Efficacy of Intravenous Mesenchymal Stem Cells for Motor Recovery After Ischemic Stroke: A Neuroimaging Study.

BACKGROUND AND PURPOSE: Stem cell-based therapy is a promising approach to repair brain damage after stroke. This study was conducted to investigate changes in neuroimaging measures using stem cell-based therapy in patients with ischemic stroke. METHODS: In this prospective, open-label, randomized controlled trial with blinded outcome evaluation, patients with severe middle cerebral artery territory infarct were assigned to the autologous mesenchymal stem cell (MSC) treatment or control group. Of 54 patients who completed the intervention, 31 for the MSC and 13 for the control groups were included in this neuroimaging analysis. Motor function was assessed before the intervention and 90 days after randomization using the Fugl-Meyer assessment scale. Neuroimaging measures included fractional anisotropy values of the corticospinal tract and posterior limb of the internal capsule from diffusion tensor magnetic resonance imaging and strength of connectivity, efficiency, and density of the motor network from resting-state functional magnetic resonance imaging. RESULTS: For motor function, the improvement ratio of the Fugl-Meyer assessment score was significantly higher in the MSC group compared with the control group. In neuroimaging, corticospinal tract and posterior limb of the internal capsule fractional anisotropy did not decrease in the MSC group but significantly decreased at 90 days after randomization in the control group. Interhemispheric connectivity and ipsilesional connectivity significantly increased in the MSC group. Change in interhemispheric connectivity showed a significant group difference. CONCLUSIONS: Stem cell-based therapy can protect corticospinal tract against degeneration and enhance positive changes in network reorganization to facilitate motor recovery after stroke. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01716481.

Determinants of Basal Collaterals in Moyamoya Disease: Clinical and Genetic Factors.

BACKGROUND/AIMS: To enable the diagnosis of moyamoya disease (MMD), detection of distal internal carotid artery stenosis and hazy network of basal collaterals (BCs) are required. This study aimed at evaluating the factors that could determine the degree of BCs in patients with angiographically confirmed MMD. METHODS: We analyzed 146 consecutive patients with MMD (age 26.2 ± 19.6, range 1-75). The degree of BCs (%) was measured based on conventional angiography. Factors associated with the degree of BCs, including clinico-radiological and genetic factors (p.Arg4810Lys variant), were analyzed. RESULTS: The degree of BCs varied among MMD patients and significantly decreased with an increase in the age of diagnosis of MMD (coefficient -1.55; p < 0.001). Although the degree of BC development depends on the MMD stage (Suzuki stage), it is less prominent in adult-onset (>18 years) MMD compared to childhood MMD. The presence of p.Arg4810Lys variant, types of MMD (bilateral vs. unilateral) and stroke (ischemic, hemorrhagic, or asymptomatic), shrinkage (outer diameter) of intracranial vessels, external carotid collateral status, and cortical neovascularization were not associated with the degree of BCs. CONCLUSION: Although prominent BCs are required for diagnosis of MMD, BCs are decreased with aging, suggesting that angiogenic capacity is altered in adult onset MMD compared to childhood MMD.

Predicting Collateral Status With Magnetic Resonance Perfusion Parameters: Probabilistic Approach With a Tmax-Derived Prediction Model.

BACKGROUND AND PURPOSE: Good collateral flow is an important predictor for favorable responses to recanalization therapy and successful outcomes after acute ischemic stroke. Magnetic resonance perfusion-weighted imaging (MRP) is widely used in patients with stroke. However, it is unclear whether the perfusion parameters and thresholds would predict collateral status. The present study evaluated the relationship between hypoperfusion severity and collateral status to develop a predictive model for good collaterals using MRP parameters. METHODS: Patients who were eligible for recanalization therapy that underwent both serial diffusion-weighted imaging and serial MRP were enrolled into the study. A collateral flow map derived from MRP source data was generated through automatic postprocessing. Hypoperfusion severity, presented as proportions of every 2-s Tmax strata to the entire hypoperfusion volume (Tmax≥2 s), was compared between patients with good and poor collaterals. Prediction models for good collaterals were developed with each Tmax strata proportion and cerebral blood volumes. RESULTS: Among 66 patients, 53 showed good collaterals based on MRP-based collateral grading. Although no difference was noted in delays within 16 s, more severe Tmax delays (Tmax16-18 s, Tmax18-22 s, Tmax22-24 s, and Tmax>24 s) were associated with poor collaterals. The probability equation model using Tmax strata proportion demonstrated high predictive power in a receiver operating characteristic analysis (area under the curve=0.9303; 95% confidence interval, 0.8682-0.9924). The probability score was negatively correlated with the volume of infarct growth (P=0.030). CONCLUSIONS: Collateral status is associated with more severe Tmax delays than previously defined. The present Tmax severity-weighted model can determine good collaterals and subsequent infarct growth.

