Attenuated stroke severity after prodromal TIA - A role for ischemic tolerance in the brain?

Background and Purpose-Ischemic tolerance has been extensively studied in e xperimental models of heart and brain ischemia, While there is some clinica l evidence of ischemic tolerance in the heart, it is not known whether the same is true for the human brain. Methods-We conducted a retrospective case-control study in 148 stroke patie nts with and without antecedent TIA, Results-Despite no significant differences in baseline characteristics, ind ependence (Rankin scale score of 0 to 1) and favorable outcome (Glasgow Com a Scale score of 5) were significantly associated with prior TIA in univari ate analysis, After correction for other cardiovascular risk factors, TIA b efore stroke also was an independent predictor of mild stroke (Canadian Neu rological Scale score of greater than or equal to 6.5) in multivariate mode ls (absolute difference 21.6%; P=0.01), Conclusions-Assuming that a TIA represents an adequate stimulus to elicit i schemic tolerance, our results suggest that ischemic tolerance might occur in the human brain.