Cerebral Perfusion Research Articles

Longitudinal trajectories of Alzheimer's disease CSF biomarkers and blood pressure in cognitively healthy subjects.

We examined whether hypertension (HTN) was associated with Alzheimer's disease-related biomarkers in cerebrospinal fluid (CSF) and how changes in blood pressure (BP) related to changes in CSF biomarkers over time. A longitudinal observation of cognitively healthy normotensive subjects (n=134, BP<140/90, withno antihypertensive medication), controlled HTN(n=36, BP<140/90, taking antihypertensive medication), and 35 subjects with uncontrolled HTN (BP ≥ 140/90). The follow-up range was 0.5to15.6 years. Total tau (T-tau) and phospho-tau181 (P-tau 181) increased in allbut controlled HTN subjects (group×timeinteraction: p<0.05 for both), but no significant Aβ42 changes were seen. SignificantBP reduction wasobserved in uncontrolled HTN, andit was related to increase in T-tau (p=0.001) and P-tau 181 (p<0.001). Longitudinal increases in T-tau and P-tau 181 were observed in most subjects; however, onlyuncontrolled HTN had both markers increase alongside BPreductions. We speculatecumulative vascular injury renders thebrain susceptible to relative hypoperfusion with BP reduction. Over the course of the study, participants with uncontrolled HTN at baseline showed greater accumulation of CSF total tau and phospho-tau181 (P-tau 181) than subjects with normal BP or with controlled HTN. In the group with uncontrolled HTN, increases in total tau and P-tau 181 coincided with reduction in BP. We believe this highlights the role of HTN in vascular injury and suggests decline in cerebral perfusion resulting in increased biomarker concentrations in CSF. Medication use was the main factor differentiating controlled from uncontrolled HTN, indicating that earlier treatment was beneficial for preventing accumulations of pathology.

A preliminary study on the application of electrical impedance tomography based on cerebral perfusion monitoring to intracranial pressure changes.

In intracranial pathologic conditions of intracranial pressure (ICP) disturbance or hemodynamic instability, maintaining appropriate ICP may reduce the risk of ischemic brain injury. The change of ICP is often accompanied by the change of intracranial blood status. As a non-invasive functional imaging technique, the sensitivity of electrical impedance tomography (EIT) to cerebral hemodynamic changes has been preliminarily confirmed. However, no team has conducted a feasibility study on the dynamic detection of ICP by EIT technology from the perspective of non-invasive whole-brain blood perfusion monitoring. In this study, human brain EIT image sequence was obtained by in vivo measurement, from which a variety of indicators that can reflect the tidal changes of the whole brain impedance were extracted, in order to establish a new method for non-invasive monitoring of ICP changes from the level of cerebral blood perfusion monitoring. Valsalva maneuver (VM) was used to temporarily change the cerebral blood perfusion status of volunteers. The electrical impedance information of the brain during this process was continuously monitored by EIT device and real-time imaging was performed, and the hemodynamic indexes of bilateral middle cerebral arteries were monitored by transcranial Doppler (TCD). The changes in monitoring information obtained by the two techniques were compared and observed. The EIT imaging results indicated that the image sequence showed obvious tidal changes with the heart beating. Perfusion indicators of vascular pulsation obtained from EIT images decreased significantly during the stabilization phase of the intervention (PAC: 242.94 ± 100.83, p < 0.01); perfusion index which reflects vascular resistance increased significantly in the stable stage of intervention (PDT: 79.72 ± 18.23, p < 0.001). After the intervention, the parameters gradually returned to the baseline level before compression. The changes of EIT indexes in the whole process are consistent with the changes of middle cerebral artery velocity related indexes shown in TCD results. The EIT image combined with the blood perfusion index proposed in this paper can reflect the decrease of cerebral blood flow under the condition of increased ICP in real time and intuitively. With the advantages of high time resolution and high sensitivity, EIT provides a new idea for non-invasive bedside measurement of ICP.