A novel magnetic resonance imaging approach to collateral flow imaging in ischemic stroke.

OBJECTIVE: Dedicated magnetic resonance (MR) imaging (MRI) sequences for evaluation of collaterals can be generated using MR perfusion (MRP) source data. We compared a novel collateral flow imaging technique with digital subtraction angiography (DSA) for determining collateral circulation in acute stroke and evaluated the ability of MR-based collateral flow maps to predict outcomes after recanalization therapy. METHODS: Consecutive patients who were candidates for endovascular treatment were enrolled. A collateral flow map derived from MRP source data was generated by manual or automatic postprocessing. Collateral grading based on the collateral flow map was performed and compared with grading based on DSA. Clinical and radiological outcomes were evaluated according to MR-based collateral grading and early reperfusion (ER) status. RESULTS: There was good correlation between MRI-based and DSA-based collateral grades (weighted κ-coefficient = 0.70). Collateral status and achievement of ER were the 2 main determinants of a favorable functional outcome and neurological improvement, in addition to infarct growth. Regardless of achievement of ER, better collaterals were significantly associated with a lower modified Rankin score at day 90 (p < 0.001 for trend in both ER(-) and ER(+) ). Most symptomatic intracranial hemorrhages occurred in patients with a poor collateral grade and ER(+) , whereas no patient with excellent collaterals suffered symptomatic intracranial hemorrhage or died. INTERPRETATION: MRI techniques to assess collaterals are rapidly being developed, and may provide insight into collateral perfusion. The combination of collateral images derived from pretreatment MRP source data and reperfusion status is a robust predictor of outcomes in acute ischemic stroke.

Diffusion-Perfusion Mismatch in Single Subcortical Infarction: A Predictor of Early Neurological Deterioration and Poor Functional Outcome.

BACKGROUND/AIMS: Early neurological deterioration (END) is frequently observed and related to poor functional outcome in patients with single subcortical infarction (SSI). We evaluated the role of diffusion-perfusion mismatch (DPM) as a predictor of END and functional outcome in patients with SSI. METHODS: We retrospectively analyzed data for 274 patients with acute SSI. DPM was positive in the presence of a lesion on the perfusion map that was larger than that on the corresponding slice on diffusion-weighted imaging. END was defined as an increase of <1 points in the motor portion of the National Institute of Health Stroke Scale (NIHSS) within 72 h from MRI acquisition. Patients with a modified Rankin Scale (mRS) score of 3 or more at day 30 were considered having a poor functional outcome. RESULTS: DPM was more frequently observed in the END (+) than in the END (-) group (21/35 (60.0%) vs. 50/239 (20.9%); p < 0.001). After adjusting for covariates, the presence of DPM and NIHSS score on admission were independently associated with END (DPM, OR 5.03, p < 0.001; NIHSS, OR 1.14, p = 0.033) and poor functional outcome (DPM, OR 2.44, p = 0.018; NIHSS, OR 1.48, p < 0.001). CONCLUSIONS: The DPM concept is applicable to prediction of END and functional disability in patients with SSI.

High-resolution magnetic resonance wall imaging findings of Moyamoya disease.

