Abstract TP114: Stroke Mimics: Uncovering The Truth In The History

Background: Inpatient acute stroke identification may be challenging given the complexity related to both concomitant and comorbid illness. Rapid and accurate diagnosis requires a skilled clinician to discern acute stroke patients from other mimics such as hypoglycemia, hemiplegic migraine, post-ictal paresis, relapse of a demyelinating disease, or recrudescence of prior stroke.

Hypothesis: Negative predictors of acute stroke can be identified in inpatients with inpatient stroke alerts.

Methods: IRB approved, retrospective analysis of prospectively obtained data was performed for all inpatient stroke alerts between March 2017 and May 2020. Patients with MRI confirmed diagnosis of acute stroke were compared to all others. Univariant analysis was performed with Wilcoxon Ranked Sum test used for non-parametric data to identify risk factors to include in the logistic regression (p<0.05).

Results: 674 inpatient stroke alerts resulted in 223 (33%) acute strokes and 451 (67%) non-stroke diagnoses. For stroke vs. non-stroke patients, median age 70.5 vs. 68.6 years, last seen well 77.5 vs. 65.0 minutes (p= 0.030), NIHSS score 10 vs. 4 (p<0.001). In the non-stroke group, 156 (23%) had a witnessed seizure documented during the alert compared to 0% in the stroke group. Negative predictors of stroke included previous diagnosis of epilepsy (0.302 odds, P<0.007), anti-seizure drug (ASDs) prescribed prior to (1.662 odds, p<0.001) or at time of the alert (2.479 odds), and previous EEG(P<0.001).

Conclusions: It is imperative to consider post-ictal paresis as a differential diagnosis when assessing patients who present as stroke alerts. The administration of thrombolytics in stroke mimics is not without harm and incorrect diagnosis will delay appropriate treatment. Witnessed seizure at time of alert, history of epilepsy diagnosis, use of ASD prior to or at the time of the alert, and prior EEG findings may serve as a tool to help differentiate between acute stroke and seizure diagnosis. Further study will be aimed at identifying alternative pathways for rapid assessment of patients with acute changes in neurologic exam.

A Phase III, prospective, double-blind, randomized, placebo-controlled trial of thrombolysis in imaging-eligible, late-window patients to assess the efficacy and safety of tenecteplase (TIMELESS): Rationale and design

RATIONALE

While thrombolysis is standard of care for patients with acute ischemic stroke (AIS) within 4.5 h of symptom onset, the benefit of tenecteplase beyond this time window is less certain.

AIM

The TIMELESS trial (NCT03785678) aims to determine if treatment with tenecteplase increases the proportion of good clinical outcomes among patients with stroke due to a large vessel occlusion who present beyond 4.5 h after symptom onset.

SAMPLE SIZE ESTIMATES

A total of 456 patients will provide ⩾90% power to detect differences in the distribution of modified Rankin Scale scores at Day 90 at the two-sided 0.049 significance level.

METHODS AND DESIGN

TIMELESS is a Phase III, double-blind, randomized, placebo-controlled trial of tenecteplase with or without endovascular thrombectomy in patients with AIS and evidence of salvageable tissue via imaging who present within the 4.5- to 24-h time window with an internal carotid artery (ICA) or middle cerebral artery (MCA) (M1/M2) occlusion.

STUDY OUTCOMES

The primary efficacy objective of tenecteplase compared with placebo will be evaluated with ordinal modified Rankin Scale scores at Day 90. Safety will be evaluated via incidence of symptomatic intracranial hemorrhage, incidence and severity of adverse events, and mortality rate.

DISCUSSION

Results from TIMELESS will contribute to understanding of the safety and efficacy of tenecteplase administered 4.5-24 h following symptom onset for patients with an ICA or MCA occlusion.

Abstract TP352: Safety and Efficacy of Andexanet Alfa in Patients With Life Threatening Intracerebral Hemorrhage: A Single Center Experience

Background: Intracerebral hemorrhage (ICH) is a devastating condition with high 30- day mortality. Up to a third of patients experience hematoma expansion within the first 24 hours; anticoagulation with factor Xa inhibitors may increase the risk of expansion and poor outcomes.

Objective: We assessed our experience using Andexanet alfa (Aα) by evaluating stabilization of the hematoma and ischemic complications.

