Thrombus migration in emergent M1 middle cerebral artery occlusion.

BACKGROUND AND PURPOSE: Thrombus migration (TM) is a well-established phenomenon in patients with intracranial vessel occlusion, particularly in those who receive alteplase. However, the relationship between TM, reperfusion success, and clinic-radiological outcomes is still being determined. This study aimed to describe the various outcomes in the event of TM in patients with M1 middle cerebral artery (M1 MCA) occlusion. MATERIALS AND METHODS: The study involved a retrospective analysis of patients undergoing endovascular thrombectomy (EVT) due to M1 MCA occlusion from two tertiary centers between January 2015 and December 2020. The proximal positions of thrombi were measured using a curve tool on CT or MR angiography before EVT. Subsequently, measurements were taken on angiographic imaging. Patients were grouped based on the amount of difference between the two measurements: growth (≤ - 10 mm), stability (> -10 mm and ≤ 10 mm), migration (> 10 mm), and resolution. RESULTS: A total of 463 patients (266 [57%] females, median 76 [interquartile range IQR: 65-83] years) were analyzed. Of them, 106 (22.8%) expressed any degree of TM. In multivariate ordinal regression analysis, the alteplase was significantly associated with TM (t = 2.192, p = 0.028), as was the greater interval from first imaging to angiography (t = 2.574, p = 0.010). In multivariate logistical regression analysis, the good clinical outcome measured by the modified Rankin scale (0-2) was not associated with TM status. CONCLUSIONS: Thrombus migration within the M1 MCA segment occurs in almost a quarter of patients, is associated with alteplase administration, and is mainly irrelevant to radiological and clinical outcome.

Effect of Cyclosporin H on ischemic injury and neutrophil infiltration in cerebral infarct model of rats via PET imaging.

BACKGROUND: Brain ischemia-reperfusion injury is a complex process, and neuroinflammation is an important secondary contributing pathological event. Neutrophils play major roles in ischemic neuroinflammation. Once activated, neutrophils express formyl peptide receptors (FPRs), which are special receptors of a class of chemoattractants and may be potential targets to regulate the activity of neutrophils and control cerebral ischemic injury. This study was aimed to explore the ameliorating effect of Cyclosporin H (CsH), a potent FPR antagonist, on brain ischemic injury by inhibiting the activation and migration of neutrophils, and improving cerebral blood flow. METHODS: We employed a middle cerebral artery occlusion (MCAO) Model on rats and performed behavioral, morphological, and microPET imaging assays to investigate the potential restoring efficacy of CsH on cerebral ischemic damages. Peptide N-cinnamoyl-F-(D)L-F-(D)L-F (cFLFLF), an antagonist to the neutrophil FPR with a high binding affinity, was used for imaging neutrophil distribution. RESULTS: We found that CsH had similar effect with edaravone on improving the neurobehavioral deficient symptoms after cerebral ischemia-reperfusion, and treatment with CsH also alleviated ischemic cerebral infarction. Compared with the MCAO Model group, [18F]FDG uptake ratios of the CsH and edaravone treatment groups were significantly higher. The CsH-treated groups also showed significant increases in [18F]FDG uptake at 144 h when compared with that of 24 h. This result indicates that like edaravone, treatment with both doses of CsH promoted the recovery of blood supply after cerebral ischemic event. Moreover, MCAO-induced cerebral ischemia significantly increased the radiouptake of [68Ga]Ga-cFLFLF at 72 h after ischemia-reperfusion operation. Compared with MCAO Model group, radiouptake values of [68Ga]-cFLFLF in both doses of CsH and edaravone groups were all decreased significantly. These results showed that both doses of CsH resulted in a similar therapeutic effect with edaravone on inhibiting neutrophil infiltration in cerebral infarction. CONCLUSION: Potent FPR antagonist CsH is promisingly beneficial in attenuating neuroinflammation and improving neurobehavioral function against cerebral infarction. Therefore, FPR may become a novel target for regulating neuroinflammation and improving prognosis for ischemic cerebrovascular disorders.

Tenecteplase for Stroke at 4.5 to 24 Hours with Perfusion-Imaging Selection.

