Journal of Cerebral Blood Flow and Metabolism最新文献

Extracorporeal cardiopulmonary resuscitation (ECPR) facilitates resuscitation with immediate and precise temperature control. This study aimed to determine the optimal reperfusion temperature to minimize neurological damage after ventricular fibrillation cardiac arrest (VFCA). Twenty-four rats were randomized (n = 8 per group) to normothermia (NT = 37°C), mild hypothermia (MH = 33°C) or moderate hypothermia (MOD = 27°C). The rats were subjected to 10 minutes of VFCA, before 15 minutes of ECPR at their respective target temperature. After ECPR weaning, rats in the MOD group were rapidly rewarmed to 33°C, and temperature maintained at 33°C (MH/MOD) or 37°C (NT) for 12 hours before slow rewarming to normothermia (MH/MOD). The primary outcome was 30-day survival with overall performance category (OPC) 1 or 2 (1 = normal, 2 = slight disability, 3 = severe disability, 4 = comatose, 5 = dead). Secondary outcomes included awakening rate (OPC ≤ 3) and neurological deficit score (NDS, from 0 = normal to 100 = brain dead). The survival rate did not differ between reperfusion temperatures (NT = 25%, MH = 63%, MOD = 38%, p = 0.301). MH had the lowest NDS (NT = 4[IQR 3-4], MH = 2[1-2], MOD = 5[3-5], p = 0.044) and highest awakening rate (NT = 25%, MH = 88%, MOD = 75%, p = 0.024). In conclusion, ECPR with 33°C reperfusion did not statistically significantly improve survival after VFCA when compared with 37°C or 27°C reperfusion but was neuroprotective as measured by awakening rate and neurological function.

Whether the dynamic development of peripheral inflammation aggravates brain injury and leads to poor outcome in stroke patients receiving intravenous thrombolysis (IVT), remains unclear and warrants further study. In this study, total of 1034 patients with acute ischemic stroke who underwent IVT were enrolled. Serum leukocyte variation (whether increase from baseline to 24 h after IVT), National Institutes of Health Stroke Scale (NIHSS), infarct volume, early neurologic deterioration (END), the unfavorable outcome at 3-month (modified Rankin Scale [mRS] score ≥3) and mortality were recorded. Serum brain injury biomarkers, including Glial fibrillary acidic protein (GFAP), ubiquitin c-terminal hydrolase L1 (UCH-L1), S100β, neuron-specific enolase (NSE), were measured to reflect the extent of brain injury. We found that patients with increased serum leukocytes had elevated brain injury biomarkers (GFAP, UCH-L1, and S100β), larger infarct volume, higher 24 h NIHSS, higher proportion of END, unfavorable outcome and mortality. Furthermore, an increase in serum leukocytes was independently associated with infarct volume, 24 h NIHSS, END, and unfavorable outcome at 3 months, and serum UCH-L1, S100β, and NSE levels. These results suggest that an increase in serum leukocytes indicates severe brain injury and may be used to predict the outcome of patients with ischemic stroke who undergo IVT.

In this work, we demonstrate a data-driven approach for estimating cerebrovascular reactivity (CVR) amplitude and lag from breathhold (BH) fMRI data alone. Our approach employs a frequency-domain approach that is independent of external recordings. CVR amplitude is estimated from the BOLD frequency spectrum and CVR lag is estimated from the Fourier phase using the global-mean BOLD signal as reference. Unlike referencing to external recordings, these lags are specific to the brain. We demonstrated our method in detecting regional CVR amplitude and lag differences across healthy (CTL), hypertensive (HT) and hypertension-plus-type-2-diabetes (HT + DM) groups of similar ages and sex ratios, with a total N of 49. We found CVR amplitude to be significantly higher in CTL compared to HT + DM, with minimal difference between CTL and HT. Also, voxelwise CVR lag estimated in the Fourier domain is a more sensitive marker of vascular dysfunction than CVR amplitude. CVR lag in HT is significantly shorter than in CTL, with minimal difference between CTL and HT + DM. Our results support the importance of joint CVR amplitude and lag assessments in clinical applications.