Methods: We conducted a single center prospective observational study on all patients receiving Aα for reversal of anticoagulation in the setting of an ICH and use of Factor Xa inhibitors. The degree of hematoma expansion within 12 hours of drug administration on non-contrast head CT was categorized as 'excellent' (<20% increase in hematoma size), ‘good' ( > 20-<35%), and 'poor' ( > 35%). Secondary outcomes included dosage, median length of stay, mortality, modified Rankin score (mRS), discharge disposition, and ischemic complications.

Results: Fifteen patients received Aα (5=lobar, 5=deep, 5= multicompartment). One patient with a presumed deep hemorrhage was excluded because subsequent imaging showed chronic mineralization. The predominant etiologies were hypertension (40%), amyloid angiopathy (26.6%) and trauma (13.3%). The median age was 86 years (IQR 19) and median ICH score on arrival was 2 (IQR 2), and median hematoma size was 14.3 mL (IQR 34.5). Most patients (71.4%) received the low dose formulation. Based on hematoma expansion, 64.3%, 14.3% and 21.4% of patients achieved excellent, good and poor hemostasis, respectively. Reduction in hematoma size was seen in 20% (n=3) while 13.3% (n=2) patients had no expansion. Median ICU and hospital length of stays were 2.0 days (IQR 2.2) and 6.6 days (IQR 9.78) respectively. Mortality was 28.6% and median mRS upon discharge was 4 (IQR 2), with most patients discharged to rehabilitation facilities (60%). There were no ischemic complications.

Conclusion: Our experience is consistent with the results of the ANNEXA 4 study with 78.6% of patients showing excellent or good hemostasis. These results led to improved clinical outcomes, with 60% of patients being discharged to rehabilitation. These data support the efficacy of this treatment paradigm in a real-world setting.

Abstract 153: Novel Machine Learning Proves Stroke Risk is Not Linear

Background: Current stroke risk assessment tools presume the impact of risk factors is linear and cumulative. However, both novel risk factors and their interplay influencing stroke incidence are difficult to reveal using traditional linear models.

Objective: To improve upon the Revised-Framingham Stroke Risk Score and design an interactive non-linear Stroke Risk Score (NSRS). Our work aimed at increasing the accuracy of event prediction and uncovering new relationships in an interpretable user-friendly fashion.

Methods: A two phase approach was used to develop our stroke risk score predictor. First, clinical examinations of the Framingham offspring cohort were utilized as the training dataset for the predictive model consisting of 14,196 samples where each clinical examination was considered an independent observation. Optimal Classification Trees (OCT) were used to train a model to predict 10-year stroke risk. Second, this model was validated with 17,527 observations from the Boston Medical Center. The NSRS was developed into an online user friendly application in the form of a questionnaire (http://www.mit.edu/~agniorf/files/questionnaire_Cohort2.html).

Results: The algorithm suggests a key dichotomy between patients with or without history of cardiovascular disease. While the model agrees with known findings, it also identified 23 unique stroke risk profiles and introduced new non-linear relationships; such as the role of T-wave abnormality on electrocardiography and hematocrit levels in a patient’s risk profile. Our results in both the training and validation populations suggested that the non-linear approach significantly improves upon the existing revised Framingham stroke risk calculator in the c-statistic (training 87.43% (CI 0.85-0.90) vs. 73.74% (CI 0.70-0.76); validation 75.29% (CI 0.74-0.76) vs 65.93% (CI 0.64-0.67), even in multi-ethnicity populations.

Conclusions: We constructed a highly predictive, interpretable and user-friendly stroke risk calculator using novel machine-learning uncovering new risk factors, interactions and unique profiles. The clinical implications include prioritization of risk factor modification and personalized care improving targeted intervention for stroke prevention.

Three Territory Sign: An MRI marker of malignancy-related ischemic stroke (Trousseau syndrome)

Background

Multiple acute cerebral territory infarcts of undetermined origin are typically attributed to cardioembolism, most frequently atrial fibrillation. However, the importance of 3-territory involvement in association with malignancy is under-recognized. We sought to highlight the "Three Territory Sign" (TTS) (bilateral anterior and posterior circulation acute ischemic diffusion-weighted imaging [DWI] lesions), as a radiographic marker of stroke due to malignancy.

Methods

We conducted a single-center retrospective analysis of patients from January 2014 to January 2016, who suffered an acute ischemic stroke with MRI-DWI at our institution, yielding 64 patients with a known malignancy and 167 patients with atrial fibrillation, excluding patients with both to eliminate bias. All DWI images were reviewed for 3-, 2-, and 1-territory lesions. Chi-square test of proportion was used to test significance between the 2 groups.

