Selective brain cooling with a novel catheter reduces infarct growth after recanalization in a canine large vessel occlusion model.

BACKGROUND: Therapeutic hypothermia has shown potential in cardiac intervention for years; however, its adoption into the neurovascular space has been limited. Studies have pointed to slow cooling and limited depth of hypothermia yielding negative outcomes. Here we present an insulated catheter that allows for consistent infusion of chilled saline directly to the brain. Direct delivery of cold saline allows a faster depth of hypothermia, which could have a benefit to the growth of ischemic lesions. METHODS: Ten canines were randomized to either receive selective brain cooling or no additional therapy. Eight animals were successfully enrolled (n = 4 per group). Each animal underwent a temporary middle cerebral artery occlusion (MCAO) for a total of 45 min. Five minutes prior to flow restoration, chilled saline was injected through the ipsilateral internal carotid artery using an insulated catheter to ensure delivery temperature. The treatment continued for 20 min, after which the animal was transferred to an MRI scanner for imaging. RESULTS: Of the 8 animals that were successfully enrolled in the study, 3 were able to survive to the 30-day endpoint with no differences between the cooled and control animals. There was no difference in the initial mean infarct size between the groups; however, animals that did not receive cooling had infarcts continuing to progress more rapidly after the MCAO was removed (13.8% vs 161.3%, p = 0.016, cooled vs control). CONCLUSIONS: Selective hypothermia was able to reduce the post-MCAO infarct progression in a canine model of temporary MCAO.

Symptomatic intracerebral hemorrhage in proximal and distal medium middle cerebral artery occlusion patients treated with mechanical thrombectomy.

BACKGROUND: Acute ischemic stroke (AIS) caused by distal medium vessel occlusions (DMVOs) represents a significant proportion of overall stroke cases. While intravenous thrombolysis (IVT) has been a primary treatment, advancements in endovascular procedures have led to increased use of mechanical thrombectomy (MT) in DMVO stroke patients. However, symptomatic intracerebral hemorrhage (sICH) remains a critical complication of AIS, particularly after undergoing intervention. This study aims to identify factors associated with sICH in DMVO stroke patients undergoing MT. METHODS: This retrospective analysis utilized data from the Multicenter Analysis of Distal Medium Vessel Occlusions: Effect of Mechanical Thrombectomy (MAD-MT) registry, involving 37 centers across North America, Asia, and Europe. Middle cerebral artery (MCA) DMVO stroke patients were included. The primary outcome measured was sICH, as defined per the Heidelberg Bleeding Classification. Univariable and multivariable logistic regression were used to identify factors independently associated with sICH. RESULTS: Among 1708 DMVO stroke patients, 148 (8.7%) developed sICH. Factors associated with sICH in DMVO patients treated with MT included older age (adjusted odds ratio (aOR) 1.01, 95% confidence interval (95% CI) 1.00 to 1.03, P=0.048), distal occlusion site (M3, M4) compared with medium occlusions (M2) (aOR 1.71, 95% CI 1.07 to 2.74, P=0.026), prior use of antiplatelet drugs (aOR 2.06, 95% CI 1.41 to 2.99, P<0.001), lower Alberta Stroke Program Early CT Scores (ASPECTS) (aOR 0.75, 95% CI 0.66 to 0.84, P<0.001), higher preoperative blood glucose level (aOR 1.00, 95% CI 1.00 to 1.01, P=0.012), number of passes (aOR 1.27, 95% CI 1.15 to 1.39, P<0.001), and successful recanalization (Thrombolysis In Cerebral Infarction (TICI) 2b-3) (aOR 0.43, 95% CI 0.28 to 0.66, P<0.001). CONCLUSION: This study provides novel insight into factors associated with sICH in patients undergoing MT for DMVO, emphasizing the importance of age, distal occlusion site, prior use of antiplatelet drugs, lower ASPECTS, higher preoperative blood glucose level, and procedural factors such as the number of passes and successful recanalization. Pending confirmation, consideration of these factors may improve personalized treatment strategies.

Risk factors for MACE and bleeding in atrial fibrillation patients undergoing surgery: Insights from the bridge trial.

