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Our practice utilizes Doppler ultrasound as one of the most objective and effective methods to assess at-risk pregnancies. This review will discuss the application of arterial and venous Doppler techniques in assessing and managing various diseases and conditions for high-risk fetuses. [ABSTRACT FROM AUTHOR]

During unilateral static and rhythmic handgrip exercise, middle cerebral artery blood velocity (MCAv) increases in the contralateral side to the exercising limb. However, whether this neurovascular coupling‐mediated increase in contralateral MCAv is apparent against a background of fluctuating perfusion pressure produced by dynamic resistance exercise (RE) is unclear. We examined the cerebral haemodynamic response to unilateral dynamic RE in 30 healthy individuals (female = 16, mean ± SD: age, 26 ± 6 years; height, 175 ± 10 cm; weight, 74 ± 15 kg; body mass index, 24 ± 5 kg m−2). Participants completed four sets of 10 paced repetitions (15 repetitions min−1) of unilateral bicep curl exercise at 60% of the predicted one‐repetition maximum (7 ± 3 kg). Beat‐to‐beat blood pressure, bilateral MCAv and end‐tidal carbon dioxide were measured throughout. One‐way ANOVA was used to analyse cardiovascular variables and two‐way ANOVA to analyse dependent cerebrovascular variables (side × sets, 2 × 5). A linear mixed model analysis was also performed to investigate the effects of end‐tidal carbon dioxide and mean arterial blood pressure on MCAv. In comparison to baseline, within‐exercise mean arterial blood pressure increased (P < 0.001) across the sets, whereas bilateral MCAv decreased (P < 0.001). However, no significant interaction effect was observed for any dependent variables (all P > 0.787). The linear mixed model revealed that end‐tidal carbon dioxide had the greatest effect on MCAv (estimate = 1.019, t = 8.490, P < 0.001). No differences were seen in contralateral and ipsilateral MCAv during dynamic RE, suggesting that neurovascular coupling contributions during dynamic RE might be masked by other regulators, such as blood pressure. What is the central question of this study?During unilateral static resistance exercise (RE), neurovascular coupling mediates an increase in cerebral blood flow in the contralateral hemisphere. Whether this response persists during dynamic RE, with concomitant large fluctuations in blood pressure, remains unclear.What is the main finding and its importance?During unilateral dynamic RE, there was no difference in blood velocity between the contralateral and ipsilateral middle cerebral arteries. The presence of bilateral fluctuations in blood velocity during unilateral dynamic RE could increase bilateral shear stress and confer beneficial vascular adaptations in both cerebral hemispheres. [ABSTRACT FROM AUTHOR]

The introduction of cadaveric dissection of cerebral vasculature as a part of the neurosurgical training module would help the neurosurgical residents to understand the complex neuroanatomy of the brain vasculature and help gain confdence during the surgical procedure.To the best of our knowledge microsurgical anatomical studies of theMCA have not been done among the Northwest Indian population. Anatomical variations of MCA that have not been described before may come in as a surprise during any surgical intervention. Hence, we intend to record the anatomical variations of the MCA anatomy and its implications in contemporary vascular surgery and neurosurgical practice. The objective of this work was to study and compare the microsurgical anatomy and variations of MCA in Northwest Indian cadavers with the available literature. [ABSTRACT FROM AUTHOR]

Background The left (Lt) and right (Rt) middle cerebral artery bifurcation (MCAB) aneurysms have mostly been regarded as identical. Considering substantial Lt–Rt differences in hemispheric infarction, however, the presence of Lt–Rt differences may not be denied totally in patients with ruptured MCAB aneurysms. We herein investigated whether such Lt–Rt differences existed by a single-center retrospective study. Materials and Methods Clinical data prospectively acquired between 2011 and 2021 on 99 patients with ruptured MCAB aneurysms were analyzed. They were dichotomized based on the laterality, and demographic and outcome parameters were compared. Additionally, a literature review was conducted to elucidate possible Lt–Rt differences in the frequency of ruptured MCAB aneurysms (Rt/Lt ratio). Results Among the 99 patients, 42 had Lt and 57 had Rt ruptured MCAB aneurysms, with the Rt/Lt ratio of 1.36. Neither demographic, radiographic, nor outcome variables differed significantly between the two groups. A total of 19 studies providing information on the laterality of the ruptured MCAB were retrieved by literature search. A sum total for the Lt and Rt MCAB aneurysms was 671 and 940, making the Rt/Lt ratio of 1.40. After adding our data, a sum total for the Lt and Rt MCAB aneurysms was 713 and 997, making the Rt/Lt ratio of 1.40. Conclusion The Rt ruptured MCAB aneurysms were 1.40 times more frequent than the Lt-sided counterpart. While there may be some Lt–Rt differences in the MCA anatomy, it remains to be seen whether such anatomical differences are truly responsible for the disproportionately higher frequency of Rt MCAB aneurysms. [ABSTRACT FROM AUTHOR]

Objectives: Sonographic evaluation of the basilar artery is challenging, and a limited number of reports are available about the prenatal period, as manual positioning of probes is technically difficult. The objective of this study was to describe a sonographic transabdominal approach based on slowflow HD for screening of the basilar artery during the second trimester scan. Methods: A total of 49 women who were enrolled in a second trimester screening were included when the fetus was in the occipitoanterior position. Dopper screening of the cerebral artery was performed, which revealed the "Y" sign indicating the basilar trunk arising from two vertebral arteries in the axial oblique view when the probe was located around the junction of the vertebral processes and occipital bone and was superior to the first vertebral body, sloping slightly to the cephalic side. The Doppler ultrasound probe was placed perpendicular to the basilar artery. The flow direction was below the baseline, away from the probe in the basilar artery, consistent with a caudocephalic orientation. Peak systolic and diastolic velocities were measured. Results: The basilar artery was identified in all 49 fetuses, with a mean gestational age of 22 weeks (range 20 to 26 weeks). The mean peak systolic velocity of the basilar artery was 15.8 cm/second (range 9.12-26.44 cm/second). There was a slight increase in peak systolic velocity according to the gestational age of the fetus. Conclusions: This study demonstrated that evaluation of the basilar artery can be performed during the second trimester via a new transabdominal approach involving slowflow HD. [ABSTRACT FROM AUTHOR]

Anti-calcitonin gene-related peptide (CGRP) monoclonal antibodies that target CGRP ligands or receptors, may cause a very rare side effect of reversible cerebral vasoconstriction syndrome (RCVS). This study is a case report of a patient who developed cerebral artery vasoconstriction documented on serial brain magnetic resonance angiography (MRA) scans without the typical manifestations of RCVS following galcanezumab loading dose. Case report: A 40-year-old female patient with high-frequency episodic migraine with visual aura on topiramate 100 mg/day developed transient numbness of the right upper and lower extremities and right face without headache and a normal neurological examination 10 min after a loading dose of galcanezumab, which resolved over the next 2 days. Magnetic resonance angiography brain imaging showed segmental arterial constriction of both middle cerebral arteries in the M1–2 segments and both posterior cerebral arteries in the P1–2 segments, which partial resolved in a subsequent study by the end of 6 months. There were no other supporting examination data, such as transcranial Doppler, which might provide additional information on the progression and improvement of the vasoconstriction. Her differential diagnosis included prolonged migraine sensory aura without headache, RCVS, or cerebral vasoconstriction secondary to the effect of an anti-CGRP monoclonal antibody. Further research needs to be conducted. Plain Language Summary: We report a case with numbness on the right upper and lower extremities and right face without headache 10 min after the loading dose of galcanezumab. These stroke-like symptoms resolved within 2 days. Cerebral blood vessels showed narrowing and then dilatation with residual narrowing of two or more vessels. The differential diagnosis is prolonged migraine aura without headache, reversible cerebral vasoconstriction syndrome, or cerebral vasoconstriction due to the effects of galcanezumab. [ABSTRACT FROM AUTHOR]

We aimed to evaluate the physiological variation in common pulsed-wave Doppler (PWD) indices of impedance to determine the number of waveforms to be averaged to minimise variability to 5%. A single-centre, prospective, cross-sectional cohort study of uncomplicated singleton pregnancies at 20–37 week's gestation. From each patient 100 PWD waveforms were acquired including the umbilical artery (UA), middle cerebral artery (MCA) and uterine arteries (UtAs), with 30 waveforms acquired from the ductus venosus. Each waveform was individually measured using the machine's in-built software in automated mode. The variability was assessed using coefficient of variation. The number of waveforms to be averaged was calculated using the moving average and standard error of mean. From a cohort of 200 pregnancies, a total of 189 were analysed. The pulsatility index (PI) demonstrated greater variability compared with the resistance index (RI) in all vessels studied. A minimum of 14 UA and MCA, and 13 UtA PWD waveforms were required to reduce PI variability to 5%, while only 2 RI waveforms were required for UA, 1 for MCA and 8 for UtAs. The variability shown across all PWD indices and between vessels means that PWD indices results should be interpreted cautiously and averaged over multiple waveforms. Consideration should be given to adoption of RI, as it showed greater stability than PI for maternal-fetal Doppler. [ABSTRACT FROM AUTHOR]

