Nasr, Deena M.

Background Computed tomography (CT) angiography collateral score (CTA-CS) is an important clinical outcome predictor following mechanical thrombectomy for ischemic stroke with large vessel occlusion (LVO). The present multireader study aimed to evaluate the performance of e-CTA software for automated assistance in CTA-CS scoring. Materials and Methods Brain CTA images of 56 patients with anterior LVO were retrospectively processed. Twelve readers of various clinical training, including junior neuroradiologists, senior neuroradiologists, and neurologists graded collateral flow using visual CTA-CS scale in two sessions separated by a washout period. Reference standard was the consensus of three expert readers. Duration of reading time, inter-rater reliability, and statistical comparison of readers’ performance metrics were analyzed between the e-CTA assisted and unassisted sessions. Results e-CTA assistance resulted in significant increase in mean accuracy (58.6% to 67.5%, p = 0.003), mean F1 score (0.574 to 0.676, p = 0.002), mean precision (58.8% to 68%, p = 0.007), and mean recall (58.7% to 69.9%, p = 0.002), especially with slight filling deficit (CTA-CS 2 and 3). Mean reading time was reduced across all readers (103.4 to 59.7 s, p = 0.001), and inter-rater agreement in CTA-CS assessment was increased (Krippendorff's alpha 0.366 to 0.676). Optimized occlusion laterality detection was also noted with mean accuracy (92.9% to 96.8%, p = 0.009). Conclusion Automated assistance for CTA-CS using e-CTA software provided helpful decision support for readers in terms of improving scoring accuracy and reading efficiency for physicians with a range of experience and training backgrounds and leading to significant improvements in inter-rater agreement.

In this case series, we describe a novel observation in which 4 patients with acute ischemic stroke secondary to large vessel occlusion and no history of seizure present with focal seizure activity localizable to a chronic, contralateral infarct. The explanation for this phenomenon is unknown but may be due to a combination of effects involving disrupted interhemispheric inhibitory connections and epileptogenic changes involving chronically infarcted tissue.

Objective: Using the Nationwide Inpatient Sample (NIS), we determined morbidity, mortality and trends in ischemic and hemorrhagic stroke complications in patients receiving Extracorporeal Membranous Oxygenation (ECMO). Materials and Methods: Using the NIS from 2001-2011, patients receiving ECMO were identified. We analyzed their ischemic and hemorrhagic stroke complication rates and compared discharge status between these patients and those without cerebrovascular complications. Morbidity was defined as discharge to a long-term facility. Ischemic and hemorrhagic stroke rates were compared between two time periods (2001-2006 and 2007-2011). Continuous variables were compared with a student’s t-test and categorical variables were compared with the chi-squared test. Results: A total of 23,950 ECMO patients were included in this study of which 22108 patients (92.3%) had no cerebrovascular complications, 980 patients (4.1%) had ischemic stroke and 862 patients (3.6%) had hemorrhagic stroke. Of those without cerebrovascular complications there was a 49.9% mortality rate and a 6.8% morbidity rate. Patients with ischemic stroke had a mortality rate of 44.3% (P=0.0006) and a morbidity rate of 14.6% (P<0.0001). Patients with hemorrhagic stroke had a mortality rate of 59.7% (P<0.0001) and a morbidity rate of 9.5% (P=0.002). The proportion of patients with ischemic stroke increased from 2.8% in 2001-2006 to 5.1% in 2007-2011 (P<0.0001) and patients with hemorrhagic stroke increased from 2.4% in 2001-2006 to 4.5% in 2007-2011(P<0.0001). Conclusion: ECMO patients complicated with ischemic and hemorrhagic stroke had higher morbidity than those with no cerebrovascular complications. Patients with hemorrhagic stroke had a 10% worsened mortality rate than those with no cerebrovascular complications. The proportion of ECMO patients with cerebrovascular complications has nearly doubled between 2001-2011.

