Contralateral Middle Cerebral Artery Research Articles

Newly formed and ruptured infectious intracranial aneurysm in few days following first intracranial aneurysm embolization concurrent with middle cerebral artery occlusion: A regrettable case in a baby child

AbstractInfectious intracranial aneurysm (IIA) and embolic cerebral infarction are well‐known devastating complications of children suffering infective endocarditis. In this report, we describe a successfully embolized IIA concurrent with bilateral middle cerebral artery (MCA) occlusion. Unfortunately, a newly formed IIA located in the contralateral MCA bifurcation ruptured at the seventh day following embolization. A 6‐month‐old female child was admitted to hospital 3 days following acute right limb mobility disorder. An interventional surgery history of congenital heart disease was confirmed. She was immediately started on antibiotic therapy and the computed tomography agiography (CTA) scan showed occlusion of the upper branch of the left MCA. Unfortunately an IIA was located in the distal artery region (DAR) of the ipsilateral anterior cerebral artery. Angiography (digital subtraction angiography) was performed and the DAR IIA was embolized by OnyX‐18 with Magic 1.2 Fr. microcatheter. On the sixth day, magnetic resonance imaging during the hospital stay showed reduced infarction area with no other special sign. Desperately, a major seizure with opisthotonos attacked the baby on the seventh day after embolization. An immediate CTA scan showed massive hematoma in the right basal ganglia and a ruptured bifurcate aneurysm of the right MCA. The parents refused positive treatment and discharged in considering the critical situation. It should be noted that IIA can be fast formed anywhere in cerebral artery and dynamic angio‐image should be performed as supervision.

Exploring the relationship between embolic acute stroke distribution and supra-aortic vessel patency: key findings from an in vitro model study

BackgroundWe investigated differences in intracranial embolus distribution through communicating arteries in relation to supra-aortic vessel (SAV) patency.MethodsFor this experimental analysis, we created a silicone model of the extracranial and intracranial...

Early haemodynamic predictors of poor functional outcomes in patients with acute ischaemic stroke receiving endovascular therapy: a single-centre retrospective study in China.

Changes in cerebral haemodynamics following endovascular therapy (EVT) for large-vessel occlusion stroke may affect the outcomes of patients with acute ischaemic stroke (AIS); however, evidence supporting this belief is limited. This study aims to identify the early haemodynamic predictors of poor outcomes in patients with AIS caused by anterior circulation large-artery occlusion after undergoing EVT and to evaluate the usefulness of these indicators in predicting functional outcomes at 90 days. This retrospective study was conducted at a single academic hospital, using prospectively collected data. We enrolled adult patients with acute anterior circulation stroke who underwent EVT. Transcranial colour-coded sonography (TCCS) examinations of the recanalised and contralateral middle cerebral artery (MCA) were performed within 12 h after undergoing EVT. Haemodynamic indicators were analysed to determine their association with poor functional outcomes (modified Rankin Scale: 3-6) 90 days after stroke. Receiver operating characteristic (ROC) curves were used to evaluate the usefulness of haemodynamic indicators in predicting functional outcomes. In total, 108 patients (median age: 66 years; 69.4% males) were enrolled in this study. Complete recanalization was achieved in 93 patients (86.1%); however, 60 patients (55.6%) had a poor 90-day outcome. The peak systolic velocity (PSV) ratio, adjusted PSV ratio, mean flow velocity (MFV) ratio, and adjusted MFV ratio of the MCA were significantly higher in patients with poor prognosis than in patients with good prognosis (p<0.02). A multivariate logistic regression analysis showed that higher PSV ratio, adjusted PSV ratio, MFV ratio, and adjusted MFV ratio were independently associated with a poor 90-day outcomes (adjusted odds ratio: 1.11-1.48 for every 0.1 increase; p<0.03). Furthermore, adding the adjusted MFV ratio significantly improved the prediction ability of the basic model for the 90-day poor functional outcome using the ROC analysis, the areas under ROC curves increased from 0.75 to 0.85 (p=0.013). Early TCCS examination may help in predicting poor functional outcomes at 90 days in patients with AIS who underwent EVT. Moreover, combining novel TCCS indicators (adjusted MFV ratio) with conventional parameters improved the prediction ability of the base model.

