A Comparison of CT Perfusion Output of RapidAI and Viz.ai Software in the Evaluation of Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: Automated CTP postprocessing packages have been developed for managing acute ischemic stroke. These packages use image processing techniques to identify the ischemic core and penumbra. This study aimed to investigate the agreement of decision-making rules and output derived from RapidAI and Viz.ai software packages in early and late time windows and to identify predictors of inadequate quality CTP studies. MATERIALS AND METHODS: One hundred twenty-nine patients with acute ischemic stroke who had CTP performed on presentation were analyzed by RapidAI and Viz.ai. Volumetric outputs were compared between packages by performing Spearman rank-order correlation and Wilcoxon signed-rank tests with subanalysis performed at early (<6 hours) and extended (>6 hours) time windows. The concordance of selecting patients on the basis of DAWN and DEFUSE 3 eligibility criteria was assessed using the McNemar test. RESULTS: One hundred eight of 129 patients were found to have adequate-quality studies. Spearman rank-order correlation coefficients were calculated on time-to-maximum >6-second volume, time-to-maximum >10-second volume, CBF <30% volume, mismatch volume, and mismatch ratio between both software packages with correlation coefficients of 0.82, 0.65, 0.77, 0.78, 0.59, respectively. The Wilcoxon signed-rank test was also performed on time-to-maximum >6-second volume, time-to-maximum >10-second volume, CBF <30% volume, mismatch volume, and mismatch ratio with P values of .30, .016, <.001, .03, <.001, respectively. In a 1-sided test, CBF <30% was greater in Viz.ai (P < .001). Although this finding resulted in statistically significant differences, it did not cause clinically significant differences when applied to the DAWN and DEFUSE 3 criteria. A lower ejection fraction predicted an inadequate study in both software packages (P = .018; 95% CI, 0.01-0.113) and (P = .024; 95% CI, 0.008-0.109) for RapidAI and Viz.ai, respectively. CONCLUSIONS: Penumbra and infarct core predictions between Rapid and Viz.ai correlated but were statistically different and resulted in equivalent triage using DAWN and DEFUSE3 criteria. Viz.ai predicted higher ischemic core volumes than RapidAI. Viz.ai predicted lower combined core and penumbra values than RapidAI at lower volumes and higher estimates than RapidAI at higher volumes. Clinicians should be cautious when using different software packages for clinical decision-making.

A Comparative Study of Hemorrhagic Conversion Patterns After Stroke Thrombolysis With Alteplase Versus Tenecteplase.

BACKGROUND AND PURPOSE: Tenecteplase is the thrombolytic drug of choice for acute ischemic stroke (AIS) as it has unique pharmacologic properties, along with results demonstrating its non-inferiority compared to alteplase. However, there are contradictory data concerning the risk of intracranial hemorrhage. The purpose of the study was to report the rate and patterns of symptomatic intracranial hemorrhage (sICH) in AIS patients after thrombolysis with tenecteplase compared to alteplase. METHODS: This is a retrospective cohort study with data collected 90 days before and after the change from alteplase to tenecteplase from 15 Texas stroke centers. The primary endpoint is the incidence of sICH according to the Safe Implementation of Thrombolysis in Stroke-Monitoring Study (SITS-MOST) and European Cooperative Acute Stroke Study III (ECASS-3) criteria. The secondary endpoints are the radiographic pattern of hemorrhagic conversion according to the Heidelberg bleeding classification (HBC). RESULTS: A total of 431 patients were eligible for thrombolytic therapy. Half of the cohort received alteplase (n=216), and the other half received tenecteplase (n=215). The average age of the alteplase group was 62.94 years old (SD=15.12) and 64.45 years old (SD=14.51) for the tenecteplase group. Seven patients in the alteplase group (3.2%) and 14 (6.5%) in the tenecteplase group had sICH, with an odds ratio of 1.44 (95% CI 0.60-3.43; P=0.41). An increased National Institutes of Health Stroke Scale (NIHSS) score on arrival (1.06; 95% CI 1.0004-1.131; P=0.04) was a statistically significant predictor of sICH. Tenecteplase was associated with a statistically significant increase in HBC-3 (P=0.040) over alteplase. CONCLUSIONS: Compared with alteplase, our study revealed a higher rate of sICH with tenecteplase that was not statistically significant and a higher rate of HBC-3 hemorrhages that was statistically significant. The proposed mechanism of bleeding is hemorrhagic conversion in clinically silent infarcts and contusions underlying the lesions. Further studies are needed to confirm our findings and determine predictive risk factors.

