Cerebral blood flow directly affects the metabolism of substances and neural activity in the brain, and is closely associated with the occurrence and development of cerebral small vessel disease (CSVD). Multiple studies have revealed that various imaging biomarkers in patients with CSVD, such as lacunar infarction, enlarged perivascular spaces, cerebral microbleeds, cerebral atrophy, and white matter hyperintensities, are closely associated with cerebral autoregulation (CA) function. Therefore, understanding the regulatory mechanism of CA in patients with CSVD is of great significance for delaying the further development of CSVD, improving cerebral ischemia and cognitive impairment. This article reviews the correlation and mechanism between CA and CSVD.

Cerebral hyperperfusion syndrome (CHS) is a rare but serious complication after cerebral revascularization, which may lead to catastrophic consequences. The mechanism of CHS is not fully understood, and it may be related to cerebral autoregulation dysfunction and the increase of blood pressure after operation. Timely detection and treatment of cerebral hyperperfusion can avoid CHS. This article reviews the pathogenesis, diagnosis, clinical manifestations, prevention and treatment of CHS.

Objective:To investigate the correlation between moderate intensity aerobic exercise and cerebral blood flow regulation in patients with mild carotid artery stenosis.Methods:A retrospective study was conducted to select 30 cases of patients with unilateral mild carotid artery stenosis and moderate intensity aerobic exercise for more than 1 year in the Central Hospital of Dalian University of Technology from July 2022 to November 2023 as the exercise group (study group), and 30 cases of patients with unilateral mild carotid artery stenosis without exercise habits matched by age, gender and other factors as the non-exercise group (control group). Transcranial Doppler ultrasound (TCD) examination was performed in both groups, and the recumbent-upright-test, breath holding test and breath exchange test were performed to calculate the occurrence rate of "w" wave in recumbent-upright position, the slope of "w" wave in recubitus position, the change rate of pulse index (PI) before and after breath holding, resistance index (RI), breath holding index (BHI), and cerebral blood flow velocity before and after breath exchange. The blood pressure and heart rate difference in the recumbent-upright position were calculated, and the correlation between moderate intensity aerobic exercise and cerebral blood flow regulation function in patients with mild carotid artery stenosis was evaluated by statistical analysis. The correlation analysis between the exercise years and BHI in the study group was carried out to explore the relationship between the exercise years and cerebrovascular reactivity.Results:The occurrence rate and slope of "w" wave in the study group were higher than those in the control group: 93.3%(28/30) vs. 86.7%(26/30), 2.27 ± 1.14 vs. 1.28 ± 0.23, 2.67 ± 0.63 vs. 1.41 ± 0.69, there were statistically significant ( P<0.05). The change rates of PI and RI before and after breath holding and ventilation in the study group were higher than those in the control group: 21.23 ± 7.67 vs. 13.89 ± 9.67, 14.62 ± 6.63 vs. 11.17 ± 1.78 and 26.26 ± 12.46 vs. 18.36 ± 12.13, 14.91 ± 4.91 vs. 10.83 ± 2.35, and the average cerebral blood flow velocity before and after ventilation was higher than that in the control group: (31.26 ± 4.92) cm/s vs. (24.89 ± 6.34) cm/s, there were statistically significant ( P<0.01). The exercise years of the study group was negatively correlated with the breath holding index. Conclusions:Moderate intensity exercise is associated with cerebral blood flow regulation in patients with mild carotid artery stenosis. Exercise years are negatively correlated with cerebral blood flow regulation. Impaired cerebral blood flow regulation may be one of the potential mechanisms of poor prognosis of stroke in carotid artery stenosis population.

Objective:To investigate the influencing factors of headache degree in migraine patients with patent foramen ovale (PFO).Methods:The clinical data of 124 migraine patients with PFO from January 2013 to June 2019 in Dalian Central Hospital Affiliated to Dalian Medical University were retrospectively analyzed. The right-to-left shunt of PFO was assessed by contrast-enhanced transcranial Doppler (c-TCD); the diameter of PFO, length of PFO tunnel and the presence of atrial septal aneurysm (ASA) were detected by transesophageal echocardiography (TEE); the degree of migraine was assessed by headache impact test-6 (HIT-6) scale. The relations between right-to-left shunt volume of PFO, diameter of PFO and degree of migraine were analyzed by Goodman-Kruskal γ test; the relations between the length of PFO tunnel, ASA and degree of migraine were analyzed by Spearman rank correlation analysis.Results:Among the 124 migraine patients with PFO, the c-TCD test result showed that small shunt volume was in 20 cases, medium shunt volume in 31 cases, and large shunt volume in 73 cases. The TEE test result showed that small foramen ovale in 76 cases, medium foramen ovale in 47 cases, and large foramen ovale in 1 case; long tunnel in 57 cases, and short tunnel in 67 cases; without ASA in 91 cases, and with ASA in 33 cases. The HIT-6 score result showed that some influence in 9 cases, significantly influence in 22 cases, and serious influence in 93 cases. The Goodman-Kruskal γ test result showed that right-to-left shunt volume of PFO and diameter of PFO were positive correlation with degree of migraine ( γ = 0.66, P<0.01; γ = 0.38, P<0.05). The Spearman rank correlation analysis result showed that ASA was positive correlation with degree of migraine ( r = 0.18, P<0.05), while the length of PFO tunnel was negative correlation with degree of migraine ( r = -0.23, P<0.05). Conclusions:The right to left shunt amount of PFO, diameter of PFO and the presence of ASA are positive correlation with degree of migraine, while the length of PFO tunnel is negative correlation with degree of migraine.