BACKGROUND: Thrombolytic agents, including tenecteplase, are generally used within 4.5 hours after the onset of stroke symptoms. Information on whether tenecteplase confers benefit beyond 4.5 hours is limited. METHODS: We conducted a multicenter, double-blind, randomized, placebo-controlled trial involving patients with ischemic stroke to compare tenecteplase (0.25 mg per kilogram of body weight, up to 25 mg) with placebo administered 4.5 to 24 hours after the time that the patient was last known to be well. Patients had to have evidence of occlusion of the middle cerebral artery or internal carotid artery and salvageable tissue as determined on perfusion imaging. The primary outcome was the ordinal score on the modified Rankin scale (range, 0 to 6, with higher scores indicating greater disability and a score of 6 indicating death) at day 90. Safety outcomes included death and symptomatic intracranial hemorrhage. RESULTS: The trial enrolled 458 patients, 77.3% of whom subsequently underwent thrombectomy; 228 patients were assigned to receive tenecteplase, and 230 to receive placebo. The median time between the time the patient was last known to be well and randomization was approximately 12 hours in the tenecteplase group and approximately 13 hours in the placebo group. The median score on the modified Rankin scale at 90 days was 3 in each group. The adjusted common odds ratio for the distribution of scores on the modified Rankin scale at 90 days for tenecteplase as compared with placebo was 1.13 (95% confidence interval, 0.82 to 1.57; P = 0.45). In the safety population, mortality at 90 days was 19.7% in the tenecteplase group and 18.2% in the placebo group, and the incidence of symptomatic intracranial hemorrhage was 3.2% and 2.3%, respectively. CONCLUSIONS: Tenecteplase therapy that was initiated 4.5 to 24 hours after stroke onset in patients with occlusions of the middle cerebral artery or internal carotid artery, most of whom had undergone endovascular thrombectomy, did not result in better clinical outcomes than those with placebo. The incidence of symptomatic intracerebral hemorrhage was similar in the two groups. (Funded by Genentech; TIMELESS ClinicalTrials.gov number, NCT03785678.).

Mechanical Thrombectomy for Acute Cardiogenic Internal Carotid Artery Occlusion with Cross-Flow through the Communicating Artery.

AIM: To report mechanical thrombectomy (MT) for internal carotid artery (ICA) occlusion with cross-flow through the communicating artery ("with" group), and to compare it with ICA or middle cerebral artery occlusion without cross-flow ("without" group). MATERIAL AND METHODS: This study included 10 and 57 cases of the "with" and "without" groups, respectively. Cases analyzed by rapid processing of perfusion and diffusion (RAPID) since October 2020 were included. RESULTS: Puncture-to-reperfusion time was 78.5 and 39 min (p=0.0155), the National Institutes of Health Stroke Scale score at discharge was 10.5 and 4 (p=0.0166), decline from pre to post Diffusion-Weighted Image-Alberta Stroke Program Early computed tomography (CT) Score was 0.5 and 0 (p=0.0495), and the modified Rankin Scale score at 90 days was 4 and 2 (p=0.0195) in the "with" and "without" groups, respectively. Furthermore, Tmax values of > 6 s (50 cc vs. 164 cc; p=0.0277) and Tmax > 4 s/Tmax > 6 s ratio (3.23 vs. 1.55) (p=0.0074) were significantly different between the "with" and "without" groups. CONCLUSION: The "with" group may have been affected by the longer treatment time and being at high risk of distal migration of thrombus due to poor prognosis. Although the region with a Tmax of > 6 s tends to be small in patients of the "with" group, it indicates a low-perfusion state that can lead to cerebral infarction, and MT should be performed.

A novel fully automated method for measuring ASPECTS to improve stroke diagnosis: Comparison to traditional ASPECTS.

