Study protocol of the ASTOP trial: A multicenter, randomized, double-blind, placebo-controlled trial of presurgical aspirin administration for the prevention of thromboembolic complications of coil embolization for ruptured aneurysms.

RATIONALE: Thromboembolism is a serious complication of endovascular treatment for ruptured cerebral aneurysms. The administration of antiplatelet agents before endovascular treatment for ruptured cerebral aneurysms may reduce the risk of thromboembolic complications. AIM: This study aimed to assess the safety and efficacy of preoperative aspirin administration in endovascular treatment for ruptured cerebral aneurysms. SAMPLE SIZE ESTIMATES: Assuming a 15% incidence rate of both intraoperative thromboembolic morbidity and symptomatic ischemic lesions on magnetic resonance imaging diffusion-weighted imaging scans assessed by an Independent Review Committee, a sample size of 484 will be required to detect a 10% improvement with aspirin administration with 90% power using the Pearson's chi-square test at a two-sided significance level of 2.5% for each primary outcome, after accounting for a 5% dropout rate. METHODS AND DESIGN: ASTOP is a multicenter, randomized, double-blind, placebo-controlled clinical trial. A total of 484 patients with ruptured cerebral aneurysms receiving coil embolization within 72 h of onset will be randomly assigned 1:1 to receive 200 mg of aspirin or placebo before the procedure. STUDY OUTCOMES: The primary outcomes will be the incidence rates of intraoperative thromboembolic complications and symptomatic ischemic lesions on magnetic resonance imaging diffusion-weighted imaging scans evaluated by the Independent Review Committee. The secondary outcomes will be the incidence rate of cerebral ischemic events and all bleeding events within 14 days of enrollment and functional outcomes defined by the modified Rankin Scale score at 90 days. DISCUSSION: This trial will provide valuable data on the role of antiplatelet agents during endovascular treatment for ruptured cerebral aneurysms. TRIAL REGISTRATION: Registration: Japan Registry of Clinical Trials, Identifier: jRCTs031210421.

Severity, Outcomes, and their Secular Changes in 33,870 Ischemic Stroke Patients with Atrial Fibrillation in a Hospital-Based Registry: Japan Stroke Data Bank.

AIM: Severity, functional outcomes, and their secular changes in acute atrial fibrillation (AF)-associated stroke patients were determined. METHODS: Acute ischemic stroke patients with AF in a hospital-based, multicenter, prospective registry from January-2000 through December-2020, were compared with those without AF. The co-primary outcomes were the initial severity assessed by the NIH Stroke Scale (NIHSS) score and favorable outcome assessed by the modified Rankin Scale scores 0-2 at hospital discharge. RESULTS: Of the 142,351 patients studied, 33,870 had AF. AF patients had higher NIHSS scores (median 9 vs. 3, adjusted coefficient 5.468, 95% CI 5.354-5.582) than non-AF patients. Favorable outcome was less common in AF patients than in non-AF patients in the unadjusted analysis (48.4% vs. 70.4%), but it was more common with adjustment for the NIHSS score and other factors (adjusted OR 1.110, 95% CI 1.061-1.161). In AF patients, the NIHSS score decreased throughout the 21-year period (adjusted coefficient -0.088, 95% CI -0.115 - -0.061 per year), and the reduction was steeper than in non-AF patients (P＜0.001). In AF patients, favorable outcome became more common over the period (adjusted OR 1.018, 95% CI 1.010-1.026), and the increase was steeper than in non-AF patients (P＜0.001); the increase was no longer significant after further adjustment by reperfusion therapy. CONCLUSIONS: Initial stroke severity became milder and functional outcomes improved in AF patients over the 21-year period. These secular changes were steeper than in non-AF patients, suggesting that AF-associated stroke seemed to reap more benefit of recent development of stroke care than stroke without AF.

Prospective Observational Study for the Comparison of Screening Methods Including Tongue Pressure and Repetitive Saliva Swallowing With Detailed Videofluoroscopic Swallowing Study Findings in Patients With Acute Stroke.