BACKGROUND AND PURPOSE: Diagnosis of Moyamoya disease (MMD) is based on the characteristic angiographic findings. However, differentiating MMD from intracranial atherosclerotic disease (ICAD) is difficult. We compared vessel wall imaging findings on high-resolution magnetic resonance imaging between MMD and ICAD. METHODS: High-resolution magnetic resonance imaging was performed on 32 patients with angiographically proven MMD and 16 patients with acute infarcts because of ICAD. Bilateral internal carotid arteries and steno-occlusive middle cerebral artery were analyzed for wall enhancement and remodeling. RESULTS: Enhancement patterns and distribution were different. Most patients with MMD (90.6%) showed concentric enhancement on distal internal carotid arteries and middle cerebral arteries, whereas focal eccentric enhancement was observed on the symptomatic segment in ICAD. MMD was characterized by middle cerebral artery shrinkage; the remodeling index and wall area were lower in MMD than in ICAD (remodeling index, 0.19±0.11 versus 1.00±0.43; wall area, 0.32±0.22 versus 6.00±2.72; P<0.001). CONCLUSIONS: MMD was characterized by concentric enhancement on bilateral distal internal carotid arteries and shrinkage of middle cerebral artery, regardless of symptoms.

Eligibility and preference of new oral anticoagulants in patients with atrial fibrillation: comparison between patients with versus without stroke.

BACKGROUND AND PURPOSE: Recent randomized clinical trials (RCTs) have evaluated the benefit of new oral anticoagulants in reducing the risk of vascular events and bleeding complications in patients with atrial fibrillation (AF). However, abundant and strict enrollment criteria may limit the validity and applicability of results of RCTs to clinical practice. We estimated the eligibility for participation in RCTs of an unselected group of patients with AF. In addition, we compared features favoring new oral anticoagulant use between patients with versus without stroke. Randomized Evaluation of Long-Term Anticoagulation Therapy METHODS: We applied enrollment criteria of 4 RCTs (RE-LY, ROCKET-AF, ARISTOTLE, and ENGAGE-AF-TIMI 48) to 695 patients with AF taking warfarin, prospectively and consecutively collected at a university medical center; 500 patients with and 195 patients without stroke. Time in therapeutic range and bleeding risk scheme (anticoagulation and risk factors in atrial fibrillation) were also measured. RESULTS: The proportions of patients fulfilling the trial enrollment criteria varied, ranging from 39% to 72.8%, depending on the differences in indications/contraindications among studies and presence/absence of stroke. The main reasons for ineligibility for RCTs were hemorrhagic risk (anticoagulation and risk factors in atrial fibrillation [ATRIA] score) (10.8%-40.5%) and planned cardioversion (5.1%-7.7%) for nonstroke patients, and a low creatinine clearance (5.6%-9.2%) and higher risk of bleeding (15.2%-20.8%) for patients with stroke. When compared with nonstroke patients, patients with stroke showed a lower time in therapeutic range (54.4±42.8% versus 65.4±34.9%, especially with severe disability) and a high hemorrhagic risk (ATRIA score) (3.06±2.30 versus 2.18±2.16) (P<0.05 in both cases). CONCLUSIONS: Patients enrolled in RCTs are partly representative of patients with AF in clinical practice. When time in therapeutic range and bleeding tendency with warfarin use were considered, the use of new oral anticoagulants was preferred in patients with stroke than in nonstroke patients, but they were more likely to be excluded in RCTs.

Role of statin in atrial fibrillation-related stroke: an angiographic study for collateral flow.

BACKGROUND: Currently, intensive lipid lowering is recommended in patients with atherosclerotic ischemic stroke or transient ischemic attack. However, the role of statin in cardioembolic stroke is unclear. We investigated the association of statin with pretreatment collateral status in cardioembolic stroke. METHODS: A collaborative study from two stroke centers in distinct geographic regions included consecutive patients with acute middle cerebral artery (MCA) infarction due to atrial fibrillation (AF) who underwent cerebral angiography. The relationship between pretreatment collateral grade and the use/dose of statin at stroke onset was assessed. The angiographic collateral grade was evaluated according to the ASITN/SIR Collateral Flow Grading System. RESULTS: Ninety-eight patients (76 statin-naïve, 22 statin users) were included. Compared with statin-naïve patients, statin users were older and more frequently had hypertension, hyperlipidemia and coronary heart disease. Excellent collaterals (grade 3-4) were more frequently observed in statin users (11 patients, 50%) than in statin-naïve patients (21 patients, 27.6%; p = 0.049). The use of atorvastatin 10 mg equivalent or higher doses of statin was associated with excellent collaterals (p for trend = 0.025). In multiple regression analysis, prestroke statin use was independently associated with excellent collaterals (odds ratio, 7.841; 95% confidence interval, CI, 1.96-31.363; p = 0.004). CONCLUSIONS: Premorbid use of statin in AF patients is associated with excellent collateral flow. Although most statin trials excluded patients with cardioembolic stroke, our data suggests the possibility that statin may be beneficial in AF-related stroke

Comparison of potential risks between intracranial and extracranial vertebral artery dissections.