BACKGROUND AND PURPOSE: To compare the accuracy of subjective Alberta Stroke Program Early CT Score (sASPECTS) evaluation and that of an automated prototype software (aASPECTS) on nonenhanced CT (NECT) in patients with early anterior territory stroke and controls using side-to-side quantification of hypoattenuated brain areas. METHODS: We retrospectively analyzed the NECT scans of 42 consecutive patients with ischemic stroke before reperfusion and 42 controls using first sASPECTS and subsequently aASPECTS. We assessed the differences in Alberta Stroke Program Early CT Score (ASPECTS) and calculated the sensitivity and specificity of NECT with CT perfusion, whereas cerebral blood volume (CBV) served as the reference standard for brain infarction. RESULTS: The clot was located in the middle cerebral artery (MCA) in 47.6% of cases and the internal carotid artery (ICA) in 28.6% of cases. Ten cases presented combined ICA and MCA occlusions. The stroke was right sided in 52.4% of cases and left sided in 47.6%. Reader-based NECT analysis yielded a median sASPECTS of 10. The median CBV-based ASPECTS was 7. Compared to the area of decreased CBV, sASPECTS yielded a sensitivity of 12.5% and specificity of 86.8%. The software prototype (aASPECTS) yielded an overall sensitivity of 65.5% and a specificity of 92.2%. The interreader agreement for ASPECTS evaluation of admission NECT and follow-up CT was almost perfect (κ = .93). The interreader agreement of the CBV color map evaluation was substantial (κ = .77). CONCLUSIONS: aASPECTS of NECT can outperform sASPECTS for stroke detection.

Neglect scoring modifications in the National Institutes of Health Stroke Scale improve right hemisphere stroke lesion volume prediction.

BACKGROUND: The National Institutes of Health Stroke Scale (NIHSS) does not equitably assess stroke severity in the two cerebral hemispheres. By attributing a maximum of two points for neglect and seven for language, it undervalues right hemisphere deficits. We aimed to investigate if NIHSS equally predicts right hemisphere lesion volumes in patients with and without neglect, and if a modification of the neglect scoring rules could increase its predictive capacity. METHODS: We analyzed a prospective cohort of acute right middle cerebral artery ischemic stroke patients. First, we calculated the correlation between NIHSS scores and lesion volume and analyzed the partial correlation of neglect. Then, we applied different modifications in the neglect scoring rules and investigated how they interfered with lesion volume predictive capacity. RESULTS: A total of 162 ischemic stroke patients were included, 108 with neglect and 54 without. The correlation between lesion volume and NIHSS was lower in patients with neglect (r = 0.540 vs. r = 0.219, p = 0.004) and neglect was a statistically significant covariate in the partial correlation analysis between NIHSS and lesion volume (p = 0.017). With the neglect score tripled and with the duplication or triplication of all neglect modalities, the correlation was significantly higher than with the standard NIHSS (p = 0.043, p = 0.005, p = 0.001, respectively). With these modifications, neglect was no longer a significant covariable in the partial correlation between lesion volume and NIHSS. CONCLUSION: A modification of NIHSS neglect scoring might improve the scale's capacity to predict lesion volume.

Hyperperfusion profiles after recanalization differentially associate with outcomes in a rat ischemic stroke model.

Futile recanalization hampers prognoses of ischemic stroke after successful mechanical thrombectomy, hypothetically through post-recanalization perfusion deficits, onset-to-groin delays and sex effects. Clinically, acute multiparametric imaging studies remain challenging. We assessed possible relationships between these factors and disease outcome after experimental cerebral ischemia-reperfusion, using translational MRI, behavioral testing and multi-model inference analyses. Male and female rats (N = 60) were subjected to 45-/90-min filament-induced transient middle cerebral artery occlusion. Diffusion, T2- and perfusion-weighted MRI at occlusion, 0.5 h and four days after recanalization, enabled tracking of tissue fate, and relative regional cerebral blood flow (rrCBF) and -volume (rrCBV). Lesion areas were parcellated into core, salvageable tissue and delayed injury, verified by histology. Recanalization resulted in acute-to-subacute lesion volume reductions, most apparently in females (n = 19). Hyperacute normo-to-hyperperfusion in the post-ischemic lesion augmented towards day four, particularly in males (n = 23). Tissue suffering delayed injury contained higher ratios of hypoperfused voxels early after recanalization. Regressed against acute-to-subacute lesion volume change, increased rrCBF associated with lesion growth, but increased rrCBV with lesion reduction. Similar relationships were detected for behavioral outcome. Post-ischemic hyperperfusion may develop differentially in males and females, and can be beneficial or detrimental to disease outcome, depending on which perfusion parameter is used as explanatory variable.

