Neuroimmune activation is associated with neurological outcome in anoxic and traumatic coma

The pathophysiological underpinnings of critically disrupted brain connectomes resulting in coma are poorly understood. Inflammation is potentially an important but still undervalued factor. Here, we present a first-in-human prospective study using the 18-kDa translocator protein (TSPO) radioligand 18F-DPA714 for PET imaging to allow in vivo neuroimmune activation quantification in patients with coma (n = 17) following either anoxia or traumatic brain injuries in comparison with age- and sex-matched controls. Our findings yielded novel evidence of an early inflammatory component predominantly located within key cortical and subcortical brain structures that are putatively implicated in consciousness emergence and maintenance after severe brain injury (i.e. mesocircuit and frontoparietal networks). We observed that traumatic and anoxic patients with coma have distinct neuroimmune activation profiles, both in terms of intensity and spatial distribution. Finally, we demonstrated that both the total amount and specific distribution of PET-measurable neuroinflammation within the brain mesocircuit were associated with the patient's recovery potential. We suggest that our results can be developed for use both as a new neuroprognostication tool and as a promising biometric to guide future clinical trials targeting glial activity very early after severe brain injury.

MRI hypoperfusion as a determinant of cognitive impairment in adults with Moyamoya angiopathy

INTRODUCTION

In Moyamoya angiopathy (MMA), mechanisms underlying cognitive impairment remain debated. We aimed to assess the association of cognitive impairment with the degree and the topography of cerebral hypoperfusion in MMA.

METHODS

A retrospective analysis of neuropsychological and perfusion MRI data from adults with MMA was performed. Ischemic and haemorrhagic lesion masks were created to account for cerebral lesions in the analysis of cerebral perfusion. Whole brain volume of hypoperfused parenchyma was outlined on perfusion maps using different Tmax thresholds from 4 to 12 s. Regional analysis produced mean Tmax values at different regions of interest. Analyses compared perfusion ratios in patients with and without cognitive impairment, with multivariable logistic regression analysis to identify predictive factors.

RESULTS

Cognitive impairment was found in 20/48 (41.7%) patients. Attention/processing speed and memory were equally impaired (24%) followed by executive domain (23%). After adjustment, especially for lesion volume, hypoperfused parenchyma volume outlined by Tmax > 4 s or Tmax > 5 s thresholds was an independent factor of cognitive impairment (OR for Tmax > 4 s = 1.06 [CI 95% 1.008-1.123]) as well as attention/processing speed (OR for Tmax > 4 s = 1.07 [CI 95% 1.003-1.133]) and executive domains (OR for Tmax > 5 s = 1.08 [CI 95% 1.004-1.158]). Regarding cognitive functions, patients with processing speed and flexibility impairment had higher frontal Tmax compared to other ROIs and to patients with normal test scores.

DISCUSSION

Cerebral hypoperfusion emerged as an independent factor of cognitive impairment in MMA particularly in attention/processing speed and executive domains, with a strong contribution of frontal areas.

CONCLUSION

Considering this association, revascularization surgery could improve cognitive impairment.

No-reflow phenomenon in stroke patients: A systematic literature review and meta-analysis of clinical data

BACKGROUND

The no-reflow phenomenon refers to the absence of microvascular reperfusion despite macrovascular reperfusion.

AIM

The aim of this analysis was to summarize the available clinical evidence on no-reflow in patients with acute ischemic stroke.

METHODS

A systematic literature review and a meta-analysis of clinical data on definition, rates, and impact of the no-reflow phenomenon after reperfusion therapy was carried out. A predefined research strategy was formulated according to the Population, Intervention, Comparison, and Outcome (PICO) model and was used to screen for articles in PubMed, MEDLINE, and Embase up to 8 September 2022. Whenever possible, quantitative data were summarized using a random-effects model.

RESULTS

Thirteen studies with a total of 719 patients were included in the final analysis. Most studies (n = 10/13) used variations of the Thrombolysis in Cerebral Infarction scale to evaluate macrovascular reperfusion, whereas microvascular reperfusion and no-reflow were mostly assessed on perfusion maps (n = 9/13). In one-third of stroke patients with successful macrovascular reperfusion (29%, 95% confidence interval (CI), 21-37%), the no-reflow phenomenon was observed. Pooled analysis showed that no-reflow was consistently associated with reduced rates of functional independence (odds ratio (OR), 0.21, 95% CI, 0.15-0.31).

CONCLUSION

The definition of no-reflow varied substantially across studies, but it appears to be a common phenomenon. Some of the no-reflow cases may simply represent remaining vessel occlusions, and it remains unclear whether no-reflow is an epiphenomenon of the infarcted parenchyma or causes infarction. Future studies should focus on standardizing the definition of no-reflow with more consistent definitions of successful macrovascular reperfusion and experimental set-ups that could detect the causality of the observed findings.

Safety and Efficacy of ApTOLL in Patients With Ischemic Stroke Undergoing Endovascular Treatment: A Phase 1/2 Randomized Clinical Trial

Importance

ApTOLL is a TLR4 antagonist with proven preclinical neuroprotective effect and a safe profile in healthy volunteers.

Objective

To assess the safety and efficacy of ApTOLL in combination with endovascular treatment (EVT) for patients with ischemic stroke.

Design, Setting, and Participants

This phase 1b/2a, double-blind, randomized, placebo-controlled study was conducted at 15 sites in Spain and France from 2020 to 2022. Participants included patients aged 18 to 90 years who had ischemic stroke due to large vessel occlusion and were seen within 6 hours after stroke onset; other criteria were an Alberta Stroke Program Early CT Score of 6 to 10, estimated infarct core volume on baseline computed tomography perfusion of 5 to 70 mL, and the intention to undergo EVT. During the study period, 4174 patients underwent EVT.

Interventions

In phase 1b, 0.025, 0.05, 0.1, or 0.2 mg/kg of ApTOLL or placebo; in phase 2a, 0.05 or 0.2 mg/kg of ApTOLL or placebo; and in both phases, treatment with EVT and intravenous thrombolysis if indicated.

Main Outcomes and Measures

The primary end point was the safety of ApTOLL based on death, symptomatic intracranial hemorrhage (sICH), malignant stroke, and recurrent stroke. Secondary efficacy end points included final infarct volume (via MRI at 72 hours), NIHSS score at 72 hours, and disability at 90 days (modified Rankin Scale [mRS] score).

Results

In phase Ib, 32 patients were allocated evenly to the 4 dose groups. After phase 1b was completed with no safety concerns, 2 doses were selected for phase 2a; these 119 patients were randomized to receive ApTOLL, 0.05 mg/kg (n = 36); ApTOLL, 0.2 mg/kg (n = 36), or placebo (n = 47) in a 1:1:√2 ratio. The pooled population of 139 patients had a mean (SD) age of 70 (12) years, 81 patients (58%) were male, and 58 (42%) were female. The primary end point occurred in 16 of 55 patients (29%) receiving placebo (10 deaths [18.2%], 4 sICH [7.3%], 4 malignant strokes [7.3%], and 2 recurrent strokes [3.6%]); in 15 of 42 patients (36%) receiving ApTOLL, 0.05 mg/kg (11 deaths [26.2%], 3 sICH [7.2%], 2 malignant strokes [4.8%], and 2 recurrent strokes [4.8%]); and in 6 of 42 patients (14%) receiving ApTOLL, 0.2 mg/kg (2 deaths [4.8%], 2 sICH [4.8%], and 3 recurrent strokes [7.1%]). ApTOLL, 0.2 mg/kg, was associated with lower NIHSS score at 72 hours (mean difference log-transformed vs placebo, -45%; 95% CI, -67% to -10%), smaller final infarct volume (mean difference log-transformed vs placebo, -42%; 95% CI, -66% to 1%), and lower degrees of disability at 90 days (common odds ratio for a better outcome vs placebo, 2.44; 95% CI, 1.76 to 5.00).

Conclusions and Relevance

In acute ischemic stroke, 0.2 mg/kg of ApTOLL administered within 6 hours of onset in combination with EVT was safe and associated with a potential meaningful clinical effect, reducing mortality and disability at 90 days compared with placebo. These preliminary findings await confirmation from larger pivotal trials.

Trial Registration

ClinicalTrials.gov Identifier: NCT04734548.

Immunohistologic Features of Cerebral Venous Thrombosis Due to Vaccine-Induced Immune Thrombotic Thrombocytopenia

OBJECTIVES

Vaccine-induced immune thrombotic thrombocytopenia (VITT), a recently described entity characterized by thrombosis at unusual locations such as cerebral venous sinus and splanchnic vein, has been rarely described after adenoviral-encoded COVID-19 vaccines. In this study, we report the immunohistological correlates in 3 fatal cases of cerebral venous thrombosis related to VITT analyzed at an academic medical center.

METHODS

Detailed neuropathologic studies were performed in 3 cases of cerebral venous thrombosis related to VITT after adenoviral COVID-19 vaccination.

RESULTS

Autopsy revealed extensive cerebral vein thrombosis in all 3 cases. Polarized thrombi were observed with a high density of neutrophils in the core and a low density in the tail. Endothelial cells adjacent to the thrombus were largely destroyed. Markers of neutrophil extracellular trap and complement activation were present at the border and within the cerebral vein thrombi. SARS-CoV-2 spike protein was detected within the thrombus and in the adjacent vessel wall.

DISCUSSION

Data indicate that neutrophils and complement activation associated with antispike immunity triggered by the vaccine is probably involved in the disease process.

Transradial access with Simmons guiding catheter for carotid artery stenting: Feasibility and procedural complications in a single-center experience

BACKGROUND

There is an increasing number of transradial approach (TRA) for carotid artery stenting (CAS), however, similar techniques and materials as for femoral access are used. We report the results of TRA lower profile technique for CAS using a 7 F Simmons guiding catheter, especially in terms of feasibility and procedural safety in a single center.