The Positional Relationship between Lacunae and White Matter Hyperintensity in Patients with Cerebral Small Vessel Disease.

Lacunae and white matter hyperintensity (WMH) are two crucial imaging biomarkers of cerebral small vessel disease (CSVD). Multiple studies have revealed a close relationship between WMH and lacunae and found that a double penumbra existed at the edge of WMH that affects lacunae formation. The study aimed to explore the spatial distribution characteristics and possible influencing factors of lacuna in relation to white matter hyperintensity in patients with CSVD. A total of 480 CSVD patients with WMH and with or without lacunae were included. Data about blood biochemical indicators, cerebrovascular CT angiography, 24-hour ambulatory blood pressure and ambulatory electrocardiogram, brain magnetic resonance imaging, and transcranial Doppler ultrasound were gathered from all subjects. They were categorised into four groups based on the spatial interaction between lacunae and WMH. Univariate analyses and multiple logistic regression analyses were used to compare the differences in traditional vascular risk factors, heart rate and blood pressure indicators, arterial pulsatility index (PI) values, and arterial stenosis among different groups. The average age of 480 patients was (58.63 ± 11.91) years, with 347 males (72.3%). Univariate analysis indicated that age, fasting blood glucose, triglycerides, total cholesterol, highdensity lipoprotein, 24-hour and daytime and night systolic and diastolic blood pressure, nocturnal heart rate, heart rate variability, PI values of ipsilateral and contralateral MCA (middle cerebral artery) and ICA (Internal carotid artery) of the lacunae, Fazekas score of PWMH (periventricular white matter hyperintensities), the proportion of MCA or ICA with stenosis rate over 50% on the ipsilateral side of the lacunae were significantly different between different groups (p < 0.05). High fasting blood glucose (OR=1.632, 95% CI= (1.128, 2.361), p =0.009), (OR=1.789, 95%CI= (1.270, 2.520), p = 0.001), (OR=1.806, 95% CI= (1.292, 2.524), p =0.001) was identified as a risk factor for lacunae formation by logistic regression analysis. High fasting blood glucose can be considered a risk factor for lacunae formation in patients with WMH. The more severe the PWMH and the higher the nocturnal heart rate, the more likely the lacunae, as well as PWMH, overlap completely. Ipsilateral arteriosclerosis and stenosis are independent risk factors for no contact between lacunae and PWMH.

Middle cerebral artery dynamic cerebral autoregulation is impaired by infarctions in the anterior but not the posterior cerebral artery territory in patients with mild strokes.

The aim of this study was to ascertain whether dynamic cerebral autoregulation (CA) in the middle cerebral artery (MCA) is disturbed by cerebral infarctions outside the MCA territory. We estimated transfer function parameters gain and phase from simultaneous recordings of spontaneous oscillation in blood pressure and MCA cerebral blood flow velocity in 10 consecutive patients with isolated anterior cerebral artery (ACA) infarctions and in 22 consecutive patients with isolated posterior cerebral artery (PCA) infarctions. All ACA infarctions were in the motor, premotor, or supplementary motor cortex areas and presented with pronounced leg hemiparesis. Twenty-eight age- and sex-matched healthy subjects served as controls. Compared to controls, phase was significantly reduced in the MCA ipsilateral to the lesion site and in the contralateral MCA (unaffected hemisphere) in the very low (0.02-0.07 Hz) and low (0.07-0.15 Hz) frequency ranges in the ACA infarctions but not in the PCA infarctions. Gain was reduced only in the very low frequency range in the MCA contralateral to the ACA lesion site. Systemic factors were unrelated to phase and gain results. Bilateral impairment of MCA dynamic CA in patients with a unilateral ACA infarction is frequent.

Subdural evacuating port system with subdural thrombolysis for the treatment of chronic subdural hematoma in patients older than 80 years.