Pretreatment CT perfusion collateral parameters correlate with penumbra salvage in middle cerebral artery occlusion.

BACKGROUND AND PURPOSE: Acute ischemic stroke due to large vessel occlusion (AIS-LVO) is a major cause of functional dependence. Collateral status (CS) is an important determinant of functional outcomes. Pretreatment CT perfusion (CTP) parameters serve as reliable surrogates of CS. Penumbra Salvage Index (PSI) is another parameter predictive of functional outcomes in AIS-LVO. The aim of this study is to assess the relationship of pretreatment CTP parameters with PSI. METHODS: In this prospectively collected, retrospectively reviewed multicenter analysis, inclusion criteria were as follows: (1) CT angiography confirmed middle cerebral artery (MCA) M1-segment and proximal M2-segment occlusion from 9/1/2017 to 9/22/2022; (2) diagnostic CTP; and (3) available diagnostic Magnetic resonance Imaging (MRI) diffusion-weighted images. Pearson correlation analysis was performed to assess the association between cerebral blood volume (CBV) index and hypoperfusion intensity ratio (HIR) with PSI. p value ≤.05 was considered statistically significant. RESULTS: In total, 131 patients (n = 86, M1 and n = 45, proximal M2 occlusion) met our inclusion criteria. CBV index showed a modest positive correlation with PSI (r = 0.34, p<.001) in patients with proximal MCA occlusion. Similar trends were noted in subgroup analysis of patients with M1 occlusion, and proximal M2 occlusion. Whereas, HIR did not have a strong trend or correlation with PSI. CONCLUSION: CBV index correlates with PSI, whereas HIR does not. Future studies are needed to expand our understanding of the adjunct role of CBV index with other similar pretreatment CTP-based markers in clinical evaluation and decision-making in patients with MCA occlusion.

Effects of repetitive transcranial magnetic stimulation on improving cerebral blood flow in patients with middle cerebral artery steno-occlusion.

BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS) has been reported to induce neurogenesis and angiogenesis. As increased neural activity can induce a hemodynamic response, we investigated the effect of rTMS on perfusion in patients with middle cerebral artery steno-occlusion. METHODS: This was a prospective, randomized, open-label, blinded end-point, pilot study. Patients were divided into two groups (rTMS intervention and non-intervention) which were both administered antiplatelet drugs to treat vascular steno-occlusion. In the intervention group, additional rTMS was performed on the area with stenosis and obstruction. Perfusion rates were compared using single-photon emission computed tomography / computed tomography (SPECT/CT). RESULTS: From June 2020 to May 2022, 16 patients were subjected to 1:1 randomization. Using the standardized uptake value ratio (SUVr) to quantify perfusion in the affected brain region, the corresponding SPECT/CT values before and after rTMS were obtained. Imaging analysis was compared between eight and seven patients in the rTMS and control groups, respectively. Based on the comparison between the target and ipsilateral cerebellum SUVmeans, four patients had a ≥ 20% increase in SUVr in the rTMS group and none in the control group. Changes in SUVr were significantly different between the initial and follow-up SPECT/CT in the rTMS group (p = 0.033); no significant difference was observed in the control group (p = 0.481). CONCLUSION: We observed a significant improvement in perfusion in the stimulation group in a perfusion test performed between 6 and 12 months after rTMS stimulation in stroke patients with steno-occlusion of the middle cerebral artery.

Dynamics of cerebral blood volume during and after middle cerebral artery occlusion in rats - Comparison between ultrafast ultrasound and dynamic susceptibility contrast-enhanced MRI measurements.