Influence of cerebrospinal fluid drainage in the first days after aneurysm rupture on the severity of early brain injury following aneurysmal subarachnoid hemorrhage

PurposeProgressive cerebral edema with refractory intracranial hypertension (ICP) requiring decompressive hemicraniectomy (DHC) is a severe manifestation of early brain injury (EBI) after aneurysmal subarachnoid hemorrhage (aSAH). The purpose of the study was to investigate whether a more pronounced cerebrospinal fluid (CSF) drainage has an influence on cerebral perfusion pressure (CPP) and the extent of EBI after aSAH.MethodsPatients with aSAH and indication for ICP-monitoring admitted to our center between 2012 and 2020 were retrospectively included. EBI was categorized based on intracranial blood burden, persistent loss of consciousness, and SEBES (Subarachnoid Hemorrhage Early Brain Edema Score) score on the third day after ictus. The draining CSF and vital signs such as ICP and CPP were documented daily.Results90 out of 324 eligible aSAH patients (28%) were included. The mean age was 54.2 ± 11.9 years. DHC was performed in 24% (22/90) of patients. Mean CSF drainage within 72 h after ictus was 168.5 ± 78.5 ml. A higher CSF drainage within 72 h after ictus correlated with a less severe EBI and a less frequent need for DHC (r=-0.33, p = 0.001) and with a higher mean CPP on day 3 after ictus (r = 0.2351, p = 0.02).ConclusionA more pronounced CSF drainage in the first 3 days of aSAH was associated with higher CPP and a less severe course of EBI and required less frequently a DHC. These results support the hypothesis that an early and pronounced CSF drainage may facilitate blood clearance and positively influence the course of EBI.

Effects of passive cycling on cerebrovascular reactivity in acute brain injured patients: A pilot study

IntroductionEarly mobilization benefits critically ill patients, but concerns persist, especially in neurologic intensive care unit patients with acute brain injuries. This study assesses early mobility's impact on cerebrovascular autoregulation (CA) and systemic hemodynamics. MethodsThis single-center retrospective study focused on adult neurologic intensive care unit patients undergoing passive cycle ergometry. Data were collected from December 2020 to April 2022. Physical therapists conducted sessions using a standardized protocol, monitoring mean arterial blood pressure (MAP) and intracranial pressure (ICP). The Pressure Reactivity Index (PRx) was calculated as a measure of CA. Statistical analysis included mixed models and repeated measures ANOVA. ResultsEleven patients undergoing continuous physiologic monitoring and early mobility were included, primarily with subarachnoid hemorrhage or intracranial hemorrhage. Median time to protocol initiation was 4 days, with two patients discontinuing due to hemodynamic disturbances. Over a total of 11-hours of neuromonitoring data, passive cycling demonstrated a significant reduction in heart rate (HR), MAP, and ICP across different rotations per minute (RPM) settings compared to baseline. No significant alterations in PRx or cerebral perfusion pressure (CPP) were noted at various RPM levels. However, a significant difference in PRx emerged between patients who completed the protocol and those who did not, particularly at 10 RPM. DiscussionThis study offers preliminary insights into the impact of early mobility on CA in acute brain injured patients. While passive cycling demonstrates promise in preserving cerebral hemodynamics, its tolerability may not be uniform across all brain-injured patients. These findings highlight the need to determine optimal early mobilization timing and intensity in this population, emphasizing the necessity for larger prospective studies to validate these findings and inform clinical practice. DetailsThis manuscript complies with all instructions to the authors. All coauthors meet the authorship requirements and have reviewed and approved the contents of the manuscript. The manuscript has not been published totally or partly, accepted for publication, or under editorial review for publication elsewhere. We have no conflicts of interest to disclose. STROBE checklist was reviewed prior to the submission of this paper. The manuscript adheres to ethical guidelines and was approved by Cleveland Clinic’s institutional research board for retrospective study. There is no funding to disclose for this study.

TRAUMATIC BRAIN INJURY AND ITS MANAGEMENT

A prevalent illness with a high morbidity and death rate is head injuries. Early detection and evacuation are crucial for serious cerebral hemorrhages in order to optimize the likelihood of independent recovery. It isthe primary cause of death for children and young people and a significant medical and socioeconomic issue. The Brain Trauma Foundation’s “Guidelines for the Management of this disease” are a major source of inspiration for critical care management of this injury. The primary goals are to maintain cerebral perfusion pressure (CPP), optimize cerebral oxygenation, and prevent and cure intracranial hypertension and secondary brain injuries. The care management of (TBI) will be covered in this review, with particular attention paid to monitoring, preventing and minimizing subsequent brain insults, and optimizing cerebral oxygenation and CPP. The influences of worrying mind damage can be profound and lengthy-lasting, affecting all aspects ofsomeone’slife. However, with suitable assist, rehabilitation, and adaptive techniques, many individuals with TBI are capable of lead pleasant and significant lives.

