Clinical study on neuroprotective effect of prior TIA in patients with ischemic cerebral infarction

Objective To study whether transient ischemic attack(TIA)in advance has the neuroprotective effect on subsequant cerebral infarction.Methods According to whether they had ipsilateral TIA in advance,638 patients were divided into 2 groups:TIA group and non-TIA group.The 2 groups were compared in such aspects as the attack duration,frequency,and the interval and site of cerebral infarction.The neurologic impairment was evaluated according to the activities of daily living(ADL) scores.Results Patients with prior TIA had a more favorable outcome than those without TIA(72% vs 63%),but the difference between these 2 groups was not significant(X~2=3.31,P＞0.05),while the patients with prior TIA lasting 5～20 min,for 2～3 times and at 1-week or short intervals were significantly different from non-TIA group in the prognosis(P＜0.05).Conclusion TIA which happens before cerebral infarction may have ischemic tolerance effects on brains,and the neuroprotection of TIA is associated with the duration and the frequency of TIA and the interval between TIA and cerebral infarction.