Our aim in this study was to investigate whether there is an association between large-for-gestational age (LGA) fetuses and myocardial performance index (MPI). This is a cross-sectional study conducted from July 2022 to July 2023. Prospectively gathered data from 65 LGA cases and 65 age and gestational-age (GA)-matched controls were analyzed. Presence of polyhydramnios and diabetes were recorded in the study group. Fetal left ventricular mod-MPI, peak systolic velocity (PSV) of E and A waves, umbilical and middle cerebral artery (MCA) pulsatility indexes (PI) were sonographically measured. Association between these sonographic measures and LGA fetuses were sought. The LGA group had 33 diabetic cases (22 GDM and 11 PGDM). The LGA group had greater mod-MPI (0.51 vs. 0.45, p = 0.0048). The LGA group also had prolonged isovolumetric contraction time (ICT), compared to controls (37 ms vs. 33 ms, p = 0.008). ICT was longer in LGA fetuses with non-diabetic mothers (38 ms vs. 33 ms, p = 0.009). LGA fetuses with polyhydramnios but without diabetic mothers had also longer ICT (39 ms vs. 33 ms, p = 0.002). Mod-MPI was similar in controls and LGA without diabetes/LGA with polyhydramnios but without diabetes subgroups. Our results indicate that fetal mod-MPI values are higher in LGA fetuses and ICT is prolonged among LGA fetuses irrespective of presence of maternal diabetes. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the relationship of diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) parameters with dysfunction in acute focal cerebral ischemia (ACI) rabbits. Methods: The model of ACI in the middle cerebral artery was made using 30 adult male New Zealand rabbits. The dysfunction severities of the ACI rabbits were assessed using Purdy's score. A paired-sample rank sum test was adopted to compare the abnormal signal zone (ASZ) volumes from T2 weighted imaging (T2WI), dynamic susceptibility contrast-enhanced (DSC) imaging, and DWI with a relative cerebral blood flow (rCBF) map; correlations were analyzed between the volume of each ASZ and Purdy's score by Spearman's rank correlation coefficient. The degree of necrotic and apoptotic cells was evaluated in the ASZ from DWI and DSC PWI-DWI mismatch (PDM) zone. Correlations were analyzed between the index of cellular damage and Purdy's score, the volume of ASZs by Spearman's rank correlation coefficient. Results: The ASZ volumes from DSC-PWI and the rCBF maps were larger than those from DWI (p < 0.001 and p < 0.001, respectively); those from the rCBF map (Z = 0.959, p < 0.001) and DSC-PWI (Z = 0.970, p < 0.001) were positively correlated with DWI; a positive correlation was found between Purdy's score and the ASZ volumes from DSC-PWI (Z = 0.889, p < 0.001), DWI (Z = 0.921, p < 0.001), and rCBF (Z = 0.891, p < 0.001). A significant difference was observed between the ASZ from DWI and the PDM zone in terms of the degree of necrotic (p < 0.001) and apoptotic cells (p < 0.001). The degree of cellular damage in the ASZ of DWI and PDM zone had no relationship with Purdy's score and the volumes of ASZs. Conclusion: The ASZ volumes from DSC-PWI, rCBF, and particularly DWI reflected the level of dysfunction in rabbits with ACI. [ABSTRACT FROM AUTHOR]

Both inflow and the partial volume effect (PVE) are sources of error when measuring the arterial input function (AIF) in dynamic contrast‐enhanced (DCE) MRI. This is relevant, as errors in the AIF can propagate into pharmacokinetic parameter estimations from the DCE data. A method was introduced for flow correction by estimating and compensating the number of the perceived pulse of spins during inflow. We hypothesized that the PVE has an impact on concentration–time curves similar to inflow. Therefore, we aimed to study the efficiency of this method to compensate for both effects simultaneously. We first simulated an AIF with different levels of inflow and PVE contamination. The peak, full width at half‐maximum (FWHM), and area under curve (AUC) of the reconstructed AIFs were compared with the true (simulated) AIF. In clinical data, the PVE was included in AIFs artificially by averaging the signal in voxels surrounding a manually selected point in an artery. Subsequently, the artificial partial volume AIFs were corrected and compared with the AIF from the selected point. Additionally, corrected AIFs from the internal carotid artery (ICA), the middle cerebral artery (MCA), and the venous output function (VOF) estimated from the superior sagittal sinus (SSS) were compared. As such, we aimed to investigate the effectiveness of the correction method with different levels of inflow and PVE in clinical data. The simulation data demonstrated that the corrected AIFs had only marginal bias in peak value, FWHM, and AUC. Also, the algorithm yielded highly correlated reconstructed curves over increasingly larger neighbourhoods surrounding selected arterial points in clinical data. Furthermore, AIFs measured from the ICA and MCA produced similar peak height and FWHM, whereas a significantly larger peak and lower FWHM was found compared with the VOF. Our findings indicate that the proposed method has high potential to compensate for PVE and inflow simultaneously. The corrected AIFs could thereby provide a stable input source for DCE analysis. [ABSTRACT FROM AUTHOR]

BACKGROUND We aim to investigate the potential causal link between blood pressure (BP) levels and cerebral artery dissection (CAD) risk by employing a 2-sample Mendelian randomization (TSMR) framework. METHODS Utilizing large-scale genome-wide association studies-retrieved data, we employed various Mendelian randomization (MR) techniques, including inverse variance weighted (IVW), MR-Egger regression, weighted median, and weighted mode, to ascertain BP's causal impact on CAD. The MR-Egger intercept was calculated to assess pleiotropy presence, determining heterogeneity by Cochran's Q statistic. RESULTS The findings highlighted a significant association between elevated systolic BP (SBP; IVW: OR = 3.09, 95% CI: 1.11–8.61, P  = 0.031) and increased diastolic BP (DBP; IVW: OR = 2.17, 95% CI: 1.14–6.21, P  = 0.023) with CAD risk. Sensitivity analyses reinforced the robustness and reliability of these results. CONCLUSIONS The results from this TSMR study suggest a causal link between high SBP and DBP and the increased likelihood of CAD, which provides genetic evidence for a reduced risk of CAD under BP control. [ABSTRACT FROM AUTHOR]

Objective Methods Results Conclusion The study's aim was to perform serial placental biometry and Doppler assessments in antenatal women and compare the characteristics of preeclampsia (PE) and normal outcome.This prospective cohort study was carried out after ethical clearance. Placental length (PL), thickness, and plavental volume (PV), along with the uterine artery (Ut), middle cerebral artery (MCA), and umbilical artery (UA) blood flow were evaluated serially at 11–14, 20–24, and 28–32 weeks of gestation. The women were followed until delivery, those with PE were considered cases, and those with no other adverse outcome were controls. The placental attributes between cases and controls were compared.A total of 135/1008 (13.4%) had hypertensive disorders of pregnancy (HDP) and 44/1008 (4.4%) had PE, and no maternal or fetal adverse outcomes were seen in 600 (59.5%) women. The PL and PV were significantly less in those with PE (P = 0.005) than in controls. The ratios of PL/Ut A PI and PV/Ut A PI were significantly lower in cases than in controls in all trimesters (P <0.001). In the first trimester, the area under the curve (AUC), sensitivity, and specificity of PV/Ut A PI for PE prediction were 0.801, 81.8%, and 70.5%, respectively. The sensitivity and specificity of the PL/Ut PI ratio was 81.8% and 70.5%, whereas that at 28–32 weeks was 73.3% & 70.7%.Placental parameters were significantly lower in PE than in normal outcome, and the ratios of PL/Ut A PI and PV/Ut A PI proved to be promising markers. [ABSTRACT FROM AUTHOR]

Background: Malignant middle cerebral artery infarction (MMI) is associated with a high incidence of severe disability and mortality. Decompressive hemicraniectomy has become a recognized treatment that can improve the prognosis for patients if performed within a certain time window. Nevertheless, despite this intervention, a mortality rate of approximately 20–40% persists following the surgery. The trends and clinical implications of intracranial pressure (ICP) in these situations remain unclear. We aimed to investigate whether intracranial pressure (ICP) trends are associated with clinical outcomes in patients undergoing decompressive hemicraniectomy for MMI. Methods: This retrospective cohort study included consecutive patients with MMI who underwent decompressive craniectomy and received ICP monitoring after surgery. Using a linear mixed model, we categorized the patients into ICP increase and decrease groups based on the ICP values obtained over 192 h. We then compared the proportion of 3-month favorable outcomes (modified Rankin Scale of 0−4) and mortality rates between these groups. Results: Of 112 MMI patients who underwent decompressive hemicraniectomy, 66 (58.9%) received invasive ICP monitoring. ICP monitoring was performed for a median of 146.5 h (IQR 72.5–181.8). Among the 66 patients, 37 (56.1%) were in the ICP increase group, and 29 (43.9%) were in the ICP decrease group. During the monitoring period, the initial monitored ICP and peak ICP did not significantly differ between the ICP increase and decrease groups. However, the ICP trend was significantly different between the two groups (P < 0.001). In multivariable logistic regression analyses, the ICP increase group had a significantly lower proportion of 3-month favorable outcomes compared to the ICP decrease group (adjusted OR 0.11; 95% CI, 0.01–0.59; P = 0.019), and significantly higher mortality in the intensive care unit (adjusted OR 6.98; 95% CI, 1.37–54.6; P = 0.031). Conclusions: In MMI patients, continuous ICP monitoring could be useful for detecting those with an increasing ICP trend that may be associated with unfavorable clinical outcomes. [ABSTRACT FROM AUTHOR]

