The Study Of The Relationship Between Progressive Ischemic Stroke And Collateral Circulation And Cerebral Tissue Perfusion

Background and Objective: Progressive ischemic stroke(PIS)is referred to as stroke in progression(SIP),which means the disease progresses within 6 hours to 1 week or the condition of patients after clinical intervention is still unstable and the symptoms of nerve defection are still progressive aggravation.SIP is an important subtype of ischemic stroke,which belongs to intractable cerebrovascular disease.Due to its high disability rate and mortality rate,SIP threatens life and health of human beings.Therefore,it is of great significance to study the risk factors of SIP and make a fast diagnosis of whether the diseases progresses,in order to predict the prognosis of cerebrovascular disease.This study aimed at the effects of the formation of collateral circulation and head MRI perfusion test on the SIP.Compared with SIP group and non-SIP group.,we analyzed the relationship between the development of SIP and the collateral circulation and cerebral tissue perfusion.Methods: From July of 2016 to October of 2017,136 patients from department of neurology of the first hospital of Jinlin University was included in this study.The patients were divided into healthy group,non-SIP group and SIP group according to whether the patients had new onset of cerebral infarction and or progression after infarction.82 patients were diagnosed and hospitalized for ischemic stroke compare with 54 healthy people.Among these groups there were 48 patients in non-SIP group and 34 patients in SIP group.The baseline of patients including age,gender,hypertension and diabetes were compared.According to whether vascular stenosis exists resulted from head and neck vascular examination,each group is divided into two subgroups:vascular stenosis group and non vascular stenosis group.According to the degree of vascular stenosis,it was divided into below moderate stenosis and above moderate(including moderate stenosis)group in order to compare the difference of degree of stenosis between each group;According to whether the formation of collateral circulation exists resulted from head and neck vascular examination,non-SIP group and SIP group were divided into two groups.In this way,we explore the relationship between the formation of collateral circulation and SIP;According to the results of MRI perfusion examination of head,we explore the relationship between SIP and cerebral tissue perfusion parameters(MTT,TTP,CBV,CBF).Results:(1)54 people were included in the health group,32males(59.3%)and 22 females(40.7%)with an average age of 58.91±8.96 years old;48 people were included in the non-SIP group,32 males(66.7%)and 16 females(33.3%)with an average age of 58.71±11.43 years old;34 patients were included in the SIP group,22 males(64.7%)and 12 females(35.3%)with an average age of 59.2±7.08 years old.There was no significant difference in gender and age between the three groups,P > 0.05.This shows that the three groups are comparable in terms of gender and age.(2)In the healthy group,33 patients(61.1%)have hypertension,15 patients(23.5%)have diabetes;In non-SIP group,26 patients(66.7%)have hypertension,19 patients(39.6%)have diabetes;In SIP group,21 patients(61.8%)have hypertension,12 patients(35.3%)have diabetes.There was no significant difference in hypertension and diabetes among these three groups,P > 0.05.This shows that the three groups are similar in terms of hypertension and diabetes.(3)In the health controls,13 patients(24.1%)included with vascular stenosis,7 patients(13%)?moderate stenosis;in non-SIP group,there are 32 patients(66.7%)with vascular stenosis,26 patients(54.2%)?moderate stenosis;in SIP group,there are 26 patients(76.5%)with vascular stenosis,21 patients(61.8%)?moderate stenosis.Compared with cerebral artery stenosis and stenosis?moderate stenosis in the three groups,P = 0.000 <0.05,indicating that there are some differences in the three groups.Correct P value,By comparison with each group,there were statistical significance between healthy controls and non-SIP group and the SIP group(P < 0.0167).There was no significant difference between SIP group and non-SIP group (P>0.0167).This suggests that ischemic stroke is associated with cerebral artery stenosis and the stenosis degree was moderate and it has nothing to do with the SIP.(4)There were 8 patients(23.5%)who have collateral circulation in SIP group and 23 patients(47.9%)in non-SIP group.This shows that the comparison between the two groups was statistically significant,P=0.025<0.05.The proportion of formation of collateral circulation in non-SIP group was higher than that in SIP group,indicating that the formation of the collateral circulation was negatively correlated with the occurrence of SIP.The more perfect the formation of collateral circulation,the lower the incidence of SIP.(5)The comparison of cerebral tissue perfusion parameters between group SIP and non SIP group(Diseased side/ healthy side): In SIP group r CBV(0.81±0.23),r CBF(0.64±0.32),r MTT(1.46±0.47),r TTP(1.09±0.83);in non-SIP group r CBV(1.07± 0.53),r CBF(0.72 ± 0.32),r MTT(1.56 ± 0.48),r TTP(1.10 ± 0.77).There was no significant difference in r CBF,r MTT and r TTP between the two groups(P>0.05),but has significant statistical difference about r CBV in the two groups(P=0.003<0.01).It showed that Although the MTT,TTP,and CBF in the ischemic area have decreased,they are still in a compensatory period,so there is no significant increase in the incidence of SIP.Only the decrease of CBV in ischemic could lead to increase in the incidence of SIP.Conclusions: 1.Ischemic stroke was associated with cerebral artery stenosis and the stenosis degree?moderate and it has nothing to do with the SIP.2.In the acute stage of cerebral infarction,the proportion of primary and secondary collateral circulation in non-SIP group was higher than that in SIP group,which indicates that the collateral circulation is related to the occurrence of SIP,good collateral circulation can effectively prevent stroke progression.3.Although the MTT,TTP,and CBF in the ischemic area have decreased,they are still in a compensatory period,so there is no significant increase in the incidence of SIP.Only the decrease of CBV in ischemic could lead to increase in the incidence of SIP.Adequate cerebral perfusion can prevent the progression of stroke.4.Whether or not SIP occurs did not depend solely on whether there were vascular stenosis or the degree of vascular stenosis.The more crucial factor depends on whether or not collateral circulation related to stenosis was formed and the time for the formation of collateral circulation.