Tomographic perfusion imaging techniques are integral to translational stroke research paradigms that advance our understanding of the disease. Functional ultrasound (fUS) is an emerging technique that informs on cerebral blood volume (CBV) through ultrasensitive Doppler and flow velocity (CBFv) through ultrafast localization microscopy. It is not known how experimental results compare with a classical CBV-probing technique such as dynamic susceptibility contrast-enhanced perfusion MRI (DSC-MRI). To that end, we assessed hemodynamics based on uUS (n = 6) or DSC-MRI (n = 7) before, during and up to three hours after 90-minute filament-induced middle cerebral artery occlusion (MCAO) in rats. Recanalization was followed by a brief hyperperfusion response, after which CBV and CBFv temporarily normalized but progressively declined after one hour in the lesion territory. DSC-MRI data corroborated the incomplete restoration of CBV after recanalization, which may have been caused by the free-breathing anesthetic regimen. During occlusion, MCAO-induced hypoperfusion was more discrepant between either technique, likely attributable to artefactual signal mechanisms related to slow flow, and processing algorithms employed for either technique. In vivo uUS- and DSC-MRI-derived measures of CBV enable serial whole-brain assessment of post-stroke hemodynamics, but readouts from both techniques need to be interpreted cautiously in situations of very low blood flow.

Combined Technique for Internal Carotid Artery Terminus or Middle Cerebral Artery Occlusions in the ASTER2 Trial.

BACKGROUND: The aim of this study was to report the results of a subgroup analysis of the ASTER2 trial (Effect of Thrombectomy With Combined Contact Aspiration and Stent Retriever vs Stent Retriever Alone on Revascularization in Patients With Acute Ischemic Stroke and Large Vessel Occlusion) comparing the safety and efficacy of the combined technique (CoT) and stent retriever as a first-line approach in internal carotid artery (ICA) terminus±M1-middle cerebral artery (M1-MCA) and isolated M1-MCA occlusions. METHODS: Patients enrolled in the ASTER2 trial with ICA terminus±M1-MCA and isolated M1-MCA occlusions were included in this subgroup analysis. The effect of first-line CoT versus stent retriever according to the occlusion site was assessed on angiographic (first-pass effect, expanded Treatment in Cerebral Infarction score ≥2b50, and expanded Treatment in Cerebral Infarction score ≥2c grades at the end of the first-line strategy and at the end of the procedure) and clinicoradiological outcomes (24-hour National Institutes of Health Stroke Scale, ECASS-III [European Cooperative Acute Stroke Study] grades, and 3-month modified Rankin Scale). RESULTS: Three hundred sixty-two patients were included in the postsubgroup analysis according to the occlusion site: 299 were treated for isolated M1-MCA occlusion (150 with first-line CoT) and 63 were treated for ICA terminus±M1-MCA occlusion (30 with first-line CoT). Expanded Treatment in Cerebral Infarction score ≥2b50 (odds ratio, 11.83 [95% CI, 2.32-60.12]) and expanded Treatment in Cerebral Infarction score ≥2c (odds ratio, 4.09 [95% CI, 1.39-11.94]) were significantly higher in first-line CoT compared with first-line stent retriever in patients with ICA terminus±M1-MCA occlusion but not in patients with isolated M1-MCA. CONCLUSIONS: First-line CoT was associated with higher reperfusion grades in patients with ICA terminus±M1-MCA at the end of the procedure. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03290885.

Effects of electroacupuncture on imaging and behavior in rats with ischemic stroke through miR-212-5p.

BACKGROUND: Ischemic stroke is a serious disease leading to significant disability in humans worldwide. Increasing evidence suggests that some microRNAs (miRNAs) participate in the pathophysiology of ischemic stroke. A key role for MiR-212 has been found in neuronal function and synaptic plasticity. Ischemic stroke can be effectively treated with electroacupuncture (EA); however, there is a lack of understanding of the relevant mechanisms. In this study, we employed behavioral test and resting-state functional magnetic resonance imaging (rs-fMRI) to detect behavioral and brain function alterations in rats suffering from ischemic stroke. The efficacy of EA therapy and miR-212-5p's role in this process were also evaluated. METHODS AND RESULTS: Forty rats were randomly divided into the following groups: Sham, middle cerebral artery occlusion/reperfusion (MCAO/R), MCAO/R + EA, MCAO/R + EA + antagomir-negative control and MCAO/R + EA + antagomir-212-5p groups. Behavioral changes were assessed by Catwalk gait analysis prior to and after modeling. Rs-fMRI was performed at one week after EA treatment, amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (ReHo) were calculated to reveal neural activity. Furthermore, neuronal apoptosis in the ischemic penumbra was analyzed using a TUNEL assay. Treatment with EA significantly improved the performance of rats in the behavioral test. The motor and cognition-related brain regions showed decreased ALFF and ReHo following focal cerebral ischemia-reperfusion, and EA treatment could reactivate these brain regions. Moreover, EA treatment significantly decreased MCAO/R-induced cell death. However, the transfection of antagomir-212-5p attenuated the therapeutic effect of EA. CONCLUSIONS: In conclusion, the results suggested that EA improved the behavioral and imaging outcomes of ischemic stroke through miR-212-5p.

