MCA Territory Research Articles

Reliable infarction of the middle cerebral artery territory in C57BL/6 mice using pterygopalatine artery ligation and filament optimization - The PURE-MCAo model.

Current techniques for inducing intraluminal filamentous middle cerebral artery occlusion (fMCAo) in mice produce highly variable results and often cause additional infarcts in the posterior cerebral artery (PCA) territory. The aim of the current study was to develop a novel procedure to overcome these shortcomings. Male C57BL/6 mice were subjected to 60 min of fMCAo with cerebral blood flow monitored by laser Doppler flowmetry. The influence of the length of the occlusion filament coating and the combination of common carotid artery (CCA) or pterygopalatine artery (PPA) ligation on lesion volume and functional outcome 24 h after reperfusion was evaluated. The use of appropriate filament and PPA ligation while maintaining CCA perfusion prevented the development of infarcts in the PCA area, resulted in pure MCA infarcts (68.3 ± 14.5 mm3) and reduced the variability of infarct volumes by more than half (from 26-38% to 14% standard deviation/mean). Using an improved fMCAo procedure, we were able to produce PCA area-unaffected reproducible (PURE) infarcts exclusively in the MCA territory. Thus PURE-MCAo reduced outcome variability by more than 50%. Our results may thus help to reduce the number of animals in preclinical stroke research and to increase the reproducibility of the fMCAo model.

Fetal MRI findings, etiology, and outcome in prenatally diagnosed schizencephaly.

Schizencephaly is a rare brain anomaly which is increasingly detected in utero. There are limited data on the etiology and outcomes in fetal schizencephaly to guide workup and counselling. We aim to determine the associated imaging findings, etiology, and outcomes in schizencephaly detected in utero. This retrospective cohort study included 22 fetuses with a total of 34 schizencephaly defects identified by keyword search of fetal MRI reports from 1996-2022 followed by image review. Follow-up fetal and postnatal imaging, when available, were reviewed. Data on demographics, etiology, and outcomes were extracted from the electronic medical record. The schizencephaly defect was open in 28/34, most common in the MCA territory (23/34), and commonly involved the frontal (16/34) lobe. Additional intracranial abnormalities were seen in all fetuses including other cortical malformations (CM, 13/22), abnormal posterior fossa (12/22), abnormal corpus callosum (10/20), and intraparenchymal hemorrhage (9/22).The cause of schizencephaly was classified as secondary (as evidenced by intraparenchymal hemorrhage at schizencephaly, monochorionic twin gestation, infection, or maternal/placental risk factor) in 64% (14/22), potentially genetic in 9% (2/22), and unknown in 27% (6/22). Among those liveborn (n=8), the following outcomes were observed: postnatal death (1/8), tube feeding (1/7), shunted hydrocephalus (1/7), epilepsy (4/7). Among those >1 year of age, cerebral palsy (4/5) and speech delay or intellectual disability (3/5) were common. CM remote from schizencephaly was associated with epilepsy (p=0.03). On postnatal imaging, open defects often involuted (8/11) and there were high rates of new/additional findings (4/6). In this cohort, fetal schizencephaly was always associated with additional intracranial abnormalities. In most cases, there was evidence that schizencephaly was likely secondary to prior injury. Imaging characteristics may provide clues regarding neurodevelopmental outcome. Postnatal imaging is crucial in assessing evolution as well as for detection of additional abnormalities. ICH = intracranial hemorrhage; CM = cortical malformation; VM = ventriculomegaly; DGN = deep grey nuclei; SP = septum pellucidum; IPH = intraparenchymal hemorrhage; CC = corpus callosum; PMG = polymicrogyria; PVNH = periventricular nodular heterotopia; TTTS = twin-twin transfusion syndrome; GA = gestational age; CP = cerebral palsy.

Establishing the distribution of cerebrovascular resistance using computational fluid dynamics and 4D flow MRI

Cerebrovascular resistance (CVR) regulates blood flow in the brain, but little is known about the vascular resistances of the individual cerebral territories. We present a method to calculate these resistances and investigate how CVR varies in the hemodynamically disturbed brain. We included 48 patients with stroke/TIA (29 with symptomatic carotid stenosis). By combining flow rate (4D flow MRI) and structural computed tomography angiography (CTA) data with computational fluid dynamics (CFD) we computed the perfusion pressures out from the circle of Willis, with which CVR of the MCA, ACA, and PCA territories was estimated. 56 controls were included for comparison of total CVR (tCVR). CVR were 33.8 ± 10.5, 59.0 ± 30.6, and 77.8 ± 21.3 mmHg s/ml for the MCA, ACA, and PCA territories. We found no differences in tCVR between patients, 9.3 ± 1.9 mmHg s/ml, and controls, 9.3 ± 2.0 mmHg s/ml (p = 0.88), nor in territorial CVR in the carotid stenosis patients between ipsilateral and contralateral hemispheres. Territorial resistance associated inversely to territorial brain volume (p < 0.001). These resistances may work as reference values when modelling blood flow in the circle of Willis, and the method can be used when there is need for subject-specific analysis.