Encephalopathy with progression to posterior reversible encephalopathy pattern in a patient with COVID-19: clinical, imaging findings and follow-up.

Neurological conditions are being more recognised in patients with COVID-19, with encephalopathy being the most prevalent problem. Posterior reversible encephalopathy is suspected to occur due to elevated blood pressure and overproduction of inflammatory markers, both of which have been reported in the setting of COVID-19 infection. Encephalopathy was the main presentation in this case, without respiratory dysfunction initially, and with imaging findings indicative of posterior reversible encephalopathy syndrome as an aetiology. Follow-up imaging showed resolution of the abnormal results with mental status returning to baseline upon discharge.

COVID-19: Neuroimaging Features of a Pandemic.

BACKGROUND AND PURPOSE: The ongoing Coronavirus Disease 2019 (COVID-19) pandemic is caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). COVID-19 is occasionally associated with manifold diseases of the central nervous system (CNS). We sought to present the neuroimaging features of such CNS involvement. In addition, we sought to identify typical neuroimaging patterns that could indicate possible COVID-19-associated neurological manifestations. METHODS: In this systematic literature review, typical neuroimaging features of cerebrovascular diseases and inflammatory processes associated with COVID-19 were analyzed. Reports presenting individual patient data were included in further quantitative analysis with descriptive statistics. RESULTS: We identified 115 studies reporting a total of 954 COVID-19 patients with associated neurological manifestations and neuroimaging alterations. A total of 95 (82.6%) of the identified studies were single case reports or case series, whereas 660 (69.2%) of the reported cases included individual information and were thus included in descriptive statistical analysis. Ischemia with neuroimaging patterns of large vessel occlusion event was revealed in 59.9% of ischemic stroke patients, whereas 69.2% of patients with intracerebral hemorrhage exhibited bleeding in a location that was not associated with hypertension. Callosal and/or juxtacortical location was identified in 58.7% of cerebral microbleed positive images. Features of hemorrhagic necrotizing encephalitis were detected in 28.8% of patients with meningo-/encephalitis. CONCLUSIONS: Manifold CNS involvement is increasingly reported in COVID-19 patients. Typical and atypical neuroimaging features have been observed in some disease entities, so that familiarity with these imaging patterns appears reasonable and may assist clinicians in the differential diagnosis of COVID-19 CNS manifestations.

Clinical Outcomes and Neuroimaging Profiles in Nondisabled Patients With Anticoagulant-Related Intracerebral Hemorrhage.

Background and Purpose- The aim of this study was to prospectively validate our prior findings of smaller hematoma volume and lesser neurological deficit in nonvitamin K oral anticoagulant (NOAC) compared with Vitamin K antagonist (VKA)-related intracerebral hemorrhage (ICH). Methods- Prospective 12-month observational study in 15 tertiary stroke centers in the United States, Europe, and Asia. Consecutive patients with premorbid modified Rankin Scale score of <2 with acute nontraumatic anticoagulant-related ICH divided into 2 groups according to the type of anticoagulant: NOAC versus VKA. We recorded baseline ICH volume, significant hematoma expansion (absolute [12.5 mL] or relative [>33%] increase), neurological severity measured by National Institutes of Health Stroke Scale score, 90-day mortality, and functional status (modified Rankin Scale score). Results- Our cohort comprised 196 patients, 62 NOAC related (mean age, 75.0±11.4 years; 54.8% men) and 134 VKA related (mean age, 72.3±10.5; 73.1% men). There were no differences in vascular comorbidities, antiplatelet, and statin use; NOAC-related ICH patients had lower median baseline hematoma volume (13.8 [2.5-37.6] versus 19.5 [6.6-52.0] mL; P=0.026) and were less likely to have severe neurological deficits (National Institutes of Health Stroke Scale score of >10 points) on admission (37% versus 55.3%, P=0.025). VKA-ICH were more likely to have significant hematoma expansion (37.4% versus 17%, P=0.008). NOAC pretreatment was independently associated with smaller baseline hematoma volume (standardized linear regression coefficient:-0.415 [95% CI, -0.780 to -0.051]) resulting in lower likelihood of severe neurological deficit (odds ratio, 0.44; 95% CI, 0.22-0.85) in multivariable-adjusted models. Conclusions- Patients with NOAC-related ICH have smaller baseline hematoma volumes and lower odds of severe neurological deficit compared with VKA-related ICH. These findings are important for practicing clinicians making anticoagulation choices.

