Subcortical infarcts in patients with nonstenotic cervical atherosclerotic disease.

BACKGROUND: Prior studies have elucidated a relationship between nonstenotic plaque in patients with cryptogenic embolic infarcts with a largely cortical topology, however, it is unclear if nonstenotic cervical internal carotid artery (ICA) plaque is relevant in subcortical cryptogenic infarct patterns. METHODS: A nested cohort of consecutive patients with anterior, unilateral, and subcortical infarcts without an identifiable embolic source were identified from a prospective stroke registry (September 2019 - June 2021). Patients with extracranial stenosis >50% or cardiac sources of embolism were excluded. Patients with computed tomography angiography were included and comparisons were made according to the infarct pattern being lacunar versus non-lacunar. Prevalence estimates for cervical internal carotid artery (ICA) plaque presence were estimated with 95% confidence intervals (CI), and differences in plaque thickness and features were compared between sides. RESULTS: Of the 1684 who were screened, 141 met inclusion criteria (n=80 due to small vessel disease, n=61 cryptogenic). The median age was 66y (interquartile range, IQR 58-73) and the National Institutes of Health Stroke Scale score was 3 (IQR 1-5). There was a higher probability of finding excess plaque ipsilateral to the stroke (41.1%, 95% CI 33.3-49.3%) than finding excess contralateral plaque (29.1%, 95% CI 22.2-37.1%; p=0.03), but this was driven by patients with non-lacunar infarcts (excess ipsilateral vs. contralateral plaque frequency of 49.2% vs. 14.8%, p<0.001) rather than lacunar infarcts (35.0% vs. 40.0%, p=0.51). CONCLUSIONS: The probability of finding ipsilateral, nonstenotic carotid plaque in patients with subcortical cryptogenic strokes exceeds the probability of contralateral plaque and is driven by larger subcortical infarcts, classically defined as being cryptogenic. Approximately 1 in 3 unilateral anterior subcortical infarcts may be due to nonstenotic ICA plaque.

Age Alters Prevalence of Left Atrial Enlargement and Nonstenotic Carotid Plaque in Embolic Stroke of Undetermined Source.

BACKGROUND: Nonstenotic carotid plaque and undetected atrial fibrillation are potential mechanisms of embolic stroke of undetermined source (ESUS), but it is unclear which is more likely to be the contributing stroke mechanism. We explored the relationship between left atrial enlargement (LAE) and nonstenotic carotid plaque across age ranges in an ESUS population. METHODS: A retrospective multicenter cohort of consecutive patients with unilateral, anterior circulation ESUS was queried (2015 to 2021). LAE and plaque thickness were determined by transthoracic echocardiography and computed tomography angiography, respectively. Descriptive statistics were used to compare plaque features in relation to age and left atrial dimensions. RESULTS: Among the 4155 patients screened, 273 (7%) met the inclusion criteria. The median age was 65 years (interquartile range [IQR] 54-74), 133 (48.7%) were female, and the median left atrial diameter was 3.5 cm (IQR 3.1-4.1). Patients with any LAE more frequently had hypertension (85.9% versus 67.2%, P<0.01), diabetes (41.0% versus 25.6%, P=0.01), dyslipidemia (56.4% versus 40.0%, P=0.01), and coronary artery disease (22.8% versus 11.3%, P=0.02). Carotid plaque thickness was greater ipsilateral versus contralateral to the stroke hemisphere in the overall cohort (median 1.9 mm [IQR 0-3] versus 1.5 mm [IQR 0-2.6], P<0.01); however, this was largely driven by the subgroup of patients without any LAE (median 1.8 mm [IQR 0-2.9] versus 1.5 mm [IQR 0-2.5], P<0.01). Compared with patients ≥70 years, younger patients had more carotid plaque ipsilateral versus contralateral (mean difference 0.42 mm±1.24 versus 0.08 mm±1.54, P=0.047) and less moderate-to-severe LAE (6.3% versus 15.3%, P=0.02). CONCLUSIONS: Younger patients with ESUS had greater prevalence of ipsilateral nonstenotic plaque, while the elderly had more LAE. The differential effect of age on the probability of specific mechanisms underlying ESUS should be considered in future studies.