INTRODUCTION: Patients with atrial fibrillation (AF) undergoing elective procedures are at risk for Major Adverse Cardiovascular Events (MACE) and symptomatic bleeding. We aimed to identify risk factors to guide perioperative risk stratification. METHODS: We conducted a post-hoc analysis of the "Bridging Anticoagulation in Patients who Require Temporary Interruption of Warfarin Therapy for an Elective Invasive Procedure or Surgery" randomized trial. The primary outcomes were MACE and symptomatic bleeding. Our statistical approach encompassed standard univariate analysis, logistic stepwise regression, and Cox regression models. Additional interaction analyses evaluated the interplay between low-molecular-weight heparin bridge therapy and other identified risk factors. RESULTS: Among a total of 1,813 participants (mean age 71.6 ± 8.8, 73.3 % male), MACE occurred in 25 (1.4 %) individuals, with pre-procedure clopidogrel use (adjusted hazard ratio [aHR] 7.73, 95 % CI 2.63-22.72, p < 0.001) and CHA2DS2-VASc score ≥ 5 (aHR 2.89, 95 % CI 1.26-6.63, p = 0.012) identified as risk factors. Symptomatic bleeding occurred in 57 (3.1 %) individuals, with bridge therapy (aHR 1.84, 95 % CI 1.07-3.19, p = 0.029), renal disease (aHR 2.50, 95 % CI 1.34-4.67, p = 0.004), post-procedure aspirin use (aHR 2.86, 95 % CI 1.66-4.91, p < 0.001), post-procedure nonsteroidal anti-inflammatory drug use excluding aspirin (aHR 3.40, 95 % CI 1.22-9.43, p = 0.019), and major surgery (aHR 3.94, 95 % CI 2.26-6.85, p < 0.001) identified as risk factors. The interactions between risk factors and bridging therapy on MACE and symptomatic bleeding outcomes were not significant (p > 0.05). CONCLUSION: We identified predictors for MACE and symptomatic bleeding in AF patients undergoing elective procedures. These insights may help guide perioperative decisions to reduce the risk of adverse outcomes.

Cerebral venous sinus thrombosis associated with cancer: analysis of the ACTION-CVT study.

Nearly one fifth of patients with venous thromboembolism (VTE) have cancer. When both of these conditions occur, especially in cases of cerebral vein thrombosis (CVT), patient management is often challenging. The aim of this study was to compare the characteristics and event courses in patients affected by CVT with and without cancer. Consecutive patients with CVT from the ACTION-CVT cohort study were included if cancer status was reported. Risk factors as well as the clinical and radiological characteristics of patients were compared. Univariable and multivariable analyses were performed to assess variables associated with cancer. Kaplan-Meier method and log-rank test, logistic regression analysis, and propensity score matching were used to investigate any association between cancer-related CVT and study outcomes (primary outcome at 3-months: recurrent VTE or major hemorrhage; recurrent VTE; major hemorrhage; recanalization status; all-cause-death). Overall, 1,023 patients with CVT were included, of which 6.5% had cancer. Older age (adjusted odds ratio [aOR] 1.28 per decade increase; 95% confidence interval [CI] 1.08-1.52) and absence of headache (aOR 0.47; 95% CI 0.27-0.84) were independently associated with cancer. Patients with cancer had a higher risk of recurrent VTE or major hemorrhage (aOR 3.87; 95% CI 2.09-7.16), all-cause-death (aOR 7.56 95% CI 3.24-17.64), and major hemorrhage (aOR 3.70 95% CI 1.76-7.80). Recanalization rates, partial or complete, was not significantly different. CVT patients with cancer were more likely to be older, have no referred headache, and have worse outcomes compared to CVT patients without cancer.

Hypoperfusion Intensity Ratio Is Associated with Early Neurologic Deficit Severity and Deterioration after Mechanical Thrombectomy in Large-Vessel Occlusion Ischemic Stroke.