Objective: To determine trends in tPA utilization, treatment outcomes and predictors of mortality for pediatric patients with acute ischemic stroke. Materials and Methods: Using the Nationwide Inpatient Sample (NIS) from 2001-2010, pediatric patients (age < 18 years) with the primary diagnosis of ischemic stroke were identified. We studied time trends of utilization of intravenous rtPA and outcomes after thrombolysis. We also analyzed the associations of demographic factors, comorbidities, and complications of acute ischemic stroke with in-hospital mortality. Results: A total of 7,379 patients were included in this study. In-hospital mortality was 4.5%. The co-morbidities associated with the highest rates of in-hospital mortality were mitochondrial disorders (19.5%, P<0.0001) and hypercoagulable states (10.9%, p<0.0001). The main complications associated with increased mortality were intracranial hemorrhage (19.9%, p<0.0001), sepsis (13.2%, p<0.0001) and pneumonia (9.3%, p=0.0007). tPA utilization rate was 1.3% (99 patients). tPA utilization increased from 0.9% of patients in 2001-2005 to 1.9% of patients in 2006-2010 (P<0.0001). While patients who received tPA did not have higher mortality rates than non-tPA patients (0.0% versus 5.5%, P=0.06), there was an increased discharge-to-long-term-facilities rate in the tPA group (50.8% versus 12.1%, P<0.0001). Conclusion: Acute ischemic stroke in the pediatric population is associated with a higher mortality rate when related to mitochondriopathies or hypercoagulability. Patients suffering complications such as intracranial hemorrhage, sepsis and pneumonia have higher mortality. rtPA utilization is increasing in pediatric patients with acute ischemic stroke. Pediatric patients receiving tPA have a low risk of fatal hemorrhage. Although patients receiving rtPA have higher rates of morbidity, this may be related to worse stroke severity in these cases.

Background and Purpose: Ultrasound is the most commonly used imaging modality for assessment of carotid artery stenosis. A number of studies have demonstrated that surface irregularities, heterogeneous echotexture and hypoechoic plaques are risk factors for acute ischemic stroke. We performed a systematic review and meta-analysis of the literature to better define the risk of stroke based off of the sonographic characteristics of carotid plaques. Materials and Methods: We performed a comprehensive literature search evaluating the association of carotid plaque characteristics on ultrasound with ischemic outcomes. We included both case-control and cohort studies examining the relationship between complex plaque and acute ischemic stroke. Complex plaque was defined as plaque that had any of the following characteristics: heterogeneous plaque echogenicity, hypoechoic plaque, plaque neovascularization, plaque surface irregularity, plaque ulceration, and intraplaque motion. Meta-analyses using the random-effects model were performed for complex plaque and each of the individual complex plaque characteristics. Results: A total of 1013 articles were screened and 30 studies with 11528 patients (3054 symptomatic and 8474 asymptomatic) were included. The odds ratios for the association between complex plaque and ischemic symptoms was 5.18 (95%CI=4.63-5.79). Heterogeneous echotexture (OR=11.72, 95%CI=9.82-13.98), intraplaque motion (OR=1.57, 95%CI=1.02-2.41), plaque echolucency (OR=3.23, 95%CI=2.72-3.84), plaque neovascularity (OR=5.66, 95%CI=3.15-10.16) and plaque ulceration (OR=2.65, 95%CI=1.89-3.73) were all associated with ischemic symptoms. Surface irregularity without frank ulceration was not associated with ischemic symptoms (OR=1.35, 95%CI=0.98-1.86). Conclusions: Complex plaque, heterogeneous plaque echogenicity, hypoechoic plaque, plaque neovascularization, plaque ulceration and intraplaque motion are associated with ischemic symptoms. Assessment of carotid plaque on ultrasound provides stroke risk information beyond measurement of luminal stenosis.

Background and Purpose: Although IV tissue plasminogen activator (tPA) is standard care for acute ischemic strokes (AIS), its administration continues to be a topic of controversy among patients with dementia. This study compared in-hospital outcomes for dementia versus non-dementia patients treated with IV tPA for acute ischemic strokes. Materials and Methods: Using the Nationwide Inpatient Sample (NIS) from 2001-2010, patients with the primary diagnosis of ischemic stroke were identified. We studied outcomes of IV-tPA treatment for acute ischemic stroke in patients with dementia versus a non-dementia control group. Using a 1:2 matched propensity score analysis we controlled for demographic factors, cardiovascular comorbidities and Charlson comorbidity index between groups. Outcomes studied included in-hospital mortality, hospital discharge status and intracranial hemorrhage (ICH). Results: A total of 24,904 patients with acute ischemic strokes who underwent IV tPA therapy for AIS were included in this study. 659 of which had a diagnosis of dementia. After 1:2 matching based off of age, gender, cardiovascular risk factors and Charlson comorbidity index there were a total of 657 patients in the dementia group and 1314 patients in the non-dementia group. Patient outcomes after propensity core analysis showed no difference with in-hospital mortality in the dementia group vs. control (13% vs 14%, p=0.67), discharge to long-term care facilities (63% vs 59%, p=0.08) and ICH (7.9% vs. 9.1%, p=0.86). Conclusions: There was no statistically significant difference in in-hospital mortality, discharge status or ICH rates in patients with AIS and dementia who received IV tPA compared to those without dementia. These results suggest that dementia is not a predictor of poor in-hospital outcome following IV tPA administration for AIS. Further longitudinal studies are needed to determine if IV tPA therapy would improve long-term outcomes for dementia patients with AIS.