Computed tomography perfusion as an early predictor of malignant cerebral infarction.

Malignant middle cerebral artery infarction (MCI) needs rapid intervention. This study aimed to enhance the prediction of MCI using computed tomography perfusion (CTP) with varied quantitative benchmarks. We retrospectively analyzed 253 patients from a single-center registry presenting with acute, severe, proximal large vessel occlusion studied with whole-brain CTP imaging at hospital arrival within the first 24 h of symptoms-onset. MCI was defined by clinical and imaging criteria, including decreased level of consciousness, anisocoria, death due to cerebral edema, or need for decompressive craniectomy, together with midline shift ⩾6 mm, or infarction of more than 50% of the MCA territory. The predictive accuracy of baseline ASPECTS and CTP quantifications for MCI was assessed by receiver operating characteristic (ROC) area under the curve (AUC) while F-score was calculated as an indicator of precision and sensitivity. Sixty-three out of 253 patients (25%) fulfilled MCI criteria and had worse clinical and imaging results than the non-MCI group. The capacity to predict MCI was lower for baseline ASPECTS (AUC 0.83, F-score 0.52, Youden's index 6), than with perfusion-based measures: relative cerebral blood volume threshold <40% (AUC 0.87, F-score 0.71, Youden's index 34 mL) or relative cerebral blood flow threshold <35% (AUC 0.87, F-score 0.62, Youden's index 67 mL). CTP based on rCBV measurements identified twice as many MCI as baseline CT ASPECTS. CTP-based quantifications may offer enhanced predictive capabilities for MCI compared to non-contrast baseline CT ASPECTS, potentially improving the monitoring of severe ischemic stroke patients at risk of life-threatening edema and its treatment.

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

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

Distribution of Silent Cerebral Infarcts in Adults With Sickle Cell Disease.

Previously we demonstrated that 90% of infarcts in children with sickle cell anemia occur in the border zone regions of cerebral blood flow (CBF). We tested the hypothesis that adults with sickle cell disease (SCD) have silent cerebral infarcts (SCIs) in the border zone regions, with a secondary hypothesis that older age and traditional stroke risk factors would be associated with infarct occurrence in regions outside the border zones. Adults with SCD 18-50 years of age were enrolled in a cross-sectional study at 2 centers and completed a 3T brain MRI. Participants with a history of overt stroke were excluded. Infarct masks were manually delineated on T2-fluid-attenuated inversion-recovery MRI and registered to the Montreal Neurological Institute 152 brain atlas to generate an infarct heatmap. Border zone regions between anterior, middle, and posterior cerebral arteries (ACA, MCA, and PCA) were quantified using the Digital 3D Brain MRI Arterial Territories Atlas, and logistic regression was applied to identify relationships between infarct distribution, demographics, and stroke risk factors. Of 113 participants with SCD (median age 26.1 years, interquartile range [IQR] 21.6-31.4 years, 51% male), 56 (49.6%) had SCIs. Participants had a median of 5.5 infarcts (IQR 3.2-13.8). Analysis of infarct distribution showed that 350 of 644 infarcts (54.3%) were in 4 border zones of CBF and 294 (45.6%) were in non-border zone territories. More than 90% of infarcts were in 3 regions: the non-border zone ACA and MCA territories and the ACA-MCA border zone. Logistic regression showed that older participants have an increased chance of infarcts in the MCA territory (odds ratio [OR] 1.08; 95% CI 1.03-1.13; p = 0.001) and a decreased chance of infarcts in the ACA-MCA border zone (OR 0.94; 95% CI 0.90-0.97; p < 0.001). The presence of at least 1 stroke risk factor did not predict SCI location in any model. When compared with children with SCD, in adults with SCD, older age is associated with expanded zones of tissue infarction that stretch beyond the traditional border zones of CBF, with more than 45% of infarcts in non-border zone regions.

Association of large core middle cerebral artery stroke and hemorrhagic transformation with hospitalization outcomes.