MATERIALS AND METHODS

We retrospectively analyzed 68 consecutive patients with symptomatic extracranial carotid stenoses who underwent 75 CAS between January 2018 and December 2021. The success and crossover rate, procedural time, fluoroscopy, clinical outcomes, technical considerations, and procedural complications were analyzed.

RESULTS

TRA CAS with Simmons guiding catheter was successful in 67/75 (89.3%) cases, with a 7 (9.3%) crossover rate. Fluoroscopy mean time was 15.8 minutes. Two forearm hematomas were described. No ischemic or surgical site complications were reported.

CONCLUSIONS

In our experience frontline TRA with a 7 F Simmons guiding catheter is feasible with high procedural success and a low rate of access site complications.

Location-weighted versus Volume-weighted Mismatch at MRI for Response to Mechanical Thrombectomy in Acute Stroke

Background A target mismatch profile can identify good clinical response to recanalization after acute ischemic stroke, but does not consider region specificities. Purpose To test whether location-weighted infarction core and mismatch, determined from diffusion and perfusion MRI performed in patients with acute stroke, could improve prediction of good clinical response to mechanical thrombectomy compared with a target mismatch profile. Materials and Methods In this secondary analysis, two prospectively collected independent stroke data sets (2012-2015 and 2017-2019) were analyzed. From the brain before stroke (BBS) study data (data set 1), an eloquent map was computed through voxel-wise associations between the infarction core (based on diffusion MRI on days 1-3 following stroke) and National Institutes of Health Stroke Scale (NIHSS) score. The French acute multimodal imaging to select patients for mechanical thrombectomy (FRAME) data (data set 2) consisted of large vessel occlusion-related acute ischemic stroke successfully recanalized. From acute MRI studies (performed on arrival, prior to thrombectomy) in data set 2, target mismatch and eloquent (vs noneloquent) infarction core and mismatch were computed from the intersection of diffusion- and perfusion-detected lesions with the coregistered eloquent map. Associations of these imaging metrics with early neurologic improvement were tested in multivariable regression models, and areas under the receiver operating characteristic curve (AUCs) were compared. Results Data sets 1 and 2 included 321 (median age, 69 years [IQR, 58-80 years]; 207 men) and 173 (median age, 74 years [IQR, 65-82 years]; 90 women) patients, respectively. Eloquent mismatch was positively and independently associated with good clinical response (odds ratio [OR], 1.14; 95% CI: 1.02, 1.27; P = .02) and eloquent infarction core was negatively associated with good response (OR, 0.85; 95% CI: 0.77, 0.95; P = .004), while noneloquent mismatch was not associated with good response (OR, 1.03; 95% CI: 0.98, 1.07; P = .20). Moreover, adding eloquent metrics improved the prediction accuracy (AUC, 0.73; 95% CI: 0.65, 0.81) compared with clinical variables alone (AUC, 0.65; 95% CI: 0.56, 0.73; P = .01) or a target mismatch profile (AUC, 0.67; 95% CI: 0.59, 0.76; P = .03). Conclusion Location-weighted infarction core and mismatch on diffusion and perfusion MRI scans improved the identification of patients with acute stroke who would benefit from mechanical thrombectomy compared with the volume-based target mismatch profile. Clinical trial registration no. NCT03045146 © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Nael in this issue.

European Stroke Organisation (ESO) guidelines on management of transient ischaemic attack

The aim of the present European Stroke Organisation Transient Ischaemic Attack (TIA) management guideline document is to provide clinically useful evidence-based recommendations on approaches to triage, investigation and secondary prevention, particularly in the acute phase following TIA. The guidelines were prepared following the Standard Operational Procedure for a European Stroke Organisation guideline document and according to GRADE methodology. As a basic principle, we defined TIA clinically and pragmatically for generalisability as transient neurological symptoms, likely to be due to focal cerebral or ocular ischaemia, which last less than 24 hours. High risk TIA was defined based on clinical features in patients seen early after their event or having other features suggesting a high early risk of stroke (e.g. ABCD2 score of 4 or greater, or weakness or speech disturbance for greater than five minutes, or recurrent events, or significant ipsilateral large artery disease e.g. carotid stenosis, intracranial stenosis). Overall, we strongly recommend using dual antiplatelet treatment with clopidogrel and aspirin short term, in high-risk non-cardioembolic TIA patients, with an ABCD2 score of 4 or greater, as defined in randomised controlled trials (RCTs). We further recommend specialist review within 24 hours after the onset of TIA symptoms. We suggest review in a specialist TIA clinic rather than conventional outpatients, if managed in an outpatient setting. We make a recommendation to use either MRA or CTA in TIA patients for additional confirmation of large artery stenosis of 50% or greater, in order to guide further management, such as clarifying degree of carotid stenosis detected with carotid duplex ultrasound. We make a recommendation against using prediction tools (eg ABCD2 score) alone to identify high risk patients or to make triage and treatment decisions in suspected TIA patients as due to limited sensitivity of the scores, those with score value of 3 or less may include significant numbers of individual patients at risk of recurrent stroke, who require early assessment and treatment. These recommendations aim to emphasise the importance of prompt acute assessment and relevant secondary prevention. There are no data from randomised controlled trials on prediction tool use and optimal imaging strategies in suspected TIA.

Assessment of Magnetic Resonance Imaging Changes and Functional Outcomes Among Adults With Severe Herpes Simplex Encephalitis

Importance

Current guidelines recommend brain magnetic resonance imaging (MRI) for clinical management of patients with severe herpes simplex encephalitis (HSE). However, the prognostic value of brain imaging has not been demonstrated in this setting.

Objective

To investigate the association between early brain MRI data and functional outcomes of patients with HSE at 90 days after intensive care unit (ICU) admission.

Design, Setting, and Participants

This multicenter cohort study was conducted in 34 ICUs in France from 2007 to 2019 and recruited all patients who received a clinical diagnosis of encephalitis and exhibited cerebrospinal fluid positivity for herpes simplex virus DNA in the polymerase chain reaction analysis. Data analysis was performed from January to April 2020.

Exposures

All patients underwent a standard brain MRI during the first 30 days after ICU admission.

Main Outcomes and Measures

MRI acquisitions were analyzed by radiologists blinded to patients' outcomes, using a predefined score. Multivariable logistic regression and supervised hierarchical classifiers methods were used to identify factors associated with poor outcome at 90 days, defined by a score of 3 to 6 (indicating moderate-to-severe disability or death) on the Modified Rankin Scale.

Results

Overall, 138 patients (median [interquartile range {IQR}] age, 62.6 [54.0-72.0] years; 75 men [54.3%]) with an admission median (IQR) Glasgow Coma Scale score of 9 (6-12) were studied. The median (IQR) delay between ICU admission and MRI was 1 (1-7) days. At 90 days, 95 patients (68.8%) had a poor outcome, including 16 deaths (11.6%). The presence of fluid-attenuated inversion recovery MRI signal abnormalities in more than 3 brain lobes (odds ratio [OR], 25.71; 95% CI, 1.21-554.42), age older than 60 years (OR, 7.62; 95% CI, 2.02-28.91), and the presence of diffusion-weighted MRI signal abnormalities in the left thalamus (OR, 6.90; 95% CI, 1.12-43.00) were independently associated with poor outcome. Machine learning models identified bilateral diffusion abnormalities as an additional factor associated with poor outcome (34 of 39 patients [87.2%] with bilateral abnormalities had poor outcomes) and confirmed the functional burden of left thalamic lesions, particularly in older patients (all 11 patients aged >60 years had left thalamic lesions).

Conclusions and Relevance

These findings suggest that in adult patients with HSE requiring ICU admission, extensive MRI changes in the brain are independently associated with poor functional outcome at 90 days. Thalamic diffusion signal changes were frequently observed and were associated with poor prognosis, mainly in older patients.

European Stroke Organisation (ESO) guidelines on management of transient ischaemic attack

The aim of the present European Stroke Organisation Transient Ischaemic Attack (TIA) management guideline document is to provide clinically useful evidence-based recommendations on approaches to triage, investigation and secondary prevention, particularly in the acute phase following TIA. The guidelines were prepared following the Standard Operational Procedure for a European Stroke Organisation guideline document and according to GRADE methodology. As a basic principle, we defined TIA clinically and pragmatically for generalisability as transient neurological symptoms, likely to be due to focal cerebral or ocular ischaemia, which last less than 24 hours. High risk TIA was defined based on clinical features in patients seen early after their event or having other features suggesting a high early risk of stroke (e.g. ABCD2 score of 4 or greater, or weakness or speech disturbance for greater than five minutes, or recurrent events, or significant ipsilateral large artery disease e.g. carotid stenosis, intracranial stenosis). Overall, we strongly recommend using dual antiplatelet treatment with clopidogrel and aspirin short term, in high-risk non-cardioembolic TIA patients, with an ABCD2 score of 4 or greater, as defined in randomised controlled trials (RCTs). We further recommend specialist review within 24 hours after the onset of TIA symptoms. We suggest review in a specialist TIA clinic rather than conventional outpatients, if managed in an outpatient setting. We make a recommendation to use either MRA or CTA in TIA patients for additional confirmation of large artery stenosis of 50% or greater, in order to guide further management, such as clarifying degree of carotid stenosis detected with carotid duplex ultrasound. We make a recommendation against using prediction tools (eg ABCD2 score) alone to identify high risk patients or to make triage and treatment decisions in suspected TIA patients as due to limited sensitivity of the scores, those with score value of 3 or less may include significant numbers of individual patients at risk of recurrent stroke, who require early assessment and treatment. These recommendations aim to emphasise the importance of prompt acute assessment and relevant secondary prevention. There are no data from randomised controlled trials on prediction tool use and optimal imaging strategies in suspected TIA.

