title: Evolution of blood-brain-barrier permeability after acute ischemic stroke.
abstract: The dynamics of BBB permeability after AIS in humans are not well understood. In the present study we measured the evolution of BBB permeability after AIS in humans using MRI. Patients presenting to our institution with a diagnosis of AIS underwent a single dynamic contrast-enhanced MRI (DCE-MRI) sequence to measure BBB permeability during their initial workup. Forty-two patients were included in the final analysis. The patient sample underwent DCE-MRI at a mean time of 23.8hrs after the onset of AIS symptoms (range: 1.3-90.7hrs). At all time-points the BBB permeability within the infarct region of the brain as defined on DWI/ADC was higher compared to the homologous region of the contralateral hemisphere (p<0.005). BBB permeability, expressed as a ratio of infarct permeability to contralateral permeability, was greatest at 6-48hrs after the onset of AIS. Although the data was not acquired longitudinally, these findings suggest that the permeability of the BBB is continually elevated following AIS, which contradicts previous assertions that BBB permeability after AIS follows a biphasic course. Knowledge of BBB dynamics following AIS may provide insight into future treatments for AIS, especially BBB stabilizing agents.
authors.affiliation: Department of Medical Imaging, University of Toronto, Toronto, Ontario, Canada.|Division of Physiology and Experimental Medicine, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Zamir
authors.initials: Z
authors.lastname: Merali
authors.affiliation: Department of Medicine, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Kun
authors.initials: K
authors.lastname: Huang
authors.affiliation: Division of Neuroradiology, Joint Department of Medical Imaging, Toronto Western Hospital, Toronto, Ontario, Canada.
authors.forename: David
authors.initials: D
authors.lastname: Mikulis
authors.affiliation: Division of Neurology, Toronto Western Hospital, Toronto, Ontario, Canada.
authors.forename: Frank
authors.initials: F
authors.lastname: Silver
authors.affiliation: Department of Medical Imaging, University of Toronto, Toronto, Ontario, Canada.|Division of Physiology and Experimental Medicine, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Andrea
authors.initials: A
authors.lastname: Kassner
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005075:Biological Evolution; D001812:Blood-Brain Barrier / Q000503:physiopathology*; D002545:Brain Ischemia / Q000503:physiopathology*; D002463:Cell Membrane Permeability; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D020521:Stroke / Q000503:physiopathology*