Results

We found an association between the groups (malignancy vs atrial fibrillation) and the number of territory infarcts (p < 0.0001). Pairwise comparisons using the Holm p value adjustment showed no difference between 1- and 2-territory patterns (p = 0.465). However, the TTS was 6 times more likely observed within the malignancy cohort as compared to patients with atrial fibrillation (23.4% [n = 15] vs 3.5% [n = 6]) and was different from both 1-territory (p < 0.0001) and 2-territory patterns (p = 0.0032).

Conclusion

The TTS is a highly specific marker and 6 times more frequently observed in malignancy-related ischemic stroke than atrial fibrillation-related ischemic stroke. Evaluation for underlying malignancy in patients with the TTS is reasonable in patients with undetermined etiology.

Abstract WP145: Depression in Stroke and TIA Survivors With Minimal or No Residual Deficits

Background: Depression after stroke can severely inhibit a patient’s recovery. While it affects roughly a third of all stroke survivors, there is a lack of literature evaluating depression in patients with minimal or no residual deficits.

Objectives: To evaluate variables associated with depression in patients with minimal or no residual deficits.

Methods: A retrospective analysis of patients with mild stroke, intracerebral hemorrhage (ICH) or TIA at our institution who presented to the stroke clinic from December 2016-July 2017 was conducted. A questionnaire gathering clinical and sociodemographic information, as well as levels of depression, was administered. Patients were assessed using the PHQ-2 and PHQ-9 depression scales. A Wilcoxon Ranked Sum test was used to analyze variables affecting depression. Statistical significance was set at 0.05.

Results: In total, 72 patients (58 ischemic, 5 ICH and 9 TIA) were identified. Approximately 4% (n=3) presented to clinic <6 weeks, 66.7% (n=48) 6-12 weeks, 23.6% (n=17) 12-24 weeks, and 5.6% (n=4) > 24 weeks from discharge. The median discharge NIH score was 1.5. Roughly 24% of patients (n=17) reported depression via the PHQ-9. Of these patients, 59% (n=10) reported depression prior to stroke and 41% (n=7) developed new depression. The median age was 62.5 years, 63.9% were female, and 70.8% Caucasian. Diabetic and unmarried patients reported significantly more depression ( p=0.005, 0.03) while patients attending occupational therapy were less depressed ( p=0.010 ). Age ( p=0.23 ), history of cancer ( p=0.95 ), prior stroke ( p=0.55 ), incontinence ( p=0. 27), stroke location (Right: p=0.72 ; Left: p=0.244 ), ability to return to work ( p=0.64 ), driving status ( p= 0.36), and discharge destination ( p=0. 09) did not significantly affect depression levels. Of the patients with no prior depression, 11.2% developed new depression after stroke.

Conclusion: In our study, a quarter of stroke and TIA patients with little to no residual deficits reported depression and roughly 1 in 10 reported new depressive symptoms. Depression is still a prevalent and concerning outcome that can have a major effect on a patient’s functional status. Further studies of depression in patients with minimal to no symptoms are needed.

Abstract 124: Clot Composition of Embolic Strokes of Undetermined Source

Background: A number of emerging studies have evaluated clot composition in acute ischemic stroke. Studies of clot composition of embolic strokes of undetermined strokes are lacking.

Objectives: We sought to analyze the RBC to platelet ratios in mechanically retrieved clots and correlate our findings with stroke etiology.

Methods: This is a prospective study analyzing clots retrieved by mechanical thrombectomy in acute ischemic stroke patients at our institution. Retrieved clot material was fixed and cut at 4-m thickness. All clots were stained with hematoxylin-eosin to identify red blood cells (RBC’s), and antibodies for platelet glycoprotein IIIa with CD61 (LifeSpan Biosciences, Seattle, Washington) for platelets. Stained slides were scanned at 200x magnification by using a Scanscope XT digital scanner (Apergio, Vista, California). Image-J software (National Institutes of Health, Bethesda, Maryland) was used for semi quantitative analysis of percentage RBC’s and platelets. Unpaired t-test was used to compare means of RBC to Platelet ratios. Statistical significance was set at 0.05. Correlation of RBC to Platelet ratios with stroke etiology was performed.