BACKGROUND/AIMS: To better understand potential risks for vertebral artery (VA) dissection (VAD), we compared intracranial and extracranial VADs. METHODS: We analyzed consecutively admitted VAD patients over a 9-year period in whom VAD was confirmed by angiography. All patients were categorized as having intracranial or extracranial VAD, and demographic and radiological characteristics of VAD were compared. We used multivariate analysis to predict the risks for intracranial and extracranial VADs. RESULTS: The study population (n = 74) had a mean age of 46.0 ± 10.3 years. VAD was more frequent in the nondominant VA (n = 49, 66.2%).Vertical nidus of VAD was more common in the intracranial segment (81.1%), and more particularly it was most frequently located within a 2-mm perimeter of the posterior inferior cerebellar artery (PICA) orifice (60.0%). Absence of traumatic history (OR 13.1, 95% CI 1.6-107.4; p = 0.016), history of hypertension (OR 14.1, 95% CI 1.1-184.6; p = 0.043)and aging (OR 1.1 per 1-year increase, 95% CI 1.0-1.2; p =0.038) were independent predictors of intracranial VAD. CONCLUSION: As compared to extracranial VAD, intracranial VAD was particularly frequent and particularly vulnerable at the perimeters of the PICA and nondominant VA and was associated with an absent trauma history, hypertension and aging. Formation of VAD appeared to be different according to intracranial or extracranial involvement.

Neovascularization precedes occlusion in moyamoya disease: angiographic findings in 172 pediatric patients.

BACKGROUND: Both basal collaterals (BC) and cortical microvascularization (CM) on angiography have been suggested as moyamoya disease (MMD)-specific findings; however, it is unknown whether the vascular network represents compensatory mechanisms for vascular occlusion or aberrant active neovascularization. METHODS: We investigated the grade of antegrade MCA flow, the degree of BC, and the presence of CM on conventional angiography in relation to disease severity in pediatric MMD. CM was defined as enlarged and winding distal cortical arteries and categorized into anterior or posterior CM depending on their sources. Findings from basal and acetazolamide stress brain perfusion SPECT studies were also evaluated. RESULTS: A total of 172 pediatric patients with MMD were enrolled in this study. As the severity of MMD increased, the grade of antegrade MCA flow gradually diminished. While the degree of BC peaked at Suzuki stage 3-4, CM was frequently observed at early MMD stages. About two-thirds of hemispheres with normal antegrade MCA flow on angiography and normal perfusion status on SPECT had anterior and/or posterior CM. Both anterior and posterior CM gradually decreased with the advancement of MMD. CONCLUSION: Our findings from a large cohort of angiographically confirmed pediatric MMD patients indicate that neovascularization may occur before significant hemodynamic impairment in MMD.

Is atrial fibrillation always a culprit of stroke in patients with atrial fibrillation plus stroke?

