Abstract: Abstract Objective: To confirm whether transient ischemic attack(TIA) is neuroprotective for secondary ischemic cerebral infarction. Methods: 60 patients suffered from ischemic cerebral infarction were recruited. 30 of them were enrolled in the TIA group, who all experienced 2~3 times TIA in one week before the cerebral infarction attacks and the TIA always persisted for 5～30 minutes. The other 30 without previous confirmed TIA history were recruited into the control group. CSS was applied to evaluate the degree of neurologic impairment when the patients were admitted. Calculation of the infarction volume was performed 72 hours later after admission. The one month prognosis after admission was assayed using ADL. Results: In TIA group, 22 (73.3%) and 8(26.7%) patients showed mild and moderate neurological impairment respectively. In the control group, the percent of the patients suffering from the mild and moderate neurological impairment was 46.7% (14 cases) and 53.3%(16 cases) respectively. When compared to the control group, more patients in the TIA one showed mild neurological impairment and less one suffered from moderate neurological injury (p<0.05). The mean cerebral infarction volume was significant less in the TIA group with (6.81±2.46) cm3 than in the control one with (10.39±4.53)cm3（p<0.05）. One month later, 24 patients (80.0%) in TIA group recovered to ADL grade I, while only 16 patients (53.3%) in the control one had the grade I outcome (p<0.05) . Conclusion: TIA can alleviate ischemic neurologic injury, reduce the infarction volume and then improve the prognosis. The reason might be TIA induces ischemic tolerance effect on brains and lead to neuroprotective effect on the subsequent cerebral infarction.

Key words: Transient ischemic attack, cerebral infarction, ischemic tolerance, neuroprotective effects, prognosis