The Impact Of Remote Ischemic Conditioning On Dynamic Cerebral Autoregulation In Patients With Cerebral Small Vessel Disease

Background and Objective:Cerebral small vessel disease（CSVD）refers to the pathological,imaging and clinical syndromes caused by cerebral small vessel disease due to various etiologies.Acute lacunar infarction is one of the imaging manifestations.The incidence of CSVD increases with age,and causes most hemorrhagic strokes and approximately onequarter of ischemic strokes,and is the most common cause of vascular dementia.Despite its high disease burden,there are currently relatively few effective treatment strategies.Dynamic cerebral autoregulation（dCA）function is an inherent selfprotection mechanism for the body to avoid hypoperfusion or hyperperfusion in brain tissue.When dCA is damaged,cerebral blood flow passively follows changes in arterial blood pressure,increasing the risk of hypoperfusion or hyperperfusion in brain tissue,leading to further damage to brain tissue.Studies have shown that dCA function in patients with ischemic stroke is impaired and associated with poor clinical outcomes.dCA function is impaired in CSVD patients as well.In CSVD patients with acute lacunar infarction,both the ipsilateral and the contralateral side of the dCA were damaged,and the damage was diffused and persistent.Therefore,intervention on dCA function may be one of the effective ways to treat CSVD.Remote ischemic conditioning（RIC）refers to one or more transient ischemia/reperfusion stimulation of an organ to improve the tolerance of distant target organs to ischemic events.Previous studies have demonstrated that RIC is safe and effective in the treatment of ischemic stroke,and RIC can also improve dCA function in healthy subjects.However,it is unclear whether RIC can improve dCA function in patients with CSVD.The purpose of this study was to investigate the effect of RIC on the dCA function of CSVD patients,in order to find an effective treatment method for CSVD patients.Materials and Methods:This study included CSVD patients with acute lacunar cerebral infarction who were admitted to the Department of Neurology,the First Hospital of Jilin University from March 2021 to January 2022,and who met the inclusion and exclusion criteria.According to the patient’s informed preference,the research subjects were divided into the experimental group and the control group.The experimental group received RIC twice per day during hospitalization on the basis of standard medical treatment;the control group received control treatment twice per day during hospitalization on the basis of standard medical treatment.RIC was performed in a total of 4 cycles of 5minutes of pressurized ischemia/5 minutes of relaxation.The pressure in the experimental group was 200 mm Hg,and the pressure in the control group was 60 mm Hg.The two groups of patients were all monitored for dCA before treatment and after the last treatment.The dCA parameters were obtained by transfer function analysis method: gain,phase and coherence function.The patients were followed up at 90±7days after the onset of the disease,and the modified Rankin Scale（mRS）scores was evaluated,with a score of 0-1 defined as a good prognosis.Multivariate linear regression model and binary logistic regression analysis model were used to evaluate the effect of RIC treatment on dCA function and prognosis of CSVD patients.Results:This study finally included 61 patients with CSVD of acute lacunar infarction on imaging.There were 29 cases in the experimental group with an average age of55.80±6.35 years and 25 males（86.2%）,and 32 cases in the control group with an average age of 57.32±10.83 years and 25 males（78.1%）.Except for the history of diabetes,smoking and drinking,there were no significant differences in other baseline clinical data between the two groups（P>0.05）.In CSVD patients with unilateral acute lacunar infarction,there was no significant difference in baseline dCA parameters between the infarcted side and contralateral side（P≥0.05）.RIC treatment had no significant effect on the cerebral blood flow velocity and pulsatility index of the middle cerebral artery in the experimental group and the control group（P>0.05）.RIC treatment was positively correlated with the phase on the contralateral side of very low frequency（β=22.735,P=0.049）,the phase on the infarcted side of low frequency（β=21.996,P<0.001）,and the phase on the contralateral side of low frequency（β=26.860,P<0.001）,suggesting that RIC could improve dCA function.There was no significant correlation between RIC treatment and 3-month mRS score（P>0.05）.Conclusions:1.RIC can improve dCA function in CSVD patients.2.There was no significant difference in dCA function between the infarcted side and the contralateral side in CSVD patients with unilateral acute lacunar infarction.3.RIC has no significant effect on cerebral blood flow velocity and pulsatility index in CSVD patients.