BACKGROUND: Some ischemic strokes in patients with atrial fibrillation (AF) are caused by noncardioembolic etiologies (AF-unrelated stroke), but not AF itself (AF-related stroke). However, most clinical trials on the risk of stroke in AF have not distinguished between these. We investigated the frequency and features of AF-unrelated versus AF-related strokes in patients with AF plus ischemic stroke. We hypothesized that certain clinical factors, including chronicity of AF, treatment at the time of stroke onset and echocardiographic findings, may help to discriminate between AF-related and AF-unrelated strokes. The mechanisms and antithrombotic medications at the time of stroke recurrence in the two groups were also examined. METHODS: Consecutive patients with ischemic stroke within 7 days of symptom onset and with AF were included. Patients were classified according to the previously published criteria. Clinical factors including CHADS2 and CHA2DS2-VASc scores and transthoracic echocardiographic (TTE) findings were evaluated. RESULTS: Of 522 patients, 424 (81.2%) were grouped as AF-related stroke and the remaining 90 (17.2%) were classified as AF-unrelated stroke. Among the patients with AF-unrelated stroke, 51 (9.8%) were categorized as possible large artery atherosclerosis and 38 (7.3%) as possible small artery occlusion; 1 patient (0.2%) was assigned to miscellaneous cause. The AF-related and AF-unrelated strokes had similar CHADS2 and CHA2DS2-VASc scores. However, compared to AF-unrelated stroke, AF-related stroke was independently associated with female sex (odds ratio, OR, 2.19; 95% confidence interval, CI, 1.18-4.05), sustained AF (OR, 2.09; 95% CI, 1.21-3.59), inadequate anticoagulation at stroke onset (OR, 3.21; 95% CI, 1.33-7.75) and left ventricular dysfunction on TTE (OR, 2.84; 95% CI, 1.40-5.74). We identified 26 patients who experienced 2 strokes during the study period. The initial stroke subtype was a strong predictor of the recurrent stroke mechanism (p < 0.001). Among 17 events of AF-related recurrent stroke in these subpopulation, only 2 strokes (11.8%) occurred in a setting of adequate anticoagulation, whereas 4 out of 9 patients (44.4%) who had AF-unrelated strokes at recurrence were sufficiently anticoagulated at the time of admission (p = 0.138). CONCLUSION: AF is not always a culprit of stroke in patients with AF plus ischemic stroke; approximately one sixth of these cases are unrelated to AF and have distinct characteristics compared to AF-related stroke. There are significant differences in terms of some clinical and TTE parameters between AF-related and AF-unrelated stroke. Future studies are warranted to optimize strategies for risk stratification, treatment and prevention of stroke in these patients.

Quantitative electroencephalography as a potential biomarker in migraine.

OBJECTIVE: The aim of this study was to investigate the utility of quantitative electroencephalography (QEEG) as a diagnostic tool for migraine and as an indicator of treatment response by comparing QEEG characteristics between migraine patients and controls, and monitoring changes in these characteristics alongside clinical symptoms in response to treatment BACKGROUND: We hypothesized that patients with migraine exhibit distinctive characteristics in QEEG measurements, which could be used as potential diagnostic biomarkers and as a tool for monitoring treatment response. METHODS: A total of 720 patients were included in the study, comprising 619 patients with migraine and 101 subjects as a control group. QEEG measurements were analyzed for absolute power across specific frequency bands: delta wave (0.5-4 Hz), theta wave (4-8 Hz), alpha wave (8-12 Hz), beta wave (12-25 Hz), and high beta wave (25-30 Hz). The absolute power was normalized against a normative dataset from NeuroGuide, with electrodes being highlighted for significance if they exceeded 1.96. Clinical symptoms were also monitored for correlation with QEEG changes. RESULTS: Our analysis showed that patients with migraine exhibited significantly higher absolute power across all frequencies, most markedly within the high beta frequency range. When considering electrodes with z-scores exceeding the threshold of 1.96 in the high beta range, a significant association with migraine diagnosis was observed (per 1 electrode increase, OR 1.06; 95% CI 1.01-1.11; p = .012). Moreover, pre- and posttreatment changes in QEEG measurements corresponded with changes in clinical symptoms. CONCLUSION: Patients with migraine have distinctive QEEG measurements, particularly regarding absolute power and the number of electrodes that surpassed the z-score threshold in high beta wave activity. These findings suggest the potential of QEEG as a diagnostic biomarker and as a tool for monitoring treatment response in migraine patients, warranting further large-scale studies for confirmation and expansion.

Microembolic signals in acute posterior circulation cerebral ischemia: sources and consequences.

