Search

Introduction: The evaluation of ischemic core is important in acute cerebral infarction with large vessel occlusion. The ischemic core is thought to approximate the region that is difficult to receive collateral circulation. We classified the ischemic core distribution pattern into four types on the basis of the tendency of cerebral blood volume (CBV) decrease in the ischemic core, and examined the prognostic ability. Methods: We included M1 or ICA occlusion which completely recanalized (TICI3) by thrombectomy in our institute from January 2015 to May 2019. The ischemic core was defined as a region where CBV were reduced less than 1.9 ml/100cc. Ischemic core distribution pattern was classified into the following 4 types. Type A: absent of ischemic core. Type B: ischemic core is confined to the basal ganglia and white matter. Type C1: ischemic core is present in the cortex but less than half of MCA region. Type C2: ischemic core is present in the cortex, and more than half of MCA region. The patient characteristics, temporal parameters, ASPECTS and ischemic core distribution pattern were analyzed with mRS0-2 at discharge as a good outcome group. Results: A total of 47 cases (14 ICA, 33 M1) were included. Ischemic core distribution pattern correlated well with mRS at discharge (p Conclusions: The distribution pattern of ischemic core defined by reduced CBV have good correlation with outcome. There is a possibility that it can be used as a simple tool to predict prognosis using CT perfusion in anterior circulation acute large vessel occlusion.

Purpose: Cerebral hyperperfusion syndrome (CHS) is a rare devastating complication associated with hyperperfusion after carotid endarterectomy. Single photon emission computed tomography (SPECT) is usually used with acetazolamide challenge to measure the cerebrovascular reserve (CVR), and a decreased CVR is indicative of a high risk of post CEA hyperperfusion. However, acetazolamide administration can rarely cause serious adverse effects, and thus, alternative methods may be required. Perfusion computed tomography (PCT) is a rapid, more accessible modality, which can be acquired with CT angiography. PCT seems to be useful as a screening tool in identifying groups at high-risk of hyperperfusion, but its usefulness has not sufficiently investigated. Our purpose was to clarify the relationship between hyperperfusion and the preoperative PCT parameters of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT). Method: We included patients who underwent carotid endarterectomy in our hospital from 2014 December to 2018 April. PCT was obtained preoperatively and on postoperative day 1. Hyperperfusion is defined as a postoperative CBF of the middle cerebral artery area which has increased twice that of the preoperative value. CHS was defined as any symptom and imaging findings related with hyperperfusion, which include headache, seizure, neurological dysfunction, and any intracranial hemorrhage in the related area. Preoperative CBF, CBV, MTT and other patient characteristics are statistically analyzed between a hyperperfusion group and non-hyperperfusion group. Result: There are 73 patients who underwent CEA during the study period, and hyperperfusion was observed in 5 cases, from which 2 were considered as CHS. In the hyperperfusion group, the preoperative CBF was significantly lower (p=0.0008), and the CBV and MTT significantly higher (p=0.0196, p=0.0002). ROC analysis showed that the PCT parameters with the maximal area under the receiver-operating characteristic curve for hyperperfusion was preoperative MTT with an optimal threshold at 8.0 seconds (sensitivity 100%, specificity 100%). Conclusion: Patient with prolonged preoperative MTT tend to develop hyperperfusion, which is related to CHS.

Introduction: From the results of NASCET and ECST, surgical treatment for carotid artery near occlusion (NO) has not been as effective as of that for severe stenosis. A meta-analysis published in 2015 supported surgical treatment for NO, but this is still controversial because recent large prospective studies such as CREST or ICSS exclude NO. Method: We conducted a retrospective single center case-controlled study in Japan. Among all NO cases from May 2006 to May 2017, we selected those who had internal carotid artery (ICA) without collapse, with collapse but with detection of vascular lumen from neck to intracranium by angiography and MRI, and without mechanical changes of vessel wall. We excluded patients who had ICA with full collapse and without the possibility for expansion. The carotid artery endarterectomy (CEA) or carotid artery stenting (CAS) was performed according to plaque character, position, and expectancy of expansion. The primary outcome was ipsilateral stroke within 90 days after surgery. Secondary outcomes included restenosis of more than 50%, and perioperative complications (postoperative procedural DWI positive, myocardial infarction, death). Result: In the eligible 60 patients, 56 were male, and the median age was 73±6.3. The number of symptomatic lesions and string signs were 27 and 5, and the CEA and CAS groups consisted of 33 and 27 patients, respectively. There was no significant difference between each group in the patient backgrounds other than the age and follow-up period (71 and 76 [p = 0.0093], 63 and 39 months, respectively [p = 0.0185]). Ipsilateral stroke within 90 days after surgery occurred in 0 and 4 patients (p = 0.0328), and restenosis in 7 (3 needed additional CAS) and 3 patients (p = 0.490). The postoperative DWI positive was 7 and 11 (p = 0.095), and all of them were asymptomatic or transient. There were no cases of perioperative myocardial infarction, and perioperative death occurred in 1 patient. Conclusion: CEA group had the advantage of procedural safety but also the risk of restenosis. In CAS group, we can expect good expansions of ICA, but perioperative complications are relatively high. Our results suggest that there exist specific factors including surgical indication which lead to good outcome by surgical treatment.