Case Report: Late Successful Thrombectomy for Ischemic Stroke in a 2-Year-Old Child

Despite extensive evidence of benefit of thrombectomy in adult ischemic stroke due to large-vessel occlusion in the 6-h window, its role remains uncertain in very young children. We describe hereafter the case of a 2-year-old female child who had a successful thrombectomy 9 h after stroke onset. The patient presented with right hemiplegia, central facial palsy, a normal level of consciousness, and speech difficulties. The PedNIHS score was 11. CT scan without contrast injection displayed spontaneous hyperdensity of the middle cerebral artery (MCA), with only limited early signs of ischemia (ASPECTS 8). CT angiography demonstrated occlusion of the proximal MCA with good collaterals. Thrombectomy was realized. Complete recanalization (TICI 3) was obtained under general anesthesia after two passes of a stent retriever. Time from symptoms onset to full recanalization was 9 h. The acute ischemic stroke was caused by embolic thrombus from a congenital heart disease. Clinical recovery was complete. Three months after the thrombectomy, the young patient was doing well without any neurological sequelae (PedNIHSS 0; modified Rankin Scale: 0). This case report is an example of a decision-making process to perform thrombectomy in a very young child, which included cardio-embolic etiology as a parameter that potentially might have participated to the successful outcome of the therapeutic procedure.

Endovascular therapy with or without intravenous thrombolysis in acute stroke with tandem occlusion

BACKGROUND

Endovascular therapy (EVT) is effective and safe in patients with tandem occlusion. The benefit of intravenous thrombolysis (IVT) prior to EVT in acute tandem occlusion is debatable.

OBJECTIVE

To compare EVT alone with EVT plus IVT in patients with acute ischemic stroke due to anterior circulation tandem occlusions.

METHODS

This is an individual patient pooled analysis of the Thrombectomy In TANdem lesions (TITAN) and Endovascular Treatment in Ischemic Stroke (ETIS) Registries. Patients were divided into two groups based on prior IVT treatment: (1) IVT+ group, which included patients who received IVT prior to EVT, (2) IVT- group, which included patients who did not receive IVT prior to EVT. Propensity score (inverse probability of treatment weighting (IPTW)) was used to reduce baseline between-group differences. The primary outcome was favorable outcome-that is, modified Rankin Scale (mRS) score 0 to 2 at 90 days.

RESULTS

Overall, 602 consecutive patients with an acute stroke with tandem occlusion were included (380 and 222 in the bridging therapy and EVT alone groups, respectively). Onset to imaging time was shorter in the IVT+ group (median 103 vs 140 min). In contrast, imaging to puncture time was longer in the IVT+ group (median 107 vs 91 min). In IPTW analysis, the IVT+ group had higher odds of favorable outcome, excellent outcome (90-day mRS score 0-1), and successful reperfusion (modified Thrombolysis in Cerebral Infarction score 2b/3 at the end of EVT). There was no difference in the risk of significant hemorrhagic complications between groups. In secondary analysis of patients treated with acute cervical internal carotid artery stenting, bridging therapy was associated with higher odds of favorable outcome and lower odds of mortality at 90 days.

CONCLUSIONS

Our results suggest that bridging therapy in patients with acute ischemic stroke due to anterior tandem occlusion is safe and may improve functional outcome, even in the setting of acute cervical internal carotid artery stenting during EVT.

Functional and Structural Integrity of Frontoparietal Connectivity in Traumatic and Anoxic Coma

OBJECTIVES

Recovery from coma might critically depend on the structural and functional integrity of frontoparietal networks. We aimed to measure this integrity in traumatic brain injury and anoxo-ischemic (cardiac arrest) coma patients by using an original multimodal MRI protocol.

DESIGN

Prospective cohort study.

SETTING

Three Intensive Critical Care Units affiliated to the University in Toulouse (France).

PATIENTS

We longitudinally recruited 43 coma patients (Glasgow Coma Scale at the admission < 8; 29 cardiac arrest and 14 traumatic brain injury) and 34 age-matched healthy volunteers. Exclusion criteria were disorders of consciousness lasting more than 30 days and focal brain damage within the explored brain regions. Patient assessments were conducted at least 2 days (5 ± 2 d) after complete withdrawal of sedation. All patients were followed up (Coma Recovery Scale-Revised) 3 months after acute brain injury.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Functional and structural MRI data were recorded, and the analysis was targeted on the posteromedial cortex, the medial prefrontal cortex, and the cingulum. Univariate analyses and machine learning techniques were used to assess diagnostic and predictive values. Coma patients displayed significantly lower medial prefrontal cortex-posteromedial cortex functional connectivity (area under the curve, 0.94; 95% CI, 0.93-0.95). Cardiac arrest patients showed specific structural disturbances within posteromedial cortex. Significant cingulum architectural disturbances were observed in traumatic brain injury patients. The machine learning medial prefrontal cortex-posteromedial cortex multimodal classifier had a significant predictive value (area under the curve, 0.96; 95% CI, 0.95-0.97), best combination of subregions that discriminates a binary outcome based on Coma Recovery Scale-Revised).

CONCLUSIONS

This exploratory study suggests that frontoparietal functional disconnections are specifically observed in coma and their structural counterpart provides information about brain injury mechanisms. Multimodal MRI biomarkers of frontoparietal disconnection predict 3-month outcome in our sample. These findings suggest that fronto-parietal disconnection might be particularly relevant for coma outcome prediction and could inspire innovative precision medicine approaches.

Abstract 2: French Acute Cerebral Multimodal Imaging to Select Patients for Mechanical Thrombectomy Final Results

Introduction: Target mismatch (TMM) identifies salvageable penumbra independent of time from stroke onset. Current guidelines do not recommend advanced imaging to select patients for mechanical thrombectomy (MT) within 6 hours after onset but indicate that more research is needed. To address this question, we designed a prospective multicenter cohort study to compare the rate of functional neurological recovery (mRS ≤2 @ 3 months) in patients treated by MT for ICA/M1/M2 occlusions within 6 hours after onset according to the presence of a TMM on baseline imaging.

Hypothesis: 60% of patients with TMM vs. 35% of no TMM, would achieve an mRS≤2 at 3 months. Sample size calculation: 200 patients.

Methods: Consecutive patients eligible for MT within 6 hrs after onset, who underwent CTP or DWI/PWI imaging before treatment were enrolled. No NIHSS or ASPECTS restrictions were applied. Treating teams were blinded of CTP/DWI/PWI maps. mRS at 3 months was rated by an investigator blinded to clinical/imaging/treatment information. Automatically processed maps by RAPID software were reviewed after the end of follow-up. TMM definition followed EXTEND-IA criteria: MM volume >10mL, MM ratio>1.2, Core volume <70 mL. Mismatch (MM) was defined by MM ratio>1.2 and MM volume>10 mL. Imaging-based subgroups (TMM vs. No TMM) were defined after the end of follow-up.

Results: 218 patients were enrolled. Baseline imaging profile distribution was 71% TMM, 29% no TMM, (in the no TMM group, 76% had a core volume > 70 mL); 82% MM and 18% no MM. Reperfusion(TICI 2B-3) was achieved in 86% of the patients after a median delay of 4.4 hrs (95%CI 3.6-5.9). 61% of the patients in the TMM group vs. 35% in the no TMM group had an mRS ≤2 @ 3 months, p<0.001 (adjustment for age, onset to reperfusion, NIHSS, reperfusion and baseline imbalances). Reperfusion vs. no reperfusion was associated with an increased rate of good outcome in the TMM and MM groups (61% vs. 38% p=0.039 and 60% vs. 32%, p=0.016) but not in the no TMM or No MM groups (35% vs. 33%, NS; 35 vs. 45%., NS).

Conclusion: Patients with salvageable penumbra on advanced imaging experienced a larger benefit from MT than those without. Patients with no penumbra did not appear to benefit from reperfusion.

Underlying Small Vessel Disease Associated With Mixed Cerebral Microbleeds

Background and Purpose: Whether patients with both lobar and deep cerebral microbleeds (mixed CMB) have advanced cerebral amyloid angiopathy (CAA), hypertensive angiopathy (HA) or both is uncertain. To get insight into the underlying small vessel disease (SVD) associated with mixed CMB, we explored its association with cortical superficial siderosis (cSS), a key marker of CAA and other MRI markers of SVD in patients with intracerebral hemorrhage (ICH).

Methods: Of 425 consecutive patients with acute ICH who had received brain MRIs, 260 had ≥1 CMB and were included in the analysis. They were categorized as strictly lobar CMB (suggesting CAA), strictly deep CMB (suggesting HA) or mixed CMB. Clinical and imaging characteristics were compared (1) between the three CMB groups and (2) within mixed CMB patients according to the symptomatic ICH location.

Results: Overall, 111 (26%) patients had mixed CMB. Compared to strictly lobar CMB (n = 111) and strictly deep CMB (n = 38), patients with mixed CMB had a more severe burden of lacune, white matter hyperintensities and CMB. cSS was observed in 24.3% of patients with mixed CMB compared to 44.1% in strictly lobar CMB and 10.5% in strictly deep CMB (p < 0.0001). Among patients with mixed CMB, 44 (39.6%) had a lobar symptomatic ICH and 67 (60.4%) had a non-lobar ICH. Patients with non-lobar ICH were more likely to have hypertension, whereas those with lobar ICH were more likely to have cSS and chronic lobar ICH and had higher ratio lobar CMB count/total CMB count.

Conclusions: Mixed CMB is frequently encountered in patients with ICH and appears as a heterogeneous group, suggesting that both CAA and HA may be contributing to mixed CMB. Neuroimaging markers including ICH location, cSS, and CMB distribution may indicate the predominant underlying vasculopathy, with potential prognostic implications.