Historically, investigators have not differentiated between patients with and without hemorrhagic transformation (HT) in large core ischemic stroke at risk for life-threatening mass effect (LTME) from cerebral edema. Our objective was to determine whether LTME occurs faster in those with HT compared to those without. We conducted a two-center retrospective study of patients with ≥ 1/2 MCA territory infarct between 2006 and 2021. We tested the association of time-to-LTME and HT subtype (parenchymal, petechial) using Cox regression, controlling for age, mean arterial pressure, glucose, tissue plasminogen activator, mechanical thrombectomy, National Institute of Health Stroke Scale, antiplatelets, anticoagulation, temperature, and stroke side. Secondary and exploratory outcomes included mass effect-related death, all-cause death, disposition, and decompressive hemicraniectomy. Of 840 patients, 358 (42.6%) had no HT, 403 (48.0%) patients had petechial HT, and 79 (9.4%) patients had parenchymal HT. LTME occurred in 317 (37.7%) and 100 (11.9%) had mass effect-related deaths. Parenchymal (HR 8.24, 95% CI 5.46-12.42, p < 0.01) and petechial HT (HR 2.47, 95% CI 1.92-3.17, p < 0.01) were significantly associated with time-to-LTME and mass effect-related death. Understanding different risk factors and sequelae of mass effect with and without HT is critical for informed clinical decisions.

Functional and Neuropsychological Outcome After Surgical Treatment of Moyamoya Disease

IntroductionMoya Moya disease(MMD) is a rare cerebrovascular disease characterized by progressive stenosis of the supraclinoid ICA. Due to chronically decreased brain perfusion, eloquent areas of the brain become hypo-perfused leading to cognitive changes in patients. Repeated infarcts and bleeds produce clinically apparent neurological deficits. Aim and Objective1) To study the functional and neuropsychological outcome in Moya Moya Disease following revascularization surgery.2) To find post revascularisation correlation between functional and neuropsychological improvement and radiological improvement. Material and methodA single-center prospective and analytical study including 21 patients of MMD during the study period from March 2021 to December 2022. Patients were evaluated and compared in the pre-and post-revascularization for functional, neuropsychological, and radiological status. ResultPost-operative functional outcome in terms of modified Rankin Score showed improvement in 33.33% of cases (p-value = 0.0769). An overall improving trend was observed in different neuropsychological domains in both adult and pediatric age groups. But, the trend of neuropsychological improvement was better in adults as compared to the pediatric patients. Radiological outcome in the forms of the Angiographic Outcome Score (AOS) significantly improved after post-revascularization (p-value = 0.0001). There was a trend towards improvement in MRI perfusion in the MCA and ACA territories, 4.7% (p-value=0.075) and 9.33% (p-value-0.058) respectively, as compared to preoperative MRI perfusion. ConclusionsPost revascularisation, significant improvement occurred in functional and neuropsychological status. This was also demonstrated radiologically as evident by improvement in MRI perfusion and cerebral angiography.

Abstract TP204: Performance of Rapidai NCCT Stroke Software in Colombia's Early Stroke System: Preliminary Results

Background: Automated stroke solutions in developing countries have the potential to reduce healthcare gaps. This study assesses the performance of the RAPID NCCT Stroke module compared to local neuroradiologists’ evaluation of acute stroke. Methods: Rapid NCCT stroke is a new multi-module AI tool that simultaneously evaluates non-contrast CT scans (NCCT) for ICH (any subtype, volume &gt;0.4 ml), the ASPECT score, and suspicion of LVO (i.e., intracranial ICA or horizontal segment of the MCA). The software determines suspicion of LVO based on an algorithm that evaluates the hyperdense MCA sign and early ischemic changes in the MCA territory. Consensus readings were defined by three blinded neuroradiologists based on a subset of Non-contrast CTs obtained between January 2013 to December 2018 at Fundacion Santa Fe De Bogota University Hospital. The overall diagnostic performance of the RAPID NCCT was compared to the assessments made by the neuroradiologists. Results: 179 total stroke cases with technically adequate NCCT scans were identified. Based on the consensus of the neuroradiologists, these cases included 151 ischemic strokes, 27 ICHs &gt;0.4 ml, 1 ICH &lt;0.4 ml, and 28 LVO cases (verified by CT angiography). The Rapid NCCT Stroke module demonstrated high specificity (96%), NPV (98%), and accuracy (95%) for the detection of ICH. For determining the ASPECT score, the software had a specificity of 93% and an NPV of 76%. Seventy percent of the CTA-verified LVOs were detected from NCCT alone with a specificity and NPV of 82%. Conclusions: The RAPID NCCT Stroke software displayed promising results for the early identification of ICH and characterization of ischemic strokes. The software identified 70% of the LVOs from NCCT alone. This tool can potentially enhance patient outcomes by bridging healthcare gaps in evolving stroke systems. Multicenter studies in additional Latin American countries are needed for further validation.