Intracranial aneurysms are localized dilatations of the cerebral arteries that carry a risk of rupture and subsequent subarachnoid hemorrhage, a life-threatening condition. Middle cerebral artery (MCA) aneurysms are a common type of intracranial aneurysm, and endovascular treatment using coils or flow diverters is a common intervention approach. Understanding the hemodynamics, or blood flow patterns, within MCA aneurysms and how they are affected by endovascular treatment is crucial for improving patient outcomes. This numerical study investigates the hemodynamics of blood flow within MCA aneurysms before and after endovascular treatment. Patient-specific geometric models of MCA aneurysms were reconstructed from medical imaging data. Simulations using computational fluid dynamics were conducted to examine flow characteristics, wall shear stress, and additional hemodynamic factors within the aneurysms. The study assessed and contrasted the impact of coil embolization and flow diverter placement on the hemodynamics inside the aneurysms. The findings offer a deeper understanding of the intricate flow dynamics within MCA aneurysms and illustrate the ways in which endovascular treatments can modify these dynamics. [ABSTRACT FROM AUTHOR]

Ischemic stroke (IS) is the leading cause of disability and the second most common cause of death in adults globally. Unfortunately, the recombinant tissue plasminogen activator (rt-PA), the only thrombolytic drug approved by the Food and Drug Administration (FDA), has numerous side effects such as hemorrhage risk and narrow therapeutic windows, which limits its clinical application. Butylphthalide (NBP) from celery seeds was approved against IS, and its derivative 6-amino-3-n-butylphthalide has been demonstrated to offer better neuroprotective effects against IS-induced injury. In this study, a series of 6-amino-3-n-butylphthalide (ABP) derivatives were designed and synthesized in order to obtain novel powerful compounds against IS. Permanent middle cerebral artery occlusion (pMCAO)-operated mice and oxygen and glucose deprivation (OGD)-treated primary cortical neurons and HT22 cell lines were used to evaluate the activity of these derivatives in protecting against ischemic injury. The results showed that the effect of compound ABP18 (ABP connecting with memantine) on alleviating OGD-induced cell death was better than that of NBP both in primary cortical neurons and HT22 cells, and the safety of ABP18 is comparable to that of NBP. In addition, ABP18 significantly reduced the brain infarct volume and improved neurological function in mice at 24 h after pMCAO. The acute toxicity test showed that ABP18 had high safety. Therefore, the present study identified that ABP18 is a potential candidate for the treatment of IS. [ABSTRACT FROM AUTHOR]

Introduction: Cerebral malaria (CM) is a devastating disease and better understanding of etiologies of the resulting neurologic injury is needed. The purpose of this study is to describe the day-to-day (DTD) pulsatility index (PI) change measured by transcranial Doppler ultrasound (TCD), a novel measure of cerebral and vascular changes, in children with CM. Methods: A retrospective analysis of 122 children in sub-Saharan Africa with CM and 3 or more sequential TCD measurements was performed. Variability of DTD PI change was calculated as a measure of changes in vasculature overtime. Neurologic outcome was determined by the Pediatric Cerebral Performance Category (PCPC) score, a measure of neurologic function. Results: Of the 122 participants, 77.9% had a good neurologic outcome (no neurologic sequelae), and 22.1% had a poor outcome (neurologic sequelae or died). Patients who had a poor neurologic outcome had higher levels of variability of DTD PI change in the right middle cerebral artery (MCA) (0.14 ± 0.21) and left MCA (0.17 ± 0.41) compared to those who had a good neurologic outcome (0.1 ± 0.1 and 0.11 ± 0.19, respectively). A higher variability of both left and right MCA DTD PI change was also associated with higher brain volume assessed through neuroimaging. Discussion: Variability of DTD PI change may provide early prognostic information regarding PCPC outcomes and brain volume changes seen in CM patients. Expanded research on pathophysiologic contributors to variability of DTD PI changes in children with CM is warranted. [ABSTRACT FROM AUTHOR]

Collaterals improve recanalization in acute ischemic stroke patients treated with intravenous thrombolysis, but the mechanisms are poorly understood. To investigate it, an in vitro flow model of the middle cerebral artery was developed with or without collaterals. An occlusion was achieved using human blood clots. Recanalization time, thrombolysis (clot length decrease and red blood cell (RBC) release), pressure gradient across the clot and clot compaction were measured. Results showed that with or without collateral alteplase-treated RBC dominant clots showed recanalization time 98±23 min vs 130±35 min (difference 32 min, 95% CI -6-58 min), relative clot reduction 31.8±14.9% vs 30.3±13.2% (difference 1.5%, 95% CI 10.4–13.4%) and RBC release 0.30±0.07 vs 0.27±0.09 (difference 0.03, 95% CI 0.04–0.10). Similar results were observed with fibrin-dominant clots. In RBC dominant clots, the presence vs absence of collateral caused different pressure gradients across the clot 0.41±0.09 vs 0.70±0.09 mmHg (difference 0.29 mmHg, 95% CI -0.17–0.41 mmHg), and caused the reduction of initial clot compaction by 5%. These findings align with observations in patients, where collaterals shortened recanalization time. However, collaterals did not increase thrombolysis. Instead, they decreased the pressure gradient across the clot, resulting in less clot compaction and easier distal displacement of the clot. [ABSTRACT FROM AUTHOR]

The transplantation of injury/ischemia-induced stem cells (iSCs) extracted from post-stroke human brains can improve the neurological functions of mice after stroke. However, the usefulness of iSCs as an alternative stem cell source remains unclear. The current study aimed to assess the efficacy of iSC and mesenchymal stem cell (MSC) transplantation. In this experiment, equal numbers of human brain-derived iSCs (h-iSCs) (5.0 × 104 cells/μL) and human bone marrow-derived MSCs (h-MSCs) (5.0 × 104 cells/μL) were intracranially transplanted into post-stroke mouse brains after middle cerebral artery occlusion. Results showed that not only h-iSC transplantation but also h-MSC transplantation activated endogenous neural stem/progenitor cells (NSPCs) around the grafted sites and promoted neurological functional improvement. However, mice that received h-iSC transplantation experienced improvement in a higher number of behavioral tasks compared with those that received h-MSC transplantation. To investigate the underlying mechanism, NSPCs extracted from the ischemic areas of post-stroke mouse brains were cocultured with h-iSCs or h-MSCs. After coincubation, NSPCs, h-iSCs, and h-MSCs were selectively collected via fluorescence-activated cell sorting. Next, their traits were analyzed via microarray analysis. The genes related to various neuronal lineages in NSPCs after coincubation with h-iSCs were enriched compared with those in NSPCs after coincubation with h-MSCs. In addition, the gene expression patterns of h-iSCs relative to those of h-MSCs showed that the expression of genes related to synapse formation and neurotransmitter-producing neurons increased more after coincubation with NSPCs. Hence, cell–cell interactions with NSPCs promoted transdifferentiation toward functional neurons predominantly in h-iSCs. In accordance with these findings, immunohistochemistry showed that the number of neuronal networks between NSPCs and h-iSCs was higher than that between NSPCs and h-MSCs. Therefore, compared with h-MSC transplantation, h-iSC transplantation is associated with a higher neurological functional improvement, presumably by more effectively modulating the fates of endogenous NSPCs and grafted h-iSCs themselves. [ABSTRACT FROM AUTHOR]

Background and Aims Glycoprotein VI (GPVI) is a platelet collagen/fibrin(ogen) receptor and an emerging pharmacological target for the treatment of thrombotic and thrombo-inflammatory diseases, notably ischaemic stroke. A first anti-human GPVI (hGPVI) antibody Fab-fragment (ACT017/glenzocimab, K D: 4.1 nM) recently passed a clinical phase 1b/2a study in patients with acute ischaemic stroke and was found to be well tolerated, safe, and potentially beneficial. In this study, a novel humanized anti-GPVI antibody Fab-fragment (EMA601; K D: 0.195 nM) was developed that inhibits hGPVI function with very high potency in vitro and in vivo. Methods Fab-fragments of the mouse anti-hGPVI IgG Emf6.1 were tested for functional GPVI inhibition in human platelets and in hGPVI expressing (hGP6tg/tg) mouse platelets. The in vivo effect of Emf6.1Fab was assessed in a tail bleeding assay, an arterial thrombosis model and the transient middle cerebral artery occlusion (tMCAO) model of ischaemic stroke. Using complementary-determining region grafting, a humanized version of Emf6.1Fab (EMA601) was generated. Emf6.1Fab/EMA601 interaction with hGPVI was mapped in array format and kinetics and quantified by bio-layer interferometry. Results Emf6.1Fab (K D: 0.427 nM) blocked GPVI function in human and hGP6tg/tg mouse platelets in multiple assays in vitro at concentrations ≥5 µg/mL. Emf6.1Fab (4 mg/kg)-treated hGP6tg/tg mice showed potent hGPVI inhibition ex vivo and were profoundly protected from arterial thrombosis as well as from cerebral infarct growth after tMCAO, whereas tail-bleeding times remained unaffected. Emf6.1Fab binds to a so far undescribed membrane proximal epitope in GPVI. The humanized variant EMA601 displayed further increased affinity for hGPVI (K D: 0.195 nM) and fully inhibited the receptor at 0.5 µg/mL, corresponding to a >50-fold potency compared with ACT017. Conclusions EMA601 is a conceptually novel and promising anti-platelet agent to efficiently prevent or treat arterial thrombosis and thrombo-inflammatory pathologies in humans at risk. [ABSTRACT FROM AUTHOR]