Rare case of duplicated middle cerebral artery and acute ischaemic stroke managed successfully with mechanical thrombectomy.

A man in his early 80s presented with acute onset aphasia and right-sided weakness with an NIH Stroke Scale (NIHSS) of 17. He was last seen normal 9 hours before the presentation. MRI of the brain showed acute infarcts in the left caudate, lentiform nucleus and corona radiata. MRI angiogram (MRA) revealed an occluded left main middle cerebral artery (MCA) and an associated ipsilateral patent duplicated middle cerebral artery (DMCA). Mechanical thrombectomy (MT) was performed, and he was discharged with an NIHSS of 8. In this report, we review and discuss the challenges during the intervention of MCA occlusion in the presence of duplicated MCA, a rare anomaly.

Analysis of the posterior cerebral perfusion status and clinical prognostic value in chronic unilateral middle cerebral artery occlusion using SWAN combined with 3D-ASL.

To investigate the predictive value of T2 star-weighted angiography (SWAN) combined with 3-dimensional (3D) arterial spin labeling (3D-ASL) to assess cerebral perfusion status and clinical prognosis in chronic unilateral middle cerebral artery (MCA) M1 occlusion. This study included 55 patients diagnosed with chronic unilateral MCA M1 occlusion using 3D time-of-flight magnetic resonance angiography between January 2018 and July 2022. Based on the prominent vessel sign (PVS) shown in the SWAN sequence, the patients were divided into PVS-positive (n = 26) and PVS-negative (n = 29) groups. Cerebral blood flow (CBF) was selected in the affected regions of the frontal, parietal, and temporal lobes (regions of interest = 200 ± 20 mm2) using pseudo-color maps in the 3D-ASL sequence. Each patient was followed up for ischemic cerebrovascular disease within 12 months of diagnosis. The collected data were statistically analyzed to evaluate the predictive value of SWAN and 3D-ASL for the clinical prognosis of patients with chronic unilateral MCA M1 occlusion. Patients were divided into 2 groups based on the occurrence of an ischemic cerebrovascular event within 12 months (ischemic cerebrovascular event [acute ischemic stroke + transient ischemic attack] and non-ischemic cerebrovascular event groups, including 30 and 25 cases, respectively). The incidence of ischemic cerebrovascular events within 12 months was significantly higher in the PVS-positive group than in the PVS-negative group (92.31% vs 20.69%). Furthermore, the CBF values of the affected frontal, parietal, and temporal lobes were significantly lower in the ischemic cerebrovascular event group than in the non-ischemic cerebrovascular event group (P < .05). According to the receiver operating characteristic curve, the CBF values of the affected frontal, parietal, and temporal lobes in patients with chronic unilateral MCA M1 occlusion strongly correlated with ischemic cerebrovascular disease within 12 months. PVS-negative display and good collateral circulation were closely related to clinical prognosis in patients with chronic unilateral MCA M1 occlusion.

Dynamic assessment of brain perfusion in a middle cerebral artery occlusion rat model by contrast-enhanced ultrasound imaging: a pilot study.

