved in executive control, attention, and self-awareness are impaired in patients with PI. The persistence of this activated and coherent network during the wake-sleep transition period (WSTP) may contribute to a better understanding of underlying mechanisms involved in difficulty in falling asleep, in sleep misperception, and in the lighter, poorer, and nonrefreshing sleep experienced by some patients with PI.
authors.affiliation: Laboratory for Sleep Research, Faculty of Psychology, Universidad Nacional Autónoma de México, México. corsi@unam.mx
authors.forename: María
authors.initials: M
authors.lastname: Corsi-Cabrera
authors.forename: Pedro
authors.initials: P
authors.lastname: Figueredo-Rodríguez
authors.forename: Yolanda
authors.initials: Y
authors.lastname: del Río-Portilla
authors.forename: Jorge
authors.initials: J
authors.lastname: Sánchez-Romero
authors.forename: Lídice
authors.initials: L
authors.lastname: Galán
authors.forename: Jorge
authors.initials: J
authors.lastname: Bosch-Bayard
mesh_terms: D000328:Adult; D001143:Arousal / Q000502:physiology*; D016022:Case-Control Studies; D004569:Electroencephalography; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology*; D006801:Humans; D008297:Male; D010296:Parietal Lobe / Q000503:physiopathology*; D017286:Polysomnography; D007319:Sleep Initiation and Maintenance Disorders / Q000503:physiopathology*; D012894:Sleep Stages / Q000502:physiology*; D055815:Young Adult