Dual antiplatelet therapy pretreatment in IV thrombolysis for acute ischemic stroke.

OBJECTIVE: We sought to determine the safety and efficacy of IV thrombolysis (IVT) in acute ischemic stroke (AIS) patients with a history of dual antiplatelet therapy pretreatment (DAPP) in a prospective multicenter study. METHODS: We compared the following outcomes between DAPP+ and DAPP- IVT-treated patients before and after propensity score matching (PSM): symptomatic intracranial hemorrhage (sICH), asymptomatic intracranial hemorrhage, favorable functional outcome (modified Rankin Scale score 0-1), and 3-month mortality. RESULTS: Among 790 IVT patients, 58 (7%) were on DAPP before stroke (mean age 68 ± 13 years; 57% men; median NIH Stroke Scale score 8). DAPP+ patients were older with more risk factors compared to DAPP- patients. The rates of sICH were similar between groups (3.4% vs 3.2%). In multivariable analyses adjusting for potential confounders, DAPP was associated with higher odds of asymptomatic intracranial hemorrhage (odds ratio = 3.53, 95% confidence interval: 1.47-8.47; p = 0.005) but also with a higher likelihood of 3-month favorable functional outcome (odds ratio = 2.41, 95% confidence interval: 1.06-5.46; p = 0.035). After propensity score matching, 41 DAPP+ patients were matched to 82 DAPP- patients. The 2 groups did not differ in any of the baseline characteristics or safety and efficacy outcomes. CONCLUSIONS: DAPP is not associated with higher rates of sICH and 3-month mortality following IVT. DAPP should not be used as a reason to withhold IVT in otherwise eligible AIS candidates. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that for IVT-treated patients with AIS, DAPP is not associated with a significantly higher risk of sICH. The study lacked the precision to exclude a potentially meaningful increase in sICH bleeding risk.

Evaluation of Acute Kidney Injury and Mortality After Intensive Blood Pressure Control in Patients With Intracerebral Hemorrhage.

BACKGROUND: We sought to assess the risk of acute kidney injury (AKI) and mortality associated with intensive systolic blood pressure reduction in acute intracerebral hemorrhage. METHODS AND RESULTS: Patients with acute intracerebral hemorrhage had spontaneous cause and symptom onset within 24 hours. We excluded patients with structural causes, coagulopathy, thrombocytopenia, and preexisting end-stage renal disease. We defined AKI using the Acute Kidney Injury Network criteria. Chronic kidney disease status was included in risk stratification and was defined by Kidney Disease Outcomes Quality Initiative staging. Maximum systolic blood pressure reduction was defined over a 12-hour period and dichotomized using receiver operating characteristic curve analysis. Descriptive statistics were done using independent sample t tests, χ2 tests, and Mann-Whitney U tests, whereas multivariable logistic regression analysis was used to evaluate for predictors for AKI and mortality. A total of 448 patients with intracerebral hemorrhage met inclusion criteria. Maximum systolic blood pressure reduction was dichotomized to 90 mm Hg and found to increase the risk of AKI in patients with normal renal function (odds ratio, 2.1; 95% confidence interval, 1.19-3.62; P=0.010) and chronic kidney disease (odds ratio, 3.91; 95% confidence interval, 1.26-12.15; P=0.019). The risk of AKI was not significantly different in normal renal function versus chronic kidney disease groups when adjusted for demographics, presentation characteristics, and medications associated with AKI. AKI positively predicted mortality for patients with normal renal function (odds ratio, 2.41; 95% confidence interval, 1.11-5.22; P=0.026) but not for patients with chronic kidney disease (odds ratio, 3.13; 95% confidence interval, 0.65-15.01; P=0.154). CONCLUSIONS: These results indicate that intensive systolic blood pressure reduction with a threshold >90 mm Hg in patients with acute intracerebral hemorrhage may be an independent predictor for AKI.