BACKGROUND AND PURPOSE: The hypoperfusion intensity ratio is a surrogate marker for collateral status and a predictor of infarct growth, malignant cerebral edema, and hemorrhagic transformation. Its utility to predict a poor NIHSS score and early neurologic deterioration after mechanical thrombectomy for large vessel (LVO) versus distal and medium vessel occlusions (DMVO) has not been investigated. The objective of this study was to determine whether the higher hypoperfusion intensity ratio is associated with a worse NIHSS score at 24 hours post-mechanical thrombectomy and early neurologic deterioration in LVO versus DMVO acute ischemic stroke. MATERIALS AND METHODS: This was a retrospective study of 231 patients with acute ischemic stroke with LVO or DMVO amenable for mechanical thrombectomy and available CTP for hypoperfusion intensity ratio assessment pre-mechanical thrombectomy. Clinical and imaging characteristics were abstracted from the medical records. The primary outcome was the NIHSS score at 24 hours post-mechanical thrombectomy. The secondary outcome was early neurologic deterioration, defined as a >4-point increase in the NIHSS score between the initial assessment and 24 hours post-mechanical thrombectomy. All analyses were first conducted in the entire cohort and then separately for the LVO versus DMVO groups. RESULTS: The optimal hypoperfusion intensity ratio threshold to detect early neurologic deterioration was 0.54. A hypoperfusion intensity ratio ≥ 0.54 was more frequently present in LVO versus DMVO (n = 37 [77.1%] versus n = 11 [22.9%]; P < .001). On multivariable linear regression, the hypoperfusion intensity ratio ≥ 0.54 was independently associated with a worse NIHSS score at 24 hours post-mechanical thrombectomy in the entire cohort (ß = 0.163; P = .002) and the LVO group (ß = 0.210; P = .005), but not in the DMVO group. The early neurologic deterioration occurred in 26 (11.3%) subjects. On multivariable logistic regression, there was no association of the hypoperfusion intensity ratio ≥ 0.54 with early neurologic deterioration in the entire cohort. However, when analyzed separately, a hypoperfusion intensity ratio ≥ 0.54 significantly increased the odds of early neurologic deterioration in subjects with LVO (OR = 5.263; 95% CI, 1.170-23.674; P = .030) but not in the DMVO group. CONCLUSIONS: The hypoperfusion intensity ratio ≥ 0.54 was independently associated with a worse 24-hour post-mechanical thrombectomy NIHSS score and early neurologic deterioration in LVO, but not in DMVO acute ischemic stroke. Pending confirmation in future, prospective studies assessing the hypoperfusion intensity ratio may help identify patients at risk of secondary decline to improve peri-thrombectomy care and clinical decision-making.

External validation of the SI2NCAL2C score for outcomes following cerebral venous thrombosis.

OBJECTIVES: Prognostication for cerebral venous thrombosis (CVT) remains difficult. We sought to validate the SI2NCAL2C score in an international cohort. MATERIALS AND METHODS: The SI2NCAL2C score was originally developed to predict poor outcome (modified Rankin Scale (mRS) 3-6) at 6 months, and mortality at 30 days and 1 year using data from the International CVT Consortium. The SI2NCAL2C score uses 9 variables: the absence of any female-sex-specific risk factors, intracerebral hemorrhage, central nervous system infection, focal neurological deficits, coma, age, lower level of hemoglobin, higher level of glucose, and cancer. The ACTION-CVT study was an international retrospective study that enrolled consecutive patients across 27 centers. The poor outcome score was validated using 90-day mRS due to lack of follow-up at the 6-month time-point in the ACTION-CVT cohort. Model performance was evaluated using the area under the receiver operating characteristic curve (AUC) and calibration plots. Missing data were imputed using the additive regression and predictive mean matching methods. Bootstrapping was performed with 1000 iterations. RESULTS: Mortality data were available for 950 patients and poor outcome data were available for 587 of 1,025 patients enrolled in ACTION-CVT. Compared to the International CVT Consortium, the ACTION-CVT cohort was older, less often female, and with milder clinical presentation. Mortality was 2.5% by 30 days and 6.0% by one year. At 90-days, 16.7% had a poor outcome. The SI2NCAL2C score had an AUC of 0.74 [95% CI 0.69-0.79] for 90-day poor outcome, 0.72 [0.60-0.82] for mortality by 30 days, and 0.82 [0.76-0.88] for mortality by one year. CONCLUSIONS: The SI2NCAL2C score had acceptable to good performance in an international external validation cohort. The SI2NCAL2C score warrants additional validation studies in diverse populations and clinical implementation studies.

Perioperative Acute Ischemic Stroke in Patients with Atrial Fibrillation.