The aim of the study is to establish local diagnostic reference levels (DRLs) in cerebral thrombectomy, according to the anatomical region of ischemic stroke. This is a retrospective study from a single center involving 255 examinations. The proposed median values (P50) for thrombectomy are: 123 Gy.cm2 for air kerma-area product (PKA) and 915 mGy for air kerma (Ka,r). For middle cerebral artery (MCA) thrombectomies, the proposed DRLs are 118 Gy.cm2 for PKA and 112 Gy.cm2 for internal carotid artery (ICA). The Ka,r values for MCA and ICA are 849 and 775 mGy, respectively. It was observed that 94.9% of patients presented grade 0 on the initial modified treatment in cerebral infarction (mTICI) scale, and after thrombectomy, 63.1% of patients reached a final mTICI grade of 3. Stents were implanted in 37 patients (14.5% of cases). It was concluded that 16.1% of patients exceeded one trigger value of the Safety in Radiological Procedures' recommended parameters. Establishing DRLs is an important tool for optimizing practices and is considered a standard for quality control. [ABSTRACT FROM AUTHOR]

Accessory middle cerebral arteries (AMCAs) are found in 0.3–4.0% of cases, and ipsilateral dual AMCAs are rare. A seventy-three-year-old man presented with right hemiplegia and total aphasia. Magnetic resonance angiography showed left carotid artery occlusion. We infused him with tissue plasminogen activator. Digital subtraction angiogram showed revascularization of the left internal carotid artery. However, the left proximal anterior cerebral artery was occluded. We performed mechanical thrombectomy and achieved partial reperfusion. CT angiography on the tenth day showed ipsilateral dual AMCAs. Due to middle cerebral artery anomalies, we performed mechanical thrombectomy using contact aspiration which is safer than other techniques. [ABSTRACT FROM AUTHOR]

Background and purpose: Despite the fundamental role of pial collateral vessels in limiting the progression of ischemic tissue injury in acute stroke with large vessel occlusion (LVO), in addition to the fact that collateral vessel abundance varies naturally from person to person for genetic reasons, there is limited knowledge regarding potential factors contributing to inherent interindividual variation in pial collateral supply. As it has been repeatedly hypothesized that chronic carotid occlusive disease may favor pial collateralization, we aimed to investigate the association between quantitatively assessed leptomeningeal collateral supply and pre-existing carotid stenosis in patients with acute stroke due to LVO. Materials and methods: Patients with proximal middle cerebral artery (MCA) occlusion with or without additional internal carotid artery (ICA) occlusion were included. The degree of collateral supply was quantitatively assessed based on signal variance in T2*-weighted time series in perfusion-weighted magnetic resonance imaging (PWI). Patients were stratified into two groups according to quantitative collateral status (poor and fair to good collateral supply). The prevalence of high-grade ICA stenosis (≥70%) was evaluated in both groups. Results: A total of 98 patients (mean age 68.8 ± 16.1 years, n = 52 (53.1%) of whom were female individuals) with MCA and/or ICA occlusion were included in the final analysis. Out of these patients, 42 had poor collateral supply, while 56 exhibited fair to good collateral supply. Additionally, 18 patients showed ipsilateral high-grade ICA stenosis. After classifying the entire cohort based on their collateral status (poor vs. fair to good collateral supply), there was no significant difference in the proportion of the patients with ipsilateral high-grade ICA stenosis between the two groups. Specifically, 6 (14.3%) patients had poor collateral supply, and 12 (21.1%) patients had fair to good collateral supply. The odds ratio (OR) was 1.58, with a 95% confidence interval (CI) of 0.490–5.685 and the p- value of 0.440. In the entire patient cohort, signal variance-based collateral supply was significantly correlated with initial stroke severity (r = −0.360, p < 0.001), baseline ischemic core volume (r = −0.362, p < 0.001), and functional outcomes (score on the modified Rankin Scale) at discharge (r = −0.367, p < 0.01). Conclusion: In this study, we performed a quantitative and observer-independent MRI-based collateral assessment in patients with LVO. We found no significant difference in the prevalence of pre-existing high-grade ICA stenosis between patients with fair to good collateral supply and those with poor collateral supply. The potential influence of demographic and clinical variables on pial collateral supply in patients with acute stroke warrants further exploration in future studies. MRI-based collateral supply is significantly related to initial stroke severity, ischemic core volume, and early functional outcomes. [ABSTRACT FROM AUTHOR]

Background: High-flow bypasses with parent vessel occlusion are required for complex aneurysms originating from the ICA or MCA. Traditional graft options are the saphenous vein however, it has a higher rate of thrombus formation than an arterial graft. The radial artery is commonly used, however, tapers in its distal course and is contraindicated in some patients while the lateral circumflex femoral artery is an excellent graft vessel and easy to harvest. Method: We present our technique and experience harvesting the lateral circumflex femoral artery as an alternative graft vessel for high-flow bypasses. Conclusion: The lateral circumflex femoral artery is easy to harvest and is a reliable graft vessel for high-flow bypasses for complex aneurysms. [ABSTRACT FROM AUTHOR]

BACKGROUND: Cerebral infarction is a health problem of global concern and brings a particular burden to medical treatment. OBJECTIVE: To analyze the correlation between insulin resistance (IR) levels and changes in cerebral atherosclerosis (AS) degree in non-diabetic patients with cerebral infarction. METHODS: A total of 134 non-diabetic patients with cerebral infarction who visited the Department of Neurology of our hospital from May 2019 to October 2020 were selected and underwent MRA/CTA (Magnetic resonance angiography/Computed tomography angiography) of cerebral arteries to refine the cerebrovascular imaging data, and according to the results of cerebral AS load, the patients were divided into mild AS group and severe AS group, and the insulin resistance index was calculated with HOMA-IR (homeostasis model assessment of insulin resistance) to evaluate the IR level and HOMA-IR was compared between the two groups. Spearman correlation was used to analyze the correlation between the levels of IR in patients and the changes in cerebral AS load. RESULTS: 54 individuals had severe AS and 80 patients had mild AS, according to an MRA/CTA of the cerebral arteries. There was a significant difference (P < 0.05) in HOMA-IR between the difficult and gentle AS groups. A significant link between HOMA-IR and the severity of cerebral AS in patients was found using Spearman correlation analysis (r = 0.850, P < 0.05). CONCLUSION: The IR phenomenon was prevalent in non-diabetic patients with cerebral infarction, and the level of IR was closely related to the severity of cerebral AS. [ABSTRACT FROM AUTHOR]

The transorbital approach (TOA) has a unique advantage to the more common lateral approaches as it provides direct access to the anterior middle fossa and medial sylvian fissure (SF) without significant dissection or retraction. However, when to use the TOA for surgical treatment of middle cerebral artery (MCA) aneurysms remains unclear. This study details the feasibility of clipping unruptured MCA aneurysms via the TOA by highlighting the anatomic features that either facilitate or hinder the approach. Virtual reality (VR) models of 25 MCA aneurysms from computed tomography angiograms of actual patients were rendered with the relevant anatomic structures, including the neighboring temporal lobe and SF. TOA was performed on the models in VR and the globe was translated medially and inferiorly, replicating retraction used intraoperatively. Anatomic data, including the area of surgical freedom (AOF) at the aneurysm, were recorded. Trials of aneurysm clipping were conducted in VR and each aneurysm was classified as "possible" or "impossible" candidates for clipping via TOA. Separately, the relationship between surgical view and SF visualized was analyzed. Sixteen aneurysms were eliminated as candidates for TOA treatment either through VR clip trial and/or because the SF was inaccessible. The remaining 9 (36%) were candidates for TOA. Comparing the details of these 2 aneurysm categories with Mann Whitney U tests, there was a statistically significant difference in the AOF of the TOA approach and the width of the aneurysm dome. A clinical case report is also provided highlighting the VR rehearsal similarity with surgery. Given the minimally invasive, technically challenging approach, the feasibility and safety of TOA for MCA aneurysms must be evaluated before wide clinical adoption. This study identified AOF, aneurysm width, and SF accessibility as three features that may significantly impact the possibility of clipping MCA aneurysms via TOA. [ABSTRACT FROM AUTHOR]