Enlarged perivascular spaces and florbetapir uptake in patients with intracerebral hemorrhage

PURPOSE

Enlarged perivascular spaces in the centrum semiovale (CSO-EPVS) have been linked to cerebral amyloid angiopathy (CAA). To get insight into the underlying mechanisms of this association, we investigated the relationship between amyloid-β deposition assessed by 18F-florbetapir PET and CSO-EPVS in patients with acute intracerebral hemorrhage (ICH).

METHODS

We prospectively enrolled 18 patients with lobar ICH (suggesting CAA) and 20 with deep ICH (suggesting hypertensive angiopathy), who underwent brain MRI and 18F-florbetapir PET. EPVS were assessed on MRI using a validated 4-point visual rating scale in the centrum semiovale and the basal ganglia (BG-EPVS). PET images were visually assessed, blind to clinical and MRI data. We evaluated the association between florbetapir PET positivity and high degree (score> 2) of CSO-EPVS and BG-EPVS.

RESULTS

High CSO-EPVS degree was more common in patients with lobar ICH than deep ICH (55.6% vs. 20.0%; p = 0.02). Eight (57.1%) patients with high CSO-EPVS degree had a positive florbetapir PET compared with 4 (16.7%) with low CSO-EPVS degree (p = 0.01). In contrast, prevalence of florbetapir PET positivity was similar between patients with high vs. low BG-EPVS. In multivariable analysis adjusted for age, hypertension, and MRI markers of CAA, florbetapir PET positivity (odds ratio (OR) 6.44, 95% confidence interval (CI) 1.32-38.93; p = 0.03) was independently associated with high CSO-EPVS degree.

CONCLUSIONS

Among patients with spontaneous ICH, high degree of CSO-EPVS but not BG-EPVS is associated with amyloid PET positivity. The findings provide further evidence that CSO-EPVS are markers of vascular amyloid burden that may be useful in diagnosing CAA.

Subarachnoid and Subdural Hemorrhages in Lobar Intracerebral Hemorrhage Associated With Cerebral Amyloid Angiopathy

Background and Purpose- Identifying underlying cerebral amyloid angiopathy (CAA) in patients with intracerebral hemorrhage (ICH) has important clinical implication. Convexity subarachnoid hemorrhage (cSAH) and subdural hemorrhage (SDH) are computed tomography features of CAA-related ICH. We explored whether cSAH and SDH could be additional magnetic resonance imaging markers of CAA in lobar ICH survivors. Methods- We analyzed data from consecutive patients with acute lobar ICH associated with CAA (CAA-ICH) or not attributed to CAA (non-CAA-ICH). Magnetic resonance imaging scans were analyzed for cSAH, SDH, and markers of small vessel disease. The associations of cSAH and SDH with the diagnosis of probable CAA based on the modified Boston criteria were explored using multivariable models. Results- We included 165 patients with acute lobar ICH (mean age 70±13 years): 72 patients with CAA-ICH and 93 with non-CAA-ICH. Patients with CAA-ICH had a higher prevalence of cSAH (73.6% versus 39.8%; P<0.001) and SDH (37.5% versus 21.5%; P=0.02) than non-CAA-ICH. In multivariate logistic regression analysis, the presence of cSAH was independently associated with CAA-ICH (odds ratio, 2.97; 95% CI, 1.26-6.99; P=0.013), whereas there was no association between SDH and CAA-ICH. Conclusions- Among survivors of acute lobar ICH, the presence of cSAH is associated with the magnetic resonance imaging-based diagnosis of CAA. Further studies should investigate whether cSAH help improve the sensitivity of magnetic resonance imaging for in vivo diagnosis of CAA.

Acute ischaemic lesions are associated with cortical superficial siderosis in spontaneous intracerebral hemorrhage

BACKGROUND AND PURPOSE

Diffusion-weighted imaging (DWI) commonly detects acute ischaemic lesions in patients with acute intracerebral hemorrhage (ICH), especially with cerebral amyloid angiopathy (CAA). We investigated the relationship between cortical superficial siderosis (cSS), a neuroimaging marker of CAA, and DWI lesions in patients with acute ICH.

METHODS

We conducted a retrospective analysis of prospectively collected data from consecutive patients with acute supratentorial ICH who underwent brain magnetic resonance imaging within 10 days after symptom onset. Magnetic resonance imaging scans were analyzed for DWI lesions, cSS and other markers for small-vessel disease. Univariate and multivariate analyses were performed to assess the association between cSS and DWI lesions.

RESULTS

Among 246 ICH survivors (mean age 71.4 ± 12.6 years) who were enrolled, 126 had lobar ICH and 120 had deep ICH. Overall, DWI lesions were observed in 38 (15.4%) patients and were more common in patients with lobar ICH than deep ICH (22.2% vs. 8.3%; P = 0.003). In multivariate logistic regression analysis, the extent of white matter hyperintensities [odds ratio (OR), 1.29; 95% confidence interval (CI), 1.05-1.58; P = 0.02] and cSS severity (focal cSS: OR, 3.54; 95% CI, 1.28-9.84; disseminated cSS: OR, 4.41; 95% CI, 1.78-10.97; P = 0.001) were independently associated with the presence of DWI lesions.

CONCLUSIONS

Diffusion-weighted imaging lesions are more frequently observed in patients with acute lobar ICH than in those with deep ICH. cSS severity and white matter hyperintensity extent are independent predictors for the presence of DWI lesions, suggesting that CAA may be involved in the pathogenesis of DWI lesions associated with acute ICH.

Hemorrhagic transformation after stroke: inter- and intrarater agreement

BACKGROUND AND PURPOSE

Hemorrhagic transformation (HT) is a complication of stroke that can occur spontaneously or after treatment. We aimed to assess the inter- and intrarater reliability of HT diagnosis.

METHODS

Studies assessing the reliability of the European Cooperative Acute Stroke Study (ECASS) classification of HT or of the presence (yes/no) of HT were systematically reviewed. A total of 18 raters independently examined 30 post-thrombectomy computed tomography scans selected from the Aspiration versus STEnt-Retriever (ASTER) trial. They were asked whether there was HT (yes/no), what the ECASS classification of the particular scan (0/HI1/HI2/PH1/PH2) (HI indicates hemorrhagic infarctions and PH indicates parenchymal hematomas) was and whether they would prescribe an antiplatelet agent if it was otherwise indicated. Agreement was measured with Fleiss' and Cohen's κ statistics.

RESULTS

The systematic review yielded four studies involving few (≤3) raters with heterogeneous results. In our 18-rater study, agreement for the presence of HT was moderate [κ = 0.55; 95% confidence interval (CI), 0.41-0.68]. Agreement for ECASS classification was only fair for all five categories, but agreement improved to substantial (κ = 0.72; 95% CI, 0.69-0.75) after dichotomizing the ECASS classification into 0/HI1/HI2/PH1 versus PH2. The inter-rater agreement for the decision to reintroduce antiplatelet therapy was moderate for all raters, but substantial among vascular neurologists (κ = 0.70; 95% CI, 0.57-0.84).

CONCLUSION

The ECASS classification may involve too many categories and the diagnosis of HT may not be easily replicable, except in the presence of a large parenchymal hematoma.

ED Referral Dramatically Reduces Delays of Initial Evaluation in a French TIA Clinic

Background: The risk of recurrent brain infarction (BI) is high within the first hours after a transient ischemic attack (TIA). Emergent, specialized, and tailored patient management in a TIA program reduces the risk of recurrent BI after TIA by 80%. New antithrombotic strategies have been successfully tested within 12 h after TIA onset. We aim to investigate the factors associated with a delay of more than 12 h from TIA onset to evaluation in our TIA clinic.

Methods: In consecutive patients evaluated in our TIA clinic from 01/2012 to 11/2013, we prospectively collected delays from onset to arrival, baseline characteristics, discharge diagnosis and recurrent BI at 1 week. Referring pathways were dichotomized between office-based physicians (OBP) and emergency departments (ED). Univariate and multivariate logistic regression were performed.

Results: 354 patients were evaluated. Mean (+/– SD) age was 61 years (+/−18). Median (IQR) ABCD2 score was 3 (2–4). Median (IQR) delay from onset to evaluation was 8 h (4–48). Overall, 185 (52%) were referred by OBP vs. 169 (48%) by ED. Evaluation was initiated within 12 h among 201 (57%) patients. After logistic regression, OBP referral was by comparison with ED the only independent factor associated with an evaluation delay >12 h (OR 5.7, 95% CI: 3.5–9.3, p < 0.0001).

Conclusion: Our results suggest that preliminary assessment by OBP may increase the delay to initiate the emergent evaluation of TIA patients. Promoting direct admission to TIA clinics through ED may be an efficient alternative for high risk TIAs.

Abstract TP220: TIA Referral Influences Delay of Evaluation in TIA Clinic

Background: Transient ischemic attacks and minor stroke are vascular emergencies associated with a high risk of brain infarction within the first hours after onset. When available those patients may be evaluated and managed in a TIA clinic. Several therapeutic strategies are currently tested within 12 hrs after TIA/minor stroke onset. We aim to investigate the factors associated with a delay of evaluation longer than 12 hours in our TIA clinic.

Subjects and Methods: Subjects are consecutive patients evaluated in an academic center TIA clinic during 2 years. Briefly patients were evaluated by a certified stroke neurologist according to 2009 AHA recommendations including MRI, vessel imaging, blood tests, EKG and when needed TTE/TEE. Referring pathways were dichotomized between office based physicians (General practitioners, others:cardiologists, ophtalmologists, ...) and Emergency medical service (local and from other hospital with no neurologists). Univariate and multivariate logistic regression were performed.