OBJECTIVE: Anticoagulation therapy is commonly interrupted in patients with atrial fibrillation (AF) for elective procedures. However, the risk factors of acute ischemic stroke (AIS) during the periprocedural period remain uncertain. We performed a nationwide analysis to evaluate AIS risk factors in patients with AF undergoing elective surgical procedures. METHODS: Using the Nationwide Readmission Database, we included electively admitted adult patients with AF and procedural Diagnosis-Related Group codes from 2016 to 2019. Diagnoses were identified based on International Classification of Disease, 9th revision-Clinical Modification (ICD-10 CM) codes. We constructed a logistic regression model to identify risk factors and developed a new scoring system incorporating CHA2 DS2 VASc to estimate periprocedural AIS risk. RESULTS: Of the 1,045,293 patients with AF admitted for an elective procedure, the mean age was 71.5 years, 39.2% were women, and 0.70% had a perioperative AIS during the index admission or within 30 days of discharge. Active cancer (adjusted OR [aOR] = 1.58, 95% confidence interval [CI] = 1.42-1.76), renal failure (aOR = 1.14, 95% CI = 1.04-1.24), neurological surgery (aOR = 4.51, 95% CI = 3.84-5.30), cardiovascular surgery (aOR = 2.74, 95% CI = 2.52-2.97), and higher CHA2 DS2 VASc scores (aOR 1.25 per point, 95% CI 1.22-1.29) were significant risk factors for periprocedural AIS. The new scoring system (area under the receiver operating characteristic curve [AUC] = 0.68, 95% CI = 0.67 to 0.79) incorporating surgical type and cancer outperformed CHA2 DS2 VASc (AUC = 0.60, 95% CI = 0.60 to 0.61). INTERPRETATION: In patients with AF, periprocedural AIS risk increases with the CHA2 DS2 VASc score, active cancer, and cardiovascular or neurological surgeries. Studies are needed to devise better strategies to mitigate perioperative AIS risk in these patients. ANN NEUROL 2023;94:321-329.

Intravital Imaging of Fluorescent Protein Expression in Mice with a Closed-Skull Traumatic Brain Injury and Cranial Window Using a Two-Photon Microscope.

The goal of this protocol is to demonstrate how to longitudinally visualize the expression and localization of a protein of interest within specific cell types of an animal's brain, upon exposure to exogenous stimuli. Here, the administration of a closed-skull traumatic brain injury (TBI) and simultaneous implantation of a cranial window for subsequent longitudinal intravital imaging in mice is shown. Mice are intracranially injected with an adeno-associated virus (AAV) expressing enhanced green fluorescent protein (EGFP) under a neuronal specific promoter. After 2 to 4 weeks, the mice are subjected to a repetitive TBI using a weight drop device over the AAV injection location. Within the same surgical session, the mice are implanted with a metal headpost and then a glass cranial window over the TBI impacting site. The expression and cellular localization of EGFP is examined using a two-photon microscope in the same brain region exposed to trauma over the course of months.

Subsequent ischemic stroke and tobacco smoking: A secondary analysis of the POINT trial.

Background: The aim of this study was to determine the effect of smoking status on subsequent stroke risk in patients with minor ischemic stroke or TIA and to determine whether smoking modifies the effect of clopidogrel-based DAPT on subsequent stroke risk. Methods: This was a post-hoc analysis of the Platelet Oriented Inhibition in New TIA and Minor Ischemic Stroke (POINT) trial, which had a 90-day follow-up period. We used multivariable Cox regression and subgroup interaction analysis to determine the effect of smoking on the risk of subsequent ischemic stroke and major hemorrhage, respectively. Results: Data from 4877 participants enrolled in the POINT trial were analyzed. Among these, 1004 were current smokers and 3873 were non-smokers at the time of index event. Smoking was associated with a non-significant trend toward an increased risk of subsequent ischemic stroke during follow up (adjusted HR, 1.31 (95% CI, 0.97-1.78), p = 0.076). The effect of clopidogrel on ischemic stroke did not differ between non-smokers (HR, 0.74 (95% CI, 0.56-0.98), p = 0.03) and smokers (HR, 0.63 (95% CI, 0.37-1.05), p = 0.078), p for interaction = 0.572. Similarly, the effect of clopidogrel on major hemorrhage did not differ between non-smokers (hazard ratio, 1.67 (95% CI, 0.40-7.00), p = 0.481) and smokers (HR, 2.59 (95% CI, 1.08-6.21), p = 0.032), p for interaction = 0.613. Conclusions: In this post-hoc analysis of the POINT trial we found that the effect of clopidogrel on reducing subsequent ischemic stroke as well as risk of major hemorrhage did not depend on smoking status, indicating that smokers benefit to a similar degree from DAPT as non-smokers.

