Analysis Of Influencing Factors Related To Cerebral Watershed Infarction And The Effect Of Perfusion Level Of CTP On Its Prognosis

Background and objectivesCerebral watershed infarction is a typical clinical type of cerebral infarction,named for its typical lesion location and imaging characteristics.In recent years,etiology studies have found that,unlike traditional causes of acute hypoperfusion on the basis of intracranial and extracranial vascular stenosis,the removal obstacle of microemboli may also play an important role in the etiology of CWI.Risk factors,stroke severity,degree of vascular stenosis and collateral compensation are also different.Besides,there were relatively few studies on perfusion imaging for this particular typed infarction.Based on this,this study explore the influencing factors of different parts of CWI,the risk factors to severe symptoms of CWI,and combined with the development of imaging,to determine the clinical value of early CTA examination in evaluating collateral circulation and CTP examination in evaluating cerebral perfusion level for prognosis estimate in CWI.Materials and MethodsThe infarction site was determined according to the patient's DWI sequence of MRI.The patients were divided into two groups: cortical watershed infarction and internal watershed infarction.The population datas and risk factors of cerebral infarction were compared between the two groups,and the influencing factors of CWI infarction were analyzed.(2)CWI patients who met the inclusion criteria were divided into mild stroke(?5 points)and non-mild stroke according to the NIHSS score on admission.The indicators between the two groups were compared,including their risk factors and imaging evaluation: differences in the degree of vascular stenosis,infarct,circle of Willis and collateral circulation;(3)The individual datas with symptomatic severe MCA/ICA stenosis and cerebral perfusion imaging examination were analyzed.According to the criterion of assessing whether the collateral circulation of the affected side/healthy is more than 50%,the patients were divided into good collateral branch group and bad collateral branch group.The ratio of perfusion parameters(lesion/opposite side)were calculated and compared between the two groups.The differences of rCBV,rCBF,rTTP and rMTT between the two groups were compared.The NIHSS scores on admission,14 d NIHSS scores and 14 d mRS scores were compared between the two groups.The clinical value of collateral circulation and perfusion level for assessing stroke progression and prognosis.Results1.The clinical datas of 160 patients with CWI were collected,including age(62.32 +9.81)years,age range(40-86)years,98 males(61.3%)and 62 females(38.7%).According to the location of lesions,32 patients with mixed-type watershed infarction,52 patients with CWSI and 76 patients with IWSI.2.Compared with IWSI,there were significant differences in risk factors between CWSI and IWSI groups,including atrial fibrillation,abnormal ventricular wall structure,the ratio of severe stenosis of MCA,the ratio of severe stenosis of ICA on the lesion side(all P < 0.05).Logister regression analysis showed that atrial fibrillation(OR = 2.222;95% CI: 2.008-4.902)and abnormal ventricular wall structure(OR = 2.825;95% CI: 1.126-7.092)were independent risk factors for CWSI.Sevrve stenosis of MCA on the lesion side(OR = 2.597;95% CI: 1.187-5.682)was an independent risk factor for IWSI.3.According to the severity of stroke,93 cases of mild ischemic stroke group and 67 cases of non-mild ischemic stroke group were obtained.There were significant differences in the history of hypertension,serum HCY concentration,type of CWI infarction,severity of MCA stenosis on the lesion side,severity of ICA stenosis on the lesion side and extent of collateral circulation between the two groups(all P < 0.05).Multivariate Logister regression analysis showed hypertension(OR = 2.497;95% CI: 1.061-5.875),MWSI(OR = 22.928;95% CI: 5.525-95.152).Severe stenosis of MCA(OR = 3.668;95% CI: 1.592-8.452)were independent risk factors for non-mild stroke,and well collateralized circulation(OR = 0.178;95% CI: 0.071-0.445)was a protective factor for mild stroke.4.41 patients with severe symptomatic MCA/ICA stenosis and CTP cerebral perfusion examination were divided into 24 patients with well collateralized circulation and 17 patients with poorly collateralized circulation.Relative perfusion parameters in rCBV,rCBF and rTTP were significantly different between the two groups(P < 0.05).There were significant differences in NIHSS scores on admission,14 d NIHSS scores and 14 d mRS scores between the two groups(P < 0.05).The perfusion parameters,symptoms and short-term prognosis of the well collateralized group were better than the poorly collateralized group.Conclusions:1.Cortical-type watershed infarction is more likely to be associated with atrial fibrillation,abnormal cardiac structure,unstable arterial plaque,etc.,which may cause microembolic appearance.Compared with other intracranial and extracranial arteries,severe stenosis of middle cerebral artery is more likely to cause internal watershed infarction.2.Hypertension,mixed watershed infarction and severe stenosis of middle cerebral artery are related to the severe symptoms of watershed infarction.3.Good collateral circulation is important for optimizing perfusion around the infarct area,reducing symptoms and improving prognosis.