Anesthesia Blunts Carbon Dioxide Effects on Glymphatic Cerebrospinal Fluid Dynamics in Mechanically Ventilated Rats.

Impaired glymphatic clearance of cerebral metabolic products and fluids contribute to traumatic and ischemic brain edema and neurodegeneration in preclinical models. Glymphatic perivascular cerebrospinal fluid flow varies between anesthetics possibly due to changes in vasomotor tone and thereby in the dynamics of the periarterial cerebrospinal fluid (CSF)-containing space. To better understand the influence of anesthetics and carbon dioxide levels on CSF dynamics, this study examined the effect of periarterial size modulation on CSF distribution by changing blood carbon dioxide levels and anesthetic regimens with opposing vasomotor influences: vasoconstrictive ketamine-dexmedetomidine (K/DEX) and vasodilatory isoflurane. End-tidal carbon dioxide (ETco2) was modulated with either supplemental inhaled carbon dioxide to reach hypercapnia (Etco2, 80 mmHg) or hyperventilation (Etco2, 20 mmHg) in tracheostomized and anesthetized female rats. Distribution of intracisternally infused radiolabeled CSF tracer 111In-diethylamine pentaacetate was assessed for 86 min in (1) normoventilated (Etco2, 40 mmHg) K/DEX; (2) normoventilated isoflurane; (3) hypercapnic K/DEX; and (4) hyperventilated isoflurane groups using dynamic whole-body single-photon emission tomography. CSF volume changes were assessed with magnetic resonance imaging. Under normoventilation, cortical CSF tracer perfusion, perivascular space size around middle cerebral arteries, and intracranial CSF volume were higher under K/DEX compared with isoflurane (cortical maximum percentage of injected dose ratio, 2.33 [95% CI, 1.35 to 4.04]; perivascular size ratio 2.20 [95% CI, 1.09 to 4.45]; and intracranial CSF volume ratio, 1.90 [95% CI, 1.33 to 2.71]). Under isoflurane, tracer was directed to systemic circulation. Under K/DEX, the intracranial tracer distribution and CSF volume were uninfluenced by hypercapnia compared with normoventilation. Intracranial CSF tracer distribution was unaffected by hyperventilation under isoflurane despite a 28% increase in CSF volume around middle cerebral arteries. K/DEX and isoflurane overrode carbon dioxide as a regulator of CSF flow. K/DEX could be used to preserve CSF space and dynamics in hypercapnia, whereas hyperventilation was insufficient to increase cerebral CSF perfusion under isoflurane.

Hypotension with neurovascular changes and cognitive dysfunction: An epidemiological, pathobiological, and treatment review.

Hypotension is a leading cause of age-related cognitive impairment. The available literature evidences that vascular factors are associated with dementia and that hypotension alters cerebral perfusion flow and can aggravate the neurodegeneration of Alzheimer's disease (AD). Despite the discovery of biomarkers and the recent progress made in neurovascular biology, epidemiology, and brain imaging, some key issues remain largely unresolved: the potential mechanisms underlying the neural deterioration observed in AD, the effect of cerebrovascular alterations on cognitive deficits, and the positive effects of hypotension treatment on cognition. Therefore, further well-designed studies are needed to unravel the potential association between hypotension and cognitive dysfunction and reveal the potential benefits of hypotension treatment for AD patients. Here, we review the current epidemiological, pathobiological, and treatment-related literature on neurovascular changes and hypotension-related cognitive dysfunction and highlight the unsettled but imminent issues that warrant future research endeavors.

P.104 Prognostic value of NIRS regional oxygen saturation based cerebrovascular reactivity in TBI: a Canadian high resolution traumatic brain injury (CAHR-TBI) cohort study