Results: 354 patients were evaluated in 2 years. Mean (+/- SD) age was 61 YO (18), Median (IQR) ABCD2 score was 3 (2-4); median (IQR) delay from onset to evaluation was 8 hours (4-48), 59% of patients did arrive in TIA clinic within 12 hours after onset. 52% were referred by an office based physician (36% general practitioner and 16% others) vs. 48% by ED (32%,local ED and EMS 16% other ED) Univariate analysis showed that ABCD2 score<4 and office based physician referral were associated with a delay>12 hrs. There was no relationships with other factors such as risk factors, previous history of stroke or recurrent TIA. Office based physician referral was the only independent factor associated with a delay of evaluation > 12 hrs OR 5.7, (95%CI:3.5-9.3, p<0.0001) after multivariate logistic regression.

Conclusion: Direct referral from ED increases the rate of patients starting their evaluation in TIA clinic within 12 hrs after onset.

Cortical superficial siderosis and acute convexity subarachnoid hemorrhage in cerebral amyloid angiopathy

BACKGROUND AND PURPOSE

Acute convexity subarachnoid hemorrhage (cSAH) and cortical superficial siderosis (cSS) are neuroimaging markers of cerebral amyloid angiopathy (CAA) that may arise through similar mechanisms. The prevalence of cSS in patients with CAA presenting with acute cSAH versus lobar intracerebral hemorrhage (ICH) was compared and the physiopathology of cSS was explored by examining neuroimaging associations.

METHODS

Data from 116 consecutive patients with probable CAA (mean age, 77.4 ± 7.3 years) presenting with acute cSAH (n = 45) or acute lobar ICH (n = 71) were retrospectively analyzed. Magnetic resonance imaging scans were analyzed for cSS and other imaging markers. The two groups' clinical and imaging data were compared and the associations between cSAH and cSS were explored.

RESULTS

Patients with cSAH presented mostly with transient focal neurological episodes. The prevalence of cSS was higher amongst cSAH patients than amongst ICH patients (88.9% vs. 57.7%; P < 0.001). In multivariable logistic regression analysis, focal [odds ratio (OR) 6.73; 95% confidence interval (CI) 1.75-25.81; P = 0.005] and disseminated (OR 11.68; 95% CI 3.55-38.35; P < 0.001) cSS were independently associated with acute cSAH, whereas older age (OR 0.93; 95% CI 0.87-0.99; P = 0.025) and chronic lobar ICH count (OR 0.45; 95% CI 0.25-0.80; P = 0.007) were associated with acute lobar ICH.

CONCLUSIONS

Amongst patients with CAA, cSS is independently associated with acute cSAH. These findings suggest that cSAH may be involved in the pathogenesis of the cSS observed in CAA. Longitudinal studies are warranted to assess this potential causal relationship.

Florbetapir imaging in cerebral amyloid angiopathy-related hemorrhages

OBJECTIVE

To assess whether ¹⁸F-florbetapir, a PET amyloid tracer, could bind vascular amyloid in cerebral amyloid angiopathy (CAA) by comparing cortical florbetapir retention during the acute phase between patients with CAA-related lobar intracerebral hemorrhage (ICH) and patients with hypertension-related deep ICH.

METHODS

Patients with acute CAA-related lobar ICH were prospectively enrolled and compared with patients with deep ICH. ¹⁸F-florbetapir PET, brain MRI, and APOE genotype were obtained for all participants. Cortical florbetapir standard uptake value ratio (SUVr) was calculated with the whole cerebellum used as a reference. Patients with CAA and those with deep ICH were compared for mean cortical florbetapir SUVr values.

RESULTS

Fifteen patients with acute lobar ICH fulfilling the modified Boston criteria for probable CAA (mean age = 67 ± 12 years) and 18 patients with acute deep ICH (mean age = 63 ± 11 years) were enrolled. Mean global cortical florbetapir SUVr was significantly higher among patients with CAA-related ICH than among patients with deep ICH (1.27 ± 0.12 vs 1.12 ± 0.12, p = 0.001). Cortical florbetapir SUVr differentiated patients with CAA-ICH from those with deep ICH (area under the curve = 0.811; 95% confidence interval [CI] 0.642-0.980) with a sensitivity of 0.733 (95% CI 0.475-0.893) and a specificity of 0.833 (95% CI 0.598-0.948).

CONCLUSIONS

Cortical florbetapir uptake is increased in patients with CAA-related ICH relative to those with deep ICH. Although ¹⁸F-florbetapir PET can label vascular β-amyloid and might serve as an outcome marker in future clinical trials, its diagnostic value in acute CAA-related ICH seems limited in clinical practice.

Abstract 212: Cortical Superficial Siderosis and Risk of Recurrent Intracerebral Haemorrhage in Cerebral Amyloid Angiopathy: A Meta-analysis

Background: Cerebral amyloid angiopathy (CAA) is a major cause of spontaneous lobar intracerebral hemorrhage (ICH) in the elderly. CAA-related ICH survivors are at substantial risk for recurrent ICH, accounting for the significant morbidity of the disease. Identifying predictors of recurrence is therefore crucial. Recent data have implicated cortical superficial siderosis (cSS) as a key hemorrhagic MRI signature of CAA, and a possible marker of increased risk for CAA-ICH recurrence. However, data remain limited. We obtained precise estimates on cSS as an independent predictor of ICH recurrence risk in CAA cohorts from a systematic review of published studies pooled with data from our centre.

Methods: We included cohort studies of consecutive CAA-related ICH patients based on the original Boston criteria, with available blood-sensitive MRI sequences at baseline for cSS assessment, and adequate follow-up for recurrent symptomatic ICH. The strength of the association between cSS and recurrent ICH was quantified using random effects models. Covariate-adjusted hazard rations (adj-HR) as provided from pre-specified Cox proportional hazard models were used for a two-stage meta-analysis.

Results: Three cohorts including 443 CAA-ICH patients were eligible for analysis. The pooled prevalence of cSS presence and disseminated cSS (>3 affected sulci) was 32% (95%CI: 32%-41%) and 21% (95%CI: 18%-25%) respectively. During a mean follow-up of 2.5 years (range: 2-3 years) 92 patients experienced recurrent ICH, a pooled risk ratio of 6.9% per year (I 2 : 63%, p=0.07). In adjusted pooled analysis, any cSS and disseminated cSS were both independently associated with increased lobar ICH recurrence risk (adj-HR: 2.4; 95%CI: 1.5-3.8; p<0.0001, I 2 : 0% and adj-HR: 4.1; 95%CI: 2.6-6.6; p<0.0001, I 2 : 47%), after adjusting for multiple strictly lobar microbleeds presence and increasing age.

Conclusions: Our findings in a large population of CAA patients with ICH and a large number of recurrence events, indicate that cSS, particularly if disseminated, is the single most important prognostic risk factor on MRI for future recurrent lobar ICH. The provided estimates may help stratify future bleeding risk in CAA, with clinical implications for prognosis and treatment.

Risk of intracerebral haemorrhage with alteplase after acute ischaemic stroke: a secondary analysis of an individual patient data meta-analysis

BACKGROUND

Randomised trials have shown that alteplase improves the odds of a good outcome when delivered within 4·5 h of acute ischaemic stroke. However, alteplase also increases the risk of intracerebral haemorrhage; we aimed to determine the proportional and absolute effects of alteplase on the risks of intracerebral haemorrhage, mortality, and functional impairment in different types of patients.

METHODS

We used individual patient data from the Stroke Thrombolysis Trialists' (STT) meta-analysis of randomised trials of alteplase versus placebo (or untreated control) in patients with acute ischaemic stroke. We prespecified assessment of three classifications of intracerebral haemorrhage: type 2 parenchymal haemorrhage within 7 days; Safe Implementation of Thrombolysis in Stroke Monitoring Study's (SITS-MOST) haemorrhage within 24-36 h (type 2 parenchymal haemorrhage with a deterioration of at least 4 points on National Institutes of Health Stroke Scale [NIHSS]); and fatal intracerebral haemorrhage within 7 days. We used logistic regression, stratified by trial, to model the log odds of intracerebral haemorrhage on allocation to alteplase, treatment delay, age, and stroke severity. We did exploratory analyses to assess mortality after intracerebral haemorrhage and examine the absolute risks of intracerebral haemorrhage in the context of functional outcome at 90-180 days.

FINDINGS

Data were available from 6756 participants in the nine trials of intravenous alteplase versus control. Alteplase increased the odds of type 2 parenchymal haemorrhage (occurring in 231 [6·8%] of 3391 patients allocated alteplase vs 44 [1·3%] of 3365 patients allocated control; odds ratio [OR] 5·55 [95% CI 4·01-7·70]; absolute excess 5·5% [4·6-6·4]); of SITS-MOST haemorrhage (124 [3·7%] of 3391 vs 19 [0·6%] of 3365; OR 6·67 [4·11-10·84]; absolute excess 3·1% [2·4-3·8]); and of fatal intracerebral haemorrhage (91 [2·7%] of 3391 vs 13 [0·4%] of 3365; OR 7·14 [3·98-12·79]; absolute excess 2·3% [1·7-2·9]). However defined, the proportional increase in intracerebral haemorrhage was similar irrespective of treatment delay, age, or baseline stroke severity, but the absolute excess risk of intracerebral haemorrhage increased with increasing stroke severity: for SITS-MOST intracerebral haemorrhage the absolute excess risk ranged from 1·5% (0·8-2·6%) for strokes with NIHSS 0-4 to 3·7% (2·1-6·3%) for NIHSS 22 or more (p=0·0101). For patients treated within 4·5 h, the absolute increase in the proportion (6·8% [4·0% to 9·5%]) achieving a modified Rankin Scale of 0 or 1 (excellent outcome) exceeded the absolute increase in risk of fatal intracerebral haemorrhage (2·2% [1·5% to 3·0%]) and the increased risk of any death within 90 days (0·9% [-1·4% to 3·2%]).