Clinical and radiographic phenotypes of patients with multifocal subcortical versus cortical cerebral infarcts.

BACKGROUND AND PURPOSE: Infarct topology is a key determinant in classification of a stroke as potentially embolic, with cortical and multifocal lesions being presumed embolic. Whether isolated subcortical multifocal infarcts are likely embolic has not been well studied. METHODS: A prospective, single-center cohort study of consecutive patients with acute multifocal strokes confirmed on diffusion-weighting imaging (DWI) was queried, and patients compared according to the presence of isolated subcortical infarct topology versus cortical ± subcortical topology. Descriptive statistics and multivariable logistic regression were used to determine independent predictors of cryptogenic, subcortical infarcts. RESULTS: Of 1739 patients screened, 743 had complete diagnostic testing with DWI evidence of acute infarction, 183 (24.6%) of whom had a multifocal stroke pattern. Isolated subcortical involvement was disproportionate among patients with ESUS (64.9%) when compared to patients with cardioembolic (24.3%) or large vessel disease (10.8%, p<0.01). Following multivariable adjustment, independent predictors of isolated subcortical multifocal infarction were milder strokes (OR 0.94, 95%CI 0.89-0.98) and higher grade Fazekas score (OR 2.32, 95%CI 1.02-5.29), while cardioembolism (OR 0.30, 95%CI 0.08-1.13) and large vessel disease (OR 0.27, 95%CI 0.08-0.91) remained inversely associated (as compared to ESUS). CONCLUSIONS: These data suggest that multifocal subcortical infarctions are less likely to have an associated proximal embolic source than multifocal infarctions with cortical involvement. The strong association with chronic microvascular disease suggests this topology is more consistent with acute-on-chronic microvascular injury rather than an occult embolic source.

Embolic infarct topology differs between atrial fibrillation subtypes and embolic stroke of undetermined source.

BACKGROUND: The lack of superiority of anticoagulation over antiplatelet therapy in embolic stroke of undetermined source (ESUS) may be in part due to the misclassification of radiographic ESUS patterns as cardioembolic. In this imaging analysis, we sought to differentiate clinical and radiographic patterns of ESUS patients from patterns in patients with a highly probable cardioembolic source. MATERIALS & METHODS: A prospective registry of consecutive adults with acute infarction on diffusion-weighted magnetic resonance imaging was queried. Patients with infarctions due to small vessel disease, large vessel disease, and other causes were excluded. Multivariable logistic regression was used to identify independent predictors of two potentially embolic patterns: (1) multifocal and (2) cortical lesions, comparing patients with ESUS against those with atrial fibrillation (AF). RESULTS: Among 1243 screened patients, 343 (27.6%) experienced strokes due to ESUS or AF. Prior to the index stroke, patients with AF as compared to ESUS were older (median 75 vs. 65, p<0.01) and had more heart failure (25.9% vs. 8.4%, p<0.01). The odds of multifocal infarction were the same between patients with ESUS and both AF subtypes (p>0.05), however, cortical involvement was more associated with both AF versus ESUS (77.7% vs. 65.7%, P=0.02). A higher Fazekas grade of white matter disease was inversely associated with cortical infarction among included patients (aOR 0.77, 95% CI 0.62-0.96). CONCLUSION: Cortical infarctions were twice as common among patients with AF versus ESUS. Subcortical infarct topography was strongly associated with chronic microvascular ischemic changes and therefore may not represent embolic phenomena. Larger-scale investigations are warranted to discern whether large or multifocal subcortical infarcts ought to be excluded from the ESUS designation.

Functional Recovery in Patients with Acute Stroke and Pre-Existing Disability: A Natural History Study.