Therapeutic Benefit of Cilostazol in Patients with Aneurysmal Subarachnoid Hemorrhage: A Meta-Analysis of Randomized and Nonrandomized Studies.

OBJECTIVE: To assess the effectiveness of cilostazol, a selective inhibitor of phosphodiesterase type III, in preventing cerebral ischemia related to cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH). METHODS: A total of six clinical studies met the inclusion criteria and were included in the meta-analysis. We calculated pooled risk ratios (RR) and 95% confidence intervals (CI) using random-effects models. The primary endpoint was cerebral ischemia related to vasospasm. Secondary endpoints were angiographic vasospasm, new cerebral infarct, mortality, and death or disability at the final follow-up. RESULTS: A total of 136 (22%) of 618 subjects (38 and 98 assigned to cilostazol and control treatments, respectively) with SAH developed cerebral ischemia related to vasospasm. The risk of cerebral ischemia related to vasospasm was significantly lower in subjects assigned to cilostazol treatment (RR 0.43; 95% CI 0.31-0.60; p< 0.001). The risks of angiographic vasospasm (RR 0.67, 95% CI 0.54-0.84, p< 0.001 ) and new cerebral infarct (RR 0.37, 95% CI 0.24-0.57, p< 0.001) were significantly lower in subjects assigned to cilostazol treatment. There was a significantly lower rate of death or disability in subjects assigned to cilostazol treatment at follow-up (PR 0.55, 95% 0.39-0.78, p = 0.001). CONCLUSION: The reduction in rates of cerebral ischemia related to vasospasm and death or disability at follow-up support further evaluation of oral cilostazol in patients with aneurysmal SAH in a large randomized clinical trial.

Higher low-density lipoprotein cholesterol levels are associated with decreased mortality in patients with intracerebral hemorrhage.

BACKGROUND AND AIMS: The relationship between lipoprotein levels, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and clinical outcome after intracerebral hemorrhage (ICH) remains controversial. We sought to evaluate the association of lipoprotein cholesterol levels and statin dosage with clinical and neuroimaging outcomes in patients with ICH. METHODS: Data on consecutive patients hospitalized with spontaneous acute ICH was prospectively collected over a 5-year period and retrospectively analyzed. Demographic characteristics, clinical severity documented by NIHSS-score and ICH-score, neuroimaging parameters, pre-hospital statin use and doses, and LDL-C and HDL-C levels were recorded. Outcome events characterized were hematoma volume, hematoma expansion, in-hospital functional outcome, and in-hospital mortality. RESULTS: A total of 672 patients with acute ICH [(mean age 61.6 ± 14.0 years, 43.6% women, median ICH score 1 (IQR: 0-2)] were evaluated. Statin pretreatment was not associated with neuroimaging or clinical outcomes. Higher LDL-C levels were associated with several markers of poor clinical outcome and in-hospital mortality. LDL-C levels were independently and negatively associated with the cubed root of hematoma volume (linear regression coefficient -0.021, 95% CI: -0.042--0.001; p = 0.049) on multiple linear regression models. Higher admission LDL-C (OR 0.88, 95% CI 0.77-0.99; p = 0.048) was also an independent predictor for decreased hematoma expansion. Higher admission LDL-C levels were independently (p < 0.001) associated with lower likelihood of in-hospital mortality (OR per 10 mg/dL increase 0.68, 95% CI: 0.57-0.80) in multivariable logistic regression models. CONCLUSIONS: Higher LDL-C levels at hospital admission were an independent predictor for lower likelihood of hematoma expansion and decreased in-hospital mortality in patients with acute spontaneous ICH. This association requires independent confirmation.

Sulfonylurea drug pretreatment and functional outcome in diabetic patients with acute intracerebral hemorrhage.