Background: Ischemic events caused by carotid artery stenosis are affected not only by stenosis but also by the instability of plaque. In symptomatic low-grade stenosis cases medical treatment is generally performed, but there are cases with repeated recurrence. The purpose of this study is to clarify the clinical features and long-term outcomes in cases of symptomatic low-grade stenosis. Methods: We included seventy-one symptomatic patients with carotid low-grade stenosis ( Results: The mean stenosis rate, rSI and ERR on admission were 20.4, 1.75 and 1.96, respectively. Seventy percent of cases involved intraplaque hemorrhage and positive remodeling. During a mean of 52-months follow-up, a recurrence of ischemic events was confirmed in 33 cases (46%), from which the duration until recurrence was within 7 days (33%), 3 months (18%), 1 year (18%), 2 years (21%), and over 2 years (15%). Nine cases had impending stroke, 3 of which were associated with major artery occlusion. CEA was performed in 28 cases (39%) for impending stroke (25%), recurrence of ischemic events (46%), asymptomatic infarction (7%), and stenosis rate progression (11%). During a mean of 47-months follow-up after CEA, 2 cases of death (fetal intracerebral hemorrhage, asphyxia) and one case of brain stem lacunar infarction were observed, but an ipsilateral ischemic event was not observed. Conclusion: Most of the symptomatic patients with low-grade stenosis had both intraplaque hemorrhage and positive remodeling. The risk of recurrence and stenosis progression was high. CEA might have had a preventive effect against ischemic events in low-grade stenosis.

Introduction: Plasma D-dimer levels elevate during acute stage of aneurysmal subarachnoid hemorrhage (SAH) and are associated with poor functional outcomes. However, the mechanism in which D-dimer elevation on admission affects functional outcomes remains unknown. Hypothesis: We hypothesize that D-dimer levels on admission are correlated with systemic complications rather than neurological complications, and therefore have an additive predictive value on conventional risk factors for poor functional outcomes. Methods: A total of 187 patients with aneurymal SAH were retrospectively analyzed from a single center, observational cohort database. Correlations of plasma D-dimer levels on admission with patients’ characteristics, initial presentation, neurological complications, and systemic complications were identified. We also evaluated additive value of D-dimer elevation on admission for poor functional outcomes by comparing predictive models with and without D-dimer. Result and Conclusions: D-dimer elevation on admission was associated with increasing age, women, and severity of SAH. Patients with higher D-dimer levels had increased likelihood of nosocomial infections (OR 1.22 [95% CI 1.07-1.39], p = 0.004), serum sodium disorders (OR 1.11 [95% CI 1.01-1.23], p = 0.033), and cardiopulmonary complications (OR 1.20 [95% CI 1.04-1.37], p = 0.01) by multivariable analysis. D-dimer elevation was an independent risk factor of poor functional outcomes (modified Rankin scale 3-6, OR 1.50 [95% CI 1.15-1.95], p = 0.003). A novel prediction model with D-dimer had significantly better discrimination ability for poor outcomes than conventional models without D-dimer, evaluated by C statistics, net reclassification improvement, and integrated discrimination improvement methods. These results suggest that elevated D-dimer levels on admission were independently correlated with systemic complications, and had an additive value for outcome prediction on conventional risk factors after aneurysmal SAH.

Backgrounds and Purpose— Predictive value of reflux of anterior spinal artery for recurrent posterior circulation ischemia in bilateral vertebral arteries steno-occlusive disease was evaluated. Methods— We retrospectively reviewed 55 patients with symptomatic posterior circulation stroke caused by bilateral stenotic (>70%) lesions of the vertebral artery. We investigated any correlation of clinical and angiographic characteristics including collateral flow patterns, with recurrent stroke. Risk factors for poor 3-month functional outcome were also evaluated. Results— Recurrent posterior circulation stroke was observed in 15 (27.3%) patients. Multivariable analysis using Cox proportional hazards model showed anterior spinal artery reflux as a significant risk factor for stroke recurrence (adjusted hazard ratio, 19.3 [95% confidence interval, 5.35–69.9]; P P =0.028). Conclusions— In patients with symptomatic bilateral vertebral artery occlusive disease, anterior spinal artery reflux predicted recurrent posterior circulation stroke and poor functional outcome.