OBJECTIVES: We aimed to determine which factors influence recovery in stroke patients with pre-existing disability, as these patients are often excluded from acute treatment trials. MATERIALS AND METHODS: A prospective stroke center registry of admitted patients from 2019-2021 with acute stroke was queried for patients with pre-stroke modified Rankin Scale (mRS) of 0-4. Multivariable logistic regression was used to estimate odds of functional recovery at 90 days (mRS 0-2, or return to pre-stroke mRS). RESULTS: Of 1228 patients, 856 (70%) included patients had pre-stroke mRS 0-4 and 90-day follow-up mRS. The median age was 68y (IQR 59-78), with a median National Institutes of Health Stroke Scale (NIHSS) of 5 (IQR 2-17). Compared to those with mRS 0-1 (n = 596), patients with pre-stroke mRS of 2 (n = 126), 3 (n = 96), or 4 (n = 38) were less likely to achieve functional recovery in univariate analysis. After multivariable adjustment, odds of functional recovery were significantly lower for patients with pre-stroke mRS of 2 (adjusted odds ratio [ORadj] 0.45, 95% confidence interval [CI] 0.28-0.72), but not those with pre-stroke mRS of 3 (ORadj 1.14, 95%CI 0.66-1.97) or 4 (ORadj 0.50, 95%CI 0.21-1.19). Older age (ORadj per year 0.97, 95%CI 0.95-0.97) and higher NIHSS (ORadj per point 0.89, 95%CI 0.88-0.91) were associated with lower odds of functional recovery, while thrombolysis (ORadj 2.43, 95%CI 1.42-4.15) and a cryptogenic stroke mechanism (ORadj 1.57, 95%CI 1.07-2.31) were protective. CONCLUSIONS: Recovery of patients with pre-existing disability was driven by age and stroke severity. Thrombolysis remained predictive of recovery irrespective of age, stroke severity, and pre-stroke disability.

Unique Clinicopathologic Subclassifiers of Cryptogenic Cerebral Emboli.

INTRODUCTION: Ipsilateral nonstenotic (<50%) internal carotid artery (ICA) plaque, cardiac atriopathy, and patent foramen ovale (PFO) may account for a substantial proportion of embolic stroke of undetermined source (ESUS). METHODS: Consecutive stroke patients at our center (2019-2021) with unilateral, anterior circulation ESUS were categorized into the following mutually exclusive etiologies: (1) nonstenotic ipsilateral ICA plaque (NSP, ≥3mm in maximal axial diameter), (2) sex-adjusted mod-to-severe left atrial enlargement (LAE), (3) PFO, and (4) "occult ESUS" (patients who failed to meet criteria for these 3 groups). Descriptive statistics and multivariable logistic regression were used to model group characteristics. RESULTS: Of 132 included patients, the median age was 65 (IQR 56-73), 74 (56%) of whom were White, and 54 (41%) were female. Twenty-one patients (16%) had NSP proximal to the infarct territory, 17 (13%) had LAE, 9 (7%) had a PFO, and 85 (64%) had no other mechanism. Patients with LAE were older (p=0.004), and had more frequent intracranial occlusions of the internal carotid and proximal middle cerebral artery (p=0.048), while tobacco use was most commonly found among patients with NSP (75%) when compared to other ESUS groups (p=0.02). Five of 9 patients with LAE who underwent outpatient telemetry had paroxysmal atrial fibrillation (56%), while zero patients with PFO or NSP had paroxysmal atrial fibrillation (p=0.005). Older age (adjusted OR [aOR] 1.05, 95%CI 1.03-1.07), coronary artery disease (aOR 3.22, 95%CI 1.61-6.44) and hypertension (aOR 2.16, 95%CI 1.14-4.06) were independently associated with LAE, while only tobacco use was associated with NSP when compared to other ESUS subclassifiers (OR 3.18, 95%CI 1.08-0.42). Age and tobacco use were both inversely associated with PFO (aOR 0.93, 95%CI 0.88-0.98, and aOR 0.10, 95%CI 0.02-0.90, respectively). CONCLUSIONS: Certain clinical and radiographic features may be useful in predicting the proximal source of occult cerebral emboli, and can be used for cost-effective outpatient diagnostic testing.