PURPOSE: Intracerebral hemorrhage (ICH) is associated with poor clinical outcome and high mortality. Sulfonylurea (SFU) use may be a viable therapy for inhibiting sulfonylurea receptor-1 and NCCa-ATP channels and reducing perihematomal edema and blood-brain barrier disruption. We sought to evaluate the effects of prehospital SFU use with outcomes in diabetic patients with acute ICH. METHODS: We retrospectively analyzed a cohort of diabetic patients presenting with acute ICH at a tertiary care center. Study inclusion criteria included spontaneous ICH etiology and age>18years. Baseline clinical severity was documented using ICH-score. Hematoma volumes (HV) on admission were calculated using ABC/2 formula. Unfavorable functional outcome was documented as discharge modified Rankin Scale scores 2-6. RESULTS: 230 diabetic patients with acute ICH fulfilled inclusion criteria (mean age 64±13years, men 53%). SFU pretreatment was documented in 16% of the study population. Patients with SFU pretreatment had significantly (p<0.05) lower median ICH-scores (0, IQR: 0-2) and median admission HV (4cm3, IQR: 1-12) compared to controls [ICH-score: 1 (IQR: 0-3); HV: 9cm3 (IQR: 3-20)]. SFU pretreatment was independently (p=0.033) and negatively associated with the cubed root of admission HV (linear regression coefficient: -0.208; 95%CI: -0.398 to -0.017) in multiple linear regression analyses adjusting for potential confounders. Pretreatment with SFU was also independently (p=0.033) associated with lower likelihood of unfavorable functional outcome (OR=0.19; 95%CI: 0.04-0.88) in multivariable logistic regression models adjusting for potential confounders. CONCLUSION: SFU pretreatment may be an independent predictor for improved functional outcome in diabetic patients with acute ICH. This association requires independent confirmation in a large prospective cohort study.

Direct oral anticoagulant- vs vitamin K antagonist-related nontraumatic intracerebral hemorrhage.

OBJECTIVE: To compare the neuroimaging profile and clinical outcomes among patients with intracerebral hemorrhage (ICH) related to use of vitamin K antagonists (VKAs) or direct oral anticoagulants (DOACs) for nonvalvular atrial fibrillation (NVAF). METHODS: We evaluated consecutive patients with NVAF with nontraumatic, anticoagulant-related ICH admitted at 13 tertiary stroke care centers over a 12-month period. We also performed a systematic review and meta-analysis of eligible observational studies reporting baseline characteristics and outcomes among patients with VKA- or DOAC-related ICH. RESULTS: We prospectively evaluated 161 patients with anticoagulation-related ICH (mean age 75.6 ± 9.8 years, 57.8% men, median admission NIH Stroke Scale [NIHSSadm] score 13 points, interquartile range 6-21). DOAC-related (n = 47) and VKA-related (n = 114) ICH did not differ in demographics, vascular risk factors, HAS-BLED and CHA2DS2-VASc scores, and antiplatelet pretreatment except for a higher prevalence of chronic kidney disease in VKA-related ICH. Patients with DOAC-related ICH had lower median NIHSSadm scores (8 [3-14] vs 15 [7-25] points, p = 0.003), median baseline hematoma volume (12.8 [4-40] vs 24.3 [11-58.8] cm3, p = 0.007), and median ICH score (1 [0-2] vs 2 [1-3] points, p = 0.049). Severe ICH (>2 points) was less prevalent in DOAC-related ICH (17.0% vs 36.8%, p = 0.013). In multivariable analyses, DOAC-related ICH was independently associated with lower baseline hematoma volume (p = 0.006), lower NIHSSadm scores (p = 0.022), and lower likelihood of severe ICH (odds ratio [OR] 0.34, 95% confidence interval [CI] 0.13-0.87, p = 0.025). In meta-analysis of eligible studies, DOAC-related ICH was associated with lower baseline hematoma volumes on admission CT (standardized mean difference = -0.57, 95% CI -1.02 to -0.12, p = 0.010) and lower in-hospital mortality rates (OR = 0.44, 95% CI 0.21-0.91, p = 0.030). CONCLUSIONS: DOAC-related ICH is associated with smaller baseline hematoma volume and lesser neurologic deficit at hospital admission compared to VKA-related ICH.

Elevated Pulse Pressure Levels Are Associated With Increased In-Hospital Mortality in Acute Spontaneous Intracerebral Hemorrhage.