Abstract TMP110: A Novel Model of Ischemia in Rats With Middle Cerebral Artery Occlusion Using a Radiopaque Blood Clot and a Microcatheter Under Fluoroscopy

Introduction: Conventional thromboembolic stroke model requires ligation of the ECA, which is problematic for research of thrombolytic agents because cerebral blood flow is different from human stroke. We aimed to develop a novel thromboembolic stroke model that does not require arterial ligation, using a radiopaque blood clot and microcatheter. Methods: Using male Sprague Dawley rats (n=14) and two sham operated rats were included, a microcatheter (inner diameter, 0.42mm; outer diameter, 0.55mm) was navigated from the caudal ventral artery to the left ICA using fluoroscopy. A blood clot (0.86 mm in diameter, 3 mm in length) containing zirconium dioxide was advanced in the catheter by injection of physiological saline to establish local occlusion. Both fluoroscopy at 1, 3, 6, 24 h and TTC staining at 24 h after stroke model creation were performed. Neurological deficit score was measured. Results: The success rate in selectively embolized of ACA and MCA bifurcation was 93% (13 of 14 cases). The median operating time was 7 min (interquartile range; 4-15 min). The median infarct volume (mm 3 ) was 248 (interquartile range; 239-280) 24 h after occlusion. Neurological deficit scores before and at 1, 3, 6, and 24 h after model creation differed significantly ( P &lt; 0.001). Fluoroscopy showed the position of the radiopaque blood clot remains the same for 24 h after creating the model in 12 of 13 cases (92%). Sham-operated rats revealed no infarction and no neurological deficit. Conclusions: We present a novel rat model for focal infarct only in the MCA territory using a radiopaque blood clot. Fluoroscopy was able to identify whether the blood clot could migrate and recanalize.

Abstract 115: Presenting Symptoms and Neuroimaging Correlates in North American Moyamoya Vasculopathy

Introduction: Moyamoya disease (MMD) is a steno-occlusion of the supraclinoid internal carotid arteries and proximal branches with the development of collateral vessels 1 . Once thought to affect primarily females of East Asian descent, more than 11,000 hospitalizations in patients with MMD of non-Asian ancestry are reported annually in the USA, with the majority presenting with ischemic stroke. Here, we present frequent non-stroke symptomatology in North American MMD along with hemodynamic imaging profiles at presentation. Methods: Participants provided informed consent and underwent anatomical MRI with hypercapnic blood oxygenation level-dependent 2 ; time regression was applied to quantify cerebrovascular reactivity (CVR) and reactivity delay time (CVR DELAY ) 3 in right and left MCA territories. A logistic regression analysis based on the Huber-White sandwich estimator compared the CVR metrics between cohorts. Significance criterion: Bonferroni corrected two-sided p&lt;0.05. Results: 74 patients (age=11-77 years; Asian=6%, White=65%, Black=29%) diagnosed with MMD with symptom durations spanning hours to years prior to presentation were enrolled. Non-stroke symptoms and frequency prior to stroke are listed in Table 1. In more than 1/3 rd of patients, unprovoked headaches preceded stroke-like symptoms. In patients exhibiting ischemic symptoms within six months of neuroimaging, cerebrovascular reserve capacity was reduced (p=0.007), and cerebrovascular reactivity delay time increased (p&lt;0.001), in the flow territory from which symptoms were derived compared to the contralateral flow territory. Discussion: North American MMD is being observed with increasing frequency and increasing the awareness of non-stroke MMD presentations may lead to early diagnosis that can lead to proactive revascularization to minimize the risk of first stroke in these patients.

Assessment of Collateral Flow in Patients with Carotid Stenosis Using Random Vessel-Encoded Arterial Spin-Labeling: Comparison with Digital Subtraction Angiography.

Collateral circulation plays an important role in steno-occlusive internal carotid artery disease (ICAD) to reduce the risk of stroke. We aimed to investigate the utility of planning-free random vessel-encoded arterial spin-labeling (rVE-ASL) in assessing collateral flows in patients with ICAD. Forty patients with ICAD were prospectively recruited. The presence and extent of collateral flow were assessed and compared between rVE-ASL and DSA by using Contingency (C) and Cramer V (V) coefficients. The differences in flow territory alterations stratified by stenosis ratio and symptoms, respectively, were compared between symptomatic (n = 19) and asymptomatic (n = 21) patients by using the Fisher exact test. Good agreement was observed between rVE-ASL and DSA in assessing collateral flow (C = 0.762, V = 0.833, both P < .001). Patients with ICA stenosis of ≥90% were more likely to have flow alterations (P < .001). Symptomatic patients showed a higher prevalence of flow alterations in the territory of the MCA on the same side of ICAD (63.2%), compared with asymptomatic patients (23.8%, P = .012), while the flow alterations in the territory of anterior cerebral artery did not differ (P = .442). The collateral flow to MCA territory was developed primarily from the contralateral internal carotid artery (70.6%) and vertebrobasilar artery to a lesser extent (47.1%). rVE-ASL provides comparable information with DSA on the assessment of collateral flow. The flow alterations in the MCA territory may be attributed to symptomatic ICAD.