BACKGROUND: Simple, noninvasive, and repeatable screening methods are essential for assessing swallowing disorders. We focused on patients with acute stroke and aimed to assess the characteristics of swallowing screening tests, including the modified Mann Assessment of Swallowing Ability score, tongue pressure, and repetitive saliva swallowing test (RSST), compared with detailed videofluoroscopic swallowing study (VFSS) findings to contribute as a helpful resource for their comprehensive and complementary use. METHODS AND RESULTS: We enrolled first-ever patients with acute stroke conducting simultaneous assessments, including VFSS, modified Mann Assessment of Swallowing Ability score, tongue pressure measurement, and RSST. VFSS assessed aspiration, laryngeal penetration, oral cavity residue, vallecular residue, pharyngeal residue, and swallowing reflex delay. Screening tests were compared with VFSS findings, and multiple logistic analysis determined variable importance. Cutoff values for each abnormal VFSS finding were assessed using receiver operating characteristic analyses. We evaluated 346 patients (70.5±12.6 years of age, 143 women). The modified Mann Assessment of Swallowing Ability score was significantly associated with all findings except aspiration. Tongue pressure was significantly associated with oral cavity and pharyngeal residue. The RSST was significantly associated with all findings except oral cavity residue. Receiver operating characteristic analyses revealed that the minimum cutoff value for all VFSS abnormal findings was RSST ≤2. CONCLUSIONS: The modified Mann Assessment of Swallowing Ability is useful for broadly detecting swallowing disorders but may miss mild issues and aspiration. The RSST, with a score of ≤2, is valuable for indicating abnormal VFSS findings. Tongue pressure, especially in oral and pharyngeal residues, is useful. Combining these tests might enhance accuracy of the swallowing evaluation.

Usefulness of PETRA-MRA for Postoperative Follow-Up of Stent-Assisted Coil Embolization of Cerebral Aneurysms.

Objective: Image evaluation after stent-assisted coil embolization (SAC) for a cerebral aneurysm is difficult with conventional MRA or CTA because of metal artifacts. Pointwise encoding time reduction with radial acquisition (PETRA)-MRA is a noninvasive imaging examination that can reduce metal artifacts. This study aimed to examine whether PETRA-MRA can be used as a follow-up imaging after SAC. Methods: Twelve patients (eight women and four men; mean age, 66.9 ± 13.2 years) underwent SAC for unruptured aneurysms and were retrospectively evaluated using time-of-flight (TOF)- and PETRA-MRA data from the same follow-up session. Two neurosurgeons independently compared the aneurysm occlusion status and flow visualization score in the stented parent artery (4-point scale, where 4 points represented excellent visualization) between TOF- and PETRA-MRA images. If DSA was performed within 3 months before or after PETRA-MRA, the aneurysm assessment was compared between MRA and DSA. The interobserver agreement for each MRA was evaluated. Results: Nine of the 12 patients underwent DSA within 3 months before and after TOF- and PETRA-MRA. The aneurysm occlusion status on DSA was more consistent with PETRA-MRA (eight of nine cases) than with TOF-MRA (one of nine cases; P = 0.023). The median visualization score of the stented parent artery was significantly higher for PETRA-MRA (4 [interquartile range {IQR} 3-4]) than for TOF-MRA (1 [IQR 1-1], P = 0.003). The interobserver agreement for evaluation of the aneurysm occlusion status and visualization score of the parent artery for PETRA-MRA were excellent (κ = 0.98 and 0.93, respectively). In one case, PETRA-MRA was able to detect aneurysm recurrence, leading to subsequent retreatment. Conclusion: PETRA-MRA is a noninvasive examination that can be used to evaluate the occlusion status of aneurysms after SAC and visualize the stented parent artery. PETRA-MRA is useful for repeated follow-up examinations after SAC.

Peak expiratory flow, but not tongue pressure, can predict pneumonia development in older adults.