Results: A total of 33 clots from 33 patients were analyzed. Stroke etiology was undetermined in 6 patients, cardioembolic in 14, Large vessel atherosclerosis (LVA) in 9, and carotid dissection in 4. The mean RBC to platelet ratio was 0.78:1 (+/- 0.65) in cardioembolic clots, 1.73:1 (+/-2.38) in LVA and 1.4:1(+/-0.70) in carotid dissections. Although patients with undetermined etiology had a similar clot composition to cardioembolic stroke (0.36:1+/-0.33), (p=0.19), it differed significantly from LVA and dissections respectively (p=0.047, p=0.01).

Conclusion: In our study, a low RBC to Platelet ratio was found among patients with embolic strokes of undetermined source, however shared similar characteristics with cardioembolic thrombi. Ongoing collection and analysis is needed to confirm these findings and its significance in evaluating stroke etiology.

Abstract WP286: Code Status Prior to Admission Dose Not Influence Timing of Transition to Inpatient Hospice in Devastating Stroke

Background: The transition of care from an aggressive disease-directed plan to comfort focused hospice care is a difficult choice for patients with devastating stroke and their family members particularly in the absence of advance directives. However, it is not clear if preexisting Do Not Resuscitate (DNR) status influences the timing of this decision.

Objectives: To evaluate factors associated with transfer time to hospice for patients with devastating stroke and, particularly, the influence of defined code status prior to admission.

Methods: A retrospective analysis of patients with stroke admitted to inpatient hospice from January 2013-December 2014 at our institution was conducted yielding 71 patients. The group was dichotomized to those with a preexisting DNR (n=19) or not (n=52). Clinical variables and sociodemographic factors were collected and compared using chi-square tests of proportion and t-tests for independent groups. Specifically, median time from admission to inpatient hospice for both groups was compared using a Wilcoxon Ranked Sum test set at 0.05 to test statistical significance.

Results: For all patients, the mean age was 82.01 +/- 9.64 years, 60.6% female and 84.5% Caucasian. Approximately 66% of strokes were ischemic and 34% hemorrhagic with a mean NIH score of 21.45 +/- 6.03. Age (83.7 +/- 9.8 vs. 81.4 +/- 9.6; p=0.377 ), ethnicity (% Caucasian: 84.2 vs. 84.6; p= 0.967 ), stroke subtype (% ischemic: 73.7 vs. 61.5; p= 0.343 ), severity (NIH: 21.2 +/- 8.8 vs. 20.9 +/- 4.6; p=0.852 ), insurance status (% Medicare Plus: 73.7 vs. 57.7; p=0.219 ), history of prior stroke (26.3% vs. 23.1%; p=0.777 ), dementia (21.1% vs. 28.9%; p=0.511 ), malignancy (10.53% vs. 13.46%; p=0.742 ), and living arrangement (% living with family: 73.7 vs. 51.9; p=0.132 ) were not statistically different in the DNR and no DNR cohorts respectively. The median time from admission to inpatient hospice for preexisting DNR vs. no DNR did not differ (3.0 vs. 4.5 days ; p=0.176 ).

Conclusion: In our study, there were no significant factors, including preexisting DNR status, that influenced transition time to inpatient hospice. Code status on admission is not an indicator of goals of care. Future studies are needed to validate these findings

Abstract WMP72: The "Three Territory Sign": An Under-Recognized Radiographic Marker of Malignancy-Related Ischemic Stroke

Background: Multiple cerebral territory infarcts of undetermined origin are typically attributed to cardioembolism; and most frequently atrial fibrillation. However the significance of three territory involvement in association with malignancy is under-recognized.

Objective: To highlight the “Three Territory Sign” (bilateral anterior and the posterior circulation DWI lesions), as a radiographic marker of stroke due to malignancy.

Methods: We conducted a retrospective analysis of patients at our institution from Jan 2014-Jan 2016 who suffered an acute ischemic stroke with MRI-DWI. We identified all ischemic strokes of undetermined etiology in patients with known malignancy (60 patients) and patients with stroke, atrial fibrillation and no malignancy (167 patients). Patients with both atrial fibrillation and malignancy were excluded. All DWI images were reviewed for 3, 2, and 1 territory lesions. Fisher Exact tests were used to identify statistical significance between the two groups. Statistical significance was set at 0.05.

Results: There was a significant association between both cohorts (malignancy vs. atrial fibrillation) and the number of territory infarcts found. While the number of 1 {71.6% (n=43) vs. 79% (n=132)} and 2 territory infarcts {10.0% (n=6) vs. 17. 4% (n=29)} were similar between the two groups, 3 territory infarcts were > 5 times more frequent in malignancy as compared to atrial fibrillation {18.3% (n=11) vs. 3.5% (n=6)} ( p < 0.002 ). Post-hoc pairwise comparisons using the Bonferroni correction for multiple tests support that the 3 territory pattern differs from both 1 territory ( p=0.0033 ) and 2 territory ( p =0.0037 ) patterns.