Influence of the COVID-19 Pandemic on Treatment Times for Acute Ischemic Stroke: The Society of Vascular and Interventional Neurology Multicenter Collaboration.

BACKGROUND AND PURPOSE: The pandemic caused by the novel coronavirus disease 2019 (COVID-19) has led to an unprecedented paradigm shift in medical care. We sought to evaluate whether the COVID-19 pandemic may have contributed to delays in acute stroke management at comprehensive stroke centers. METHODS: Pooled clinical data of consecutive adult stroke patients from 14 US comprehensive stroke centers (January 1, 2019, to July 31, 2020) were queried. The rate of thrombolysis for nontransferred patients within the Target: Stroke goal of 60 minutes was compared between patients admitted from March 1, 2019, and July 31, 2019 (pre-COVID-19), and March 1, 2020, to July 31, 2020 (COVID-19). The time from arrival to imaging and treatment with thrombolysis or thrombectomy, as continuous variables, were also assessed. RESULTS: Of the 2955 patients who met inclusion criteria, 1491 were admitted during the pre-COVID-19 period and 1464 were admitted during COVID-19, 15% of whom underwent intravenous thrombolysis. Patients treated during COVID-19 were at lower odds of receiving thrombolysis within 60 minutes of arrival (odds ratio, 0.61 [95% CI, 0.38-0.98]; P=0.04), with a median delay in door-to-needle time of 4 minutes (P=0.03). The lower odds of achieving treatment in the Target: Stroke goal persisted after adjustment for all variables associated with earlier treatment (adjusted odds ratio, 0.55 [95% CI, 0.35-0.85]; P<0.01). The delay in thrombolysis appeared driven by the longer delay from imaging to bolus (median, 29 [interquartile range, 18-41] versus 22 [interquartile range, 13-37] minutes; P=0.02). There was no significant delay in door-to-groin puncture for patients who underwent thrombectomy (median, 83 [interquartile range, 63-133] versus 90 [interquartile range, 73-129] minutes; P=0.30). Delays in thrombolysis were observed in the months of June and July. CONCLUSIONS: Evaluation for acute ischemic stroke during the COVID-19 period was associated with a small but significant delay in intravenous thrombolysis but no significant delay in thrombectomy time metrics. Taking steps to reduce delays from imaging to bolus time has the potential to attenuate this collateral effect of the pandemic.

Cerebral Venous Sinus Thrombosis in COVID-19 Patients: A Multicenter Study and Review of Literature.

BACKGROUND: COVID-19 infection has been known to predispose patients to both arterial and venous thromboembolic events such as deep venous thrombosis, pulmonary embolism, myocardial infarction, and stroke. A few reports from the literature suggest that Cerebral Venous Sinus Thrombosis (CVSTs) may be a direct complication of COVID-19. OBJECTIVE: To review the clinical and radiological presentation of COVID-19 positive patients diagnosed with CVST. METHODS: This was a multicenter, cross-sectional, retrospective study of patients diagnosed with CVST and COVID-19 reviewed from March 1, 2020 to November 8, 2020. We evaluated their clinical presentations, risk factors, clinical management, and outcome. We reviewed all published cases of CVST in patients with COVID-19 infection from January 1, 2020 to November 13, 2020. RESULTS: There were 8 patients diagnosed with CVST and COVID-19 during the study period at 7 out of 31 participating centers. Patients in our case series were mostly female (7/8, 87.5%). Most patients presented with non-specific symptoms such as headache (50%), fever (50%), and gastrointestinal symptoms (75%). Several patients presented with focal neurologic deficits (2/8, 25%) or decreased consciousness (2/8, 25%). D-dimer and inflammatory biomarkers were significantly elevated relative to reference ranges in patients with available laboratory data. The superior sagittal and transverse sinuses were the most common sites for acute CVST formation (6/8, 75%). Median time to onset of focal neurologic deficit from initial COVID-19 diagnosis was 3 days (interquartile range 0.75-3 days). Median time from onset of COVID-19 symptoms to CVST radiologic diagnosis was 11 days (interquartile range 6-16.75 days). Mortality was low in this cohort (1/8 or 12.5%). CONCLUSIONS: Clinicians should consider the risk of acute CVST in patients positive for COVID-19, especially if neurological symptoms develop.