BACKGROUND AND PURPOSE: The clinical significance of microembolic signals (MES) in the posterior circulation remains unclear. The aim of this study was to investigate the sources and consequences of MES in acute posterior circulation cerebral ischemia. METHODS: We evaluated a total of 140 consecutive patients (93 males, mean age 62.9 years) who had acute posterior circulation cerebral ischemia. The MES monitoring was conducted at the basilar artery through the suboccipital window for a 30-minute period. RESULTS: MES were detected in 18 (12.9%) of the 140 patients. Clinical characteristics and laboratory data did not differ between the MES-positive and MES-negative groups. Intracranial vertebrobasilar artery (VBA) stenosis was independently associated with the presence of MES (odds ratio, 9.85; 95% confidence interval, 1.22-79.48; P=0.032), whereas the patients with vertebral artery stenosis that was limited to the extracranial portion did not show an association. Microembolic signals occurred significantly more frequently in patients with severe degree of VBA stenosis compared to those with nonsignificant stenosis (odds ratio, 9.88; 95% confidence interval, 1.23-79.07; P=0.031). In a subgroup analysis of the 79 patients who had lesions on diffusion-weighted images and relevant VBA stenosis, the MES-positive group showed more frequent embolic infarction (P=0.010) and multiple lesion patterns (P=0.007) than single perforating infarctions. CONCLUSIONS: In acute posterior circulation cerebral ischemia, intracranial and severe VBA stenosis is associated with MES and may be its root causes. The presence of MES in VBA stenosis suggests that multiple and embolic type infarctions are the mechanisms of stroke.

Sulcal effacement on fluid attenuation inversion recovery magnetic resonance imaging in hyperacute stroke: association with collateral flow and clinical outcomes.

BACKGROUND AND PURPOSE: The clinical significance of sulcal effacement has been widely investigated in CT studies, but the results are controversial. In this study, we evaluated the presence of perisylvian sulcal effacement (PSE) on fluid attenuation inversion recovery MRI and hypothesized that PSE may be related to collateral flow status together with hyperintense vessels on fluid attenuation inversion recovery in hyperacute stroke. In addition, we investigated whether an association between PSE and clinical outcome could be found in these patients. METHODS: Consecutive patients with acute middle cerebral artery infarcts within 6 hours of symptom onset were included. All patients had internal carotid artery or middle cerebral artery occlusion and underwent MRI including FLAIR. The presence of PSE and hyperintense vessels on fluid attenuation inversion recovery and the collateral status and occurrence of early recanalization (ER) on conventional angiography were evaluated. RESULTS: Of 139 patients, 79 (56.8%) had PSE. Multivariate testing revealed PSE was independently associated with collateral status. The association between hyperintense vessels and collaterals was different depending on PSE. Compared to PSE-positive and ER-negative patients, PSE-negative and ER-negative patients (odds ratio, 4.11; 95% confidence interval, 1.12-15.17) and PSE-negative and ER-positive patients (odds ratio, 34.62; 95% confidence interval, 5.75-208.60), but not PSE-positive and ER-positive patients, were more likely to experience favorable clinical outcomes (modified Rankin Scale score ≤ 2 at 3 months). CONCLUSIONS: PSE is independently associated with collateral status in patients with acute middle cerebral artery stroke. Moreover, PSE in conjunction with recanalization status can predict clinical outcomes in these patients.

Characterization of the infarct pattern caused by vulnerable aortic arch atheroma: DWI and multidetector row CT study.

BACKGROUND: Aortic arch atheroma (AAA) has been accepted as a possible embolic source in patients with ischemic stroke, especially cryptogenic stroke. However, despite its well-known role as a risk factor for stroke, research focused on the mechanism or characteristics of stroke caused by AAA is insufficient. In this study, we aimed to evaluate clinical and radiological characteristics including lesion pattern on DWI in acute stroke patients associated with vulnerable AAA detected by multidetector row computed tomography (MDCT). METHODS: From September 2008 through May 2011, patients who presented with acute ischemic stroke and underwent MDCT were found in a prospective stroke registry. Patients without evident stroke etiology were included and classified by presence of vulnerable AAA. Vulnerable AAA was defined as (i) at least 6 mm thick adjacent to the aortic wall; (ii) ulcerated plaque, or (iii) soft plaque. Soft plaque was defined as the presence of clearly visualized area of hypoattenuation (<80 Hounsfield units) suggestive of thrombus. The patients without vulnerable AAA were classified as no/simple AAA group. The characteristics of diffusion-weighted MRI (DWI) lesions were analyzed in terms of the number and size of the lesions, and the involved vascular territories. RESULTS: A total of 63 cryptogenic stroke patients were included in this study. Vulnerable AAA was observed in 15 (23.8%) patients. The patients with vulnerable AAA were older than those with no/simple AAA (p = 0.026). DWI analysis revealed that the vulnerable AAA group had a greater chance of having multiple and small lesions in multiple vascular territories that were mainly located in cortical and border-zone regions than the no/simple AAA group. Multiple logistic regression analysis showed that age (odds ratio 1.17; 95% confidence interval 1.02-1.34) and multiple small lesions in multiple vascular territories (odds ratio 33.18; 95% confidence interval 4.26-258.45) were independently associated with vulnerable AAA. CONCLUSION: Vulnerable AAA is independently associated with a DWI pattern characterized by multiple small scattered lesions in multiple vascular territories in conjunction with age. It may help determine stroke mechanism quickly and easily, and provide more information about the pathomechanism of vulnerable AAA-related stroke.