Background/Objectives: Microsurgical clipping has traditionally been considered a standard treatment for middle cerebral artery (MCA) aneurysms. Recently, a caseload reduction related to improved endovascular treatment options has occurred in cerebrovascular neurosurgery. Therefore, studies that report the clinical and radiological outcomes after clipping are highly warranted. Methods: Patients with an unruptured MCA bifurcation aneurysm, who were surgically treated at the Department of Neurosurgery in Linz between 2002 and 2019, were included in this study. Clinical and radiological outcome parameters were evaluated for each patient. Results: Overall, 272 patients were eligible for inclusion. Complete aneurysm occlusion was demonstrated in 266 (99.3%) of the 268 (98.5%) patients who underwent postoperative digital subtraction angiography. In six (2.2%) patients, a permanent new neurological deficit (pNND) persisted after treatment. Intraoperative aneurysm rupture was a significant factor (p = 0.0049) in the logistic regression. At the last follow-up, only two patients (0.7%) had an unfavorable outcome (mRS > 2). More recent surgeries were associated with fewer cases of pNND (p = 0.009). A transient new neurological deficit occurred in 13 patients (4.8%), with aneurysm size being a significant risk factor (p = 0.009). Surgical site infections were reported in four patients (1.5%), with patient age (p = 0.039) and time (p = 0.001) being significant factors. Two patients died (0.7%) perioperatively and two patients (0.7%) needed a retreatment in the long-term follow-up. Conclusions: The findings indicate that microsurgical clipping is a safe procedure with minimal need for retreatment. It achieves a high occlusion rate while maintaining a very low rate of adverse outcomes. Continuous intraoperative enhancements over time have contributed to a progressive improvement in clinical outcomes in recent years. This trend is exemplified by the absence of detectable pNND in the era of ICG angiography. Consequently, these data support the conclusion that microsurgical clipping should still be considered an appropriate treatment option for unruptured MCA bifurcation aneurysms. [ABSTRACT FROM AUTHOR]

Ischemic stroke is a leading cause of disability and mortality worldwide. Recently, increasing evidence implicates microRNAs (miRs) in the pathophysiology of ischemic stroke. Studies have shown that miR-15a/16-1 is abnormally expressed in brains after ischemic stroke, and its upregulation may increase ischemic damage. Given that sex and age are significant modifiers of stroke outcomes, here we investigated whether inhibiting miR-15a/16-1 with antagomirs mitigates cerebral ischemia/reperfusion (I/R) injury in a sex- and age-dependent manner. Young (3 months) and aged (18 months) male and female C57/BL mice underwent 1-h middle cerebral artery occlusion and 3–7 days reperfusion (tMCAO). We administered miR-15a/16-1 antagomir (30 pmol/g) or control antagomir (NC, 30 pmol/g) via tail vein 2 h post-MCAO. Neurobehavioral testing and infarct volume assessment were performed on days 3 and 7. Compared to controls, antagomir treatment significantly improved neurobehavioral outcomes and reduced infarct volume in tMCAO mice at day 7, with the effects being more pronounced in young mice. Notably, young female mice exhibited superior survival and sensorimotor function compared to young male mice. These results were also replicated in a permanent MCAO (pMCAO) mice model. This suggests miR-15a/16-1 antagomir and estradiol may synergistically regulate genes involved in neurovascular cell death, inflammation, and oxidative stress, with sex and age-dependent expression of miR-15a/16-1 and its targets likely underlying the observed variations. Overall, our findings identify miR-15a/16-1 antagomir as a promising therapeutic for ischemic stroke and suggest that sex and age should be considered when developing miR-based therapeutic strategies. [ABSTRACT FROM AUTHOR]

Objective: Identifying the predictive factors of mortality and functional outcomes following decompressive craniectomy (DC) surgery in patients with malignant middle cerebral artery infarction (MMCAI) is essential for decision-making regarding conservative versus surgical treatment. This study aimed to assess the mortality and functional outcomes of MMCAI patients after DC surgery and to identify the predictive factors associated with mortality and functional outcomes. Methods: A total of 76 patients with MMCAI who underwent surgical DC were included. The mortality rates and functional outcomes were assessed, and factors associated with mortality and functional outcomes were identified through univariate analysis followed by multivariate logistic regression analysis. Results: The mortality rate was 44.8%, while a favorable functional outcome was observed in 28.9% of the patients. modified Glasgow coma scale (GCS) before DC (OR = 0.416, 95% CI = 0.261–0.662, P < 0.001) and infarct volume before DC (OR = 1.000-1.012, 95% CI = 1.000-1.012, P = 0.037) were independent risk factors for death. Age (OR = 0.88, 95% CI = 0.812–0.952, P = 0.002), modified GCS before DC (OR = 2.477, 95% CI = 1.395-4.4, P = 0.002), and infarct volume before DC (OR = 0.987, 95% CI = 0.975–0.999, P = 0.035) were independent factors associated with favorable functional outcomes. Conclusion: Preoperative modified GCS and preoperative infarct volume were independent factors associated with both mortality and functional outcomes. Age was only associated with functional outcomes. [ABSTRACT FROM AUTHOR]

Cerebral hemodynamics have been quantified during exercise via transcranial Doppler ultrasound, as it has high-sensitivity to movement artifacts and displays temporal superiority. Currently, limited research exists regarding how different exercise modalities and postural changes impact the cerebrovasculature across the cardiac cycle. Ten participants (4 females and 6 males) ages 20–29 completed three exercise tests (treadmill, supine, and upright cycling) to volitional fatigue. Physiological data collected included middle cerebral artery velocity (MCAv), blood pressure (BP), heart rate, and respiratory parameters. Normalized data were analyzed for variance and effect sizes were calculated to examine differences between physiological measures across the three exercise modalities. Systolic MCAv was greater during treadmill compared to supine and upright cycling (p < 0.001, (large) effect size), and greater during upright versus supine cycling (p < 0.017, (large)). Diastolic MCAv was lower during treadmill versus cycling exercise only at 60% maximal effort (p < 0.005, (moderate)) and no differences were observed between upright and supine cycling. No main effect was found for mean and diastolic BP (p > 0.05, (negligible)). Systolic BP was lower during treadmill versus supine cycling at 40% and 60% intensity (p < 0.05, (moderate–large)) and greater during supine versus upright at only 60% intensity (p < 0.003, (moderate)). The above differences were not explained by partial pressure of end-tidal carbon dioxide levels (main effect: p = 0.432). The current study demonstrates the cerebrovascular and cardiovascular systems respond heterogeneously to different exercise modalities and aspects of the cardiac cycle. As physiological data were largely similar between tests, differences associated with posture and modality are likely contributors. [ABSTRACT FROM AUTHOR]

Introduction: The aim of this study was to investigate the presence of aortic isthmus flow reversal and its associated factors in fetuses with positive and false‐positive coarctation of the aorta (CoA) compared with normal controls. Material and Methods: Pregnant women with fetuses suspected of CoA and normal control were enrolled, and these women experienced prenatal ultrasound scan and followed up for 6 months after birth to confirm the presence of CoA. All the ultrasound parameters were analyzed. Results: A total of 134 pregnant women were enrolled, with 43 CoA‐positive fetuses and 91 CoA false‐positive fetuses, and 334 matched pregnant women were enrolled in the control group. Aortic isthmus flow reversal occurred in 28 (65.1%) fetuses in the CoA‐positive group, significantly (p < 0.05) more than in the false‐positive (37 or 40.7%) or control group (64 or 19.2%). Aortic isthmus flow reversal was mostly in the full systole (n = 17 or 60.7%) or late systole and early‐middle diastole (n = 10 or 35.7%) in the CoA‐positive fetuses (n = 27 or 96.4%), significantly (p < 0.001) different from that in the false‐positive or control group. The aortic isthmus flow reversal peak systolic velocity (PSV), flow volume, and ratio of reversed flow/forward flow were significantly (p < 0.05) increased in the CoA‐positive and false‐positive groups than in the control group. The aortic isthmus flow reversal incidence was significantly (p < 0.05) correlated with the middle cerebral artery (MCA) PSV in the total three groups or in the false‐positive group but was significantly (p < 0001) negatively correlated with the MCA resistance index (RI) in the CoA‐positive group. The incidence of the aortic isthmus flow reversal was significantly (p < 0.05) positively correlated with the umbilical artery (UA) RI in the false‐positive group and with the UA RI in the total three groups. Independently associated factors for aortic isthmus flow reversal were isthmic flow volume/CCO (combined cardiac output) in the CoA‐positive group. Conclusions: Reversal of flow in the aortic isthmus is much more common in true‐positive cases of CoA as compared to controls, and isthmic flow reversal in the full systolic phase only suggests presence of CoA. The aortic isthmic reversed flow volume accounts for over half of the isthmic forward flow volume in the CoA‐positive fetuses than in the normal controls. [ABSTRACT FROM AUTHOR]

Ischaemic stroke is a common condition that can lead to cerebral ischaemia–reperfusion injury. Phillygenin (PHI), a natural bioactive compound derived from Forsythia suspensa, has been shown to play a crucial role in regulating inflammation across various diseases. However, its specific regulatory effects in ischaemic stroke progression remain unclear. In this study, we established a middle cerebral artery occlusion (MCAO) rat model. Treatment with PHI (50 or 100 mg/kg) significantly reduced cerebral infarction in MCAO rats. PHI treatment also mitigated the increased inflammatory response observed in these rats. Additionally, PHI suppressed microglial activation by reducing iNOS expression, a marker of M1‐type polarization of microglia, and attenuated increased brain tissue apoptosis in MCAO rats. Furthermore, PHI's anti‐inflammatory effects in MCAO rats were abrogated upon co‐administration with GW9662, a peroxisome proliferator‐activated receptor γ (PPARγ) inhibitor. In summary, PHI attenuated microglial activation and apoptosis in cerebral ischaemia–reperfusion injury through PPARγ activation, suggesting its potential as a therapeutic agent for mitigating cerebral ischaemia–reperfusion injury. [ABSTRACT FROM AUTHOR]