PURPOSE: Pneumonia is the leading cause of mortality and morbidity in aging populations. Major causes of pneumonia in older adults are swallowing dysfunction and decreased airway clearance capacity, including an impaired cough reflex. Maximal tongue pressure is useful for evaluating swallowing function, and peak expiratory flow indirectly reflects cough strength. However, it is unclear whether they can predict pneumonia development in older adults. In this study, we investigated whether tongue pressure and peak expiratory flow could predict pneumonia development in older adults. METHODS: This two-center prospective observational study included older adults aged 65 years or older without respiratory disease or head and neck cancer. We enrolled 383 consenting participants, many of whom had a history of stroke, and followed them for 2 years. The association between time to pneumonia development and tongue pressure or peak expiratory flow at enrollment was examined in a Cox proportional hazards model. RESULTS: The mean age of the participants was 77.1 ± 6.2 years, and 36.0% of them were women. The mean tongue pressure was 35.4 ± 10.5 kPa and median peak expiratory flow was 218 L/min at enrollment. Six patients developed pneumonia during the study period. A low peak expiratory flow at enrollment was significantly associated with pneumonia development in the multivariate Cox proportional hazards model, but this association was not observed for tongue pressure. CONCLUSION: Decreased peak expiratory flow may predict pneumonia development in older adults. Future studies should investigate interventions for peak expiratory flow improvement.

Association between Carotid Wall Shear Stress-Based Vascular Vector Flow Mapping and Cerebral Small Vessel Disease.

AIM: Wall shear stress (WSS) is the frictional force caused by viscous blood flowing along the vessel wall. Decreased WSS is associated with local vascular endothelial dysfunction and atherosclerosis. The vector flow mapping (VFM) technique detects the direction of intracardiac blood flow and WSS on the vessel wall with echocardiography. In this study, we examined carotid WSS by applying the VFM technique to the carotid arteries and evaluated its relationship with cerebral small vessel disease (SVD). METHODS: This is a single-center, prospective, observational study. We investigated the association between carotid WSS and SVD imaging, and cognitive outcomes in consecutive 113 patients with acute lacunar infarction. RESULTS: Carotid WSS was negatively associated with age (r=-0.376, p＜0.001). Lower WSS was correlated with total SVD scores (ρ=-0.304, p=0.004), especially with enlarged perivascular space (EPVS) in the basal ganglia ＞10 (p＜0.001). The carotid intima-media thickness was not associated with the total SVD score (ρ=-0.183, p=0.052). Moreover, lower WSS was associated with executive dysfunction. CONCLUSION: EPVS has recently been reported as a marker of early SVD imaging, and executive dysfunction is common in vascular cognitive impairment. These results suggested that decreased carotid WSS based on vascular VFM, which can be measured easily, is associated with imaging and cognitive changes in the early stages of SVD.

Diffusion-Weighted Imaging Hyperintensities in Acute and Subacute-Phase Intracerebral Hemorrhage.

OBJECTIVE: Diffusion-weighted imaging hyperintensities are observed in intracerebral hemorrhage patients at times and might be associated with unfavorable functional outcomes. However, the suitable time to evaluate diffusion-weighted imaging hyperintensities to influence stroke outcome remains unclear. This study investigated the associations between acute and sub-acute diffusion-weighted imaging hyperintensities and functional outcomes among patients with acute intracerebral hemorrhage. METHODS: Diffusion-weighted imaging hyperintensities were evaluated within 24 h (acute phase) and at 14 ± 5 days (sub-acute phase). An unfavorable functional outcome was a score of 5-6 on the modified Rankin Scale at 3 months. RESULTS: Among 268 intracerebral hemorrhage patients, diffusion-weighted imaging hyperintensities in the acute phase were observed in 32 (11.9%). Among 227 patients who underwent a second magnetic resonance imaging in the sub-acute phase, diffusion-weighted imaging hyperintensities were observed in 57 (25.1%). Multivariable analysis revealed that the baseline intracerebral hemorrhage volume, history of stroke, and severe white matter lesions were associated with sub-acute diffusion-weighted imaging hyperintensities. The patients with unfavorable outcomes (n = 37) had a higher frequency of sub-acute diffusion-weighted imaging hyperintensities than those without (n = 190) (51.4% vs. 20.0%, P < 0.001); the frequencies of acute diffusion-weighted imaging hyperintensities were not significantly different between the groups (13.5% vs. 10.0%, P = 0.559). Sub-acute diffusion-weighted imaging hyperintensities were independently associated with unfavorable outcomes after adjusting for confounding factors (Odds Ratio, 3.35, 95% CI 1.20-9.35, P = 0.021). CONCLUSION: The rate of sub-acute diffusion-weighted imaging hyperintensities was higher than acute diffusion-weighted imaging hyperintensities among acute intracerebral hemorrhage patients and likely to be associated with unfavorable outcomes.