OBJECTIVE Symptomatic nonsaccular vertebrobasilar aneurysms (NSVBAs) are associated with high rates of aneurysm-related death. Anecdotal evidence suggests that brainstem infarction may be a harbinger of aneurysm rupture. The authors aimed to investigate the association between brainstem infarction and subsequent NSVBA rupture. METHODS The clinical records and radiographic imaging studies of patients presenting to the authors’ institution between 1996 and 2019 for evaluation and management of an NSVBA were retrospectively reviewed to determine the effect of perforating artery infarction on the natural history of NSVBAs. Kaplan-Meier curves for patients with and patients without perforator infarction were constructed, and predictors of aneurysm rupture were identified using a multivariate Cox proportional hazards model. RESULTS There were 98 patients with 591.3 person-years of follow-up who met the inclusion criteria for analysis. There were 20 patients who experienced perforator infarction during follow-up. Ten patients (10.2%) experienced aneurysm rupture during follow-up and 26 patients (26.5%) died due to aneurysm-related complications, with annual rates of rupture and aneurysm-related death of 1.7% and 4.4%, respectively. Five patients with a perforator infarction later experienced aneurysm rupture, with a median time between infarction and rupture of 3 months (range 0–35 months). On multivariate analysis, the presence of intraaneurysmal thrombus (risk ratio [RR] 4.01, 95% confidence interval [CI] 1.12–14.44, p = 0.033) and perforator infarction (RR 6.37, 95% CI 1.07–37.95, p = 0.042) were independently associated with risk of aneurysm rupture. CONCLUSIONS NSVBAs continue to be extremely challenging clinical entities with a poor prognosis. These results suggest that brainstem infarction due to perforating artery occlusion may be a harbinger of near-term aneurysm rupture.

Carotid web is thought to be a focal intimal variant of fibromuscular dysplasia, which comprises a high risk of stroke because of blood stasis and subsequent coagulative reactions that occur distal to the web. These lesions generally involve the posterolateral wall of the carotid and their developmental pathogenesis is controversial. This case report describes a 51-year-old woman who presented to the hospital with sudden onset aphasia, right hemi-sensory loss, and right visual field cut. Magnetic resonance imaging (MRI) of the brain demonstrated a left middle cerebral artery (MCA) distribution embolic ischemic infarct with shelf-like linear filling defects in the carotid bulb bilaterally on a computed tomography angiography (CTA) of the head and neck consistent with bilateral carotid webs that were confirmed by catheter angiography. The carotid webs were projecting on the left posteriorly and on the right anteriorly into the inferior aspects of the bilateral proximal internal carotid arteries. The patient was started on clopidogrel and a high-intensity statin and remained on Plavix monotherapy for a 10-month follow up without a recurrent ischemic event.

Introduction There is increased interest in the use of artificial intelligence-based (AI) software packages in the evaluation of neuroimaging studies for acute ischemic stroke. We studied whether, compared to standard image interpretation without AI, Brainomix e-ASPECTS software improved interobserver agreement and accuracy in detecting ASPECTS regions affected in anterior circulation LVO. Methods We included 60 consecutive patients with anterior circulation LVO who had TICI 3 revascularization within 60 minutes of their baseline CT. A total of 16 readers, including senior neuroradiologists, junior neuroradiologists and vascular neurologists participated. Readers interpreted CT scans on independent workstations and assessed final ASPECTS and evaluated whether each individual ASPECTS region was affected. Two months later, readers again evaluated the CT scans, but with assistance of e-ASPECTS software. We assessed interclass correlation coefficient for total ASPECTS and interobserver agreement with Fleiss’ Kappa for each ASPECTS region with and without assistance of the e-ASPECTS. We also assessed accuracy for the readers with and without e-ASPECTS assistance. In our assessment of accuracy, ground truth was the 24 hour CT in this cohort of patients who had prompt and complete revascularization. Results Interclass correlation coefficient for total ASPECTS without e-ASPECTS assistance was 0.395, indicating fair agreement compared, to 0.574 with e-ASPECTS assistance, indicating good agreement (P < 0.01). There was significant improvement in inter-rater agreement with e-ASPECTS assistance for each individual region with the exception of M6 and caudate. The e-ASPECTS software had higher accuracy than the overall cohort of readers (with and without e-ASPECTS assistance) for every region except the caudate. Conclusions Use of Brainomix e-ASPECTS software resulted in significant improvements in inter-rater agreement and accuracy of ASPECTS score evaluation in a large group of neuroradiologists and neurologists. e-ASPECTS software was more predictive of final infarct/ASPECTS than the overall group interpreting the CT scans with and without e-ASPECTS assistance.