The subdural evacuating port system (SEPS) is a minimally invasive approach that can be performed under local anesthesia for the treatment of chronic subdural hematoma (CSDH). Subdural thrombolysis has been described as an exhaustive drainage strategy and found to be safe and effective for improving drainage. We aim to analyze the effectiveness of SEPS with subdural thrombolysis in patients older than 80 years. Consecutive patients aged ≥80 years old who presented with symptomatic CSDH and underwent SEPS followed by subdural thrombolysis between January 2014 and February 2021 were retrospectively studied. Outcome measures included complications, mortality, recurrence, and modified Rankin Scale (mRS) scores at discharge and 3 months. In total, 52 patients with CSDH in 57 hemispheres were operated on, with a mean age of 83.9 ± 3.3 years, and 40 (76.9%) patients were men. The preexisting medical comorbidities were observed in 39 patients (75.0%). Postoperative complications occurred in nine patients (17.3%), with two having significant complications (3.8%). The complications observed included pneumonia (11.5%), acute epidural hematoma (3.8%), and ischemic stroke (3.8%). One patient experienced contralateral malignant middle cerebral artery infarction and died of subsequent severe herniation, contributing to a perioperative mortality rate of 1.9%. Discharge and 3 months of favorable outcomes (mRS score 0-3) were achieved in 86.5% and 92.3% of patients, respectively. CSDH recurrence was observed in five patients (9.6%), and repeat SEPS was performed. As an exhaustive drainage strategy, SEPS followed by thrombolysis is safe and effective with excellent outcomes among elderly patients. It is a technically easy and less invasive procedure with similar complications, mortality, and recurrence rates compared with burr-hole drainage in the literature.

Abstract WMP95: External Validation Of Acute Atherosclerotic Ischemic Stroke Radiological Markers

Introduction: Intracranial atherosclerosis-related acute large vessel occlusion (ICAS-LVO) is the dominant cause of acute middle cerebral artery (MCA) occlusions that can be passed with wire or microcatheter but cannot be completely opened (5-15% of all middle cerebral artery (MCA) infarcts). The major challenge of ICAS-LVO is the tendency of reocclusion or cause a residual, fixed severe stenosis rendering the vessel with suboptimal revascularization. These patients carry a poor functional outcome and high mortality despite mechanical thrombectomy (MT). We aimed to externally validate three preidentified markers of ICAS-LVO on early non-contrast computed tomography (NCCT) and CT Angiogram (absent hyperdense MCA sign (HMCAS), Hounsfield measurements (HU ratio≤1.1 and Delta HU&lt;6) and CTA truncal occlusion). Methods: We conducted a retrospective analysis of 77 consecutive patients presenting with acute M1 occlusions undergoing MT. Based on our previous observational experiences, NCCT and CTA patterns that had been associated with ICAS-LVO included the absent HMCAS, HU ratio and Delta HU between site of occlusion and contralateral MCA and CTA truncal occlusion. ICAS-LVO was identified if an occlusion was difficult to cross, had tendency to reocclude after successful recanalization or demonstrated residual fixed severe stenosis. These markers were also compared with reperfusion rates and functional outcomes at 3 months. Results: Out of 77 patients, 13 (16%) had suspected ICAS-LVO. Absent HMCAS had a sensitivity of 91% and specificity of 90% (AUC 0.91), HU ratio ≤1.1 and delta HU &lt;6 had sensitivity of 100% and specificity of 98% (AUC 0.992) and CTA truncal occlusion had sensitivity of 91% and specificity of 97% (AUC 0.943), in predicting ICAS-LVO. These radiological markers were also significantly associated with unsuccessful reperfusion (TICI 0-2a) and poor functional outcomes (mRS&gt;2) at 3 months. Conclusion: Initial non-contrast CT and CTA markers are highly sensitive and specific in predicting atherosclerotic M1 occlusions and significantly associated with failed reperfusion, and poor functional outcomes after mechanical thrombectomy.

Unilateral developmental absence of internal carotid artery with contralateral middle cerebral artery occlusion.