Neurovascular coupling (NVC) is the functional hyperemia of the brain responding to local neuronal activity. It is mediated by astrocytes and affected by subcortical ascending pathways in the cortex that convey information, such as sensory stimuli and the animal condition. Here, we investigate the influence of the raphe serotonergic system, a subcortical ascending arousal system in animals, on the modulation of cortical NVC and cerebral blood flow (CBF). Raphe serotonergic neurons were optogenically activated for 30 s, which immediately awakened the mice from non-rapid eye movement sleep. This caused a biphasic cortical hemodynamic change: a transient increase for a few seconds immediately after photostimulation onset, followed by a large progressive decrease during the stimulation period. Serotonergic neuron activation increased intracellular Ca²⁺ levels in cortical pyramidal neurons and astrocytes, demonstrating its effect on the NVC components. Pharmacological inhibition of cortical neuronal firing activity and astrocyte metabolic activity had small hypovolemic effects on serotonin-induced biphasic CBF changes, while blocking 5-HT_1B receptors expressed primarily in cerebral vasculature attenuated the decreasing CBF phase. This suggests that serotonergic neuron activation leading to animal awakening could allow the NVC to exert a hyperemic function during a biphasic CBF response, with a predominant decrease in the cortex.

The effectiveness and safety of human urinary kallidinogenase (HUK) in acute ischemic stroke (AIS) patients undergoing endovascular therapy (EVT) due to large vessel occlusion (LVO) was unclear. A pooled analysis was performed using individual data from the DEVT and RESCUE BT trials. Patients were divided into two groups based on HUK treatment. The primary outcome was the 90-day modified Rankin Scale (mRS) score. Safety outcomes included 90-day mortality and symptomatic intracranial hemorrhage (sICH) within 48 hours. A total of 1174 patients were included in the study. Of these, 150 (12.8%) patients received HUK. The adjusted common odds ratio (OR) of the mRS score was 1.458 (95% confidence interval [CI] = 1.072-1.983; p = 0.016) favoring HUK. The incidence of sICH (2.0% vs. 8.6%; adjusted OR: 0.198; 95% CI: 0.061-0.638; p = 0.007) and mortality (11.3% vs.18.5%; adjusted OR: 0.496; 95% CI: 0.286-0.862; p = 0.013) was lower in HUK group than non-HUK group. This association was consistent with propensity score-matching and the inverse probability of treatment weighting analysis. In conclusion, HUK was safe and associated with a preferable prognosis in AIS patients due to LVO in the anterior circulation.

Atherosclerosis can underly internal carotid artery stenosis (ICAS), a major risk factor for ischemic stroke, as well as small vessel disease (SVD). This study aimed to investigate hemodynamics and structural alterations associated with SVD in ICAS patients. 28 patients with unilateral asymptomatic ICAS and 30 age-matched controls underwent structural (T1-/T2-weighted and diffusion tensor imaging [DTI]) and hemodynamic (pseudo-continuous arterial spin labeling and dynamic susceptibility contrast) magnetic resonance imaging. SVD-related alterations were assessed using free water (FW), FW-corrected DTI, and peak-width of skeletonized mean diffusivity (PSMD). Furthermore, cortical thickness, cerebral blood flow (CBF), and capillary transit time heterogeneity (CTH) were analyzed. Ipsilateral to the stenosis, cortical thickness was significantly decreased in the posterior dorsal cingulate cortex (p = 0.024) and temporal pole (p = 0.028). ICAS patients exhibited elevated PSMD (p = 0.005), FW (p < 0.001), and contralateral alterations in FW-corrected DTI metrics. We found significantly lateralized CBF (p = 0.011) and a tendency for lateralized CTH (p = 0.067) in the white matter (WM) related to ICAS. Elevated PSMD and FW may indicate a link between SVD and WM changes. Contralateral alterations were seen in FW-corrected DTI, whereas hemodynamic and cortical changes were mainly ipsilateral, suggesting SVD might influence global brain changes concurrent with ICAS-related hemodynamic alterations.