To prospectively assess the value of a test bolus of diluted contrast medium (CM) combined with a personalized contrast protocol in craniocervical computed tomography angiography (cc-CTA) with low radiation and CM doses. Eighty-six consecutive subjects were divided into two groups at random (43 in each one): group A: 100/Sn140 kVp, filtered back-projection reconstruction, iopromide (370 mgI/ml) 50 ml; group B: 80/Sn140 kVp, iterative reconstruction, iodixanol (270 mgI/ml). In group B, the test bolus contained 27 ml of diluted CM, a personalized protocol with low-concentration CM was used for angiography, and the test bolus injection duration in angiography remained the same. Artery values over 200 Hounsfield units were considered significant. Image quality for all cases was found to be diagnostic. No significant differences were found in the arterial densities of the ascending aorta or basilar artery between the groups. The values of the common carotid artery, internal carotid artery, and middle cerebral artery in group B were significantly lower. The effective dose and average iodine uptake were significantly lower in group B. With double-low-dose cc-CTA, test bolus scanning based on diluted CM combined with a personalized contrast protocol can yield diagnostic-quality images and significantly reduce the radiation and CM doses. • Test bolus with diluted contrast medium (CM) allows for precise anticipation of the scan trigger time. • A personalized CM protocol made it feasible to further reduce iodine uptake. • The double low dose protocol can get images with diagnostic quality in craniocervical computed tomography angiography. [ABSTRACT FROM AUTHOR]

Purpose: The main purpose of this study was to investigate the dimensions of cerebral arteries in the Thai population using digital subtraction angiography (DSA), with a focus on the anterior cerebral artery (ACA), middle cerebral artery (MCA), and posterior cerebral artery (PCA). The research aimed to explore anatomical variations in diameters and lengths of these arteries across different sexes and age groups, which are crucial for cerebrovascular interventions. Methods: This retrospective study measured the diameters and lengths of the ACA, MCA, and PCA in 177 Thai patients with an average age of 47.6 years (range: 11–82 years) with normal cerebral angiograms. Digital subtraction angiography (DSA) was used for the measurements. Results: The study found significant sex-based differences in the mean diameters of the left ACA (males: 2.12 ± 0.28 mm, females: 1.92 ± 0.20 mm; p < 0.01), right MCA (males: 2.50 ± 0.25 mm, females: 2.31 ± 0.17 mm; p < 0.01), and left MCA (males: 2.44 ± 0.19 mm, females: 2.30 ± 0.17 mm; p < 0.01) with males exhibiting larger diameters. The right ACA length was significantly longer in males (15.46 ± 1.74 mm) compared to females (13.98 ± 1.92 mm; p < 0.01). While no significant age-related differences were observed in diameters, a significant increase in length with age was noted for the left ACA in the ≥ 60 years group (13.61 ± 1.64 mm) compared to the < 60 years group (12.63 ± 1.36 mm; p < 0.01). Among others, significant correlations were found between the diameters of the left ACA and right MCA (r = 0.699; p < 0.01), and a strong correlation between left ACA length and left PCA diameter (r = 0.975; p < 0.01). Conclusion: The findings provide invaluable data for tailoring neurosurgical approaches and designing angiographic equipment for the Thai population, emphasizing the importance of considering anatomical variations in clinical practice. These results highlight the necessity for personalized medical care based on anatomical differences to improve cerebrovascular intervention outcomes. [ABSTRACT FROM AUTHOR]

Retropharyngeal internal carotid artery (ICA) is a rare, yet well-described anatomical variant that poses significant challenges to the management of carotid artery stenosis. In this case report, we discuss the treatment of symptomatic ICA stenosis with a retropharyngeal ICA using the transcarotid artery revascularization (TCAR) technique. A 70-year-old female with comorbidities presented with neurological symptoms and severe ICA stenosis. After diagnostic evaluation, TCAR was chosen for surgical intervention. The patient did well postoperatively. This case emphasizes the importance of considering TCAR when treating ICA stenosis in patients with anatomic variation of ICA location. It also supports adding anatomic variants such as retropharyngeal ICA to the list of indications for TCAR. [ABSTRACT FROM AUTHOR]

We aim to explore the feasibility of head and neck time‐of‐flight (TOF) magnetic resonance angiography (MRA) at ultra‐low‐field (ULF). TOF MRA was conducted on a highly simplified 0.05 T MRI scanner with no radiofrequency (RF) and magnetic shielding. A flow‐compensated three‐dimensional (3D) gradient echo (GRE) sequence with a tilt‐optimized nonsaturated excitation RF pulse, and a flow‐compensated multislice two‐dimensional (2D) GRE sequence, were implemented for cerebral artery and vein imaging, respectively. For carotid artery and jugular vein imaging, flow‐compensated 2D GRE sequences were utilized with venous and arterial blood presaturation, respectively. MRA was performed on young healthy subjects. Vessel‐to‐background contrast was experimentally observed with strong blood inflow effect and background tissue suppression. The large primary cerebral arteries and veins, carotid arteries, jugular veins, and artery bifurcations could be identified in both raw GRE images and maximum intensity projections. The primary brain and neck arteries were found to be reproducible among multiple examination sessions. These preliminary experimental results demonstrated the possibility of artery TOF MRA on low‐cost 0.05 T scanners for the first time, despite the extremely low MR signal. We expect to improve the quality of ULF TOF MRA in the near future through sequence development and optimization, ongoing advances in ULF hardware and image formation, and the use of vascular T1 contrast agents. [ABSTRACT FROM AUTHOR]

Tenecteplase (TNK), as a thrombolytic treatment for acute ischemic stroke (AIS), has been found to be effective when used within 4.5 hours of symptom onset. However, the efficacy of TNK after 4.5 hours is not well established, especially in patients with large vessel occlusion and with no access to thrombectomy. In this article, we will discuss the results of the recently published TRACE-III trial. The study involved 516 patients with large vessel occlusion, either proximal middle cerebral artery or internal carotid artery, with salvageable brain tissue and no endovascular thrombectomy access. Key safety outcomes included symptomatic intracranial hemorrhage and death. TNK treatment resulted in a higher percentage of patients with a modified Rankin scale score of 0 or 1 at 90 days than standard medical treatment. Mortality at 90 days was 13.3% with TNK and 13.1% with standard medical treatment. The trial found that TNK treatment for Chinese patients with ischemic stroke resulted in less disability and similar survival compared to standard medical treatment. However, there was a higher incidence of symptomatic intracranial hemorrhage within 36 hours. [ABSTRACT FROM AUTHOR]

Background Intracranial hemorrhage (ICH) is a potentially severe complication of endovascular thrombectomy (EVT). However, the relationship between the incidence and severity of ICH and vascular occlusion location is not well described. Objective To present a comprehensive analysis of subtypes of ICHs and their relationship to the occlusion site following EVT in the anterior circulation. Methods All patients with anterior circulation vessel occlusion stroke (internal carotid (ICA) and middle cerebral artery's first (M1) and later segments (M2 and beyond)) registered in the two Swedish national quality registers for stroke care and endovascular therapy during 2015-2020 were included. Hemorrhagic complications identified on imaging within 36 hours post-EVT were classified according to Heidelberg Bleeding Classification and further divided into symptomatic (sICH) or non-symptomatic (non-sICH). Results Of the 3077 patients, ICH frequency was 24.2%, which included 4.5% sICH. Subarachnoid hemorrhage (SAH) was the most frequent subtype of hemorrhage (10.9%). The hemorrhagic subtypes differed significantly by occlusion site, but the frequency of any bleed did not. EVT performed in and beyond the M2 more often resulted in SAH, frequently classified as non-sICH. EVT performed in the ICA was associated with more severe hemorrhages, such as intraventricular and large parenchymal hematomas, that were more often classified as sICH. Conclusion In this nationwide unselected EVT cohort we found that ICH severity significantly differed between different vessel occlusion sites. [ABSTRACT FROM AUTHOR]

Background and Purpose Methods Results Conclusions Decompressive hemicraniectomy (DH) improves survival and functional outcome in large middle cerebral artery (MCA) infarcts. However, long‐term cognitive outcomes after DH remain underexplored. In a cohort of patients with large right‐hemisphere MCA infarction undergoing DH, we assessed the rates of long‐term cognitive impairment over 3‐year follow‐up.We prospectively evaluated consecutive patients included in the Lille Decompressive Surgery Database (May 2005–April 2022) undergoing DH according to existing guidelines for large hemisphere MCA infarction. We included patients with right‐sided stroke and screened with the Mini‐Mental State Examination (MMSE) in at least one of the prespecified follow‐ups (3‐month, 1‐year, 3‐year). Cognitive impairment was defined as an MMSE score < 24. We included only right‐hemisphere strokes to avoid testing biases related to severe aphasia. We compared clinical and neuroimaging data in patients with and without cognitive impairment.Three hundred four patients underwent DH during the study period. Among 3‐month survivors, 95 had a right‐hemisphere stroke and underwent at least one cognitive screening (median age = 51 years, 56.8% men). Forty‐four patients (46.3%) exhibited cognitive impairment at least once during the 3‐year follow‐up. Baseline characteristics did not significantly differ between patients with and without cognitive impairment. Regarding long‐term temporal trends, cognitive impairment was observed in 23 of 76 (30.3%), 25 of 80 (31.3%), and 19 of 66 (28.8%) patients at 3‐month, 1‐year, and 3‐year follow‐up, respectively, and it was associated with higher rates of functional disability (all p < 0.05).The persistently high rates of cognitive impairment after DH highlight the importance of cognitive monitoring to improve the long‐term management of survivors. [ABSTRACT FROM AUTHOR]