Developmental absence of the internal carotid artery (ICA) is a rare congenital anomaly that results from an insult to the third aortic arch or dorsal aorta during early embryogenesis. Patients are often asymptomatic and are diagnosed incidentally during imaging to investigate neurological complaints. We report a rare finding of an absent ICA during a workup of stroke in a middle-aged patient. CT brain perfusion (CTP) and CT angiography (CTA) revealed the right middle cerebral artery (MCA) thrombotic stroke with the demonstration of contralateral left ICA absence. The patient showed spontaneous recovery, and no thrombolysis or neurointervention was considered. This article highlights the importance of screening the head CT on bone window settings in case of the non-visualization of ICA to differentiate congenital absence from a steno-occlusive disease. It also illustrates the role of Magnetic resonance imaging (MRI) and MR Angiography (MRA) in demonstrating further possible vascular anomalies, structural brain malformations, and collateral circulation.

The age factor influencing long-term physical functionality in stroke patients undergoing intra-arterial thrombectomy treatment.

The treatment of acute ischemic stroke is heavily time-dependent, and even though, with the most efficient treatment, the long-term functional outcome is still highly variable. In this current study, the authors selected acute ischemic stroke patients who were qualified for intravenous thrombolysis with recombinant tissue plasminogen activator and followed by intra-arterial thrombectomy. With primary outcome defined by the functional level in a 1-year follow-up, we hypothesize that patients with older age are at a disadvantage in post-stroke recovery. However, an age-threshold should be determined to help clinicians in selection of patients to undergo such therapy. This is a retrospective chart review study that include 92 stroke patients in Changhua Christian hospital with a total of 68 evaluation indexes recorded. The current study utilized the forward stepwise regression model whose Adj-R2 and P value in search of important variables for outcome prediction. The chngpt package in R indicated the threshold point of the age factor directing the better future functionality of the stroke patients. Datasets revealed the threshold of the age set at 79 the most appropriate. Admission Barthel Index, Age, ipsilateral internal carotid artery resistance index (ICA RI), ipsilateral vertebral artery (VA) PI, contralateral middle cerebral artery (MCA) stenosis, contralateral external carotid artery (ECA) RI, and in-hospital pneumonia are the significant predicting variables. The higher the age, in-hospital pneumonia, contralateral MCA stenosis, ipsilateral ICA RI and ipsilateral VA PI, the less likely patient to recover from functional deficits as the result of acute ischemic stroke; the higher the value of contralateral ECA RI and admission Barthel Index, the better chance to full functional recovery at 1-year follow up. Parameters of pre-intervention datasets could provide important information to aid first-line clinicians in decision making. Especially, in patients whose age is above 79 receives diminish return in the benefit to undergo such intervention and should be considered seriously by both the patients and the physicians.

Post-reperfusion hyperperfusion after endovascular stroke treatment: a prospective comparative study of TCD versus MRI

BackgroundIncreased middle cerebral artery (MCA) blood flow velocities on transcranial duplex sonography (TCD) were recently reported in individual patients after successful mechanical thrombectomy (MT) and were related to intracranial hemorrhage...

Aberrant right subclavian artery with right type 1 proatlantal artery and segmental dysplasia of the right internal carotid artery: a case report

We present a case of an aberrant right subclavian artery (ARSA) with extremely rare vascular anomalies. A 69-year-old woman was suspected to have right internal carotid artery (ICA) stenosis. Computed tomography angiography demonstrated an ARSA and hypoplasia of the right ICA. The proximal segment of the right vertebral artery (VA) was aplasia, and a right type 1 proatlantal artery (PA) arose from the right common carotid artery. Cerebral angiography demonstrated segmental dysplasia of the right ICA. The ascending intrapetrous segment and the ascendingforamen lacerum-horizontal intracavernous segment of the right ICA demonstrated hypoplasia. The collateral pathways promoted reconstitution of each of the distal segments. Left internal carotid angiography demonstrated anterior communicating artery aneurysm and sufficient cross flow to the contralateral middle cerebral artery via the AcomA. A type 1 PA with an ARSA may result in the regression of the right dorsal aorta with persistence of the first cervical intersegmental artery. Although there are few findings of a relationship between an ARSA and intracranial artery anomalies, a developmental error of the right dorsal aorta may cause such complex vascular anomalies. Knowledge of anatomical variations in patients with ARSA is useful when performing angiography or endovascular therapy, as well as during clinical follow-up.