Decline in Rehab Transfers Among Rehab-Eligible Stroke Patients During the COVID-19 Pandemic.

OBJECTIVE: To characterize differences in disposition arrangement among rehab-eligible stroke patients at a Comprehensive Stroke Center before and during the COVID-19 pandemic. MATERIALS AND METHODS: We retrospectively analyzed a prospective registry for demographics, hospital course, and discharge dispositions of rehab-eligible acute stroke survivors admitted 6 months prior to (10/2019-03/2020) and during (04/2020-09/2020) the COVID-19 pandemic. The primary outcome was discharge to an inpatient rehabilitation facility (IRF) as opposed to other facilities using descriptive statistics, and IRF versus home using unadjusted and adjusted backward stepwise logistic regression. RESULTS: Of the 507 rehab-eligible stroke survivors, there was no difference in age, premorbid disability, or stroke severity between study periods (p>0.05). There was a 9% absolute decrease in discharges to an IRF during the pandemic (32.1% vs. 41.1%, p=0.04), which translated to 38% lower odds of being discharged to IRF versus home in unadjusted regression (OR 0.62, 95%CI 0.42-0.92, p=0.016). The lower odds of discharge to IRF persisted in the multivariable model (aOR 0.16, 95%CI 0.09-0.31, p<0.001) despite a significant increase in discharge disability (median discharge mRS 4 [IQR 2-4] vs. 2 [IQR 1-3], p<0.001) during the pandemic. CONCLUSIONS: Admission for stroke during the COVID-19 pandemic was associated with a significantly lower probability of being discharged to an IRF. This effect persisted despite adjustment for predictors of IRF disposition, including functional disability at discharge. Potential reasons for this disparity are explored.

Utility of transesophageal echocardiography in the identification and treatment of occult mechanisms of cerebral infarction.

Cryptogenic stroke comprises approximately 25% of all cases of ischemic stroke. The diagnostic evaluation of these patients remains a challenge in clinical practice. Transesophageal echocardiography (TEE) has been shown to have superior diagnostic accuracy in identifying potential cardioembolic sources of ischemic stroke when compared to transthoracic echocardiography (TTE). However, there has been inconsistent data on the management implications of these new cardiac findings. The addition of TEE to the comprehensive stroke evaluation will better identify potential cardiac sources of embolism (CSE) and will result in significant management changes. A prospective registry of consecutively admitted patients with acute ischemic stroke (1/1/2015-8/10/2020) was retrospectively queried. Patients 18 to 60 years of age with stroke due to mechanisms other than large or small vessel disease, or atrial fibrillation were eligible for inclusion. The primary outcome was any high-risk CSE identified on TEE following unrevealing TTE. Of the 2,404 consecutive stroke patients evaluated during the study period, 263 (11%) met inclusion criteria and the median age was 53 (IQR 46-57). TEE was performed in 108 patients (41%). A high-risk CSE was identified in 36 patients (33%), the majority of which were PFOs (n = 29). TEE led to a clinical management change in 14 patients (39%) after identification of a high-risk CSE; 6 underwent PFO closure and 8 had adjustment to their antithrombotic therapy. The addition of TEE to the comprehensive stroke evaluation led to the identification of a high-risk CSE in one in three patients resulting in significant management changes.

