title: Spreading and synchronous depressions of cortical activity in acutely injured human brain.
abstract: OBJECTIVE
  Cortical spreading depression (CSD) has been much studied experimentally but never demonstrated unequivocally in human neocortex by direct electrophysiological recording. A similar phenomenon, peri-infarct depolarization, occurs in experimental models of stroke and causes the infarct to enlarge. Our current understanding of the mechanisms of deterioration in the days after major traumatic or ischemic brain injury in humans has not yielded any effective, novel drug treatment. This study sought clear evidence for the occurrence and propagation of CSD in the injured human brain.
  
  
  METHODS
  In 14 patients undergoing neurosurgery after head injury or intracranial hemorrhage, we placed electrocorticographic (ECoG) electrodes near foci of damaged cortical tissue.
  
  
  RESULTS
  Transient episodes of depressed ECoG activity that propagated across the cortex at rates in the range of 0.6 to 5.0 mm/min were observed in 5 patients; this rate of propagation is characteristic of CSD. We also observed, in 8 of the 14 patients, transient depressions of ECoG amplitude that appeared essentially simultaneous in all recording channels, without clear evidence of spread.
  
  
  CONCLUSIONS
  These results indicate that CSD or similar events occur in the injured human brain and are more frequent than previously suggested. On the basis of these observations, we suggest that the related phenomenon, peri-infarct depolarization, is indeed likely to occur in boundary zones in the ischemic human cerebral cortex.
authors.affiliation: Departments of Neurosurgery, King's College London, London, United Kingdom. Anthony.strong@kcl.ac.uk
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Strong
authors.forename: Martin
authors.initials: M
authors.lastname: Fabricius
authors.forename: Martyn G
authors.initials: MG
authors.lastname: Boutelle
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Hibbins
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Hopwood
authors.forename: Robina
authors.initials: R
authors.lastname: Jones
authors.forename: Mark C
authors.initials: MC
authors.lastname: Parkin
authors.forename: Martin
authors.initials: M
authors.lastname: Lauritzen
mesh_terms: D001783:Blood Flow Velocity; D001930:Brain Injuries / Q000503:physiopathology* / Q000601:surgery; D002540:Cerebral Cortex / Q000098:blood supply / Q000293:injuries* / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D013181:Cortical Spreading Depression; D003399:Craniotomy; D004566:Electrodes; D004569:Electroencephalography / Q000295:instrumentation / Q000379:methods; D004594:Electrophysiology; D006801:Humans; D002532:Intracranial Aneurysm / Q000503:physiopathology / Q000601:surgery; D020198:Intracranial Hemorrhage, Traumatic / Q000503:physiopathology / Q000601:surgery; D020127:Recovery of Function