BACKGROUND: The middle cerebral artery occlusion model (MCAo) is a commonly used animal model for cerebral ischemia studies but lacks accessible imaging techniques for the assessment of hemodynamic changes of the model. PURPOSE: The study aims to explore the value of contrast-enhanced ultrasound (CEUS) in evaluating brain perfusion in the early stages after MCAo surgery. MATERIAL AND METHODS: In total, 18 adult male Sprague-Dawley rats were subjected to right MCAo using an intraluminal filament model, and CEUS was performed at the three following timepoints: before (T0), immediately after (T1), and 6 h after permanent MCAo (T2). Twelve rats successfully completed the study, and their brains were removed and stained using 2, 3, 5-triphenyltetrazolium chloride (TTC). CEUS video images were visualized offline, and the time-intensity curves (TICs) were analyzed. Different cerebrovascular patterns and manifestations of the contrast enhancement in rat ischemic hemispheres were observed. Semi-quantitative parameters of TICs in ischemic areas (ROIi) and the surrounding normal- or hypo-perfused areas (ROIn) were calculated and compared between T0, T1, and T2, and also between ROIi and ROIn. RESULTS: A significant correlation was found between the lesion volume (%) determined by TTC and CEUS parameters (r = -0.691, P = 0.013 for peak intensity; r = -0.742, P = 0.006 for area under the curve) at T2. After the same occlusion, there were differences in contrast perfusion in each group. CONCLUSION: This study suggests that CEUS could be an effective imaging tool for studying cerebral ischemia and perfusion in small animals as long as the transcranial acoustic window allows it.

[Staged treatment of a patient with malignant ischemic cerebral infarction]. / Sluchai etapnogo lecheniya patsienta so zlokachestvennym ishemicheskim infarktom mozga.

The authors discuss surgical decompression of the brain in patients with malignant ischemic cerebral infarcts. Successful staged treatment of a middle-aged patient with malignant ischemic stroke in the middle cerebral artery basin is presented.

Transient Middle Cerebral Artery Occlusion Model of Stroke.

Stroke stands as a major cause of death or chronic disability globally. Nevertheless, existing optimal treatments are limited to reperfusion therapies during the acute phase of ischemic stroke. To gain insights into stroke physiopathology and develop innovative therapeutic approaches, in vivo rodent models of stroke play a fundamental role. The availability of genetically modified animals has particularly propelled the use of mice as experimental stroke models. In stroke patients, occlusion of the middle cerebral artery (MCA) is a common occurrence. Consequently, the most prevalent experimental model involves intraluminal occlusion of the MCA, a minimally invasive technique that doesn't require craniectomy. This procedure involves inserting a monofilament through the external carotid artery (ECA) and advancing it through the internal carotid artery (ICA) until it reaches the branching point of the MCA. After a 45 min arterial occlusion, the monofilament is removed to allow reperfusion. Throughout the process, cerebral blood flow is monitored to confirm the reduction during occlusion and subsequent recovery upon reperfusion. Neurological and tissue outcomes are evaluated using behavioral tests and magnetic resonance imaging (MRI) studies.

Extracranial-Intracranial Bypass and Risk of Stroke and Death in Patients With Symptomatic Artery Occlusion: The CMOSS Randomized Clinical Trial.

Importance: Prior trials of extracranial-intracranial (EC-IC) bypass surgery showed no benefit for stroke prevention in patients with atherosclerotic occlusion of the internal carotid artery (ICA) or middle cerebral artery (MCA), but there have been subsequent improvements in surgical techniques and patient selection. Objective: To evaluate EC-IC bypass surgery in symptomatic patients with atherosclerotic occlusion of the ICA or MCA, using refined patient and operator selection. Design, Setting, and Participants: This was a randomized, open-label, outcome assessor-blinded trial conducted at 13 centers in China. A total of 324 patients with ICA or MCA occlusion with transient ischemic attack or nondisabling ischemic stroke attributed to hemodynamic insufficiency based on computed tomography perfusion imaging were recruited between June 2013 and March 2018 (final follow-up: March 18, 2020). Interventions: EC-IC bypass surgery plus medical therapy (surgical group; n = 161) or medical therapy alone (medical group; n = 163). Medical therapy included antiplatelet therapy and stroke risk factor control. Main Outcomes and Measures: The primary outcome was a composite of stroke or death within 30 days or ipsilateral ischemic stroke beyond 30 days through 2 years after randomization. There were 9 secondary outcomes, including any stroke or death within 2 years and fatal stroke within 2 years. Results: Among 330 patients who were enrolled, 324 patients were confirmed eligible (median age, 52.7 years; 257 men [79.3%]) and 309 (95.4%) completed the trial. For the surgical group vs medical group, no significant difference was found for the composite primary outcome (8.6% [13/151] vs 12.3% [19/155]; incidence difference, -3.6% [95% CI, -10.1% to 2.9%]; hazard ratio [HR], 0.71 [95% CI, 0.33-1.54]; P = .39). The 30-day risk of stroke or death was 6.2% (10/161) in the surgical group and 1.8% (3/163) in the medical group, and the risk of ipsilateral ischemic stroke beyond 30 days through 2 years was 2.0% (3/151) and 10.3% (16/155), respectively. Of the 9 prespecified secondary end points, none showed a significant difference including any stroke or death within 2 years (9.9% [15/152] vs 15.3% [24/157]; incidence difference, -5.4% [95% CI, -12.5% to 1.7%]; HR, 0.69 [95% CI, 0.34-1.39]; P = .30) and fatal stroke within 2 years (2.0% [3/150] vs 0% [0/153]; incidence difference, 1.9% [95% CI, -0.2% to 4.0%]; P = .08). Conclusions and Relevance: Among patients with symptomatic ICA or MCA occlusion and hemodynamic insufficiency, the addition of bypass surgery to medical therapy did not significantly change the risk of the composite outcome of stroke or death within 30 days or ipsilateral ischemic stroke beyond 30 days through 2 years. Trial Registration: ClinicalTrials.gov Identifier: NCT01758614.