Chronic cerebral ischemia (CCI) is a clinical syndrome characterised by brain dysfunction due to decreased chronic cerebral perfusion. CCI initiates several inflammatory pathways, including pyroptosis. RNA-binding proteins (RBPs) play important roles in CCI. This study aimed to explore whether the interaction between RBP-Cpeb4 and Dclk2 affected Ehf phosphorylation to regulate neuronal pyroptosis. HT22 cells and mice were used to construct oxygen glucose deprivation (OGD)/CCI models. We found that Cpeb4 and Dclk2 were upregulated in OGD-treated HT22 cells and CCI-induced hippocampal CA1 tissues. Cpeb4 upregulated Dclk2 expression by increasing Dclk2 mRNA stability. Knockdown of Cpeb4 or Dclk2 inhibited neuronal pyroptosis in OGD-treated HT22 cells and CCI-induced hippocampal CA1 tissues. By binding to the promoter regions of Caspase1 and Caspase3, the transcription factor Ehf reduced their promoter activities and inhibited the transcription. Dclk2 phosphorylated Ehf and changed its nucleoplasmic distribution, resulting in the exit of p-Ehf from the nucleus and decreased Ehf levels. It promoted the expression of Caspase1 and Caspase3 and stimulated neuronal pyroptosis of HT22 cells induced by OGD. Cpeb4/Dclk2/Ehf pathway plays an important role in the regulation of cerebral ischemia-induced neuronal pyroptosis.

The disruption of the blood-brain barrier marks a pivotal early pathological event in ischemic stroke that significantly contributes to subsequent permanent damage. Here we delve into the ramifications of a study conducted by Xu and colleagues, which underscores the essential role of the protein peroxiredoxin-4 in cerebrovascular endothelial cells. Peroxiredoxin-4 was shown to preserve blood-brain barrier integrity during the early stages after cerebral ischemia and reperfusion, ultimately leading to improved long-term outcomes.

A metabolic coupling between glutamate and N-acetylaspartate measured by in vivo magnetic resonance spectroscopy has been recently reported in the literature with inconsistent findings. In this study, confounders originating from Pearson's spurious correlation of ratios and spectral correlation due to overlapping magnetic resonance spectroscopy signals of glutamate and N-acetylaspartate were practically eliminated to facilitate the determination of any metabolic link between glutamate and N-acetylaspartate in the human brain using in vivo magnetic resonance spectroscopy. In both occipital and medial prefrontal cortices of healthy individuals, correlations between glutamate and N-acetylaspartate were found to be insignificant. Our results do not lend support to a recent hypothesis that N-acetylaspartate serves as a significant reservoir for the rapid replenishment of glutamate during signaling or stress.

Preterm birth is associated with cerebrovascular development disruption and can induce white matter injuries (WMI). Transfontanellar ultrasound Doppler is the most widely used clinical imaging technique to monitor neonatal cerebral vascularisation and haemodynamics based on vascular indexes such as the resistivity index (RI); however, it has poor predictive value for brain damage. Indeed, these RI measurements are currently limited to large vessels, leading to a very limited probing of the brain's vascularisation, which may hinder prognosis. Here we show that ultrafast Doppler imaging (UfD) enables simultaneous quantification, in the whole field of view, of the local RI and vessel diameter, even in small vessels. Combining both pieces of information, we defined two new comprehensive resistivity parameters of the vascular trees. First, we showed that our technique is more sensitive in the early characterisation of the RI modifications between term and preterm neonates and for the first time we could show that the RI depends both on the vessel diameter and vascular territory. We then showed that our parameters can be used for early prediction of WMI. Our results demonstrate the potential of UfD to provide new biomarkers and pave the way for continuous monitoring of neonatal brain resistivity.