Clinical presentation and ischemic zone on MRI in cancer patients with acute ischemic stroke.

AIMS: This study was conducted to evaluate the clinical and MRI profiles in acute cancer strokes, and to demonstrate our experience with thrombolytic therapy in cancer stroke patients. METHODS: We prospectively studied active cancer patients with acute ischemic stroke who underwent MRI within 48 h of the onset of symptoms. Patients were grouped based on the presence of conventional stroke mechanisms (CSM). Clinical characteristics and MRI profiles were evaluated. RESULTS: A total of 70 patients were finally included in this study. Patients without CSM were more frequently presented with encephalopathy than those with CSM (29.4 vs. 2.8%, p = 0.002). The diffusion-perfusion mismatch pattern was more prevalent in patients with CSM (21 patients, 58.3%) than in patients without CSM (8 patients, 23.5%). Patients who had a higher tertiles of D-dimer level were significantly less likely to have the diffusion-perfusion mismatch pattern (p = 0.015). Among patients who presented within 6 h of the onset of stroke, revascularization therapy was performed in 4 of 16 (25%) patients with CSM, but none of the patients without CSM. CONCLUSION: Based on the stroke mechanisms, the optimal strategy of thrombolytic therapy should be considered differently in cancer patients with acute ischemic stroke.

Multiphasic perfusion computed tomography as a predictor of collateral flow in acute ischemic stroke: comparison with digital subtraction angiography.

BACKGROUND: Assessing collateral status is important in acute ischemic stroke. The purpose of this study was to compare multiphasic perfusion computed tomography (MPCT) with digital subtraction angiography (DSA) in predicting leptomeningeal collateral flow in acute middle cerebral artery (MCA) infarction. METHODS: Consecutive patients underwent MPCT and DSA for acute MCA infarction that presented within 6 h of symptom onset. We included patients who showed MCA occlusion in the same location on both modalities and assessed the agreement rate and correlation between the MPCT and DSA collateral grades. RESULTS: Of 54 patients, 44 (81.5%) had proximal MCA (M1) occlusions and 10 (18.5%) had distal MCA (M2) occlusions based on MPCT and DSA. The κ-coefficients were 0.87 and 0.81 in the MPCT and DSA collateral grade systems, respectively. Forty-four patients (81.5%) belonged to the same category in both collateral-grading systems. MPCT collateral grades correlated positively with those of DSA (Spearman's correlation coefficient 0.827, p < 0.001). CONCLUSION: Our data show that MPCT can predict leptomeningeal collateral flow in acute ischemic stroke. Based on collateral status assessed by MPCT, different therapeutic approaches might be warranted.

Are stroke biomarkers seeing brain vessels in patients with ischemic stroke?: a C-reactive protein and homocysteine study.

BACKGROUND AND PURPOSE: The significance of asymptomatic coronary artery atherosclerosis burden (CAB) in the interpretation of stroke biomarker results is unknown. We investigated biomarker values to determine if they are related to cerebral atherosclerosis with consideration of CAB. METHODS: We prospectively recruited patients with noncardioembolic ischemic cerebrovascular disease who had no history of coronary artery disease. Patient-based vascular assessment was conducted using MRA for the cerebral arteries and cardiac CT angiography for the coronary arteries. Biomarkers including the C-reactive protein and homocysteine were measured. RESULTS: A total of 178 patients were included in the study. The extracranial carotid stenosis was associated with the highest quartile of C-reactive protein (OR, 2.24; 95% CI, 1.04-4.55), whereas age was the only predictor of the highest quartile of homocysteine (OR, 1.06; 95% CI, 1.02-1.11). However, with consideration of CAB, CAB (≥2 segments with ≥50% stenosis) remained the only independent predictor for the highest quartile of C-reactive protein (OR, 8.69; 95% CI, 2.41-31.30) and homocysteine (OR, 11.44; 95% CI, 2.61-50.11). CONCLUSIONS: Our data emphasize the importance of CAB in biomarker studies of patients with ischemic stroke.