Background: Near-infrared spectroscopy regional cerebral oxygen saturation (rSO2) has gained interest as a raw parameter and as a basis for measuring cerebrovascular reactivity (CVR). This study aimed to identify threshold values of rSO2 and rSO2 based CVR at which outcomes worsened following traumatic brain injury (TBI). Methods: A retrospective multi-institutional cohort study was performed. The cerebral oxygen indices, COx (using rSO2 and cerebral perfusion pressure) as well as COx_a (using rSO2 and arterial blood pressure) were calculated for each patient. 2x2 tables were created grouping patients by alive/dead and favorable/unfavorable outcomes at various thresholds of COx and COx_a as well as rSO2 itself. Chi-square values were calculated to identify the most discriminative significant threshold. Results: In the cohort of 129 patients rSO2 did not have any statistically significant threshold value. For COx and COx_a, an optimal threshold value of 0.2 was identified for both survival and favorable outcomes with values above this associated with worse outcomes. Conclusions: In this study, raw rSO2was found to contain no significant prognostic information. However, rSO2 based indices of CVR, were found to have a uniform threshold of 0.2, above which clinical outcomes worsened. This study lays the groundwork to transition to less invasive means of continuously measuring CVR.

#1551 The presence of proteinuria is associated with impaired cerebral oxygenation during exercise in chronic kidney disease

Abstract Background and Aims Cognitive impairment and reduced exercise tolerance are common in patients with chronic kidney disease (CKD), in part due to reduced brain function. Cerebral perfusion and oxygenation are significant determinants of brain activation and have been shown to be significantly impaired in CKD. This analysis aims to examine the impact of proteinuria on cerebral oxygenation during a mild physical stress in patients with pre-dialysis CKD. Method 66 patients with CKD stage 2-4 were included in this post-hoc analysis; 24-h urine samples were used for evaluation of proteinuria. All participants underwent a 3-min intermittent handgrip exercise (HG) at 35% of their maximal voluntary contraction. Changes in cerebral oxygenation (oxyhemoglobin-O2Hb) and deoxyhemoglobin-HHb) and regional blood volume (total hemoglobin-tHb) were continuously recorded during HG-exercise by near-infrared spectroscopy (NIRS). Results No significant differences between the 2 groups were detected in age (proteinuric vs nonproteinuric: 68.4 ± 10.6 vs 67.2 ± 10.8; p = 0.676), eGFR (41.3 ± 18.9 vs 46.3 ± 14.8; p = 0.248) and BMI (28.4 ± 4.9 vs 28.1 ± 4.8; p = 0.803). The MMSE score (proteinuric vs nonproteinuric: 28.0 ± 1.6 vs 28.0 ± 1.7; p = 0.938) and MVC (22.3 ± 7.0 vs 23.9 ± 7.5; p = 0.416) were not significantly different between groups. The average response in cerebral oxygenation during exercise was lower in patients with proteinuric CKD (O2Hb: 1.02 ± 0.87 vs 1.61 ± 0.95; p = 0.018 and diffO2Hb 1.53 ± .97 vs 2.07 ± 1.25; p = 0.065). The average tHb response (index of regional-blood-volume) was also lower in patients with proteinuria (0.51 ± 1.08 vs 1.16 ± 0.92 p = 0.013); however, no differences in HHb (-0.50 ± 0.55 vs -0.45 ± 0.54; p = 0.717) –an index of oxygen extraction capacity- among groups were detected. In univariate linear analysis the level of proteinuria did not show significant correlations with NIRS parameters. Conclusion The presence and not the level of proteinuria is associated with impaired brain activation during a mild physical task in patients with predialysis CKD. Future studies evaluating the role of proteinuria in the decline of cerebral function and cognitive impairment are needed.

#1806 Cycling is safe – effect of intradialytic cycle ergometry on cerebral oxygenation and cognitive function – a pilot study