Association of ankle-brachial index with cognitive decline in patients with lacunar infarction.

Atherosclerosis is an important risk factor for cognitive decline. This study aimed to investigate the relationship of ankle-brachial pressure index (ABI) and brachial-ankle pulse wave velocity (baPWV) with cognitive function in patients with lacunar infarction. We included records of consecutive patients with their first-ever acute stroke and a diagnosis of lacunar infarction through magnetic resonance imaging (MRI) from July 1, 2011 to December 31, 2018. We excluded patients diagnosed with dementia, including strategic single-infarct dementia, before or after stroke onset. Moreover, we excluded patients with one or more microbleeds, severe white matter lesions, or severe medial temporal atrophy on MRI. For ABI, we used the lower ankle side and divided the results into ABI < 1.0 and ABI ≥ 1.0. For baPWV, we used the higher ankle side and divided the results into two groups based on the median value of the participants. We analyzed 176 patients with stroke (age 72.5 ± 11.4 years, 67 females). The median score on the Mini-Mental State Examination (MMSE) was 27. The number of patients with ABI < 1.0 was 19 (10.8%). Univariate analysis revealed that the MMSE score was associated with age, body mass index, education, chronic kidney disease, periventricular hyperintensity, and ABI < 1.0 (p < 0.10), but not baPWV. Multivariate analysis revealed that body mass index (p = 0.039) and ABI < 1.0 (p = 0.015) were independently associated with the MMSE score. For patients with lacunar infarction, a lower ABI, but not a higher PWV, was associated with cognitive decline.

Effect of region-wide use of prehospital stroke triage scale on management of patients with acute stroke.

BACKGROUND: Prehospital stroke triage scales help with the decision to transport patients with suspected stroke to suitable hospitals. OBJECTIVE: To explore the effect of the region-wide use of the Japan Urgent Stroke Triage (JUST) score, which can predict several types of stroke: large vessel occlusion (LVO), intracranial hemorrhage (ICH), subarachnoid hemorrhage (SAH), and cerebral infarction other than LVO (CI). METHODS: We implemented the JUST score and conducted a retrospective and prospective multicenter cohort study at 13 centers in Hiroshima from April 1, 2018, to March 31, 2020. We investigated the success rate of the first request to the hospital, on-scene time, and transport time to hospital. We evaluated the door-to-puncture time, puncture-to-reperfusion time, and 90-day outcome among patients with final diagnoses of LVO. RESULTS: The cohort included 5141 patients (2735 before and 2406 after JUST score implementation). Before JUST score implementation, 1269 strokes (46.4%) occurred, including 140 LVO (5.1%), 394 ICH (14.4%), 120 SAH (4.4%), and 615 CI (22.5%). The JUST score was used in 1484 (61.7%) of the 2406 patients after implementation, which included 1267 (52.7%) cases of stroke (186 LVO (7.7%), 405 ICH (16.8%), 109 SAH (4.5%), and 567 CI (23.6%)). Success rate of the first request to the hospital significantly increased after JUST score implementation (76.3% vs 79.7%, p=0.004). JUST score implementation significantly shortened the door-to-puncture time (84 vs 73 min, p=0.03), but the prognosis remained unaltered among patients with acute LVO. CONCLUSIONS: Use of prehospital stroke triage scales improved prehospital management and preparation time of intervention among patients with acute stroke.