INTERPRETATION

Among patients given alteplase, the net outcome is predicted both by time to treatment (with faster time increasing the proportion achieving an excellent outcome) and stroke severity (with a more severe stroke increasing the absolute risk of intracerebral haemorrhage). Although, within 4·5 h of stroke, the probability of achieving an excellent outcome with alteplase treatment exceeds the risk of death, early treatment is especially important for patients with severe stroke.

FUNDING

UK Medical Research Council, British Heart Foundation, University of Glasgow, University of Edinburgh.

Abstract WMP93: Cortical Superficial Siderosis in Cerebral Amyloid Angiopathy: Higher Prevalence Among Convexity Subarachnoid Hemorrhage Than Among Intracerebral Hemorrhage

Introduction: Cerebral amyloid angiopathy (CAA) is a major cause of both lobar intracerebral hemorrhage (ICH) and cerebral microbleeds (CMB), especially in the elderly. Recently, acute convexity subarachnoid hemorrhage (cSAH) and cortical superficial siderosis (cSS) has been identified as markers of CAA. Although the clinical feature and the increased risk of future lobar ICH of cSS is well established, little is known about the specific pattern of CAA-related cSAH.

Hypothesis: We hypothesized that clinical and imaging characteristics of CAA-related cSAH differ from CAA-related lobar ICH.

Methods: We retrospectively analyzed clinical and MRI data of a monocentric cohort of 45 consecutive patients with an acute cSAH related to probable CAA and a comparison group of 70 consecutive patients presenting with an acute lobar ICH meeting Boston criteria for probable CAA.

Results: cSAH patients were younger than ICH patients (mean age +/-SD: 75 +/-7 vs 78 +/-7; p=0.046). Transient focal neurological episodes (TFNE) were common among cSAH patients (84.4% vs 0%; p<0.001). Persistent focal neurological deficits were frequent among ICH patients (15.6% vs 98.6%; p<0.001). Prevalence of cSS was significantly higher among cSAH patients than among ICH patients (88.9% vs 60%; p<0.001) especially disseminated (66.7% vs 37.1%; p=0.002) and bilateral cSS (48.9% vs 28.6%; p=0.027). Number of lobar macrobleeds (median number [IQR]: 0 [0-1] vs 1[1-2]; p=0.07) and lobar CMB (median number [IQR]: 3 [1-6] vs 6 [2-14.75]; p=0.405) did not differ between the two groups.

Conclusions: In CAA, patients presenting with cSAH are characterized by a younger age, TFNE as presenting symptoms and a higher prevalence of cSS than those presenting with Lobar ICH. These findings suggest that restricted hemorrhage into the subarachnoid space may play a crucial role in cSS physiopathology.

Abstract WP52: Impact of Baseline DWI ASPECTS Lesion Topology on Functional Outcome after Endovascular Treatment

Introduction: Acute brain infarction (BI) topology determined by diffusion weighted imaging - Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECTS) on post-treatment magnetic resonance imaging (MRI) has been associated with clinical outcome in internal carotid artery (ICA) or proximal middle cerebral artery (MCA) occlusion treated by endovascular reperfusion therapy (EVRT).

Hypothesis: We hypothesize that among the same type of patients, the topology of acute BI captured by DWI ASPECTS on baseline MRI may be associated with 3 months functional outcome after EVRT.

Methods: Consecutive patients with an acute BI complicating ICA or proximal MCA occlusion treated by EVRT after a baseline MRI before treatment at a single center between April 2007 and March 2013 were enrolled. Poor functional outcome was defined by modified Rankin Scale (mRS) of 3 to 6 at 3 months. We used penalized logistic regression due to the multicollinearity between DWI-ASPECTS sites to assess the relationship between each DWI-ASPECTS sites and functional outcome after adjustment for age, sex, blood pressure, DWI lesion volume and infarct side. We estimated this relationship in the full cohort of patients and according to the achievement of a complete recanalization.

Results: We enrolled 206 patients [mean age 71 ± 16.5, median NIHSS 16 (IQR 10-21)]. Among them 58 (28%) had an ICA occlusion, 115 (56%) a MCA M1 occlusion and 33 (16%) a MCA M2 occlusion. Median DWI lesion volume was 13 mL (IQR 4-43), and median DWI ASPECTS score was 6 (IQR 4-8). A complete recanalization was achieved among 96 patients (47%), after a median time from onset of 237 min (IQR:185-282). The involvement of the lentiform nucleus was associated with poor functional outcome in the full cohort of patients [OR : 10; 95% CI (5-23); p<0.0001]. This relationship was observed in the subgroup of patients who did experience a complete recanalization [OR : 4; 95% CI (1.5-12); p=0.007] and among those who did not [OR : 21; 95% CI (5-92); p<0.0001].

Conclusions: In conclusion, the involvement of the DWI ASPECTS lentiform region on baseline MRI in patients experiencing an acute BI complicating an ICA or MCA occlusion treated by EVRT was associated with poor functional outcome, overall and despite a complete recanalization.

Abstract T MP50: Novel TIA Serum Biomarkers Identified by Mass-Spectroscopy Proteomics

Background: One of the “holy grails” in vascular neurology is a TIA serum marker. Mass spectrometry-based proteomics, a unique, unbiased method to identify candidate proteins, was used to test the serum of patients with transient neurologic symptoms for biomarkers of cerebral ischemia.

Methods: Patients with transient neurologic symptoms were prospectively enrolled. Mass spectrometry was performed on the serum samples, and results were searched against the Human Uniport database. Three candidate proteins were found, and serum concentrations of these proteins were measured by ELISA in a second cohort of prospectively enrolled patients. The student’s t-test was used for comparison. The Benjamini-Hochberg false discovery rate controlling procedure for multiple comparison adjustments determined significance for the proteomic screen.

Results: Patients with TIA (n=20), minor stroke (n=15), and controls (i.e. migraine, seizure, n=12) were enrolled in the first cohort. Ceruloplasmin, complement component C8 gamma (C8γ) and platelet basic protein (PBP) were significantly different between the ischemic samples (TIA and minor stroke) and the controls (p = 0.0001, p=0.00027, p=0.00105 respectively). A second cohort of patients with TIA (n=16), minor stroke (n=20), and controls’ (n=12) serum was tested. PBP serum concentrations were increased in the ischemic samples compared to control (for TIA and stroke, p= 0.04, for TIA alone, p=0.027). Ceruloplasmin trended towards increased concentrations in the ischemic groups (p=0.10), and an insignificant increase in C8γ (p=0.23) was found.

Conclusions: PBP has been identified as potential serum biomarker for TIA. Larger sample size may find that ceruloplasmin is an additional candidate. Ultimately, a panel of proteins may be required. Larger studies are needed to determine the validity of these proteins in clinical use.

Effect of treatment delay, age, and stroke severity on the effects of intravenous thrombolysis with alteplase for acute ischaemic stroke: a meta-analysis of individual patient data from randomised trials

BACKGROUND

Alteplase is effective for treatment of acute ischaemic stroke but debate continues about its use after longer times since stroke onset, in older patients, and among patients who have had the least or most severe strokes. We assessed the role of these factors in affecting good stroke outcome in patients given alteplase.

METHODS

We did a pre-specified meta-analysis of individual patient data from 6756 patients in nine randomised trials comparing alteplase with placebo or open control. We included all completed randomised phase 3 trials of intravenous alteplase for treatment of acute ischaemic stroke for which data were available. Retrospective checks confirmed that no eligible trials had been omitted. We defined a good stroke outcome as no significant disability at 3-6 months, defined by a modified Rankin Score of 0 or 1. Additional outcomes included symptomatic intracranial haemorrhage (defined by type 2 parenchymal haemorrhage within 7 days and, separately, by the SITS-MOST definition of parenchymal type 2 haemorrhage within 36 h), fatal intracranial haemorrhage within 7 days, and 90-day mortality.

FINDINGS

Alteplase increased the odds of a good stroke outcome, with earlier treatment associated with bigger proportional benefit. Treatment within 3·0 h resulted in a good outcome for 259 (32·9%) of 787 patients who received alteplase versus 176 (23·1%) of 762 who received control (OR 1·75, 95% CI 1·35-2·27); delay of greater than 3·0 h, up to 4·5 h, resulted in good outcome for 485 (35·3%) of 1375 versus 432 (30·1%) of 1437 (OR 1·26, 95% CI 1·05-1·51); and delay of more than 4·5 h resulted in good outcome for 401 (32·6%) of 1229 versus 357 (30·6%) of 1166 (OR 1·15, 95% CI 0·95-1·40). Proportional treatment benefits were similar irrespective of age or stroke severity. Alteplase significantly increased the odds of symptomatic intracranial haemorrhage (type 2 parenchymal haemorrhage definition 231 [6·8%] of 3391 vs 44 [1·3%] of 3365, OR 5·55, 95% CI 4·01-7·70, p<0·0001; SITS-MOST definition 124 [3·7%] vs 19 [0·6%], OR 6·67, 95% CI 4·11-10·84, p<0·0001) and of fatal intracranial haemorrhage within 7 days (91 [2·7%] vs 13 [0·4%]; OR 7·14, 95% CI 3·98-12·79, p<0·0001). The relative increase in fatal intracranial haemorrhage from alteplase was similar irrespective of treatment delay, age, or stroke severity, but the absolute excess risk attributable to alteplase was bigger among patients who had more severe strokes. There was no excess in other early causes of death and no significant effect on later causes of death. Consequently, mortality at 90 days was 608 (17·9%) in the alteplase group versus 556 (16·5%) in the control group (hazard ratio 1·11, 95% CI 0·99-1·25, p=0·07). Taken together, therefore, despite an average absolute increased risk of early death from intracranial haemorrhage of about 2%, by 3-6 months this risk was offset by an average absolute increase in disability-free survival of about 10% for patients treated within 3·0 h and about 5% for patients treated after 3·0 h, up to 4·5 h.