Trends in Venous Thromboembolism Readmission Rates after Ischemic Stroke and Intracerebral Hemorrhage.

BACKGROUND AND PURPOSE: Venous thromboembolism (VTE) is a life-threatening complication of stroke. We evaluated nationwide rates and risk factors for hospital readmissions with VTE after an intracerebral hemorrhage (ICH) or acute ischemic stroke (AIS) hospitalization. METHODS: Using the Healthcare Cost and Utilization Project (HCUP) Nationwide Readmission Database, we included patients with a principal discharge diagnosis of ICH or AIS from 2016 to 2019. Patients who had VTE diagnosis or history of VTE during the index admission were excluded. We performed Cox regression models to determine factors associated with VTE readmission, compared rates between AIS and ICH and developed post-stroke VTE risk score. We estimated VTE readmission rates per day over a 90-day time window post-discharge using linear splines. RESULTS: Of the total 1,459,865 patients with stroke, readmission with VTE as the principal diagnosis within 90 days occurred in 0.26% (3,407/1,330,584) AIS and 0.65% (843/129,281) ICH patients. The rate of VTE readmission decreased within first 4-6 weeks (P<0.001). In AIS, cancer, obesity, higher National Institutes of Health Stroke Scale (NIHSS) score, longer hospital stay, home or rehabilitation disposition, and absence of atrial fibrillation were associated with VTE readmission. In ICH, longer hospital stay and rehabilitation disposition were associated with VTE readmission. The VTE rate was higher in ICH compared to AIS (adjusted hazard ratio 2.86, 95% confidence interval 1.93-4.25, P<0.001). CONCLUSIONS: After stroke, VTE readmission risk is highest within the first 4-6 weeks and nearly three-fold higher after ICH vs. AIS. VTE risk is linked to decreased mobility and hypercoagulability. Studies are needed to test short-term VTE prophylaxis beyond hospitalization in high-risk patients.

CRISPR/Cas9-mediated excision of ALS/FTD-causing hexanucleotide repeat expansion in C9ORF72 rescues major disease mechanisms in vivo and in vitro.

A GGGGCC24+ hexanucleotide repeat expansion (HRE) in the C9ORF72 gene is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), fatal neurodegenerative diseases with no cure or approved treatments that substantially slow disease progression or extend survival. Mechanistic underpinnings of neuronal death include C9ORF72 haploinsufficiency, sequestration of RNA-binding proteins in the nucleus, and production of dipeptide repeat proteins. Here, we used an adeno-associated viral vector system to deliver CRISPR/Cas9 gene-editing machineries to effectuate the removal of the HRE from the C9ORF72 genomic locus. We demonstrate successful excision of the HRE in primary cortical neurons and brains of three mouse models containing the expansion (500-600 repeats) as well as in patient-derived iPSC motor neurons and brain organoids (450 repeats). This resulted in a reduction of RNA foci, poly-dipeptides and haploinsufficiency, major hallmarks of C9-ALS/FTD, making this a promising therapeutic approach to these diseases.

Predictors of Recurrent Venous Thrombosis After Cerebral Venous Thrombosis: Analysis of the ACTION-CVT Study.