Characteristics and Prognostic Factors of Swallowing Dysfunction in Patients with Lateral Medullary Infarction.

OBJECTIVES: Lateral medullary infarction mainly impairs the pharyngeal phase of swallowing. We aimed to investigate the utility of the assessment tools of swallowing function in patients with lateral medullary infarction and to determine the factors that could predict the outcomes of swallowing function. MATERIALS AND METHODS: 15 patients with lateral medullary infarction who were admitted to Suiseikai Kajikawa Hospital between August 1, 2016, and March 31, 2020 (age 62.7 ± 14.8 years, 5 women) were enrolled in this prospective study. The diagnosis was made using brain magnetic resonance imaging. We analyzed the factors associated with severe swallowing dysfunction, which was defined as the necessity for tube feeding on the 90th day from admission, with multiple logistic regression analysis. RESULTS: Multivariate analyses identified the repetitive saliva swallowing test, modified water swallowing test, and vertical spread of stroke lesions as independent significant factors affecting severe swallowing dysfunction (p = 0.002, 0.016, and 0.011, respectively). The sub-scores of the pharyngeal phase of the Mann Assessment of Swallowing Ability were also significantly associated with severe swallowing dysfunction (p < 0.001). However, tongue pressure, severe passage pattern abnormality on videofluoroscopic examination, and vertebral artery dissection were not significantly associated with swallowing dysfunction. CONCLUSIONS: Since lateral medullary infarction presents with swallowing dysfunction mainly in the pharyngeal phase, tools that can be used to evaluate the pharyngeal phase of swallowing, such as repetitive saliva swallowing test and modified water swallowing test, are moreuseful than tongue pressure measurement.

Relationship between tongue pressure and dysphagia diet in patients with acute stroke.

A dysphagia diet is important for patients with stroke to help manage their nutritional state and prevent aspiration pneumonia. Tongue pressure measurement is a simple, non-invasive, and objective method for diagnosing dysphagia. We hypothesized that tongue pressure may be useful in making a choice of diet for patients with acute stroke. Using balloon-type equipment, tongue pressure was measured in 80 patients with acute stroke. On admission, a multidisciplinary swallowing team including doctors, nurses, speech therapists, and management dietitians evaluated and decided on the possibility of oral intake and diet form; the tongue pressure was unknown to the team. Diet form was defined and classified as dysphagia diet Codes 0 to 4 and normal form (Code 5 in this study) according to the 2013 Japanese Dysphagia Diet Criteria. In multivariate analysis, only tongue pressure was significantly associated with the dysphagia diet form (p<0.001). Receiver operating characteristic analyses revealed that the optimal cutoff tongue pressure for predicting diet Codes 1, 2, 3, 4, and 5 was 3.6 (p<0.001, area under the curve [AUC] = 0.997), 9.6 (p<0.001, AUC = 0.973), 12.8 (p<0.001, AUC = 0.963), 16.5 (p<0.001, AUC = 0.979), and 17.3 kPa (p<0.001, AUC = 0.982), respectively. Tongue pressure is one of the sensitive indicators for choosing dysphagia diet forms in patients with acute stroke. A combination of simple modalities will increase the accuracy of the swallowing assessment and choice of the diet form.

The right hemisphere is important for driving-related cognitive function after stroke.