Introduction: Intraplaque hemorrhage (IPH) has been reported to be a characteristic feature of a vulnerable plaque, indicated by an area of high signal intensity on carotid MRI. It has been reported that symptomatic low-grade stenosis with IPH is strongly associated with ischemic events, but there are limited data regarding the dynamics of the carotid plaque signal. The aim of this study was to assess the time-dependent change of carotid plaque in the symptomatic patient with low-grade stenosis. Methods: Thirty-eight symptomatic patients with carotid low-grade stenosis (0.31 between time points was considered significant. We then investigated changes in rSI and subsequent ipsilateral ischemic events. Result: Of the 38 patients, there were strong-positive and positive plaque at baseline in 22 and 12 patients, respectively. During a mean follow-up period of 42.5 months, 26 positive plaques (74%) at baseline kept an rSI of >1.25, and all of 4 negative plaques at baseline changed positive. Strong-positive plaques at baseline showed a lower tendency to be negative than positive plaque (p=0.08). Twenty-one of the 38 patients (55%) experienced a total of 26 recurrent ischemic events. In patients who experienced recurrent ischemic events, 19 plaques (73%) were strong-positive and 5 plaques (19%) were positive. Compared to the most recent carotid MRI, rSI at the event was stable in 18 patients (69%) and increased in 8 patients (31%). Conclusions: Most symptomatic plaque with low-grade stenosis retained its hyperintensity after ischemic events and had a high rate of subsequent ipsilateral ischemic events. A sustaining high signal intensity might be associated with an increased risk of subsequent ischemic events. Follow-up observation by carotid MRI has the potential to increase the accuracy of stroke risk stratification in the management of carotid low-grade stenosis.

Background An association between magnetic resonance imaging detection of intraplaque hemorrhage and the risk of cerebral ischemic events has been described. However, few studies have followed patients with intraplaque hemorrhage. Objective We used 3-dimensional gradient-echo black-blood T1-weighted imaging (screening BB [S-BB]) as a magnetic resonance imaging sequence to evaluate acute cerebrovascular stroke. The association between S-BB high signal plaques and the risk of subsequent ipsilateral ischemic events was investigated. Methods A total of 928 consecutive patients hospitalized for a stroke or transient ischemic attack according to the Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification were evaluated. Recurrence was retrospectively evaluated in S-BB-positive patients and patients with severe stenosis (SS) (≥70%) by magnetic resonance angiography. Based on clinical and imaging findings, recurrence was defined as a carotid artery stroke or transient ischemic attack that developed after hospital discharge as an initial event. Results Sixty-six patients were S-BB positive and 62 patients had severe stenosis (S-BB positive with SS, 32 patients; S-BB negative with SS, 30 patients; S-BB positive without SS, 34 patients). During a mean follow-up period of 9.1 months, 7 S-BB-positive patients with SS (18.7%) and 1 S-BB-negative patient with SS (3%) had a recurrent event (P = .051). In the S-BB-positive group, in 34 patients without SS, the recurrence rate was 14.7% (5/34); the difference in the recurrence rate between S-BB-positive group with and without SS was not significant (P = .34). Conclusion Patients with carotid artery lesions and intraplaque hemorrhage tend to be at higher risk of a subsequent ipsilateral ischemic event. Risk evaluation of carotid artery disease should include plaque characteristics.

Background: Assessment of plaque vulnerability is important in evaluating the future risk of stroke. Plaque characteristics and plaque volume are important components of plaque vulnerability. Expansive remodeling (ER) is one of the criteria for vulnerable plaque in the coronary arteries, and influences the plaque volume. The aim of this study is risk stratification of carotid plaque through the evaluation of quantitative ER and MRI plaque signal intensity. Methods: We studied and obtained both pre-operation carotid MRI T1-weighted axial and long axis images of 72 patients who underwent carotid endarterectomy or carotid aretery stenting. ER ratio (ERR) was calculated from the ratio of the linear diameter of the artery at the thickest segment of the plaque to the diameter of the artery beyond any poststenotic dilatation on the long axis image on carotid MRI. We also calculated relative plaque signal intensity (rSI) from the axial image and grouped the patients as follows: Group A, rSI≥1.4 and ERR≥1.8; Group B, rSI Results: Of the 72 patientis, the number of patients in each group was as follows: Group A, 20 patients; B, 12 patients; C, 19 patients; D, 21 patients. Fifteen patients (75%) in Group A, 6 patients (50%) in Group B, 8 patients (42%) in Group C and 7 patients (33%) in Group D had ischemic events within 6 months. Ischemic events in Group A was significantly higher than in Group C and D (p Conclusion: The combined assessment of plaque characterization with MRI and morphological evaluation using ERR are useful in risk stratification for carotid lesions.