Flow-augmentation STA-MCA bypass for acute and subacute ischemic stroke due to internal carotid artery occlusion and the role of advanced neuroimaging with hemodynamic and flow-measurement in the decision-making: preliminary data.

A major clinical challenge is the adequate identification of patients with acute (<1 week) and subacute (1-6 weeks) ischemic stroke due to internal carotid artery (ICA) occlusion who could benefit from a surgical revascularization after a failure of endovascular and/or medical treatment. Recently, two novel quantitative imaging modalities have been introduced: (I) quantitative magnetic resonance angiography (qMRA) with non-invasive optimal vessel analysis (NOVA) for quantification of blood flow in major cerebral arteries (in mL/min), and (II) blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging to assess cerebrovascular reactivity (CVR). The aim of this study is to present our cohort of patients who underwent surgical revascularization in the acute and subacute phase of ischemic stroke as well as to demonstrate the importance of hemodynamic and flow assessment for the decision-making regarding surgical revascularization in patients with acute and subacute stroke and ICA-occlusion. Symptomatic patients with acute and subacute ischemic stroke because of persistent ICA-occlusion despite optimal medical/endovascular recanalization therapy who were treated at the Neuroscience Clinical Center of the University Hospital Zurich underwent both BOLD-CVR and qMRA-NOVA to study the hemodynamic and collateral vessel status. Patients selected for surgical revascularization according to our previously published flowchart were included in this prospective cohort study. Repeated NOVA and BOLD-CVR investigations were done after bypass surgery as follow up as well as clinical follow up. Continuous BOLD-CVR and qMRA-NOVA variables were compared using paired Student t-test. Between May 2019 and September 2022, superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery was performed in 12 patients with acute and subacute stroke because of ICA-occlusion despite of optimal endovascular and/or medical treatment prior to the surgery. Impaired BOLD-CVR in the occluded vascular territory [MCA territory: ipsilateral vs. contralateral: -0.03±0.07 vs. 0.11±0.07 %BOLD/mmHgCO2, P<0.001] as well as reduced hemispheric flow with qMRA-NOVA (ipsilateral vs. contralateral: 228.00±54.62 vs. 384.50±70.99 mL/min, P=0.01) were measured indicating insufficient collateralization. Post-operative qMRA-NOVA showed improved hemispheric flow (via bypass) (pre-bypass vs. post-bypass: 236.60±76.45 vs. 334.20±131.33 mL/min, P=0.02) and the 3-month-follow-up with BOLD-CVR showed improved cerebral hemodynamics (MCA territory: pre-bypass vs. post-bypass: -0.01±0.05 vs. 0.06±0.03 %BOLD/mmHgCO2, P=0.02) in all patients studied. Quantitative assessment with BOLD-CVR and qMRA-NOVA allows us to evaluate the pre- and post-operative cerebral hemodynamics and collateral vessel status in patients with acute/subacute stroke due to ICA occlusion who may benefit from surgical revascularization after failure of endovascular/medical treatment.