Collateral flow averts hemorrhagic transformation after endovascular therapy for acute ischemic stroke.

BACKGROUND AND PURPOSE: Collaterals sustain the ischemic penumbra to limit growth of the infarct core before revascularization, yet the impact of baseline collateral flow on hemorrhagic transformation (HT) after endovascular therapy remains unknown. METHODS: A collaborative study from 2 stroke centers in distinct geographic regions included 222 consecutive patients who received endovascular therapy for acute cerebral ischemia. The influence of collaterals on HT was analyzed in distinct case scenarios relative to baseline collateral grade at angiography (0 to 1 versus 2 to 4) and recanalization (Thrombolysis in Myocardial Ischemia scale, 0 to 1 versus 2 to 3): good collaterals and successful recanalization (n=98), poor collaterals with successful recanalization (n=43), good collaterals and no recanalization(n=46), and poor collaterals and no recanalization (n=35). RESULTS: HT after endovascular therapy occurred in 103 (46.4%) patients; 42 (18.9%) were symptomatic. HT was more frequently observed in patients with poor collaterals and recanalization than in other groups (P=0.048). When revascularization was achieved, patients with poorer collaterals were more likely to have symptomatic worsening with HT (r=-0.181, P=0.032). Multiple logistic regression analysis identified aggressive treatment (OR, 2.558 for Merci clot retrieval; 95% CI, 1.153 to 5.678; OR, 3.618 for combined fibrinolytics and mechanical therapy; 95% CI, 1.551 to 8.437; and OR, 2.085 for intravenous thrombolysis before endovascular therapy; 95% CI, 1.096 to 3.969), poor collaterals and recanalization (OR, 2.666; 95% CI, 1.163 to 6.113), and serum glucose levels (OR, 1.007; 95% CI, 1.000 to 1.014) as independent predictors of HT. CONCLUSIONS: Angiographic grade of collateral flow strongly influences the rate of HT after therapeutic recanalization for acute ischemic stroke. Collateral status readily available from baseline angiography may therefore refine therapeutic decision-making in acute cerebral ischemia.

Collateral flow predicts response to endovascular therapy for acute ischemic stroke.

BACKGROUND AND PURPOSE: Collaterals sustain the penumbra before recanalization and offset infarct growth, yet the influence of baseline collateral flow on recanalization after endovascular therapy remains relatively unexplored. METHODS: We analyzed consecutive patients who received endovascular therapy for acute cerebral ischemia from 2 distinct study populations. We assessed the relationship between pretreatment collateral grade and vascular recanalization (Thrombolysis In Myocardial Ischemia [TIMI] scale). In addition, we assessed infarct growth on serial MRI. RESULTS: A total of 222 patients was included, 138 from the United States and 84 from South Korea. Complete revascularization occurred in 14.1% (11 of 78) patients with poor pretreatment collateral grades, whereas it was observed in 25.2% (26 of 103) patients with good collaterals and 41.5% (17 of 41) patients with excellent collaterals (P<0.001). This relationship was consistently observed in both study populations, although the mode of endovascular therapy was different between them. After adjustment for other factors, including mode of endovascular therapy, prior use of intravenous tissue plasminogen activator, and site of occlusion, pretreatment collateral grade was independently associated with recanalization. When revascularization was achieved, greater infarct growth occurred in patients with poor collaterals than in those with good collaterals (P=0.012). CONCLUSIONS: Our data indicate that angiographic collateral grade determines the recanalization rate after endovascular revascularization therapy. When therapeutic revascularization was achieved, beneficial effects were not observed in patients with poor collaterals. Angiographic collateral grade may therefore help guide treatment decision-making in acute cerebral ischemia.