• Definition: a non-REM-related parasomnia that occurs during the N3 sleep stage (slow-wave sleep), characterized by episodes of sleep terror
• Epidemiology: Discrete episodes of sleep terrors are relatively common in children (∼ 20% of children and ∼ 2% of adults), but the disorder is rare.
• Risk factors
  • Stress or fatigue
  • Fever
  • Sleep deprivation
• Clinical features
  • Screaming or crying suddenly upon awakening, usually in the first part of the night (rarely during daytime naps)
  • Intense fear and agitation
  • Tachypnea, diaphoresis, tachycardia during episodes
  • Difficulty arousing patients during episodes
  • Patients usually return to sleep after the episode.
  • Typically no recollection of the arousal episode (unlike with nightmare disorder)
    • Nightmare disorder
      • a REM-related parasomnia characterized by recurrent nightmares
      • Patient remembers the dream after awakening (REMember)