Individuals who experience prolonged sitting daily are reported to be at risk of developing cerebrovascular disease, which is associated, in part, with attenuation in cerebral blood flow regulation. However, the effect of prolonged sitting on dynamic cerebral autoregulation (dCA), a crucial mechanism of cerebral blood flow regulation, remains unclear. Additionally, cerebrovascular disease occurs heterogeneously within cerebral arteries. The purpose of the present study was to examine the hypothesis that prolonged sitting attenuates dCA in the cerebral circulation heterogeneously. Twelve young, healthy participants were instructed to maintain a seated position for 4 h without moving their lower limbs. Mean arterial pressure and mean blood velocities of the middle cerebral artery (MCA Vm) and the posterior cerebral artery (PCA Vm) were measured continuously throughout the experiment. The dCA was assessed using transfer function analysis (TFA) with mean arterial pressure and either MCA Vm or PCA Vm. In the MCA, very low‐frequency TFA‐normalized gain decreased significantly during 4 h of prolonged sitting (P = 0.029), indicating an improvement rather than attenuation in dCA, despite a significant reduction in MCA Vm after 4 h of continuous sitting (P = 0.039). In the PCA, PCA Vm remained stable throughout the 4 h sitting period (P = 0.923), and all TFA parameters remained unchanged throughout the 4 h of sitting. Contrary to our hypothesis, these results suggest that the dCA in both the MCA and the PCA was well stabilized in healthy young individuals during acute prolonged sitting. [ABSTRACT FROM AUTHOR]

Objectives: The diagnosis of intracranial atherosclerotic stenosis (ICAS) is of great significance for the prevention of stroke. Deep learning (DL)-based artificial intelligence techniques may aid in the diagnosis. The study aimed to identify ICAS in the middle cerebral artery (MCA) based on a modified DL model. Methods: This retrospective study included two datasets. Dataset1 consisted of 3,068 transcranial Doppler (TCD) images of the MCA from 1,729 patients, which were assessed as normal or stenosis by three physicians with varying levels of experience, in conjunction with other medical imaging data. The data were used to improve and train the VGG16 models. Dataset2 consisted of TCD images of 90 people who underwent physical examination, which were used to verify the robustness of the model and compare the consistency between the model and human physicians. Results: The accuracy, precision, specificity, sensitivity, and area under curve (AUC) of the best model VGG16  +  Squeeze-and-Excitation (SE)  +  skip connection (SC) on dataset1 reached 85.67  ±  0.43(%),87.23  ±  1.17(%),87.73  ±  1.47(%),83.60  ±  1.60(%), and 0.857  ±  0.004, while those of dataset2 were 93.70  ±  2.80(%),62.65  ± 11.27(%),93.00  ±  3.11(%),100.00  ±  0.00(%), and 0.965  ±  0.016. The kappa coefficient showed that it reached the recognition level of senior doctors. Conclusion: The improved DL model has a good diagnostic effect for MCV stenosis in TCD images and is expected to help in ICAS screening. [ABSTRACT FROM AUTHOR]

Introduction: Extraction of Doppler-based measurements from feto-placental Doppler images is crucial in identifying vulnerable new-borns prenatally. However, this process is time-consuming, operator dependent, and prone to errors. Methods: To address this, our study introduces an artificial intelligence (AI) enabled workflow for automating feto-placental Doppler measurements from four sites (i.e., Umbilical Artery (UA), Middle Cerebral Artery (MCA), Aortic Isthmus (AoI) and Left Ventricular Inflow and Outflow (LVIO)), involving classification and waveform delineation tasks. Derived from data from a low-and middle-income country, our approach's versatility was tested and validated using a dataset from a high-income country, showcasing its potential for standardized and accurate analysis across varied healthcare settings. Results: The classification of Doppler views was approached through three distinct blocks: (i) a Doppler velocity amplitude-based model with an accuracy of 94%, (ii) two Convolutional Neural Networks (CNN) with accuracies of 89.2% and 67.3%, and (iii) Doppler view- and dataset-dependent confidence models to detect misclassifications with an accuracy higher than 85%. The extraction of Doppler indices utilized Doppler-view dependent CNNs coupled with post-processing techniques. Results yielded a mean absolute percentage error of 6.1 ± 4.9% (n = 682), 1.8 ± 1.5% (n = 1,480), 4.7 ± 4.0% (n = 717), 3.5 ± 3.1% (n = 1,318) for the magnitude location of the systolic peak in LVIO, UA, AoI and MCA views, respectively. Conclusions: The developed models proved to be highly accurate in classifying Doppler views and extracting essential measurements from Doppler images. The integration of this AI-enabled workflow holds significant promise in reducing the manual workload and enhancing the efficiency of feto-placental Doppler image analysis, even for non-trained readers. [ABSTRACT FROM AUTHOR]

Cardiovascular plaques result from atherosclerosis. Autopsy investigations of unnatural deaths provide atherosclerosis research. A Central European cohort was studied in a cross-sectional study to determine the origin of atherosclerosis and the link between arterial status and pathobiological variables. This study incorporated 3400 autopsy reports (n = 2318 men; aged 0─96 years; 1928─2010) of persons who died by unnatural causes (suicide, homicide, accident). Age, sex, BMI, abdominal fat thickness, and arterial status of six vascular areas were gathered. The arterial state was divided into five subgroups according to its status. BMI declined from 22.82 kg/m2 in 1931 to 18.43 kg/m2 in 1947, then increased to 27.88 kg/m2 in 2005. Atherosclerotic degeneration begins in the abdominal aorta, then the thoracic, coronary, carotid, ascending, and cerebral arteries. All blood arteries deteriorated faster in men than women until 55. Abdominal aorta damage was the fastest in both sexes. Age is the biggest predictor of atherosclerosis, followed by sex, overweight, and abdominal thickness, according to logistic regression. This is the largest Central European autopsy investigation of six vascular areas. Both sexes develop atherosclerosis in the abdominal aorta in the first decade of life. Being overweight increases the risk. The findings of this study aid healthcare providers in personalized therapy. [ABSTRACT FROM AUTHOR]

We describe a protocol to examine neurophysiological (electroencephalography, EEG), cerebrovascular (ultrasound assessments of middle cerebral artery blood velocity, MCAv) and cardiorespiratory (blood pressure, oxygen saturation, end-tidal gases, respiratory rate) responses inside a hypobaric chamber. This procedure aims to standardize the methodology in experiments conducted within a hypobaric chamber such as comparing normobaric and hypobaric hypoxia. This is important because current understanding of relationships between neurophysiological activity, and cerebrovascular and cardiorespiratory responses under varying environmental conditions remains limited. This procedure combines simultaneous neurophysiological, cardiorespiratory and cerebrovascular evaluations, allowing a comprehensive understanding of electro-neurophysiological activity. Our protocol requires an hour and a half of equipment setup, 1–1.5 hours of participant set-up, and 30 minutes of experimental data collection. Since multiple simultaneous physiological recordings, including EEG in this environment, can be fraught with pitfalls, we also provide practical considerations for experimental design and recording setup. Advanced knowledge of hypobaric chamber operation is required, alongside expertise in EEG and transcranial Doppler ultrasonography. Following our procedure one will acquire simultaneous recordings of neurophysiological, cerebrovascular and cardiorespiratory data. [ABSTRACT FROM AUTHOR]

Background: Endovascular recanalization is a feasible option for treating symptomatic non-acute middle cerebral artery occlusion (MCAO) patients. Hence, we aimed to establish a new angiographic scoring to grade the recanalization difficulty of MCAO to determine the suitable patients for endovascular treatment. Methods: We retrospectively analyzed a total of 113 consecutive recurrent symptomatic non-acute MCAO patients who underwent endovascular recanalization from July 2015 to August 2021 in four Chinese comprehensive stroke centers. All patients were reappraised using a new angiographic scoring based on the stump morphology, the MCA occlusion length, MCA bend, and the distal vascular bed of MCAO. We used the final results to establish the patients' outcomes. Results: The total successful recanalization and perioperative complication rates were 83.2% (94/113) and 15.9% (18/113), respectively. No deaths occurred within 30 days. Moreover, 96.9, 90, 87.5, 52.6, and 50% of the patients achieved recanalization with scores of 0, 1, 2, 3, and 4 (p < 0.001), respectively. However, the perioperative complication rate showed the opposite trend. (3.1% vs. 7.5% vs. 6.3% vs. 52.6% vs. 50%; p < 0.001). The median time of successful microwire crossing of the occlusion lesion (TMO) in the score 0 group was shorter than the other groups (2 min, 9 min, 8.5 min, 14 min, and 20 min; p < 0.001). When a score of 2 was used as the optimal cut-off point, the sensitivity and specificity were 86.2 and 63.2%, respectively. Conclusion: The new angiographic scoring can effectively predict the successful recanalization rate, perioperative complication rate, and TMO of endovascular recanalization for non-acute MCAO. It can also be used as an effective clinical evaluation tool to determine the suitable non-acute MCAO patients for recanalization, especially with a score = 2. [ABSTRACT FROM AUTHOR]