Abstract Background and Aims Patients on chronic hemodialysis benefit from intradialytic exercise with improvements in endurance, muscle strength and health-related quality of life. It is not known whether the increased oxygen demand during intradialytic exercise negatively affects cerebral oxygenation and cerebral function. The aim of the study was to assess the risk of cerebral undersupply by measuring cerebral oxygenation, perfusion and cognitive function during and after intradialytic ergometer training. Method Twelve patience on maintenance hemodialysis (HD) trice weekly were included in the study. In an initial ramp test, using bed cycle ergometer, we first determined the maximum physical strength (Pmax) at the level of exhaustion (HD A). Then, one hour after start of a second HD (HD B), patients performed 40%, 50% and 60% of Pmax for 6 min. Pulmonary function tests, blood volume (BVM), cardiac output (by electrical cardiometry), regional cerebral oxygen saturation (rSO2) (by near-infrared spectroscopy) and cerebral blood flow (CBF, by Doppler sonography) were measured. The relative changes in rSO2, CBF and hematocrit were used to calculate cerebral oxygen supply (DO2). Cognitive tests (Stroop, Trail Making and Mini Addenbrookes Cognitive Examination Test) were performed before and after HD sessions with and, as controls, without ergometry (HD-C). Results Median age was 68 (42-85) years, 9/12 were male, complete data set was obtained in 10 patients. During step test exercise (HD B), at the highest exercise level (according to Borg (1-10) 6.75 ± 2.9), rSO2 increased (+6 ± 9%, p=0.034) without a significant change in CBF. In the meantime, relative blood volume decreased during ergometry (-5.8 ± 2.73%; p=0.002), causing a temporary increase of hematocrit. Despite a small decrease in CBF in 3 patients, the mean change of rSO2, CBF and hematocrit always had a positive trend in all patients, as a surrogate of stable cerebral oxygen supply (Table 1). In comparative cognitive tests (B vs. C), we observed no significant changes in cognitive functions. Conclusion In this pilot study, intradialytic bed-cycle ergometry during the first hour of HD for &amp;lt;20 min at 40-60% of patients’ individual maximum intensity had no negative effects on cerebral oxygenation and function. Specific studies testing the safety intradialytic exercise with different conditions, such as increasing intensity or duration, are needed.

Imaging Assessments and Clinical Significance of Brain Frailty in Moyamoya Disease.

Imaging assessment of brain frailty in ischemic stroke has been extensively studied, while the correlation between brain frailty and Moyamoya disease remains obscure. This study aimed to investigate the imaging characteristics of brain frailty and its clinical applications in Moyamoya disease. This study included 60 patients with Moyamoya disease (107 hemispheres). All patients were divided into stroke and nonstroke groups based on clinical symptoms and imaging findings. The modified brain frailty score was adapted to consider 4 imaging signs: white matter hyperintensity, enlargement of perivascular space, old vascular lesions, and cerebral microbleed. The relative CBF of the MCA territory was quantified using pseudocontinuous arterial-spin labeling. Surgical outcome after revascularization surgery was defined by the Matsushima grade. The relative CBF of the MCA territory decreased as the modified brain frailty score and periventricular white matter hyperintensity grades increased (ρ = -0.22, P = .02; ρ = -0.27, P = .005). Clinically, the modified brain frailty score could identify patients with Moyamoya disease with stroke (OR = 2.00, P = .02). Although the modified brain frailty score showed no predictive value for surgical outcome, basal ganglia enlargement of the perivascular space had a significant correlation with the postoperative Matsushima grade (OR = 1.29, P = .03). The modified brain frailty score could reflect a cerebral perfusion deficit and clinical symptoms of Moyamoya disease, and its component basal ganglia enlargement of perivascular space may be a promising marker to predict surgical outcome and thus aid future clinical decision-making.

SPFS: SNR peak-based frequency selection method to alleviate resolution degradation in MPI real-time imaging

Objective. The primary objective of this study is to address the reconstruction time challenge in magnetic particle imaging (MPI) by introducing a novel approach named SNR-peak-based frequency selection (SPFS). The focus is on improving spatial resolution without compromising reconstruction speed, thereby enhancing the clinical potential of MPI for real-time imaging. Approach. To overcome the trade-off between reconstruction time and spatial resolution in MPI, the researchers propose SPFS as an innovative frequency selection method. Unlike conventional SNR-based selection, SPFS prioritizes frequencies with signal-to-noise ratio (SNR) peaks that capture crucial system matrix information. This adaptability to varying quantities of selected frequencies enhances versatility in the reconstruction process. The study compares the spatial resolution of MPI reconstruction using both SNR-based and SPFS frequency selection methods, utilizing simulated and real device data. Main results. The research findings demonstrate that the SPFS approach substantially improves image resolution in MPI, especially when dealing with a limited number of frequency components. By focusing on SNR peaks associated with critical system matrix information, SPFS mitigates the spatial resolution degradation observed in conventional SNR-based selection methods. The study validates the effectiveness of SPFS through the assessment of MPI reconstruction spatial resolution using both simulated and real device data, highlighting its potential to address a critical limitation in the field. Significance. The introduction of SPFS represents a significant breakthrough in MPI technology. The method not only accelerates reconstruction time but also enhances spatial resolution, thus expanding the clinical potential of MPI for various applications. The improved real-time imaging capabilities of MPI, facilitated by SPFS, hold promise for advancements in drug delivery, plaque assessment, tumor treatment, cerebral perfusion evaluation, immunotherapy guidance, and in vivo cell tracking.