Neuroimaging in Cerebrovascular Accidents

Introduction: The incidence rate and the death rate from stroke increase dramatically with age. The one who survive are usually left with permanent disability. Thus, stroke has become a great medical and social problem. Accurate and early diagnosis may improve the morbidity and mortality rates in the future as newer and more effective therapies are currently being instituted. Neuroimaging in stroke patients, especially in acute ischemic stroke patients, plays an essential role. It helps to differentiate other causes of stroke (i.e., stroke mimics such as migraine headache, tumors, seizure, metabolic disturbance, and peripheral or cranial nerve disorders), early detection of hemorrhagic stroke, distinguish irreversible infarcted tissues from salvageable tissue, identify vascular malformations, treatment planning for intravenous thrombolysis and intra-arterial thrombectomy, and outcomes prediction. The aim of the study is to characterize type of stroke hemorrhagic vs. ischemic on neuroimaging. Radiological evaluation of stroke regarding –site, size, volume and duration. Correlation of neuroimaging findings with clinical findings and patient demographics. Materials and Methods: In 100 patient single-center, prospective observational study was conducted in the department of radiology, Shri Ram Murti Smarak Institute of Medical Sciences, Bareilly and adult patients with suspected stroke on computed tomography (CT) and magnetic resonance imaging (MRI) and characterization and correlation with clinical findings were done from the study. Infarcts were grouped into hyperacute (0–24 hours), (acute 1–7 days), early subacute (7–10 days), late subacute (10–21 days) Results: Out of 100 patients, the study showed male predominance. The majority of cases had a history of weakness. Comorbidities like diabetes, hypertension, and dyslipidemia increase the risk of stroke On the basis of GCS score the majority of the cases were, having GCS score greater than 10 (72.0%). Cranial nerve palsies and LOC were also common among patients of stroke. Out of a total 69 ischemic stroke cases, CT was positive in 55 patients, while MRI was positive in all the cases. Arterial infarcts (89.8%) are much more common than the venous infarcts 7 cases (10.2%). The majority of cases that reached our department were in the acute stage (56 cases, 81.2%), and the majority had MCA territory involvedThe basal ganglia complex was the most common location for the hemorrhage and was seen in 15 cases (48.3%). The mean volume of bleeding was large in cases of lobar bleeding. There was a strong positive correlation between altered sensorium (Phi value .64) and vomiting (.60), while the symptoms showed a positive correlation. The correlation of cerebrovascular accidents with age was seen more in patients aged &gt; 60 as compared to those age &lt; 60 (Phi value .1). Conclusion: This study depicts the predominance of the older age group (&gt; 40 years). The ischemic stroke was more common than the hemorrhagic stroke, the commonest cause being the MCA territory infarcts. In the cases of hemorrhagic stroke, the ganglion-capsular bleed was the commonest. Stroke imaging has undergone significant advances over last decade. It remains very crucial for the management of hyperacute stroke in the first few hours, where aim is to recognize patients eligible for thrombolytic therapy and expected to have good outcomes. Both CT, and MRI are useful for a comprehensive assessment of acute stroke MRI is sensitive for ischemic infarct detection and can provide important and necessary information for therapy planning. Both clinical examination and early diagnosis of stroke by imaging can lead to better patient outcomes.

Early histopathological changes of secondary degeneration in the spinal cord after total MCA territory stroke

Previous research has not demonstrated secondary degeneration of the spinal cord (SpC) motoneurons after cerebral infarct. The aim of the present study is to investigate the involvement of the anterior horn cells (AHC) in the early post-stroke period using histomorphological and immunohistochemical methods. Post-mortem analysis of the 6th cervical segment was performed in 7 patients who had total MCA stroke within 1 month before death. Nissl-stained sections were used for morphometry, while CD68 and synaptophysin (SYP) immunohistochemistry to monitor microglial activation and synaptic changes in the anterior horn (AH), respectively. Contralateral to the cerebral lesion (contralesional side), cells were smaller after 3 days and larger after 1 week of stroke, especially regarding the large alpha motoneurons. CD68 density increased mainly on the contralesional Rexed’s IX lamina of the SpC. SYP coverage of the large motoneurons was reduced on the contralesional side. Early microglial activation in the AH and electrophysiological signs has suggested the possibility of impairment of anterior horn cells (AHC-s). Our study supported that early microglial activation in the contralesional side of the SpC may primarily affect the area corresponding to the location of large motoneurons, and is accompanied by a transient shrinkage followed by increase in size of the large AHC-s with a reduction of their synaptic coverage. After MCA stroke, early involvement of the SpC motoneurons may be suspected by their morphological and synaptic changes and by the pattern of microglial activation.

CNSC-36. INDOLENT INTRAVASCULAR LARGE B-CELL LYMPHOMA (IVLBCL) ORIGINALLY PRESENTING AS A STROKE MIMIC

Abstract BACKGROUND IVBCL is a rare subtype of extranodal diffuse large B-cell lymphoma, characterized by the growth of neoplastic cells in blood vessels with no other apparent extravascular mass, making diagnosis a challenge. It usually has an aggressive and fast-paced course; however, there is limited data regarding incidence due to its rarity. CASE A 73 year-old woman presented with progressive gait worsening a year prior to presentation to our institution. Her symptoms then developed to include left-sided hemiparesis with associated headaches, warranting a local emergency department visit. Brain magnetic resonance imaging (MRI) without contrast showed a Flair hyperintense lesion in the right MCA territory with restricted diffusion, assumed to be an ischemic stroke, and she was started on stroke prevention measures. The patient continued to decline, becoming wheelchair-bound and developing short-term memory loss, chronic headaches, and pseudobulbar affect. Repeat brain MRI without contrast five months later showed progression of the Flair hyperintensity to the left hemisphere with restricted diffusion. Brain MRI with contrast followed, revealing subtle enhancement. Vessel imaging was unremarkable, and cerebrospinal fluid (CSF) analysis was normal with negative cytology and flow cytometry, yet elevated beta-2-microglobulin at 3.25 mcg/mL. A year after symptoms onset, the patient presented to our Neuro-Oncology clinic. Repeat Brain MRI with contrast and spectroscopy showed progression on the left-sided lesion with persistent restriction diffusion and enhancement, prompting a biopsy. Pathology confirmed large B cell lymphoma. PET-CT body scan showed no evidence of systematic disease. The patient was treated with Rituximab, Methotrexate, Vincristine, and Procarbazine (RMVP) with complete response demonstrated by complete resolution of the diffusion restriction and symptoms improvement. CONCLUSIONS Although IVLBCL is known for being a fast progressive disease, we present a case of indolent course delaying diagnosis. Unexplained progressive neurological symptoms with restricted diffusion on MRI should prompt consideration for this diagnosis.