Geometric features of middle cerebral artery are associated with spontaneous basal ganglia intracerebral haemorrhage

Background and purposeHaemodynamics around the middle cerebral artery (MCA) and lenticulostriate arteries is believed to play important roles in the vascular rupture and local haemodynamics is subject to vascular geometry....

Bilateral mechanical thrombectomy for internal carotid artery occlusion and contralateral middle cerebral artery occlusion during transvenous thrombolysis: Case report

【緒言】両側中大脳動脈（MCA）の急性閉塞症は稀で，予後は悪い．両側MCA急性閉塞症に対し両側の血栓回収術を施行した症例を報告する．【症例】87歳，男性．初診時 JCS II-10，重度左片麻痺，NIHSS 29点で，MRAで右内頚動脈と右MCAの閉塞を認めたが，左MCAは開通していた．アルテプラーゼ静注療法後，突然に昏睡，四肢麻痺となり，呼吸状態が悪化した．血管撮影で両側MCA閉塞を認め，左右両側で順に機械的血栓回収術を行い，完全再開通が得られた．救命し得たが，全介助で転院となった．【結語】両側MCA閉塞症に対し機械的血栓回収術が有用な可能性がある．

Geometric Features Associated with Middle Cerebral Artery Bifurcation Aneurysm Formation: A Matched Case-Control Study

ObjectivesThe pathogenesis of intracranial aneurysms is multifactorial and includes genetic, environmental, and anatomic influences. We aimed to identify image-based morphological parameters that were associated with middle cerebral artery (MCA) bifurcation aneurysms. Materials and methodsWe evaluated three-dimensional morphological parameters obtained from CT angiography (CTA) or digital subtraction angiography (DSA) from 317 patients with unilateral MCA bifurcation aneurysms diagnosed at the Brigham and Women's Hospital and Massachusetts General Hospital between 1990 and 2016. We chose the contralateral unaffected MCA bifurcation as the control group, in order to control for genetic and environmental risk factors. Diameters and angles of surrounding parent and daughter vessels of 634 MCAs were examined. ResultsUnivariable and multivariable statistical analyses were performed to determine statistical significance. Sensitivity analyses with smaller (≤ 3 mm) aneurysms only and with angles excluded, were also performed. In a multivariable conditional logistic regression model we showed that smaller diameter size ratio (OR 0.0004, 95% CI 0.0001–0.15), larger daughter-daughter angles (OR 1.08, 95% CI 1.06–1.11) and larger parent-daughter angle ratios (OR 4.24, 95% CI 1.77–10.16) were significantly associated with MCA aneurysm presence after correcting for other variables. In order to account for possible changes to the vasculature by the aneurysm, a subgroup analysis of small aneurysms (≤ 3 mm) was performed and showed that the results were similar. ConclusionsEasily measurable morphological parameters of the surrounding vasculature of the MCA may provide objective metrics to assess MCA aneurysm formation risk in high-risk patients.

Effects of LI11 Acupuncture on CO2 reactivity in the anterior and middle cerebral arteries during hyperventilation-induced hypocapnia in normal subjects: A before and after study