Resident-Driven Dysphagia Screening Protocol for Expedited Antithrombotic Delivery in Acute Ischemic Stroke.

Background: We implemented a multi-disciplinary process improvement intervention at our Comprehensive Stroke Center with speech/language pathologists to expedite oral medication delivery in stroke patients. Following a failed nursing dysphagia screen, trained neurology physicians screened dysphagia further to approve use of oral medications. We analyzed the safety and efficacy of this intervention. Methods: We analyzed retrospectively collected data for hospital course, timing of first screen, first oral medication use, and complications (e.g., aspiration pneumonia) in consecutive ischemic stroke patients (9/2019-07/2021). Patients were included if they passed a dysphagia assessment by physicians (Ph), nurses (RN), or speech/language pathologists (SLP). Arrival-to-dysphagia screen and arrival-to-antithrombotic were assessed using restricted mean survival time (RMST). Results: Of the 789 included patients, 673 were passed by RN, 104 by SLP, and 12 by Ph. Compared to patients passed by SLP, those passed by Ph were younger and had less severe deficits (P < .01 for both). Patients were screened more quickly by Ph than RN or SLP (median 38 vs 182 vs 1330-min post-arrival, P = .0001; 299-min RMST difference vs RN [95%CI 22-575, P = .03]; 470-min RMST difference vs SLP [95%CI 175-765, P = .002]). This translated to faster oral antithrombotic use for Ph-passed patients (138-min RMST difference vs RN [95%CI 59-216]; 332-min RMST difference vs SLP [95%CI 253-411]). No patients passed by Ph experienced aspiration pneumonia (0%). Conclusions: We safely conducted a physician-driven dysphagia screening paradigm which led to faster oral antithrombotic delivery without signal of patient harm. Physician availability to complete dysphagia screens in acute stroke patients was a limitation.

Decline in mild stroke presentations and intravenous thrombolysis during the COVID-19 pandemic: The Society of Vascular and Interventional Neurology Multicenter Collaboration.

BACKGROUND: To evaluate overall ischemic stroke volumes and rates, specific subtypes, and clinical presentation during the COVID-19 pandemic in a multicenter observational study from eight states across US. METHODS: We compared all ischemic strokes admitted between January 2019 and May 2020, grouped as; March-May 2020 (COVID-19 period) and March-May 2019 (seasonal pre-COVID-19 period). Primary outcome was stroke severity at admission measured by NIHSS stratified as mild (0-7), moderate [8-14], and severe (>14). Secondary outcomes were volume of large vessel occlusions (LVOs), stroke etiology, IV-tPA rates, and discharge disposition. RESULTS: Of the 7969 patients diagnosed with acute ischemic stroke during the study period, 933 (12 %) presented in the COVID-19 period while 1319 (17 %) presented in the seasonal pre-COVID-19 period. Significant decline was observed in the mean weekly volumes of newly diagnosed ischemic strokes (98 ± 3 vs 50 ± 20,p = 0.003), LVOs (16.5 ± 3.8 vs 8.3 ± 5.9,p = 0.008), and IV-tPA (10.9 ± 3.4 vs 5.3 ± 2.9,p = 0.0047), whereas the mean weekly proportion of LVOs (18 % ±5 vs 16 % ±7,p = 0.24) and IV-tPA (10.4 % ±4.5 vs. 9.9 % ±2.4,p = 0.66) remained the same, when compared to the seasonal pre-COVID-19 period. Additionally, an increased proportion of patients presented with a severe disease (NIHSS > 14) during the COVID-19 period (29.7 % vs 24.5 %,p < 0.025). The odds of being discharged to home were 26 % greater in the COVID-19 period when compared to seasonal pre-COVID-19 period (OR:1.26, 95 % CI:1.07-1.49,p = 0.016). CONCLUSIONS: During COVID-19 period there was a decrease in volume of newly diagnosed ischemic stroke cases and IV-tPA administration. Patients admitted to the hospital had severe neurological clinical presentation and were more likely to discharge home.