INTERPRETATION

Irrespective of age or stroke severity, and despite an increased risk of fatal intracranial haemorrhage during the first few days after treatment, alteplase significantly improves the overall odds of a good stroke outcome when delivered within 4·5 h of stroke onset, with earlier treatment associated with bigger proportional benefits.

FUNDING

UK Medical Research Council, British Heart Foundation, University of Glasgow, University of Edinburgh.

Hypoperfusion intensity ratio predicts infarct progression and functional outcome in the DEFUSE 2 Cohort

BACKGROUND AND PURPOSE

We evaluate associations between the severity of magnetic resonance perfusion-weighted imaging abnormalities, as assessed by the hypoperfusion intensity ratio (HIR), on infarct progression and functional outcome in the Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution Study 2 (DEFUSE 2).

METHODS

Diffusion-weighted magnetic resonance imaging and perfusion-weighted imaging lesion volumes were determined with the RAPID software program. HIR was defined as the proportion of TMax >6 s lesion volume with a Tmax >10 s delay and was dichotomized based on its median value (0.4) into low versus high subgroups as well as quartiles. Final infarct volumes were assessed at day 5. Initial infarct growth velocity was calculated as the baseline diffusion-weighted imaging (DWI) lesion volume divided by the delay from symptom onset to baseline magnetic resonance imaging. Total Infarct growth was determined by the difference between final infarct and baseline DWI volumes. Collateral flow was assessed on conventional angiography and dichotomized into good and poor flow. Good functional outcome was defined as modified Rankin Scale ≤2 at 90 days.

RESULTS

Ninety-nine patients were included; baseline DWI, perfusion-weighted imaging, and final infarct volumes increased with HIR quartiles (P<0.01). A high HIR predicted poor collaterals with an area under the curve of 0.73. Initial infarct growth velocity and total infarct growth were greater among patients with a high HIR (P<0.001). After adjustment for age, DWI volume, and reperfusion, a low HIR was associated with good functional outcome: odds ratio=4.4 (95% CI, 1.3-14.3); P=0.014.

CONCLUSIONS

HIR can be easily assessed on automatically processed perfusion maps and predicts the rate of collateral flow, infarct growth, and clinical outcome.

Abstract W P173: The Use of Mass Spectroscopy-Based Proteomics to Identify Novel Biomarkers of Cerebral Ischemia

Background: Cerebral ischemia and its mimics are often difficult to differentiate. While MRI is the gold standard for stroke diagnosis, a marker for TIA remains elusive. Proteomics offers a unique method to identify biomarkers of ischemic disease. Through the use of mass spectrometry-based proteomics, we analyzed the serum of patients with transient neurologic symptoms in our emergency department to determine candidate proteins to serve as indicators of cerebral ischemia.

Methods: Patients with transient neurologic symptoms were prospectively enrolled and their serum was obtained. Mass spectrometry was performed on the samples, and the results were searched against the Human Uniport database to identify the most likely proteins. The student’s t-test was utilized to compare protein levels between the different clinical conditions, and significance was determined by using the Benjamini-Hochberg false discovery rate (FDR) controlling procedure for multiple comparison adjustments.

Results: Twenty patients with TIAs, fifteen patients with minor strokes, and twelve control patients (i.e. migraine, seizure) were enrolled. Ceruloplasmin (p = 0.00027) and complement component C8 gamma chain (p = 0.00105) were increased in TIA and minor stroke compared with the control group, while platelet basic protein (p = 0.00010) was decreased. TIA patients tended to have higher Ig kappa chain 6 region AG and platelet basic protein levels and lower apolipoprotein F levels than stroke patients (p <0.05), but these differences were not significant after FDR adjustments.

Conclusions: Mass spectroscopy-based proteomics is a potential new tool to help identify biomarkers for cerebral ischemia. Ultimately, a panel of proteins may serve as a marker for cerebral ischemia or TIA. We have identified three candidate proteins as possible indicators for cerebral ischemia. Larger studies are needed to confirm our results.

Radiological examinations of transient ischemic attack

Neuroimaging is critical in the evaluation of patients with TIA. CT and MRI are the two available options for imaging. Head CT is more widely available and commonly used. Diffusion MRI is the recommended modality to image an ischemic lesion. The presence of a diffusion lesion in a patient with transient neurological symptoms is an indicator of a high risk of recurrent stroke. Perfusion imaging with perfusion MRI or CT perfusion may improve the detection of ischemic lesions. Noninvasive vessel imaging may detect a symptomatic vessel lesion associated with an increased risk of stroke.

Reduction in early stroke risk in carotid stenosis with transient ischemic attack associated with statin treatment

BACKGROUND AND PURPOSE

Statins reduce stroke risk when initiated months after transient ischemic attack (TIA)/stroke and reduce early vascular events in acute coronary syndromes, possibly via pleiotropic plaque stabilization. Few data exist on acute statin use in TIA. We aimed to determine whether statin pretreatment at TIA onset modified early stroke risk in carotid stenosis.

METHODS

We analyzed data from 2770 patients with TIA from 11 centers, 387 with ipsilateral carotid stenosis. ABCD2 score, abnormal diffusion weighted imaging, medication pretreatment, and early stroke were recorded.

RESULTS

In patients with carotid stenosis, 7-day stroke risk was 8.3% (95% confidence interval [CI], 5.7-11.1) compared with 2.7% (CI, 2.0%-3.4%) without stenosis (P<0.0001; 90-day risks 17.8% and 5.7% [P<0.0001]). Among carotid stenosis patients, nonprocedural 7-day stroke risk was 3.8% (CI, 1.2%-9.7%) with statin treatment at TIA onset, compared with 13.2% (CI, 8.5%-19.8%) in those not statin pretreated (P=0.01; 90-day risks 8.9% versus 20.8% [P=0.01]). Statin pretreatment was associated with reduced stroke risk in patients with carotid stenosis (odds ratio for 90-day stroke, 0.37; CI, 0.17-0.82) but not nonstenosis patients (odds ratio, 1.3; CI, 0.8-2.24; P for interaction, 0.008). On multivariable logistic regression, the association remained after adjustment for ABCD2 score, smoking, antiplatelet treatment, recent TIA, and diffusion weighted imaging hyperintensity (adjusted P for interaction, 0.054).

CONCLUSIONS

In acute symptomatic carotid stenosis, statin pretreatment was associated with reduced stroke risk, consistent with findings from randomized trials in acute coronary syndromes. These data support the hypothesis that statins started acutely after TIA symptom onset may also be beneficial to prevent early stroke. Randomized trials addressing this question are required.

Abstract TMP16: Hypoperfusion Severity Is Associated With Poor Collaterals And Progresses Over Time

Background: We hypothesized that cerebral perfusion deficits are more severe in acute stroke patients with poor collaterals and that the severity would increase over time if reperfusion does not occur.

Methods: This is a substudy of DEFUSE 2. Collaterals were assessed on conventional angiography and dichotomized as poor vs. good flow. DWI and PWI were performed before and within 12 hrs after endovascular therapy; PWI lesion volumes were determined using a Tmax>6sec threshold. The hypoperfusion ratio (HR) was calculated by determining the proportion of the PWI lesion that had severe Tmax delay (>10sec). Acute lesion growth was defined as the difference between the baseline and follow-up DWI volume.

Part 1: In patients with an ICA or M1 occlusion we compared the HR to the collateral score. An ROC curve assessed whether the HR predicts the collateral score.

Part 2: Among patients who did not experience early reperfusion, the difference between the baseline and follow-up HR was assessed and correlated with early infarct growth.

Results: Part 1: Fifty six patients were eligible. Poor collateral flow was associated with larger baseline PWI lesion volume, p=0.012 and a higher HR compared to patients with good flow [median HR 45% (IQR: 35-52%) vs. 34% (IQR 14-41), p=0.003]. A HR > 41% predicted poor collateral flow with an AUC=0.73 (sensitivity 65%, specificity 78%, p=0.003).

Part 2: Thirty two patients who did not achieve reperfusion were included; PWI Tmax >6sec lesions volumes at baseline and follow-up were similar (median volume 75 mL at both time points). The median HR at follow-up was significantly higher than baseline [46% IQR (34-65) vs. 40% (24-48), p=0.007; median difference = 13% (IQR: 3.5-17)]. Patients who had worsening of their HR between baseline and follow-up were more likely to experience early ischemic lesion growth (R=0.53, p=0.002).

Conclusion: The size and severity of Tmax lesions are associated with angiographic collateral scores. Patients who have a high percentage of their PWI lesion comprised of severe Tmax delays are likely to have poor collaterals. When early reperfusion is not achieved, the severity of hypoperfusion progresses and this progression is associated with early infarct growth.

Abstract 2676: Lipoprotein associated-phospholipase A2 Activity Level is Increased in Acute Cerebral Ischemic Events

Introduction: Lipoprotein associated -phospholipase A2 (Lpa-A2) mass and activity can help identify high risk TIA patients. We evaluate the yield of Lpa-A2 mass and activity to differentiate acute cerebral ischemic events from non-ischemic events.

Methods: From July 2007 to March 2009, 48 patients presenting to the Stanford Unversity Medical Center Emergency room with stroke or TIA symptoms were prospectively enrolled and blood samples were obtained at time of presentation, 24 hours, and 72 hours after presentation. Blood samples were analyzed for Lpa-A2 mass and activity using commercially available assays (diaDexus, Inc). Patients with final diagnosis of stroke or TIA were classified as ischemic and others as non-ischemic. The size of the ischemic lesion was measured among stroke patients on diffusion weighted imaging (DWI).