Conclusion: Cerebral territory infarctions involving the bilateral anterior and posterior circulation are 5 times more frequent in malignancy-related ischemic stroke than atrial fibrillation. The “Three territory sign” is a robust marker of malignancy-related stroke and should prompt evaluation for malignancy after exclusion of other known causes.

High Mortality among 30-Day Readmission after Stroke: Predictors and Etiologies of Readmission

BACKGROUND

Although some risk factors for stroke readmission have been reported, the mortality risk is unclear. We sought to evaluate etiologies and predictors of 30-day readmissions and determine the associated mortality risk.

METHODS

This is a retrospective case-control study evaluating 1,544 patients admitted for stroke (hemorrhagic, ischemic, or TIA) from January 2013 to December 2014. Of these, 134 patients readmitted within 30 days were identified as cases; 1,418 other patients, with no readmissions were identified as controls. Patients readmitted for hospice or elective surgery were excluded. An additional 248 patients deceased on index admission were included for only a comparison of mortality rates. Factors explored included socio-demographic characteristics, clinical comorbidities, stroke characteristics, and length of stay. Chi-square test of proportions and multivariable logistic regression were used to identify independent predictors of 30-day stroke readmissions. Mortality rates were compared for index admission and readmission and among readmission diagnoses.

RESULTS

Among the 1,544 patients in the main analysis, 67% of index stroke admissions were ischemic, 22% hemorrhagic, and 11% TIA. The 30-day readmission rate was 8.7%. The most common etiologies for readmission were infection (30%), recurrent stroke and TIA (20%), and cardiac complications (14%). Significantly higher proportion of those readmitted for recurrent strokes and TIAs presented within the first week (p = 0.039) and had a shorter index admission length of stay (p = 0.027). Risk factors for 30-day readmission included age >75 (p = 0.02), living in a facility prior to index stroke (p = 0.01), history of prior stroke (p = 0.03), diabetes (p = 0.03), chronic heart failure (p ≤ 0.001), atrial fibrillation (p = 0.03), index admission to non-neurology service (p < 0.01), and discharge to other than home (p < 0.01). On multivariate analysis, index admission to a non-neurology service was an independent predictor of 30-day readmission (p ≤ 0.01). The mortality after a within 30-day readmission after stroke was higher than index admission (36.6 vs. 13.8% p ≤ 0.001) (OR 3.6 95% CI 2.5-5.3). Among those readmitted, mortality was significantly higher for those admitted for a recurrent stroke (p = 0.006).

CONCLUSION

Approximately one-third of 30-day readmissions were infection related and one-fifth returned with recurrent stroke or TIA. Index admission to non-neurology service was an independent risk factor of 30-day readmissions. The mortality rate for 30-day readmission after stroke is more than 2.5 times greater than index admissions and highest among those readmitted for recurrent stroke. Identifying high-risk patients for readmission, ensuring appropriate level of service, and early outpatient follow-up may help reduce 30-day readmission and the high associated risk of mortality.

Rheumatoid Meningitis: Diagnostic and Therapeutic Observations

A 75-year-old female with untreated rheumatoid arthritis presented with two weeks of behavioral changes and cognitive decline. A neurologic examination showed severe encephalopathy, brisk reflexes, and bilateral Babinski sign. A contrast-enhanced brain MRI demonstrated right meningeal enhancement and periventricular white matter disease. A computed tomographic angiogram (CTA) of the head and neck was negative for vasculitis. The cerebrospinal fluid (CSF) demonstrated lymphocytic pleocytosis. The patient's serum rheumatoid factor levels were elevated. A biopsy of the leptomeninges and cortex showed lymphocytic vasculitis of the cortical tissue and patchy lymphoplasmacytic infiltrates of dural small vessels consistent with rheumatoid meningitis. The patient received pulse-dose steroids followed by cyclophosphamide infusions. At her three month follow-up appointment, the patient's mental status had improved mildly. A follow-up brain MRI showed resolution of enhancement, but progression of subcortical bihemispheric white matter disease. Subsequently, the patient developed a respiratory infection and passed away. In rheumatoid arthritis, symptoms of encephalopathy, headaches, seizures, or focal neurologic deficits should raise suspicion for CNS involvement. This potentially treatable disease warrants prompt diagnosis.