Considering quality of life (QOL) after stroke, car driving is one of the most important abilities for returning to the community. In this study, directed attention and sustained attention, which are thought to be crucial for driving, were examined. Identification of specific brain structure abnormalities associated with post-stroke cognitive dysfunction related to driving ability would help in determining fitness for car driving after stroke. Magnetic resonance imaging was performed in 57 post-stroke patients (51 men; mean age, 63 ± 11 years) who were assessed for attention deficit using a standardized test (the Clinical Assessment for Attention, CAT), which includes a Continuous Performance Test (CPT)-simple version (CPT-SRT), the Behavioral Inattention Test (BIT), and a driving simulator (handle task for dividing attention, and simple and selective reaction times for sustained attention). A statistical non-parametric map (SnPM) that displayed the association between lesion location and cognitive function for car driving was created. From the SnPM analysis, the overlay plots were localized to the right hemisphere during handling the hit task for bilateral sides (left hemisphere damage related to right-side neglect and right hemisphere damage related to left-side neglect) and during simple and selective reaction times (false recognition was related to damage of both hemispheres). A stepwise multiple linear regression analysis confirmed the importance of both hemispheres, especially the right hemisphere, for cognitive function and car driving ability. The present study demonstrated that the right hemisphere has a crucial role for maintaining directed attention and sustained attention, which maintain car driving ability, improving QOL for stroke survivors.

Low-dose Contrast-induced Encephalopathy During Diagnostic Cerebral Angiography.

Contrast-induced encephalopathy (CIE) is a rare complication of contrast agent use. We herein report a case of acute lacunar infarction in a 70-year-old woman. During diagnostic cerebral angiography for asymptomatic common carotid stenosis, she experienced transient drowsiness. After angiography, generalized tonic-clonic seizures occurred in her left arm and leg, with eye deviation to the left. The patient was diagnosed with CIE due to the acute onset of symptoms during angiography and characteristic computed tomography findings of high-density signaling in the cortex. Our findings suggest that it is important to pay close attention to acute neurological symptoms during and immediately after examinations, even with small amounts of contrast agents.

Patient Health Questionnaire-9 predicts the functional outcome of stroke patients in convalescent rehabilitation ward.

INTRODUCTION: Poststroke depression (PSD) negatively affects the functional outcome of stroke patients. Patient Health Questionnaire-9 (PHQ-9) is a validated screening tool for detecting PSD. This study investigated the relationship between PHQ-9 score and functional outcomes in stroke patients in a convalescent rehabilitation ward by evaluating functional independence measure (FIM) gain scores and the proportion of patients discharged. METHODS: In this retrospective study conducted from January 2017 to September 2019, consecutive stroke patients who were admitted to the convalescent rehabilitation ward and could answer PHQ-9 were assessed. The association between PHQ-9 scores at the time of admission to the convalescent rehabilitation ward and outcomes (FIM gain score and the proportion of patients discharged) was statistically analyzed. RESULTS: Among the 215 patients enrolled in the study, 62 (28.8%) were assessed as having depression, in whom PHQ-9 scores were 5 or above. Multivariate analysis revealed that the PHQ-9 score on admission to the convalescent rehabilitation ward was a significant independent factor influencing the FIM gain score (p = .009). In addition, a multivariate analysis revealed that the PHQ-9 score at the time of admission to the convalescent rehabilitation ward was a significant independent factor influencing the inability to discharge a patient (odds ratio 1.24, 95% confidence interval 1.12-1.39, p < .001). CONCLUSIONS: The PHQ-9 score is a useful tool for predicting patient functional outcome, admission to the facility, and screening for poststroke depression.

Simplified cough test can predict the risk for pneumonia in patients with acute stroke.

We investigated the association between the results of a simplified cough test and pneumonia onset in 226 patients with acute stroke admitted to Suiseikai Kajikawa Hospital from April to December, 2018. For the simplified cough test, performed on admission, patients orally inhaled a mist of 1% citric acid-physiological saline using a portable mesh nebulizer. When the first cough was evoked or if it remained absent for 30 seconds (indicating an abnormal result), the test was ended. Patients also completed the repetitive saliva swallowing test (RSST) and modified water swallowing test. We monitored patients for pneumonia signs for 30 days post-admission. Eighteen patients exhibited an abnormal simplified cough test result. On multivariate analysis, an abnormal RSST result was independently associated with an abnormal simplified cough test result. Seventeen patients developed pneumonia. The adjusted Cox proportional hazard model for pneumonia onset revealed that the simplified cough test had predictive power for pneumonia onset (hazard ratio, 10.52; 95% confidence interval, 3.72-29.72). The simplified cough test is a strong indicator for predicting the pneumonia development in patients with acute stroke; it should be added to existing bedside screening tests for predicting pneumonia risk, allowing appropriate and timely intervention.

