Spreading and synchronous depressions of cortical activity in acutely injured human brain.
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.
Strong
Anthony J
AJ
Departments of Neurosurgery, King's College London, London, United Kingdom. Anthony.strong@kcl.ac.uk
Fabricius
Martin
M
Boutelle
Martyn G
MG
Hibbins
Stuart J
SJ
Hopwood
Sarah E
SE
Jones
Robina
R
Parkin
Mark C
MC
Lauritzen
Martin
M
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