Abstract 14028: Stroke Location, White Matter Disconnections, and Neurodevelopmental Outcomes in Infants With Congenital Heart Disease

Objectives: Infants with congenital heart disease (CHD) are at risk for stroke, although associations with neurodevelopmental outcomes have varied. In adults with stroke, location and altered structural connectivity (disconnections) have been linked to neurologic symptoms. We assessed whether stroke (1) location and (2) white matter disconnections are related to neurodevelopment in infants with CHD. Methods: Infants underwent pre- and post-operative brain MRI in prospective studies at 3 centres (UBC, UCSF, SickKids) and completed 18-month neurodevelopmental assessments using Bayley Scales with separate motor and cognitive composites. Adverse outcomes were defined as composite score &lt;85. Strokes were manually segmented. Voxel-wise lesion symptoms maps (VLSM) were used to assess relationships between lesion location and neurodevelopment. Disconnectomes were generated using stroke segmentations as seeds for tractography and diffusion MRI from healthy controls. Voxel-wise disconnectome-symptoms maps (VDSM) of associations between structural disconnections and neurodevelopment were developed. Results: 50 infants with strokes had neurodevelopmental outcomes data. Most strokes were small (&lt;1/3 of arterial territory; n= 33) and in the left MCA territory (Fig 1A). However, strokes in the right basal ganglia and adjacent central white matter were most strongly associated with adverse motor and cognitive outcomes (Fig 1B). White matter disconnections extended beyond areas of injury (Fig 1C); these were extensive even in small strokes. Disconnections of tracts passing through the right basal ganglia were most strongly associated with adverse motor and cognitive outcomes (Fig 1D). Conclusions: Strokes involving the basal ganglia, particularly in the right hemisphere, were associated with worse motor and cognitive outcomes in infants with CHD. These data draw increasing attention to the right hemisphere in early-life stroke and neurodevelopment.

Blood-brain barrier disruption imaging in postoperative cerebral hyperperfusion syndrome using DCE-MRI

Little has been reported about the association between cerebral hyperperfusion syndrome (CHS) and blood-brain barrier (BBB) disruption in human. We aimed to investigate the changes in permeability after bypass surgery in cerebrovascular steno-occlusive diseases using dynamic contrast-enhanced MRI (DCE-MRI) and to demonstrate the association between CHS and BBB disruption. This retrospective study included 36 patients (21 hemispheres in 18 CHS patients and 20 hemispheres in 18 controls) who underwent combined bypass surgery for moyamoya and atherosclerotic steno-occlusive diseases. DCE-MRI and arterial spin labeling perfusion-weighted imaging (ASL-PWI) were obtained at the baseline, postoperative state, and discharge. Perfusion and permeability parameters were calculated at the MCA territory (CBF(territorial), Ktrans(territorial), Vp(territorial)) and focal perianastomotic area (CBF(focal), Ktrans(focal), Vp(focal)) of operated hemispheres. As compared with the baseline, both CBF(territorial) and CBF(focal) increased in the postoperative period and decreased at discharge, corresponding well to symptoms in the CHS group. Vp(focal) was lower in the postoperative period and at discharge, as compared with the baseline. In the control group, no parameters significantly differed among the three points. In conclusion, Vp at the focal perianastomotic area significantly decreased in patients with CHS during the postoperative period. BBB disruption may be implicated in the development of CHS after bypass surgery.