Objectives: The LI11 (Quchi) acupuncture point has always been included in the Seven acupoints for stroke; however, additional LI11 acupuncture research is needed. In this study, the effect of LI11 acupuncture on cerebral blood flow of the anterior cerebral arteries (ACA) and middle cerebral arteries (MCA) was investigated.Method: This study included 10 healthy young male subjects. Cerebral blood flow velocity and cerebrovascular reactivity were measured using transcranial Doppler sonography. Changes in hyperventilation-induced carbon dioxide (CO2) reactivity and modified ACA and MCA blood flow velocity at 40 mmHg (CV40), blood pressure, and heart rate were observed before and after LI11 acupuncture treatment.Results: A statistically significant increase in contralateral anterior cerebral artery CO2 reactivity (p=0.036) and decrease in contralateral middle cerebral artery CV40 (p=0.047) were observed. No significant difference in mean blood pressure was shown. A statistically significant increase in heart rate occurred after LI11 acupuncture; however, it was not clinically significant as there were negligible changes in the heart rhythm.Conclusions: LI11 acupuncture treatment could improve cerebral blood flow velocity. These results might be explained by regulating endothelium-dependent vessel dilation in the anterior cerebral artery region.Trial registration: This trial has been registered with Clinical Research Information Service, a service of the Korea Centers for Disease Control and Prevention: KCT0004494 (retrospectively registered). https://cris.nih.go.kr/cris/search/search_result_st01.jsp?seq=15359

Transcranial Doppler 6 h after Successful Reperfusion as a Predictor of Infarct Volume

ObjectivesThe aim of the study is to analyze the hemodynamic changes in the middle cerebral artery (MCA) after endovascular revascularization in acute ischemic stroke (AIS) due to large vessel occlusion and its association with the infarct volume size in the control head CT. Materials and MethodsProspective study of patients with AIS due to internal carotid artery terminus or M1 segment of the MCA occlusion, who underwent endovascular treatment with a final TICI 2b-3 score, without concomitant stenosis ≥50% in both cervical carotid arteries. Transcranial Doppler ultrasound (TCD) of both MCAs was carried out at 6 h after the endovascular procedure. Mean flow velocities (MFV) after arterial reperfusion and its association with the infarct volume size in 24−36 h control head CT were determined. Results91 patients (51 women) were included with a median age of 78 years and National institute of Health Stroke Scale of 18. The MCA was occluded in 76.92%, and intravenous thrombolysis was administered in 40.7%. The incidence of symptomatic intracranial hemorrhage was 5.5%. At three months, mortality was 19.8% and a 52.7% of patients achieved functional independence (modified Rankin Scale 0-2). After a multivariable logistic regression analysis, an increase in the MFV greater than 50% at 6 h in the treated MCA compared to contralateral MCA, was an independent predictor of large infarct volume in the control head CT with an OR 9.615 (95%CI: 1.908−47.620), p=0.006 ConclusionsIncreased MFV assessed by TCD examination following endovascular recanalization is independently associated with larger infarct volume

Type 4 persistent primitive olfactory artery associated with contralateral accessory middle cerebral artery arising from the fenestrated segment of the distal anterior cerebral artery

Persistent primitive olfactory artery (PPOA) is a rare variation of the proximal anterior cerebral artery (ACA) that generally follows an extreme anteroinferior course and takes a hairpin turn before continuing to the A2 segment of the ACA (type 1). There are four other types of extremely rare variations. The type 4 variation continues to the accessory middle cerebral artery (MCA) instead of the ACA. Only a few cases have been reported. We herein report a case of type 4 PPOA in which the contralateral side of the accessory MCA arose from the fenestrated segment of the distal ACA. No similar cases were found in the relevant English-language literature. For the identification of these variations on MR angiography, volume-rendering images were superior to maximum-intensity-projection images.

Quantitative susceptibility mapping in ischemic stroke patients after successful recanalization