Tongue thickness measured by ultrasonography is associated with tongue pressure in the Japanese elderly.

The term "oral frailty" reflects the fact that oral health is associated with physical frailty and mortality. The gold standard methods for evaluating the swallowing function have several problems, including the need for specialized equipment, the risk of radiation exposure and aspiration, and general physicians not possessing the requisite training to perform the examination. Hence, several simple and non-invasive techniques have been developed for evaluating swallowing function, such as those for measuring tongue pressure and tongue thickness. The aim of this study was to investigate the relationship between tongue thickness ultrasonography and tongue pressure in the Japanese elderly. We evaluated 254 elderly patients, who underwent tongue ultrasonography and tongue pressure measurement. To determine tongue thickness, we measured the vertical distance from the surface of the mylohyoid muscle to the tongue dorsum using ultrasonography. The results of the analyses revealed that tongue thickness was linearly associated with tongue pressure in both sexes. In male participants, dyslipidemia, lower leg circumference, and tongue pressure were independently and significantly associated with tongue thickness. In female participants, body mass index and tongue pressure were independently and significantly associated with tongue thickness. The optimal cutoff for tongue thickness to predict the tongue pressure of < 20 kPa was 41.3 mm in males, and 39.3 mm in females. In the Japanese elderly, tongue thickness using ultrasonography is associated with tongue pressure. Tongue thickness and tongue pressure, which are sensitive markers for oral frailty, decrease with age. We conclude that tongue ultrasonography provides a less invasive technique for determining tongue thickness and predicts oral frailty for elderly patients.

Magnetic resonance vessel wall imaging predicts morphological deterioration in unruptured intracranial artery dissection.

OBJECTIVE: The mechanism involved in progression of unruptured intracranial artery dissection (IAD) is poorly understood. We investigated the relationship between contrast enhancement of dissecting lesions on magnetic resonance vessel wall imaging (MR-VWI) and unruptured IAD progression on the hypothesis that this finding might predict its instability. METHODS: A total of 49 unruptured IADs were investigated retrospectively. Three-dimensional T1-weighted fast spin-echo sequences were obtained before and after injection of contrast medium, and the dissecting lesion/pituitary stalk contrast enhancement ratio (CRstalk) was calculated. Unruptured IAD progression was defined as morphological deterioration; progressive dilatation or stenosis. The relations between unruptured IAD progression and potential risk factors were statistically investigated. RESULTS: Morphological deterioration was demonstrated in eleven of 49 unruptured IADs (22 %). The CRstalk value and male predominance was significantly higher in progressed IADs than stable ones (1.0 vs. 0.65; p = 0.0035, 82% vs 37%; p= 0.015, respectively). On stepwise multivariable logistic regression analysis, the CRstalk value was independently associated with unruptured IAD progression with odds ratio of 102.5 (95% CI, 2.59-4059, P=0.0013). The optimal cutoff value of CRstalk to estimate IADs with progression was 0.87 (sensitivity, 0.82; specificity, 0.74). Multimodalic images showed contrast enhancement on VWI corresponded to residual stagnant flow in dissecting lesions. CONCLUSIONS: Quantitative analysis of contrast enhancement on VWI could predict instability of unruptured IADs. Contrast enhancement in dissecting lesions would be a clue to understand the mechanism of unruptured IAD progression.

Early venous filling after reperfusion therapy in acute ischemic stroke.