Posterior Cerebral Artery Perfusion Is Associated With Cognitive Prognosis After Endarterectomy in Patients With Asymptomatic Severe Carotid Stenosis

Posterior Cerebral Artery Perfusion Is Associated With Cognitive Prognosis After Endarterectomy in Patients With Asymptomatic Severe Carotid Stenosis

Effects of Targeted Hypercapnia on Mortality and Length of Stay of Post-cardiac Arrest Patients: A Systematic Review and Meta-Analysis.

Therapeutic hypercapnia has been proposed as a potential strategy to enhance cerebral perfusion and improve outcomes in patients after cardiac arrest. However, the effects of targeted hypercapnia remain unclear. We conducted a systematic review and meta-analysis to evaluate the impact of hypercapnia compared to normocapnia on mortality and length of stay in post-cardiac arrest patients. We searched major databases for randomized controlled trials and observational studies comparing outcomes between hypercapnia and normocapnia in adult post-cardiac arrest patients. Data on in-hospital mortality and the ICU and hospital length of stay were extracted and pooled using random-effects meta-analysis. Five studies (tworandomized controlled trials(RCTs) and three observational studies) with a total of 1,837 patients were included. Pooled analysis showed hypercapnia was associated with significantly higher in-hospital mortality compared to normocapnia (56.2% vs. 50.5%, OR 1.24, 95% CI 1.12-1.37, p<0.001). There was no significant heterogeneity (I2 = 25%, p = 0.26). No statistically significant differences were found for ICU length of stay (mean difference 0.72 days, 95% CI -0.51 to 1.95) or hospital length of stay (mean difference 1.13 days, 95% CI -0.67 to 2.93) between the groups. Sensitivity analysis restricted to mild hypercapnia studies did not alter the mortality findings. This meta-analysis did not find a mortality benefit with targeted hypercapnia compared to normocapnia in post-cardiac arrest patients. The results align with current guidelines recommending a normalpartial pressure of arterial carbon dioxide(PaCO2) target range and do not support routinely targeting higher carbon dioxide levels in this setting.

Electroacupuncture enhances cerebral blood perfusion by inhibiting HIF-1α in rat subarachnoid hemorrhage

ObjectiveCerebral blood perfusion (CBP) reduction is a prevalent complication following subarachnoid hemorrhage (SAH) in clinical practice, often associated with long-term cognitive impairment and prognosis. Electroacupuncture (EA), a widely utilized traditional Chinese therapy for central nervous system disorders, has demonstrated promising therapeutic effects. This study aims to investigate the therapeutic potential of EA in restoring CBP in SAH rats and to explore the mechanisms involving HIF-1α in this process. MethodsRats were randomly assigned to one of five groups, including Sham, SAH, EA, EA + Saline, and EA + dimethyloxallyl glycine (DMOG) groups. EA treatment was administered for 10 min daily, while DMOG were intraperitoneally injected. Behavioral tests, cerebral blood flow monitoring, vascular thickness measurement, western blotting, and immunofluorescence staining were conducted to assess the therapeutic effects of EA on cerebral blood flow. ResultsSAH resulted in elevated levels of HIF-1α, endothelin (ET), ICAM-1, P-SELECTIN, E-SELECTIN, and decreased level of eNOS in the brain. This led to cerebral vasospasm, decreased CBF, and cognitive deficits in the rat SAH model. EA intervention downregulated the expression of HIF-1α, ET, ICAM-1, P-SELECTIN, and E-SELECTIN, while increasing eNOS expression. This alleviated cerebral vasospasm, restored CBF, and improved cognitive function. However, the administration of the HIF-1α stabilizer (DMOG) counteracted the therapeutic effects of EA. ConclusionEA promotes the recovery of cerebral blood flow after SAH injury, attenuates cerebral vasospasm, and accelerates the recovery of cognitive dysfunction, and its mechanism of action may be related to the inhibition of the HIF-1α signaling pathway.

Microstructure and Perfusion Alterations of Globus Pallidus in Neonates with Hyperbilirubinemia.

