An Observational Study Of Supine-to-standing TCD Test In Patients With Mild Acute Ischemic Stroke

Objective: The study aims to explore the clinical characteristics,related risk factors and prognosis of neurocirculatory abnormalities in patients with Acute Ischemic Stroke(AIS)through analyzing the results of Transcranial Doppler(TCD)combined with supine-to-standing test.Methods: 120 cases of AIS patients with NIHSS score ≦4 and being able to coordinate with the supine and upright test were admitted to the Department of Neurology from June 2019 to May 2020.All data were collected within 7 days of onset.TCD was used to continuously monitor the MCA-CBFV of each patient.The blood pressure,heart rate and the MCA-m CBFV of the subjects were recorded at baseline when lying flat and at 1 minute,3 minutes,5 minutes and 10 minutes after standing upright.According to these aforementioned parameters,patients were divided into normal and abnormal groups,and the latter includes OH,OHT,OHP and POTS groups.General clinical data were collected.The National Institute of Health Stroke Scale,Modified Rankin Scale was conducted according to the degree of neurological deficit of cerebral infarction;And VM test was finished;Then,the location of the cerebral infarction,the characteristics of magnetic resonance,orthostatic intolerance questionnaire and the general symptoms of autonomic dysfunction were recorded in detail.Finally,during the one-year follow-up,the main end-point events were recurrent ischemic stroke events and secondary end-point events: stroke events of various causes and all-cause death were recorded.The difference between the normal and the abnormal groups were compared.Results:1.120 cases of AIS patients were enrolled,including 96(80.0%)males and 24(20.0%)females.Median age was 57(51-67)years old.According to the characteristics of changes in CBFV,blood pressure and heart rate,the supine to standing tests were normal in 27(22.5%)patients,and 15 cases(12.5%)of OH,36 cases(30.0%)of OHT,42 cases(35.0%)of OHP in 93(77.5%)abnormal patients.No POTS patient was recorded.According to the orthostatic intolerance questionnaire,there were 55 cases(45.8%)with symptoms of orthostatic intolerance and 65cases(54.2%)without symptoms.2.Compared to normal group in the supine-to-standing test,the OH group had a higher proportion of patients with diabetes,a history of stroke,and myocardial damage,while the OHT group had a higher proportion of patients with cardiac structure abnormalities.The difference was statistically significant(P<0.05).The results showed that cerebral infarction combined with OH was correlated with the history of diabetes,and cerebral infarction combined with OHT was correlated with abnormal heart structure,according to multivariate cox regression analysis.3.Comparison of the two group AIS + OI and AIS-OI showed that the former group was older in age.In AIS +OI group,subgroups of OH and OHP had significant differences compared with normal group,which were statistically significant.In AIS-OI group,differences were statistically significant in OHT group.(P<0.05).4.During the supine-to-standing test,compared to the normal group in the supine to standing test,in the OH group,lower systolic blood pressure in standing position,higher m CBFV of bilateral brain in supine position,and larger difference of m CBFV in infarct side from supine to standing were recorded;In the OHT group,higher systolic and diastolic blood pressures in the standing position,higher m CBFV in both the supine and standing positions on the infarct side,and larger difference of m CBFV in infarct lateral from supine to standing were recorded;In the OHP group,higher CBFV of the non-stroke side,larger PI in the supine position,and larger difference of m CBFV in bilateral sides from supine to standing were recorded.The difference was statistically significant.The orthostatic intolerance questionnaire is positively correlated with the degree of decrease in orthostatic CBFV.(P<0.05).5.Compared to the normal group,during the VM test,the proportion of VR<1.21 is higher in the OH group and in the OHP group,the cerebral blood flow indexⅢ is smaller in the OH group and in the OHP group.The baseline m CBFV of phase I was larger in the abnormal groups and the lowest m CBFV of phase II was larger in the OH group than in the normal group.In the OH group,the change rate of the m CBFV at the end of phase II-L compared with the baseline m CBFV of phase I and the lowest m CBFV of phase II was lower than that in the normal group,then the change rate of the m CBFV of phase IV callback compared with the baseline m CBFV of phase I was lower than that in the normal group.In the OHT group,the change rate of the m CBFV of phase IV callback compared with the baseline m CBFV of phase I was lower than that in the normal group.In the OHP group,the change rate of the m CBFV at the end of II-L compared with the baseline m CBFV of phase I was lower than that in the normal group.The difference was statistically significant.(P<0.05).6.Comparison of the two group AIS + OI and AIS-OI showed that the former group had higher baseline level in MCA-m CBFV and VM1,and lower level in VM2.Differences were statistically significant between the two groups.7.Compared to the normal group,more patients were recorded erect dizziness in the OH group and OHP group.The difference was statistically significant.(P<0.05).8.The incidence of end-point events in the OH group was higher than that in the normal supine orthostatic test group.(P<0.05).Conclusion:1.TCD combined with supine-to-standing test is helpful for the diagnosis of neurocirculatory abnormalities.2.Diabetes history and abnormal cardiac structure are the risk factors of neurocirculatory abnormality in mild AIS.3.Mild AIS with OH or OHP is frequent dizziness from supine to standing.The orthostatic intolerance questionnaire is positively correlated with the degree of decrease in orthostatic CBFV.4.Mild AIS with OH is associated with poor prognosis.