BACKGROUND AND OBJECTIVE: Cerebral venous thrombosis (CVT) is a rare cause of stroke carrying a nearly 4% risk of recurrence after 1 year. There are limited data on predictors of recurrent venous thrombosis in patients with CVT. In this study, we aim to identify those predictors. METHODS: This is a secondary analysis of the ACTION-CVT study which is a multicenter international study of consecutive patients hospitalized with a diagnosis of CVT over a 6-year period. Patients with cancer-associated CVT, CVT during pregnancy, or CVT in the setting of known antiphospholipid antibody syndrome were excluded per the ACTION-CVT protocol. The study outcome was recurrent venous thrombosis defined as recurrent venous thromboembolism (VTE) or de novo CVT. We compared characteristics between patients with vs without recurrent venous thrombosis during follow-up and performed adjusted Cox regression analyses to determine important predictors of recurrent venous thrombosis. RESULTS: Nine hundred forty-seven patients were included with a mean age of 45.2 years, 63.9% were women, and 83.6% had at least 3 months of follow-up. During a median follow-up of 308 (interquartile range 120-700) days, there were 5.05 recurrent venous thromboses (37 VTE and 24 de novo CVT) per 100 patient-years. Predictors of recurrent venous thrombosis were Black race (adjusted hazard ratio [aHR] 2.13, 95% CI 1.14-3.98, p = 0.018), history of VTE (aHR 3.40, 95% CI 1.80-6.42, p < 0.001), and the presence of one or more positive antiphospholipid antibodies (aHR 3.85, 95% CI 1.97-7.50, p < 0.001). Sensitivity analyses including events only occurring on oral anticoagulation yielded similar findings. DISCUSSION: Black race, history of VTE, and the presence of one or more antiphospholipid antibodies are associated with recurrent venous thrombosis among patients with CVT. Future studies are needed to validate our findings to better understand mechanisms and treatment strategies in patients with CVT.

Relationship of white matter lesion severity with early and late outcomes after mechanical thrombectomy for large vessel stroke.

BACKGROUND: White matter lesions (WML) are associated with poor outcome after mechanical thrombectomy (MT) for large vessel stroke; the reasons are uncertain. To elucidate this issue we sought to determine the association of WML with multiple early and late outcome measures after MT. METHODS: We retrospectively analyzed 181 MT patients prospectively included in our local stroke registry (January 2012 to November 2016). Using multiple regression modeling, we assessed whether WML was independently associated with early outcomes (successful recanalization, degree of National Institutes of Health Stroke Scale (NIHSS) improvement, hemorrhagic transformation, duration of hospitalization) as well as an unfavorable 90-day modified Rankin Scale score (mRS) (≥3) and 90-day survival. Explorative analyses examined the association with the 90-day home-time and 90-day risk for hospital readmission. RESULTS: WML were not significantly associated with early outcome measure (P>0.05, each). Patients with moderate-to-severe WML more often had an unfavorable mRS (OR 2.93, 95% CI 1.04 to 8.33) and risk of death (HR 1.98, 95% CI 1.03 to 3.84) after adjustment for pertinent confounders. Patients with moderate-to-severe WML had a significantly shorter home-time (19±32 vs 47±38 days, P<0.001) and Kaplan-Meier analyses indicated a significantly greater risk for hospital readmission within 90 days (log rank P=0.045), with the most frequent reasons being recurrent stroke and transient ischemic attack. CONCLUSION: Our analyses suggest that poor outcomes among patients with moderate-to-severe WML were related to factors unrelated to procedural success and risk. WML should not be used to render treatment decisions in otherwise eligible patients. Aggressive monitoring of medical complications after MT could represent a viable strategy to improve outcome in affected patients.

Risk of Ischemic Stroke in Patients With Atrial Fibrillation After Extracranial Hemorrhage.

BACKGROUND AND PURPOSE: Anticoagulation therapy not only reduces the risk of ischemic stroke in atrial fibrillation (AF) but also predisposes patients to hemorrhagic complications. There is limited knowledge on the risk of first-ever ischemic stroke in patients with AF after extracranial hemorrhage (ECH). METHODS: We conducted a retrospective study using the California State Inpatient Database including all nonfederal hospital admissions in California from 2005 to 2011. The exposure variable was hospitalization with a diagnosis of ECH with a previous diagnosis of AF. The outcome variable was a subsequent hospitalization with acute ischemic stroke. We excluded patients with stroke before or at the time of ECH diagnosis. We calculated adjusted hazard ratios for ischemic stroke during follow-up and at 6-month intervals using Cox regression models adjusted for pertinent demographics and comorbidities. In subgroup analyses, subjects were stratified by primary ECH diagnosis, severity/type of ECH, age, CHA2DS2-VASc score, or the presence/absence of a gastrointestinal or genitourinary cancer. RESULTS: We identified 764 257 patients with AF (mean age 75 years, 49% women) without a documented history of stroke. Of these, 98 647 (13%) had an ECH-associated hospitalization, and 22 748 patients (3%) developed an ischemic stroke during the study period. Compared to patients without ECH, subjects with ECH had ≈15% higher rate of ischemic stroke (overall adjusted hazard ratio, 1.15 [95% CI, 1.11-1.19]). The risk appeared to remain elevated for at least 18 months after the index ECH. In subgroup analyses, the risk was highest in subjects with a primary admission diagnosis of ECH, severe ECH, gastrointestinal-type ECH, with gastrointestinal or genitourinary cancer, and age ≥60 years. CONCLUSIONS: Patients with AF hospitalized with ECH may have a slightly elevated risk for future ischemic stroke. Particular consideration should be given to the optimal balance between the benefits and risks of anticoagulation therapy and the use of nonanticoagulant alternatives, such as left atrial appendage closure in this vulnerable population.

