Correlation Between Cerebrovascular Reactivity And White Matter Lesions In Cryptogenic Stroke Patients With Right-to-Left Shunts

Objective: Right-to-left shut(RLS)was thought to be a possible pathogenesis of Cryptogenic stroke(CS),which was involved with changes in cerebrovascular reactivity(CVR).So far,it has not been clinically confirmed whether the changes of CVR in CS patients are caused by cerebral infarction itself or by RLS.lesions of this study was to analyze the relationship between CS and CVR with RLS,and to explore the association between changes in CVR and the development of White matter lesions(WML).Method: 260 patients in the experimental group with cryptogenic stroke admitted to the Neurology Department of Qingdao University Affiliated Hospital from December2016 to January 2022,while 73 non stroke patients admitted during the same period served as the control group.CS patients were screened using the International Heparin like Drug Therapy for Acute Ischemic Stroke(TOAST)classification,and enhanced Doppler(c-TCD)foaming test was used to diagnose RLS and evaluate the degree of RLS shunt.Severity classification based on RLS.In this study,levels 1 and 2 were classified as small shunts,while levels 3 and 4 were classified as large shunts.CVR was evaluated using transcranial Doppler ultrasound(TCD)to monitor the mean and maximum cerebral blood flow velocity(MFVmean)of the middle cerebral artery,and the breath holding index(BHI)was calculated.Continue to perform brain magnetic resonance imaging(MRI)testing on CS patients who have undergone RLS examination.White matter hyperintensity(WMH)refers to the diffuse fusion or patchy distribution of the periventricular and subcortical regions of the brain,with low or equal signal on T1 weighted sequence(T1WI),and abnormal lesions with high signal on T2 weighted sequence(T2WI)and T2 fluid attenuation inversion recovery(T2 Fair).The presence or absence of a WML group was determined through cranial MRI.Single factor analysis was used to compare the differences in CVR between the CS group,control group,and small and large shunt subgroups.In addition,by comparing the changes in CVR between the WML group and the non WML group,P<0.05 in univariate analysis was included in multiple logistic regression analysis.Pearson analysis was used to study the relationship between CS and CVR,RLS,WML,and to analyze the relationship between CVR changes and WML formation.Result: The 333 patients in this study were divided into the CS patient group(78.1%)and the control group(21.9%).In both groups,compared with the control group,the breath holding index(BHI)in the CS patient group was 0.68 ± 0.27 vs 0.87 ± 0.43,with a statistically significant difference(P=0.001).Among CS patients,there were 125cases(48.1%)in the RLS+group and 135 cases(51.9%)in the RLS-group.The BHI of CS patients with RLS was lower than that of CS patients without RLS(0.64 ± 0.28 vs0.71 ± 0.25,P=0.030).However,there was no statistically significant difference in BHI indicators between small and large shunt subgroups(0.64 ± 0.24 vs 0.64 ± 0.31,P=0.981).Compared the sex,age and vascular risk factors(including history of diabetes,hypertension and smoking)between the two groups,there was no significant difference between RLS group and non RLS group,small shunt group and large shunt group(P<0.05).Compared to CS patients without WML,there was no statistically significant difference in BHI among CS patients in the WML group(0.50 ± 0.22 vs.0.60 ± 0.35,P=0.012).Among WML patients,there were 78 cases in the PVH group and 42 cases in the DWMH group.The BHI in the PVH group was significantly lower than that in the DWMH group(0.45 ± 0.24 vs 0.58 ± 0.16,P=0.003).The higher the level of WMHs,the lower the BHI(0.60 ± 0.35 vs.0.51 ± 0.21 vs.0.48 ± 0.20 vs.0.38 ± 0.28,P=0.025).Logistic regression analysis found that a decrease in BHI was an independent factor associated with the occurrence of WML(OR: 0.283,95% CI: 0.081-0.995,P=0.049).Conclusion: The decrease in CVR in CS patients may be related to RLS,and the decrease in CVR in CS patients is not only related to the occurrence of WML,but also to the location and severity of WML.The decrease in CVR of CS with RLS may be an independent influencing factor for the occurrence of WML in CS patients.