BACKGROUND AND PURPOSE: Early venous filling after endovascular mechanical thrombectomy in acute ischemic stroke (AIS) is a specific finding that may serve as a biomarker for intracranial hemorrhage. However, the pathophysiology of early venous filling and postoperative hemorrhage remains unclear. The aim of this study was to investigate correlation between early venous filling and various factors involving patient demographics and perioperative imaging. METHODS: We prospectively analyzed 35 patients with AIS due to cardioembolism (CE) who underwent successful acute revascularization (TICI ≥2). Ischemic lesions were scored by magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI). Outcomes were assessed using the modified Rankin Scale (mRS) 90 days after stroke onset. Blood flow analysis was evaluated by MRI with arterial spin labeling (ASL). Early venous filling was assessed by digital subtraction angiography (DSA). Univariate analysis was performed to investigate correlations between early venous filling and patient demographics and imaging findings. RESULTS: Early venous filling was observed in 22 of 35 (66%) patients after reperfusion therapy. There was a significant correlation between early venous filling and DWI-ASPECTS (6.2 vs 8.8, p=0.0003), outcome (5 vs 9, p=0.006), hyperperfusion (17 vs 1, p< 0.0001), and hemorrhagic transformation (17 vs 1, p=0.005). CONCLUSIONS: This comprehensive study revealed that early venous filling after reperfusion therapy is associated with postoperative hyperperfusion. Early venous filling may be a marker of the process of hyperperfusion, leading to hemorrhage and an unfavorable outcome. Detection of early venous filling may be an important finding on DSA for subsequent intensive perioperative management.

Blood Flow Pattern Analysis for Carotid Plaque Evaluation.

BACKGROUND AND PURPOSE: Previous studies suggested that turbulent flow is closely related to plaque vulnerability. Two-dimensional (2D) flow analysis is a novel modality that enables real-time blood flow analysis by picturing particle movement in the contrast medium. We evaluated flow patterns in the carotid plaque to investigate the correlation between blood flow and plaque vulnerability. MATERIAL AND METHODS: A total of 36 consecutive patients with cervical carotid artery stenosis were evaluated. The flow pattern of carotid artery stenosis was evaluated using 2D real-time flow analysis in the digital subtraction angiography (DSA). The flow pattern was classified into either turbulent or laminar flow as vectors. Plaque vulnerability was evaluated on MR plaque imaging. Univariate analysis was performed to assess the correlation between the flow pattern and plaque features. RESULTS: The turbulent pattern was identified in 28 of 36 plaques (77.8%). Turbulence around plaques was significantly associated with Gadolinium enhancement (P = .0004). The maximum degree of stenosis (P = .0005) and concomitant ulceration (P = .02) were significantly associated with the turbulent pattern. There was no relationship between the turbulent pattern and clinical neurological symptoms. CONCLUSIONS: In the present study, the majority of carotid plaques exhibited a turbulent flow pattern, which was significantly associated with Gadolinium enhancement on MR plaque imaging and morphologic factors. Thus, real-time flow analysis may clarify the pathophysiology of plaque instability and the formation of ulceration.

Lessons from Vessel Wall Imaging of Intracranial Aneurysms: New Era of Aneurysm Evaluation beyond Morphology.

Recent basic studies have clarified that aneurysmal wall inflammation plays an important role in the pathophysiology of intracranial aneurysms. However, it remains an interdisciplinary challenge to visualize aneurysm wall status in vivo. MR-vessel wall imaging (VWI) is a current topic of advanced imaging techniques since it could provide an additional value for unruptured intracranial aneurysms (UIAs) risk stratification. With regard to ruptured intracranial aneurysms, VWI could identify a ruptured aneurysm in patients with multiple intracranial aneurysms. Intraluminal thrombus could be a clue to interpret aneurysm wall enhancement on VWI in ruptured intracranial aneurysms. The interpretation of VWI findings in UIAs would require much caution. Actually aneurysm wall enhancement in VWI was significantly associated with consensus morphologic risk factors. However, aneurysmal wall with contrast enhancement oftentimes associated with atherosclerotic, degenerated and thickened wall structure. It remains ill defined if thin wall without wall enhancement (oftentimes invisible in VWI) could be actually safe or look over wall vulnerability. We reviewed currently available studies, especially focusing on VWI for intracranial aneurysms and discussed the clinical utility of VWI.