"Don't lose hope early": Hemorrhagic diffuse axonal injury on head computed tomography is not associated with poor outcome in moderate to severe traumatic brain injury patients.

BACKGROUND: Diffuse axonal injury (DAI) on magnetic resonance imaging has been associated with poor functional outcome after moderate-severe traumatic brain injury (msTBI). Yet, DAI assessment with highly sensitive magnetic resonance imaging techniques is unfeasible in the acute trauma setting, and computed tomography (CT) remains the key diagnostic modality despite its lower sensitivity. We sought to determine whether CT-defined hemorrhagic DAI (hDAI) is associated with discharge and favorable 3- and 12-month functional outcome (Glasgow Coma Scale score ≥4) after msTBI. METHODS: We analyzed 361 msTBI patients from the single-center longitudinal Outcome Prognostication in Traumatic Brain Injury study collected over 6 years (November 2009 to November 2015) with prospective outcome assessments at 3 months and 12 months. Patients with microhemorrhages on CT were designated "CT-hDAI-positive" and those without as "CT-hDAI-negative." For secondary analyses "CT-hDAI-positive" was stratified into two phenotypes according to presence ("associated") versus absence ("predominant") of concomitant large acute traumatic lesions to determine whether presence versus absence of additional focal mass lesions portends a different prognosis. RESULTS: Seventy (19%) patients were CT-hDAI-positive (n = 36 predominant; n = 34 associated hDAI). In univariate analyses, CT-hDAI-positive status was associated with discharge survival (p = 0.004) and favorable outcome at 3 months (p = 0.003) and 12 months (p = 0.005). After multivariable adjustment, CT-hDAI positivity was no longer associated with discharge survival and functional outcome (all ps > 0.05). Stratified by hDAI phenotype, predominant hDAI patients had worse trauma severity, longer intensive care unit stays, and more systemic medical complications. Predominant hDAI, but not associated hDAI, was an independent predictor of discharge survival (adjusted odds ratio, 24.7; 95% confidence interval [CI], 3.2-192.6; p = 0.002) and favorable 12-month outcome (adjusted odds ratio, 4.7; 95% CI, 1.5-15.2; p = 0.01). Sensitivity analyses using Cox regression confirmed this finding for 1-year survival (adjusted hazard ratio, 5.6; 95% CI, 1.3-23; p = 0.048). CONCLUSION: The CT-defined hDAI was not an independent predictor of unfavorable short- and long-term outcomes and should not be used for acute prognostication in msTBI patients. Predominant hDAI patients had good clinical outcomes when supported to intensive care unit discharge and beyond. LEVEL OF EVIDENCE: Prognostic study, level III.

Endovascular treatment of acute ischemic stroke in nonagenarians compared with younger patients in a multicenter cohort.