Objective:To investigate the influence of Covid-19 epidemic on the number of acute ischemic stroke patients with intravenous thrombolytic therapy in Dalian in 2020, the way to hospital, onset to door time (ODT), door to needle time(DNT), onset to needle time(ONT), and the National Institute of Health Stroke Scale (NIHSS) before and after intravenous thrombolytic therapy.Methods:This was a retrospective descriptive study on 13 map-participating hospitals in Dalian from August 2020 to December 2020. The number of acute ischemic stroke patients with intravenous thrombolytic therapy, ODT, DNT, ONT, modes of transport to hospital, the NIHSS score before and after intravenous thrombolytic therapy, etc were analyzed. Data were collected from August 1, 2020 to December 31, 2020, and compared with the baseline data from the same period in 2019.Results:SPSS 22.0 statistical software and Data Analysis ToolPak were used for statistical analysis of the obtained data, and T tests statistic was used for data analysis. In 2020,the number of acute ischemic stroke patients with intravenous thrombolytic therapy increased (681 cases vs 416 cases), and DNT increased [50 minutes vs 45 minutes P = 0.01]. In 2020, 83.55% of patients indicated self-visit as their main mode of transport to the hospital. In 2020, among the self-visit patients with NIHSS score<15 scores,the number of the patients with the NHISS score unchanged or decreased after intravenous thrombolytic therapy was more (562 scores vs. 535 scores, P<0.001), and the patients with NIHSS score ≥15 scores were more willing to call ambulances to hospital. Conclusions:During the Covid-19 epidemic period of 2020, the number of acute ischemic stroke patients receiving intravenous thrombolytic therapy increased, DNT increase; the patients withNIHSS score<15 scores are more willing to choose to visit the hospital using their own transportation and benefit from intravenous thrombolytic therapy. The patients with NIHSS ≥15 scores prefer to call ambulances to hospital.

Objective To investigate the correlations of risk factors of age,delirium-inducing factors,dementia,delirium severity,and disease severity with the prognosis of elderly patients with delirium.Methods A total of 112 patients aged 70 years and older with initial onset of delirium during hospital stay were enrolled in this study.They were hospitalized in Dalian Municipal Central Hospital from Jan.2013 to Dec.2015.The severity of delirium was evaluated by delirium rating scalerevised-98(DRS-R-98).The acute physiology and chronic health enquiry(APACHE-Ⅱ)score and the sequential organ failure assessment(SOFA)score were recorded within 48 h after delirium onset.After periods of hospitalization of Jan.2013 to Dec.2015,patients were followed up until 31 Dec 2017.Correlations of age,delirium-inducing factors and dementia with survival time and long-term viability after delirium onset were statistically analyzed.Results Age,delirium-inducing factors,cognitive impairment,duration of cognitive impairment,type of dementia,and delirium severity had no correlations with the lifetime and long-term viability in patients with delirium.While,APACHE Ⅱ score for assessment of severity degree of delirium(P ＜0.001,r =-0.390) and SOFA score(P ＜0.001,r=-0.638)were negatively correlated with the lifetime in patients with delirium.SOFA score (P =0.004) and delirium recurrence (P ＜ 0.001) were significantly correlated with the long-term viability in patients with delirium.Conclusions The severity and recurrence of delirium are strongly correlated with the lifetime and quality of life in patients with delirium.Compared with APACHE Ⅱ score,SOFA score may have a more important clinical application value in predicting the prognosis of patients with delirium.

Objective To compare remifentanil?propofol target?controlled infusion ( TCI ) with sufentanil?propofol TCI for sedation and analgesia in the patients undergoing local anesthesia. Methods Sixty patients, aged 17?54 yr, with body mass index <30 kg∕m2, scheduled for elective plastic surgery underlocal anesthesia, were equally and randomly divided into remifentanil group (group R) and sufentanil group(group S) by using a random number table. Remifentanil (the initial target plasma concentration 1?? 0ng∕ml) and propofol (the initial target plasma concentration 1?? 0 μg∕ml) were given by TCI in group R.Sufentanil (the initial target plasma concentration 0?? 10 ng∕ml) and propofol (the initial target plasma con?centration 1?? 0 μg∕ml) were given by TCI in group S. The target plasma concentration was adjusted to main?tain the modified Observer′s Assessment of Alertness∕Sedation Scale score of 2 or 3. The occurrence of painresponses, hypoxemia, bradypnea and∕or apnea was recorded during operation. The total amount of propofolconsumed was calculated. Results There was no significant difference in the incidence of pain response,hypoxemia, bradypnea and∕or apnea, and total amount of propofol consumed between the two groups (P >0?? 05). Conclusion Remifentanil?propofol TCI provides similar sedative and analgesic efficacy to that a?chieved by sufentanil?propofol TCI in the patients undergoing local anesthesia.