Quantitative susceptibility mapping (QSM) is a novel processing method for gradient-echo magnetic resonance imaging (MRI). Higher magnetic susceptibility in cortical veins have been observed on susceptibility maps in the ischemic hemisphere of stroke patients, indicating an increased oxygen extraction fraction (OEF). Our goal was to investigate susceptibility in veins of stroke patients after successful recanalization in order to analyze the value of QSM in predicting tissue prognosis and clinical outcome. We analyzed MR images of 23 patients with stroke due to unilateral middle cerebral artery (MCA)-M1/M2 occlusion acquired 24–72 h after successful thrombectomy. The susceptibilities of veins were obtained from QSM and compared between the stroke territory, the ipsilateral non-ischemic MCA territory and the contralateral MCA territory. As outcome variables, early infarct size and functional disability (modified Rankin Scale, mRS) after 3–5 months was used. The median susceptibility value of cortical veins in the ischemic core was 41% lower compared to the ipsilateral non-ischemic MCA territory and 38% lower than on the contralateral MCA territory. Strikingly, in none of the patients prominent vessels with high susceptibility signal were found after recanalization. Venous susceptibility values within the infarct did not correlate with infarct volume or functional disability after 3–5 months. Low venous susceptibility within the infarct core after successful recanalization of the occluded vessel likely indicates poor oxygen extraction arising from tissue damage. We did not identify peri-infarct tissue with increased susceptibility values as potential surrogate of former penumbral areas. We found no correlation of QSM parameters with infarct size or outcome.

Internal carotid artery agenesis and contralateral middle cerebral artery infarction

Internal carotid artery agenesis is usually an asymptomatic condition. It is detected incidentally by radiological imaging performed for other reasons. It may rarely present with clinical manifestations such as subarachnoid hemorrhage associated with aneurysm, transient ischemic attack, or stroke. Agenesis can be erroneously interpreted as occlusion in case of insufficient clinical experience. The absence of the carotid canal on the bone window in the computed tomography scan of the brain helps confirm the diagnosis. The well-developed collateral circulation in patients with internal carotid artery agenesis is an effective factor in recovering from cerebrovascular diseases with less damage. Here, a rare case of agenesis of the right internal carotid artery and contralateral middle cerebral artery infarction is presented.

Abstract P509: Signal Intensity in the Middle Cerebral Artery as a Practical and Feasible Index of Hemodynamic Insufficiency Due to Carotid Artery Stenosis

Introduction: Intracranial hemorrhage occasionally occurs after carotid revascularization in presents with hemodynamic insufficiency. Positron emission tomography is unavailable in most facilities, and a feasible index is required to identify high-risk patients. Reduced signal intensity (SI) of the middle cerebral artery (MCA) on magnetic resonance angiography (MRA) is associated with postoperative hyperperfusion. Hypothesis: Reduced signal intensity (SI) of the MCA on MRA is associated with decreased regional cerebral blood flow (rCBF) on single-photon emission CT (SPECT) and increased blood-sampling whole-brain oxygen extraction fraction (wb-OEF). Methods: We included patients who: 1) were admitted from 2015 to 2019 for carotid artery stenting (CAS), 2) MRA, and SPECT before CAS, and 3) examined the wb-OEF immediately before CAS. We measured bilateral MCA SI on MRA and defined the MCA relative SI as (SI in the affected MCA)/ (SI in the contralateral MCA). We defined the rCBF% as rCBF in the affected MCA territory against the ipsilateral cerebellum. Before CAS, we sampled blood, measured the arterial oxygen and the venous oxygen content in the dominant-sided jugular vein, and calculated the wb-OEF. We evaluated the correlation between the MCA relative SI, the MCA slow flow, the rCBF%, and the wb-OEF. We estimated the upper limits of the MCA relative SI for the rCBF% &lt; 80% or wb-OEF ≥ 0.40 using the area under the curve (AUC) values derived from the receiver operating characteristic (ROC) curves. Results: During the study period, 150 patients met our inclusion criteria. The MCA relative SI was positively correlated with rCBF% and negatively with the wb-OEF. The ROC curve for the rCBF% &lt; 80% showed that the upper limit of the relative SI was 0.77 (the sensitivity of 53.9%, the specificity of 83.9%, AUC of 0.723). The ROC curve for the wb-OEF ≥ 0.40 showed that the upper limit of the relative SI was 0.95 (the sensitivity of 67.7%, the specificity of 55.2%, AUC of 0.625). Conclusion: Reduced MCA SI on MRA ≤ 0.77 is a practical and feasible index of hemodynamic insufficiency, indicating the decreased rCBF and increased wb-OEF.