BACKGROUND: Recent studies have demonstrated the superiority of endovascular therapy (EVT) for emergent large vessel occlusion. OBJECTIVE: To determine the effectiveness of EVT in nonagenarians, for whom data are limited. METHODS: We retrospectively reviewed clinical and imaging data of all patients who underwent EVT at two stroke centers between January 2012 and August 2014. The 90-day functional outcome (modified Rankin Scale (mRS) score) was compared between younger patients (age 18-89 years; n=175) and nonagenarians (n=18). The relationship between pre-stroke and 90-day post-stroke mRS was analyzed in these two groups. Multivariable analysis of age, recanalization grade, and admission National Institutes of Health Stroke Scale (NIHSS) for predicting outcome was performed. RESULTS: Age ≥90 years was associated with a poor (mRS >2) 90-day outcome relative to those under 90 (89% vs 52%, OR=8, 95% CI 1.7 to 35.0; p=0.0081). Nonagenarians had a higher pre-stroke mRS score (0.77; 95% CI 0.44 to 1.30) than younger patients (0.24; 95% CI 0.17 to 0.35; p=0.005). No difference was observed between nonagenarians and younger patients in the rate of mRS change from pre-stroke to 90 days (p=0.540). On multivariable regression, age (OR=1.05, 95% CI 1.03 to 1.08; p<0.0001), recanalization grade (OR=0.62 95% CI 0.42 to 0.91; p=0.015), and admission NIHSS (OR=1.07 95% CI 1.02 to 1.13; p=0.01) were associated with a poor 90-day outcome. CONCLUSIONS: Nonagenarians are at a substantially higher risk of a poor 90-day outcome after EVT than younger patients. However, a small subset of nonagenarians may benefit from EVT, particularly if they have a good pre-stroke functional status. Further research is needed to identify factors associated with favorable outcome in this age cohort.

Preclinical acute ischemic stroke modeling.

Preclinical ischemic stroke is at the crossroads in search of reliable and robust simulation models as past experiences with their translation from the laboratory to the standard of clinical care have often been disappointing. The efficacy of neuroprotective agents is still elusive, and the use of thrombolytics alone is limited to the narrow time window of presentation from the onset of the deficit. Hence, the focus has shifted to interventional revascularization to salvage the parenchyma at the risk of infarction. As the burden of disease morbidity and mortality is so enormous, neurointerventionalists have adopted a more aggressive approach to mechanical revascularization with the limited approved tools available-the Penumbra and the MERCI retrieval system, and the recently incorporated stent retrievers. In fact, the interventional space is among the fastest growing fields in stroke research today. Assessing treatment efficacy in these scenarios is infinitely complex as the heterogeneity of the cerebrovasculature, physical and mechanical nature of the occlusive embolus and the time of presentation are all confounders in assessing treatment outcomes. As no single thromboembolic model is apt to address all of these questions, an integrated methodology with a combination of both in vitro and in vivo assessment needs to be adopted. This involves clinically relevant thromboembolic analogs in device evaluation in vascular replicas, thromboembolic stroke induction in large animal gyrencephalic ischemic stroke models for thrombolytic, imaging and neuroprotection research and a native cerebrovascular target for evaluation of the safety and efficacy of mechanical thrombectomy devices.

Electrophysiology and neuronal integrity following systemic arterial hypotension in a rat model of unilateral carotid artery occlusion.

Patients with carotid artery stenosis may be particularly susceptible to hypotension-associated cerebral ischemia and subsequent neurological sequelae. Measuring somatosensory evoked potentials (SEP), electroencephalogram (EEG), direct current (DC) potential, and histology, we compared the temporal evolution of cortical functional perturbations as well as neuronal integrity in a model of unilateral carotid artery occlusion and systemic hypobaric hypotension (HH) at the lower limit of cerebral blood flow autoregulation (50 mm Hg). Serial measurements of EEG power spectra as well as SEP-amplitudes and latencies of N10.3 were performed before, during, and up to 60 min after 30 min-HH (n=7) or the control condition (n=7) in male Wistar rats. In two additional groups (with [n=7] or without [n=7] HH), cortical spreading depressions (CSD) were elicited to ascertain their contribution to brain injury. Hematoxilin-Eosin (H&E) staining was used to assess neuronal cell death at 5 days after surgery. Relative to baseline, HH attenuated ipsilateral EEG power spectrum (by maximally 62%), increased SEP-latencies (by approximately 6-10%) and amplitudes (by approximately 57-70%), and induced selective neuronal cell death in the cerebral cortex and hippocampus (P<0.05 vs. contralateral). Spontaneous CSD occurred in approximately 30% of HH-animals. Repolarization of the DC-potential during HH was significantly prolonged relative to normotensive conditions (10.3+/-11.5 min, P<0.001). Our model may help to understand underlying pathophysiology and improve outcome in a clinical subset of patients with carotid artery stenosis and transient systemic hypotension.