Previous studies have indicated the abnormality of the globus pallidus in neonates with hyperbilirubinemia. This study aims to explore the microstructure and cerebral perfusion of globus pallidus in neonatal hyperbilirubinemia by using Diffusion Tensor Imaging (DTI) and Arterial Spin Labeling (ASL) approaches. Thirty-seven neonates were enrolled in this study, which were classified into Bilirubin-Induced Neurologic Dysfunction (BIND) group (hyperbilirubinemia with BIND, n=12), non-BIND group (hyperbilirubinemia without BIND, n=15), and healthy controls (HC) group (n=10). The quantitative values of globus pallidus were calculated from DTI, including the Apparent Diffusion Coefficient (ADC), the Fractional Anisotropy (FA), and Volume Ratio (VR) values. Additionally, the relative Cerebral Blood Flow (rCBF) values were obtained from ASL. It was observed that the mean DTI signal of globus pallidus was significantly different among the three groups (p < 0.05). However, there were no significant differences in the rCBF of globus pallidus among the three groups (p > 0.05). A positive correlation was also observed between the fractional anisotropy (FA) value and serum bilirubin level (r = 0.561, p = 0.002), while the VR value showed a negative correlation with serum bilirubin level (r=-0.484, p=0.011). The area under the curve (AUC) of FA, VR, and FA and VR combined was 0.897, 0.858, and 0.933, respectively. The alterations of microstructure in globus pallidus, especially FA and VR value, may be valuable and sensitive at the early stage of hyperbilirubinemia encephalopathy, suggesting that early hyperbilirubinemia may lead to cytotoxic edema and decreased permeability of the cell membrane.

Brain tissue oxygen partial pressure monitoring and prognosis of patients with traumatic brain injury: a meta-analysis.

To assess whether monitoring brain tissue oxygen partial pressure (PbtO2) or employing intracranial pressure (ICP)/cerebral perfusion pressure (CCP)-guided management improves patient outcomes, including mortality, hospital length of stay (LOS), mean daily ICP and mean daily CCP during the intensive care unit(ICU)stay. We searched the Web of Science, EMBASE, PubMed, Cochrane Library, and MEDLINE databases until December 12, 2023. Prospective randomized controlled and cohort studies were included. A meta-analysis was performed for the primary outcome measure, mortality, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Eleven studies with a total of 37,492 patients were included. The mortality in the group with PbtO2 was 29.0% (odds ratio: 0.73;95% confidence interval [CI]:0.56-0.96; P = 0.03; I = 55%), demonstrating a significant benefit. The overall hospital LOS was longer in the PbtO2 group than that in the ICP/CPP group (mean difference:2.03; 95% CI:1.03-3.02; P<0.0001; I = 39%). The mean daily ICP in the PbtO2 monitoring group was lower than that in the ICP/CPP group (mean difference:-1.93; 95% CI: -3.61 to -0.24; P = 0.03; I = 41%). Moreover, PbtO2 monitoring did not improve the mean daily CPP (mean difference:2.43; 95%CI: -1.39 to 6.25;P = 0.21; I = 56%).Compared with ICP/CPP monitoring, PbtO2 monitoring reduced the mortality and the mean daily ICP in patients with severe traumatic brain injury; however, no significant effect was noted on the mean daily CPP. In contrast, ICP/CPP monitoring alone was associated with a short hospital stay.

"Brain-First" Total Body Retrograde Perfusion and Retrograde Cerebral Perfusion in Hemi-Arch Replacement

Objective: The purpose of this study is to compare the early outcomes of brain-first total body retrograde perfusion (Bf-TBRP) in comparison with reverse cerebral perfusion (RCP) under moderate hypothermia circulatory arrest (MHCA) for hemi-arch replacement surgery. Methods: We analyzed the data of 88 patients who underwent hemi-arch replacement with Bf-TBRP (n = 18) or RCP (n = 70) under MHCA at West China Hospital of Sichuan University between 1 January 2020, and 31 July 2022. In-hospital mortality, neurological deficits, and other adverse events were recorded, which were evaluated with logistic regression to determine risk factors. Results: There was no significant difference between the Bf-TBRP and RCP groups in in-hospital mortality, cardiac events, neurological deficits, dialysis, gastrointestinal complications, and paralysis (p &gt; 0.05). The Bf-TBRP group was associated with significantly shorter hospital stay [Bf-TBRP: 8 d (interquartile range (IQR), 7–10) vs. RCP: 10 d (IQR, 8–13), p = 0.03] and fewer platelet transfusions [Bf-TBRP: 1.0 (IQR, 0–1.0) vs. RCP: 1.0 (IQR, 1.0–2.0), p = 0.05] than the RCP group. On multivariable logistic regression analysis, emergency surgery (p = 0.05) and surgery duration (p = 0.03) were determined to be risk factors. Conclusions: The study showed that Bf-TBRP is a safe technique for patients undergoing hemi-arch replacement with MHCA.