Objective To explore the application value oftranscranial doppler (TCD) in carotid endarterectomy (CEA) through monitoring the hemodynamic changes of intracranial arteries during the perioperative period.Methods Eighty-two patients with internal carotid artery stenosis (ICAS),admitted to our hospital from January 2012-January 2013,were chosen in our study.Preoperative,intraoperative and postoperative TCD evaluations on these patients accepted CEA were performed; degrees of artery stenosis and fluency of lateral branch of the patients before CEA were evaluated; microembolic signals (MESs) and hemodynamics of the middle cerebral artery (MCA) in the surgery side were monitored during the perioperative period; the MCA velocity (VMCA) and the states of collateral circulation were observed after CEA.Results All 82 patients showed severe ICAS,low blood VMCA and low pulsatility index of MCA; anterior and posterior communicating branch did not exist in 6 patients; the other 76 patients showed different status of communicating artery.MESs were captured immediately after opening the clamp of common carotid artery (CCA) in 31 patients; when the ipsilateral CCA was clamped,2 patients showed a rapidly decreased VMCA to 0 cm/s,and a vascular shunt was used to ensure the brain blood supply.About 93.9％ patients presented an increase in the blood velocity and pulsatility index ofipsilateral MCA,together with a subsequent close of collateral circulation; over 1.5 times increase of VMCA was observed in about 24.7％ patients.Acute cerebral infarction in one patient occurred on the same day of CEA.Conclusions TCD could assess the hemodynamics of the contralateral MCA and the closure of collateral communication,thus,helping us predict the hyperperfusion and analyze the pathogenesis of cerebral infarction during perioperative CEA.

Objective To evaluate the renal protective effect of targeted abdominal perfusion pressure (APP) treatment in intra-abdominal hypertension (IAH) and further investigate its related mechanisms.Methods Twelve healthy pigs were randomly divided into experimental group and control group,each group had 6 pigs.All animals were collected urine volume each hour,continuously monitored mean arterial pressure (MAP) and renal cortical blood flow after anesthesia.IAH models were established by intraperitoneally injecting carbon dioxide in all animals,the baseline MAP,intra-abdominal pressure (IAP)and APP were obtained before IAH models established.In both groups,IAP was raised gradually from 0 mm Hg to 10 mm Hg,20 mm Hg and 30 mm Hg.In control group,IAP was maintained at 30 mm Hg for 8 hours with-out any other interventions.In experimental group,the animals were intravenously given with norepinephrine in order to get a target level of APP equal to its baseline values after 15 minutes of the onset of 30 mm Hg IAP.Changes of renal cortical blood flow,serum creatinine,TNF-α,IL-6 and urine IL-18 with the alteration of IAP in both groups were explored.Animals were then sacrificed for renal histopathology after 8 hours of the onset of 30 mm Hg IAP.Results With the increase of IAP,renal cortical blood flow in both groups was significantly decreased (P ＜ 0.01).Compared to its baseline,serum Cr and urinary IL-18 were significantly up-regulated after the maintenance of IAP at 30 mm Hg for 6 hours in both groups (P ＜ 0.05).However,in experimental group,which utilized a strategy of targeted APP,significant improvement of the renal cortical blood flow was observed (P ＜ 0.01),and urinary IL-18 was significantly lower than the control group (P ＜ 0.05).Renal histopathological examination found no obvious abnormalities either in control group or in experimental group.Conclusions The targeted APP treatment may have some renal protective function within the first 8 hours of IAH by improving renal cortical blood flow rather than affecting systemic inflammatory response.

Objective To compare the sedative and analgesic effects of remifentanil combined with propofol administered by target-controlled infusion(TCI)and intravenous infusion during local anesthesia.Methods Sixty ASA Ⅰ or Ⅱ patients,aged 18-55 yr,with body mass index ＜ 30 kg/m2,scheduled for plastic surgery under local anesthesia,were equally and randomly divided into TCI group(group T)and intravenous infusion group (group V).Remifentanil(the initial target plasma concentration 1.0 ng/ml)and propofol(the initial target plasma concentration 1.0 ng/ml)were given by TCI before local anesthesia in group T.Remifentanil was infused at a rate of 0.05 μg·kg-1 ·min-1 after a loading dose of 0.25 μg/kg and propofol was infused at a rate of 3 mg·kg-1 ·h-1 after a loading dose of 0.5 mg/kg in group V.The target plasma concentration or infusion rate was adjusted to maintain the modified OAA/S score of 2 or 3.Hypoxemia,bradypnea and/or apnea were recorded during operation.The total amount of remifentanil and propofol consumed was calculated.Results Compared with group V,the incidence of hypoxemia,bradypnea and/or apnea were significantly decreased during operation,and the total amount of remifentanil and propofol consumed was significantly reduced in group T(P ＜ 0.05).Conclusion The sedative and analgesic effects of remifentanil combined with propofol given by TCI are superior to those given by intravenous infusion during local anesthesia,with better safety.