Background: The questions of whether the spatial resolution of navigated 3D-ultrasound (3D-US) power-Doppler angiography imaging rendered by existing 3D-US systems is sufficient for the intraoperative visualization of cerebral aneurysms, and in what percentage of cases, are largely unanswered. A study on this topic is lacking in the literature. Methods: From 2015 to 2022, we performed 86 surgeries on 83 aneurysm patients. Navigated 3D-US was used at the discretion of the operating neurosurgeons when available (i.e., not being used during parallel tumor surgeries). Twenty-five aneurysms (15 ruptured) were operated on using 3D-US; 22 aneurysms were located at the middle cerebral artery (MCA). Patient 3D-US power-Doppler angiography images and surgical reports were retrospectively reviewed to assess the intraoperative ultrasound visibility of aneurysms. Results: In 20 patients (80%) the aneurysms were successfully visualized. In five patients (20%), the aneurysms visualization was insufficient or absent. Nineteen of 22 aneurysms (86.4%) were visualized in the MCA aneurysm subgroup. We observed no association between aneurysm visibility and aneurysm size or the presence of subarachnoid hemorrhage. In the subgroup of MCA aneurysms, no association between aneurysm visibility and the presence of subarachnoid hemorrhage was found; a trend toward poor sonographic visibility of smaller aneurysms was observed (p = 0.09). Conclusions: Our initial data show that intraoperative 3D-US power-Doppler angiography, rendered by current navigated 3D-US systems, clearly depicts the majority of aneurysms in the MCA aneurysm subgroup. However, future prospective studies performed on a higher number of aneurysms localized at various anatomic sites are needed to confirm our initial findings and determine their potential clinical relevance. [ABSTRACT FROM AUTHOR]

Background: Hypertensive disorders of pregnancy (HDP) are associated with placental insufficiency and adverse perinatal outcomes—over half (58.9%) of women with HDP at Mbarara Regional Referral Hospital (MRRH) have adverse perinatal outcomes. The cerebroplacental ratio (CPR) is an important predictor and prevents approximately 30% of these adverse perinatal outcomes. We determined the prevalence and factors associated with abnormal CPR among women with HDP at MRRH. Methods: We conducted a cross‐sectional study from December 2022 to May 2023 at the high‐risk obstetrics unit of MRRH. We consecutively enrolled all women with hypertensive disorders and gestational ages ≥ 26 weeks and performed obstetric Doppler studies to document the pulsatility index (PI) of the umbilical artery (UA) and middle cerebral artery (MCA) and then calculated the CPR as a ratio of the MCA‐PI and UA‐PI. The prevalence of women with an abnormal CPR ≤ 1.0 was expressed as a percentage. We used robust modified Poisson regression analysis to determine the factors associated with abnormal CPR. Results: We enrolled 128 women with hypertensive disorders in pregnancy, with a mean age of 28.8 ± 6.3 years. Of these, 67 (52.3%) had abnormal CPR. The factors associated with abnormal CPR were severe pre‐eclampsia (adjusted prevalence ratio (aPR): 5.0, 95% CI: 1.28, 29.14) and eclampsia (aPR: 5.27, 95% CI: 1.11, 34.27). Conclusion: On average, half of the women with hypertensive disorders have abnormal CPR. Women with severe pre‐eclampsia or eclampsia are more likely to have abnormal CPR. Obstetric Doppler studies with CPR may be warranted for all pregnant women with severe pre‐eclampsia and eclampsia. We recommend further research to assess perinatal outcomes among those with and without abnormal CPR to profile women with HDP at increased risk of adverse perinatal outcomes. [ABSTRACT FROM AUTHOR]

Background and Purpose Experimental Approach Key Results Conclusions and Implications Intracranial atherosclerosis is one of the most common causes of ischaemic stroke. However, there is a substantial knowledge gap on the development of intracranial atherosclerosis. Intracranial arteries are characterized by an upregulation of tight junctions between endothelial cells, which control endothelial permeability. We investigated the role of N6‐methyladenosine (m6A), a common RNA modification, on endothelial integrity, focusing on the pro‐atherogenic microRNA miR‐494‐3p and tight junction proteins TJP1 and PECAM1.We assessed the m6A landscape, along with the expression of miR‐494‐3p, TJP1 and PECAM1 in postmortem human vertebral arteries (VA), internal carotid arteries (ICA), and middle cerebral arteries (MCA) with various stages of intimal thickening and plaque formation. The interactions between m6A‐modified miR‐494‐3p mimics, TJP1 and PECAM1, were investigated in vitro using primary human (brain) endothelial cells.Increased m6A expression was observed in the luminal lining of atherosclerosis‐affected VAs, accompanied by reduced TJP1 and PECAM1, but not VE‐cadherin, expression. Colocalization of m6A and miR‐494‐3p in the luminal lining of VA plaques was confirmed, indicating m6A methylation of miR‐494‐3p in intracranial atherosclerosis. Moreover, site‐specific m6A‐modification of miR‐494‐3p led to repression specifically of TJP1 protein expression at cell–cell junctions of brain microvascular endothelial cells, while unmodified miR‐494‐3p showed no effect.This study highlights increasing m6A levels during intracranial atherogenesis. Increases in m6A‐miR‐494‐3p contribute to the observed decreased TJP1 expression in endothelial cell–cell junctions. This is likely to have a negative effect on endothelial integrity and may thus accelerate intracranial atherosclerosis progression. [ABSTRACT FROM AUTHOR]

Sirtuin 3 has been shown to regulate endothelial function and coronary flow reserve in mice. Knockout of SIRT3 reduced endothelial nitric oxide synthase expression in the mouse hearts. In this study, we investigate whether endothelial SIRT3 regulates vascular function and myogenic responses in distal intramural branches of the left anterior descending coronary artery (CA) and middle cerebral artery (MCA) of mice. Both male and female endothelial SIRT3 knockout (SIRT3ECKO) mice and control SIRT3LoxP mice were used and CA and MCA were dissected and mounted in a myograph system. The myogenic response was evaluated by measuring changes in inner diameter in response to 20 mmHg stepwise increases in intraluminal pressure in PSS (active diameter) and Ca2+‐free PSS (passive diameter). Acetylcholine (Ach)‐induced endothelial‐dependent relaxation (EDR) and sodium nitroprusside (SNP)‐induced endothelial‐independent relaxation (EIR) were examined. Our results showed that the myogenic responses were significantly impaired in both the CA and MCA of SIRT3ECKO mice. Furthermore, female mice had worsened myogenic response in MCA. In CA, EDR was abolished in both male and female SIRT3ECKO mice. Intriguingly, EIR was only reduced in the female mice. In MCA, EDR was reduced in male SIRT3ECKO mice, whereas EIR was decreased in both male and female mice. Female SIRT3ECKO mice had profound dysfunction in CA, whereas male mice exhibited more dysfunction in MCA. These data revealed a sex and organ‐specific role of endothelial SIRT3 in vascular function and myogenic responses. Our study suggests that endothelial SIRT3 is necessary for maintaining vascular function and blood flow autoregulation. [ABSTRACT FROM AUTHOR]

Purpose: This technical note introduces the novel faucet technique, which enables neurosurgeons to evaluate the patency of a bypass during superficial temporal artery–middle cerebral artery bypass surgery. The technique is particularly useful when there is a lack of equipment such as micro-Doppler or indocyanine green in the operating rooms. This is often the case in Central Asian countries. Methods: The faucet technique involves carefully examining the graft by gently opening a valve, comparable to a faucet, to observe the blood flow through the bypassed vessel. Overall, 36 procedures underwent the faucet technique for assessing the superficial temporal artery–middle cerebral artery bypass patency. Results: The results indicate that the bypass remained patent in all cases, as confirmed through the intraoperative faucet technique, postoperative magnetic resonance angiography, or cerebral angiography. Conclusion: By visually inspecting the blood flow through the faucet technique, surgeons can confirm the effectiveness of the graft and ensure that the bypass remains unobstructed during the surgery. [ABSTRACT FROM AUTHOR]

Changes in local cerebral blood flow (CBF) are a major cause of transient neurological events (TNEs) after revascularization for moyamoya disease (MMD); however, the influence of preoperative collateral pathway development on TNEs has not yet been investigated. This study included 28 hemispheres from 28 consecutive patients with MMD who underwent surgical revascularization, including a superficial temporal artery (STA) to middle cerebral artery (MCA) bypass, between January 2014 and March 2022. The collateralization pathways included the anterior communicating artery (AcomA) collaterals, posterior communicating artery (PcomA) collaterals, transdural collaterals, posterior pericallosal anastomosis, lenticulostriate anastomosis, thalamic anastomosis, and choroidal anastomosis. These collateral pathways were analyzed to identify predictive factors significantly associated with TNEs. TNEs were observed in 11 (39.3%) hemispheres. The development of posterior pericallosal anastomosis and choroidal anastomosis was a significant independent predictor of the occurrence of TNEs after bypass surgery for MMD (P = 0.01, OR 26.9, 95% CI 1.50–480.0; P = 0.002, OR 47.6, 95% CI 2.65–856.6). The development of choroidal and posterior pericallosal anastomosis could be reliable preoperative predictors of TNEs after bypass surgery for MMD. Our results provide useful information for future studies aimed at clarifying the mechanisms underlying TNEs. [ABSTRACT FROM AUTHOR]