In vivo monitoring of hemodynamic changes in ischemic stroke using photoacoustic tomography.

Ischemic stroke occurs when a blood vessel supplying the brain is blocked, leading to decreased blood flow. Early diagnosis and treatment are crucial. However, existing clinical imaging methods have limitations, such as safety issues and low time resolution. To address these challenges, we propose using photoacoustic tomography (PAT) with a contrast agent, known for its high resolution and contrast capabilities. Our study involved imaging brain vasculature in three groups: normal, unilateral common carotid artery ligation (UCAL), and middle cerebral artery occlusion (MCAO). On the ischemic stroke side, we observed reduced blood vessel density and hemodynamic changes were evident after injecting indocyanine green for PAT. The photoacoustic intensity was notably lower in the ligated sides of the UCAL and MCAO groups, with statistically significant differences between the three groups. This work highlights PAT's potential as a powerful tool for early diagnosis and guidance in ischemic stroke cases.

Association of intravascular enhancement sign on 3D-T1W TSE with collateral status in middle cerebral artery occlusion stroke.

OBJECTIVE: The significance of the intravascular enhancement sign (IVES) on high-resolution magnetic resonance vascular wall imaging (HR-VWI) remains unclear. This study aimed to investigate the correlation between the IVES and collateral assessment derived from digital subtraction angiography (DSA). METHOD: A total of 75 patients with occlusion of the first segment of the middle cerebral artery (MCA) who underwent HR-VWI and DSA examinations at our research institution between November 2016 and February 2023 were included. The number of vessels with IVES, IVES-Alberta Stroke Program Early Computed Tomography Score (ASPECTS), American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) collateral grade, and DSA collateral blood flow grade were retrospectively evaluated. Correlations between these indicators were assessed using Spearman's correlation. RESULTS: Interrater agreement was good for the assessment of HR-VWI and DSA indicators. After adjustments for age, degree of wall enhancement, and hypertension, a multivariable ordinal logistic regression model identified both the number of IVES vessels (OR = 1.37; 95%CI [1.06-1.78]; P = 0.017) and IVES-ASPECTS (OR = 2.00; 95%CI [1.03-3.87]; P = 0.041) as independent predictors of ischemic stroke. In the patient group with acute ischemic stroke, we found weak correlations between the number of IVES vessels and the ASITN/SIR collateral grade (rho = -0.35; P = 0.002) and between the IVES-ASPECTS and ASITN/SIR collateral grade (rho = -0.27; P = 0.02). Moreover, there were strong correlations between the number of IVES vessels and the DSA collateral blood flow grade (rho = -0.74; P < 0.001) and between the IVES-ASPECTS and the DSA collateral blood flow grade (rho = -0.65; P < 0.001). The number of IVES vessels correlated strongly with the IVES-ASPECTS (rho = 0.92, P < 0.001). CONCLUSION: We find that the IVES is closely associated with sluggish collateral blood flow, which further confirms the hemodynamic mechanism underlying the IVES in MCA occlusion.