Abstract 212: Percutaneous Carotid access in Mechanical Thrombectomy ‐ a safe alternative to transfemoral approach

Introduction Emergent percutaneous carotid artery MER approach for acute ischemic large vessel strokes are rare given the risk of complications and seldom reported. Methods 75‐year‐old left‐handed functional male (mRs:0) with past medical history of HTN, HLD presented to ED after being found on the floor by his family with slurred speech, new onset right sided weakness, with a last known well of 17 hours. NIHSS on arrival was 14 for expressive aphasia, right visual field defect, right facial weakness, significant dysarthria, right hemiparesis, and sensory defect. CT Head demonstrated left MCA territory early ischemic changes. CTA head/neck demonstrated left M1 occlusion with large penumbra. Perfusion data demonstrated no area of core infarct with area of ischemic penumbra in the left MCA territory involving the left frontal, temporal and parietal lobes measuring 161 ml. ASPECT score 5‐6. The patient was deemed a candidate for mechanical endovascular thrombectomy (MER). The procedure was initiated via ultrasound‐guided right common femoral access. After multiple attempts using a wide range of techniques and wire/catheter combinations in order to establish left intracranial access and given extreme angulation/tortuosity/elongation in the proximal left common carotid artery, it was decided to proceed with the catheter position in the left common carotid or the left internal carotid artery that would allow for subsequent catheterization of the intracranial circulation for MER. Results Near complete revascularization with minimal distal thrombus material beyond endovascular reach corresponding to a TICI 2C degree of revascularization was achieved. Closure of the femoral puncture site was performed using an Angio seal femoral closure device. Surgical closure of the puncture site was performed by vascular surgery. The patient was eventually discharged to short term acute rehabilitation and continues to follow up outpatient with the Stroke clinic. Conclusion Older patients with ischemic stroke commonly have tortuous vessels or peripheral vascular disease. As a result, they may greatly benefit from emergent direct carotid access, as the trans‐femoral approach often poses challenges in accessing the thrombus. For patients with complex and unfavorable vascular anatomy for mechanical endo‐vascularization, direct percutaneous carotid puncture can be advantageous, effectively reducing the aforementioned difficulties. When opting for such an approach it is vital to factor in the aortic arch appearance and its branches.

Abstract 115: Carotid Intraluminal Thrombus Obscuring Underlying Carotid Web: Case Report

Introduction Carotid webs (CaW) have been increasingly recognized as a unique cause of recurrent ischemic strokes.1 They are defined as thin, intraluminal, shelf‐like lesions along the posterior aspect of the carotid bulb.1,2 Despite more awareness and ongoing studies into their pathogenesis, diagnosis, and management,3 they are still overlooked in clinical practice as a primary carotid ischemic etiology. Our case describes a patient with right extracranial internal carotid artery (ICA) thrombus secondary to later‐diagnosed CaW on close follow‐up imaging. Methods We report a 55‐year‐old African American man with history of hypertension, type 2 diabetes mellitus and hyperlipidemia presented with acute onset slurred speech and left facial droop (FP). His last known well was 24 hours prior to presentation, and NIHSS upon arrival was 3 (FP 2, dysarthria 1). CT angiography (CTA) of the head and neck demonstrated a nearly occlusive thrombus of the distal right M2 segment MCA as well as non‐hemodynamic stenosis of the proximal right ICA with possible underlying sidewall filling defect‐appearing lesion concerning for a posterior wall thrombus without underlying atherosclerosis at the bulb or otherwise. The patient was admitted to the neurovascular intensive care unit and started on aspirin and high‐risk heparin drip. His MRI Brain demonstrated multiple acute/subacute right MCA territory strokes, predominately in the right posterior insula, right frontal lobe, and right posterior corona radiata. His stroke workup was otherwise unrevealing, and he was discharged on apixaban 5mg BID. Results Close surveillance follow‐up imaging with CTA head and neck was planned and obtained one month later, which demonstrated resolution of the filling defect that was obscuring the currently visualized underlying right CaW pocket (Figure‐1). The prevalence of CaWs has been reported to be between 1.2% and 2.5% of patients with acute ischemic stroke. CaWs are most frequently seen in younger, female patients, and patients with these lesions are at increased risk of recurrent stroke.4,5 Determining the optimal management for these lesions remains essential, but the available data thus far have not been conclusive. Most patients are treated with antiplatelet therapy, but some elect to treat with anticoagulation due to the focal hemostasis caused by CaWs.6 However, multiple studies have suggested that medical management alone is likely not sufficient in reducing the recurrent stroke risk caused by CaWs.5,7 Neuro‐interventional procedures including carotid artery stenting have been reported as secondary prevention strategies in patients with recurrent strokes.5,7,8 Although data regarding the rate of recurrence of strokes secondary to these lesions remains unclear, the current data does suggest benefit and safety in pursuing carotid stenting to prevent recurrent strokes.5‐8 Conclusion In young patients with proximal ICA thrombosis without underlying atherosclerosis or other conventional stroke risk factors, CaW should be considered among other differentials including hypercoagulable status. Following acute medical management, short‐term surveillance imaging is essential to confirm or rule out the diagnosis. In our case, the patient’s proximal ICA thrombus resolved after short course of anticoagulation and was determined to be secondary to the obscured underlying CaW.