SURGERY OF TYPE A AORTIC DISSECTIONS: WHAT HAS CHANGED? SINGLE CENTER EXPERIENCE

Abstract Introduction Our knowledge on type A aortic dissection (ATAAD) has evolved, and there are some differences in surgical approach. In this paper, we focused on what changed in the surgical treatment of ATAAD and on the impact of these changes on patients’ survival, analyzing our center experience and comparing it with literature latest evidences. Materials and Methods From 2010 to 2022, 342 consecutive patients underwent surgery for Acute Type A Aortic dissection at our institution. In order to identify changes in these patients’ management over time, we divided our population in two groups according to the year of surgery: Group A before 2016 (146 patients) and Group B after 2016 (196 patients). Results Patients from Group B (after 2016) showed more comorbidities and a worse clinical presentation than patients from Group A (chronic kidney disease 9.2% vs 2.1% p=0.006, neurological deficit on admission 8.7% vs 0% p &amp;lt; 0.001, cardiac tamponade 12.2% vs 0.7% p &amp;lt; 0.001, and pre–operative catecholamine support 4.1% vs 0% p=0.012). Also of pre–operative malperfusion was more frequent (coronary 6.6% vs 0% p &amp;lt; 0.001 and peripheral 6.6% vs 0% p &amp;lt; 0.001). In Group B in 70.4% of the population the circulatory arrest with antegrade selective cerebral perfusion was used vs 30.8% in Group A (p &amp;lt; 0.001) and we find a bigger percentage of emiarch replacement (43.4% vs 23.3% P=0.008) and total arch replacement (27% vs 13.7% p=0.017) than in Group A. In–hospital mortality resulted to be 10.2% with no differences between the groups. Neurological events (p&amp;lt;0.001) and post–operative dialysis (p=0.036) were more frequent in Group B. On the other hand, in Group A post–operative cardiac tamponade (9.65 vs 3.1% p=0.007) and red blood cells transfusions were higher. Conclusions Nowadays surgery is performed on more critical patients with higher surgical risk and the tendency is to perform more complex operations with replacement of a largest portion of the diseased aorta in order to reduce reintervention rate. Recently, clinical studies and guidelines highlighted the importance of creating a multidisciplinary aortic team to discuss and manage these patients in order to assure the best treatment options to each patient and to reduce mortality and morbidity.

Cognitive dysfunctions in the course of SARS‑CoV‑2 virus infection, including NeuroCOVID, frontal syndrome and cytokine storm (Review).

During the coronavirus disease 2019 (COVID-19) pandemic, cognitive impairment of varying degrees of severity began to be observed in a significant percentage of patients. The present study discussed the impact of immunological processes on structural and functional changes in the central nervous system and the related cognitive disorders. The purpose of the present review was to analyse and discuss available information from the scientific literature considering the possible relationship between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral infection and cognitive impairment, including NeuroCOVID, frontal syndrome and cytokine storm. A systematic literature review was conducted using: Google Scholar, Elsevier and the PubMed database. When searching for materials, the following keywords were used: 'cognitive dysfunctions', 'SARS-CoV-2', 'COVID-19', 'Neuro-SARS2', 'NeuroCOVID', 'frontal syndrome', 'cytokine storm', 'Long COVID-19'. A total of 96 articles were included in the study. The analysis focused on the characteristics of each study's materials, methods, results and conclusions. SARS-CoV-2 infection may induce or influence existing cognitive disorders of various nature and severity. The influence of immunological factors related to the response against SARS-CoV-2 on the disturbance of cerebral perfusion, the functioning of nerve cells and the neuroprotective effect has been demonstrated. Particular importance is attached to the cytokine storm and the related difference between pro- and anti-inflammatory effects, oxidative stress, disturbances in the regulation of the hypothalamic-pituitary-adrenal axis and the stress response of the body.