title: Functional imaging of sleep vertex sharp transients.
abstract: OBJECTIVE
  The vertex sharp transient (VST) is an electroencephalographic (EEG) discharge that is an early marker of non-REM sleep. It has been recognized since the beginning of sleep physiology research, but its source and function remain mostly unexplained. We investigated VST generation using functional MRI (fMRI).
  
  
  METHODS
  Simultaneous EEG and fMRI were recorded from seven individuals in drowsiness and light sleep. VST occurrences on EEG were modeled with fMRI using an impulse function convolved with a hemodynamic response function to identify cerebral regions correlating to the VSTs. A resulting statistical image was thresholded at Z>2.3.
  
  
  RESULTS
  Two hundred VSTs were identified. Significantly increased signal was present bilaterally in medial central, lateral precentral, posterior superior temporal, and medial occipital cortex. No regions of decreased signal were present.
  
  
  CONCLUSIONS
  The regions are consistent with electrophysiologic evidence from animal models and functional imaging of human sleep, but the results are specific to VSTs. The regions principally encompass the primary sensorimotor cortical regions for vision, hearing, and touch.
  
  
  CONCLUSIONS
  The results depict a network comprising the presumed VST generator and its associated regions. The associated regions functional similarity for primary sensation suggests a role for VSTs in sensory experience during sleep.
authors.affiliation: Department of Neurology, University of California, Los Angeles, United States. jstern@ucla.edu
authors.forename: John M
authors.initials: JM
authors.lastname: Stern
authors.forename: Matteo
authors.initials: M
authors.lastname: Caporro
authors.forename: Zulfi
authors.initials: Z
authors.lastname: Haneef
authors.forename: Hsiang J
authors.initials: HJ
authors.lastname: Yeh
authors.forename: Carla
authors.initials: C
authors.lastname: Buttinelli
authors.forename: Agatha
authors.initials: A
authors.lastname: Lenartowicz
authors.forename: Jeanette A
authors.initials: JA
authors.lastname: Mumford
authors.forename: Josef
authors.initials: J
authors.lastname: Parvizi
authors.forename: Russell A
authors.initials: RA
authors.lastname: Poldrack
mesh_terms: D000328:Adult; D002560:Cerebrovascular Circulation; D004569:Electroencephalography; D055724:Electrophysiological Phenomena; D004827:Epilepsy / Q000503:physiopathology; D004833:Epilepsy, Temporal Lobe / Q000503:physiopathology; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D012890:Sleep / Q000502:physiology*; D012894:Sleep Stages / Q000502:physiology; D012895:Sleep, REM / Q000502:physiology; D013003:Somatosensory Cortex / Q000502:physiology; D055815:Young Adult