OBJECTIVES: Clinical outcome after intracerebral hemorrhage (ICH) remains poor. Definitive phase-3 trials in ICH have failed to demonstrate improved outcomes with intensive systolic blood pressure (SBP) lowering. We sought to determine whether other BP parameters-diastolic BP (DBP), pulse pressure (PP), and mean arterial pressure (MAP)-showed an association with clinical outcome in ICH. METHODS: We retrospectively analyzed a prospective cohort of 672 patients with spontaneous ICH and documented demographic characteristics, stroke severity, and neuroimaging parameters. Consecutive hourly BP recordings allowed for computation of SBP, DBP, PP, and MAP. Threshold BP values that transitioned patients from survival to death were determined from ROC curves. Using in-hospital mortality as outcome, BP parameters were evaluated with multivariable logistic regression analysis. RESULTS: Patients who died during hospitalization had higher mean PP compared to survivors (68.5 ± 16.4 mm Hg vs. 65.4 ± 12.4 mm Hg; P = 0.032). The following admission variables were associated with significantly higher in-hospital mortality (P < 0.001): poorer admission clinical condition, intraventricular hemorrhage, and increased admission normalized hematoma volume. ROC analysis showed that mean PP dichotomized at 72.17 mm Hg, provided a transition point that maximized sensitivity and specific for mortality. The association of this increased dichotomized PP with higher in-hospital mortality was maintained in multivariable logistic regression analysis (odds ratio, 3.0; 95% confidence interval, 1.7-5.3; P < 0.001) adjusting for potential confounders. CONCLUSION: Widened PP may be an independent predictor for higher mortality in ICH. This association requires further study.

Neurogenic stunned myocardium in subarachnoid hemorrhage.

"Stunned myocardium," characterized by reversible left ventricular dysfunction, was first described via animal models using transient coronary artery occlusion. However, this phenomenon has also been noted with neurologic pathologies and collectively been labeled "neurogenic stunned myocardium" (NSM). Neurogenic stunned myocardium resulting from subarachnoid hemorrhage (SAH) is a challenging pathology due to its diagnostic uncertainty. Traditional diagnostic criteria for NSM after SAH focus on electrocardiographic and echocardiographic abnormalities and troponemia. However, tremendous heterogeneity still exists. Traditional pathophysiological mechanisms for NSM encompassed hypothalamic and myocardial perivascular lesions. More recently, research on pathophysiology has centered on myocardial microvascular dysfunction and genetic polymorphisms. Catecholamine surging as a mechanism has also gained attention with particular focus placed on the role of adrenergic blockade in both the prehospital and acute settings. Management remains largely supportive with case reports acknowledging the utility of inotropes such as dobutamine and milrinone and intra-aortic balloon pump when NSM is accompanied by cardiogenic shock. Neurogenic stunned myocardium that follows SAH can result in many complications such as arrhythmias, pulmonary edema, and prolonged intubation, which can negatively impact long-term recovery from SAH and increase morbidity and mortality. This necessitates the need to accurately diagnose and treat NSM.

FABS: An Intuitive Tool for Screening of Stroke Mimics in the Emergency Department.

BACKGROUND AND PURPOSE: A large number of patients with symptoms of acute cerebral ischemia are stroke mimics (SMs). In this study, we sought to develop a scoring system (FABS) for screening and stratifying SM from acute cerebral ischemia and to identify patients who may require magnetic resonance imaging to confirm or refute a diagnosis of stroke in the emergency setting. METHODS: We designed a scoring system: FABS (6 variables with 1 point for each variable present): absence of Facial droop, negative history of Atrial fibrillation, Age <50 years, systolic Blood pressure <150 mm Hg at presentation, history of Seizures, and isolated Sensory symptoms without weakness at presentation. We evaluated consecutive patients with symptoms of acute cerebral ischemia and a negative head computed tomography for any acute finding within 4.5 hours after symptom onset in 2 tertiary care stroke centers for validation of FABS. RESULTS: A total of 784 patients (41% SMs) were evaluated. Receiver operating characteristic curve (C statistic, 0.95; 95% confidence interval [CI], 0.93-0.98) indicated that FABS≥3 could identify patients with SM with 90% sensitivity (95% CI, 86%-93%) and 91% specificity (95% CI, 88%-93%). The negative predictive value and positive predictive value were 93% (95% CI, 90%-95%) and 87% (95% CI, 83%-91%), respectively. CONCLUSIONS: FABS seems to be reliable in stratifying SM from acute cerebral ischemia cases among patients in whom the head computed tomography was negative for any acute findings. It can help clinicians consider advanced imaging for further diagnosis.