Results: Twenty eight patients (58%) had a diagnosis of brain infarction [median NIHSS=7 (IQR=4-12)], 9 (19%) had a diagnosis of TIA [median ABCD2=4, (IQR=3-6)] and 11(23%) had a non ischemic event (1 peripheral vertigo, 2 infections, 3 seizures, 4 peripheral neuropathy/myopathy, 1 multiple sclerosis relapse). Among the 37 ischemic patients, stroke mechanisms were according to TOAST criteria: 6 (16%) large artery atherosclerosis, 21 (57%) cardioembolic, 1 (3%) small artery, 4 (11%) other determined and 5 (13%) undetermined. At admission, Lpa-A2 activity level was higher among patients experiencing an ischemic event (stroke or TIA) compared to non ischemic event (p=0.007). Among ischemic patients, Lpa-A2 activity measured at admission was lower than the activity measured at day 1 (p=0.006) and day 3 (p=0.002) and was stable among non ischemic patients. Among the 24 ischemic patients who underwent acute MRI and were found to have an ischemic lesion on DWI, there was no relation between Lpa-A2 activity level and infarct volume. Lipoprotein associated -phospholipase A2 mass level was not different between ischemic and non ischemic patients. The mass levels remained stable over time in each group and were not related to infarct volume.

Conclusions: Lpa-A2 activity levels were higher among ischemic patients compared with non ischemic etiologies. Lpa-A2 activity levels rose during the first days after brain ischemia. This exploratory data suggests Lpa-A2 activity level could possibly help physicians discriminate cerebral ischemic from non ischemic events. Further research is warranted and ongoing.

Abstract 2126: Twoaces (tia Work-up Asoutpatient: Assessment Of Clincal Efficacy And Safety)

Background: Much controversy exists as to which TIA patients need to be admitted to the hospital for evaluation and treatment and which can be sent home. One commonly used trigae tool is the ABCD 2 score (Age, presenting Blood Pressure, Clinical symptoms and Duration, and Diabetes). Although this tool gives good information for determining populations at low risk (score of 0-3) and high risk (score of 6-7) of stroke after TIA, it leaves a large moderate risk population (score of 4-5) for whom no clear triage guidance can be given. As previous studies have found large artery atherosclerosis to be a potent risk factor for stroke after TIA, we attempted to further delineate low and high risk TIA populations with the addition of non-invasive arterial imaging to the ABCD 2 score.

Methods: All patients referred to the Stanford Stroke Service for possible TIA within 72 hrs of symptom onset between July 2007 and February 2010, and all patients referred to the Highland Park Stroke Service for possible TIA within 72 hrs of symptom onset after October 2009 were screened for enrollment in this observational study. Exclusion criteria included age <18 years, use of TPA at initial presentation, and symptoms lasting >24 hours. 352 patients were invited to enroll, 3 refused. Of the 349 enrolled, follow-up was obtained in 346 patients at 30 days. Patients were placed into two groups: 1) those with ABCD 2 scores of 0-3 or scores of 4-5 AND no sign of hemodynamically significant stenosis in an artery within the distribution of the TIA (Low Risk Group); and 2) those with ABCD 2 scores of 6-7 or scores of 4-5 AND a hemodynamically significant stenosis in an artery within the distribution of the TIA (High Risk Group). Non-invasive arterial imaging included CT angiogram, MR angiogram, and carotid ultrasound - all used at the discretion of the treating physician. 30 day stroke rates with 95% confidence intervals were recorded.

Results: Of the 346 patients enrolled, 295 (85.3%) fell into the "Low Risk Group" based on ABCD 2 scoring and non-invasive arterial imaging. Within that group, the stroke rate at 30 days was 1.0% (3 strokes, 95% CI 0.2-3.1%). Within the "High Risk Group", the stroke rate at 30 days was 5.9% (3 strokes, 95% CI 1.4-16.5%). Within the "Low Risk Group", all 3 of the strokes occurred in patients with ABCD 2 scores of 4-5 (3/133 patients - 2.3% stroke rate with 95% CI 0.5-6.7%). The overall stroke rate was 6/346 (1.7%, 95% CI 0.7-3.8%).

Conclusions: In our observational study we found that the overall 30 day stroke rate after TIA was quite low. The percentage of all TIA patients falling into the “Low Risk Group” was quite high, and these patients had a particularly low rate of stroke at 30 days. Given the high number of "Low Risk" patients and the low rate of stroke in that group at 30 days, the vast majority of TIA patients could likely be safely evaluated in an rapid outpatient setting provided that the treating physician is confident of the diagnosis.

MRI guides diagnostic approach for ischaemic stroke

BACKGROUND AND AIM

Identification of ischaemic stroke subtype currently relies on clinical evaluation supported by various diagnostic studies. The authors sought to determine whether specific diffusion-weighted MRI (DWI) patterns could reliably guide the subsequent work-up for patients presenting with acute ischaemic stroke symptoms.

METHODS

273 consecutive patients with acute ischaemic stroke symptoms were enrolled in this prospective, observational, single-centre NIH-sponsored study. Electrocardiogram, non-contrast head CT, brain MRI, head and neck magnetic resonance angiography (MRA) and transoesophageal echocardiography were performed in this prespecified order. Stroke neurologists determined TOAST (Trial of Org 10172 in Acute Stroke Treatment) classification on admission and on discharge. Initial TOAST stroke subtypes were compared with the final TOAST subtype. If the final subtype differed from the initial assessment, the diagnostic test deemed the principal determinant of change was recorded. These principal determinants of change were compared between a CT-based and an MRI-based classification schema.

RESULTS

Among patients with a thromboembolic DWI pattern, transoesophageal echocardiography was the principal determinant of diagnostic change in 8.8% versus 0% for the small vessel group and 1.7% for the other group (p<0.01). Among patients with the combination of a thromboembolic pattern on MRI and a negative cervical MRA, transoesophageal echocardiography led to a change in diagnosis in 12.1%. There was no significant difference between groups using a CT-based scheme.

CONCLUSIONS

DWI patterns appear to predict stroke aetiologies better than conventional methods. The study data suggest an MRI-based diagnostic algorithm that can potentially obviate the need for echocardiography in one-third of stroke patients and may limit the number of secondary extracranial vascular imaging studies to approximately 10%.

Early stroke risk and ABCD2 score performance in tissue- vs time-defined TIA: a multicenter study

OBJECTIVES

Stroke risk immediately after TIA defined by time-based criteria is high, and prognostic scores (ABCD2 and ABCD3-I) have been developed to assist management. The American Stroke Association has proposed changing the criteria for the distinction between TIA and stroke from time-based to tissue-based. Research using these definitions is lacking. In a multicenter observational cohort study, we have investigated prognosis and performance of the ABCD2 score in TIA, subcategorized as tissue-positive or tissue-negative on diffusion-weighted imaging (DWI) or CT imaging according to the newly proposed criteria.

METHODS

Twelve centers provided data on ABCD2 scores, DWI or CT brain imaging, and follow-up in cohorts of patients with TIA diagnosed by time-based criteria. Stroke rates at 7 and 90 days were studied in relation to tissue-positive or tissue-negative subcategorization, according to the presence or absence of brain infarction. The predictive power of the ABCD2 score was determined using area under receiver operator characteristic curve (AUC) analyses.

RESULTS

A total of 4,574 patients were included. Among DWI patients (n = 3,206), recurrent stroke rates at 7 days were 7.1%(95% confidence interval 5.5-9.1) after tissue-positive and 0.4% (0.2-0.7) after tissue-negative events (p diff < 0.0001). Corresponding rates in CT-imaged patients were 12.8% (9.3-17.4) and 3.0% (2.0-4.2), respectively (p diff < 0.0001). The ABCD2 score had predictive value in tissue-positive and tissue-negative events (AUC = 0.68 [95% confidence interval 0.63-0.73] and 0.73 [0.67-0.80], respectively; p sig < 0.0001 for both results, p diff = 0.17). Tissue-positive events with low ABCD2 scores and tissue-negative events with high ABCD2 scores had similar stroke risks, especially after a 90-day follow-up.

CONCLUSIONS

Our findings support the concept of a tissue-based definition of TIA and stroke, at least on prognostic grounds.

Addition of Brain Infarction to the ABCD 2 Score (ABCD 2 I)

Background and Purpose— The ABCD system was developed to predict early stroke risk after transient ischemic attack. Incorporation of brain imaging findings has been suggested, but reports have used inconsistent methods and been underpowered. We therefore performed an international, multicenter collaborative study of the prognostic performance of the ABCD 2 score and brain infarction on imaging to determine the optimal weighting of infarction in the score (ABCD 2 I).

Methods— Twelve centers provided unpublished data on ABCD 2 scores, presence of brain infarction on either diffusion-weighted imaging or CT, and follow-up in cohorts of patients with transient ischemic attack diagnosed by World Health Organization criteria. Optimal weighting of infarction in the ABCD 2 I score was determined using area under the receiver operating characteristic curve analyses and random effects meta-analysis.

Results— Among 4574 patients with TIA, acute infarction was present in 884 (27.6%) of 3206 imaged with diffusion-weighted imaging and new or old infarction was present in 327 (23.9%) of 1368 imaged with CT. ABCD 2 score and presence of infarction on diffusion-weighted imaging or CT were both independently predictive of stroke (n=145) at 7 days (after adjustment for ABCD 2 score, OR for infarction=6.2, 95% CI=4.2 to 9.0, overall; 14.9, 7.4 to 30.2, for diffusion-weighted imaging; 4.2, 2.6 to 6.9, for CT; all P <0.001). Incorporation of infarction in the ABCD 2 I score improved predictive power with an optimal weighting of 3 points for infarction on CT or diffusion-weighted imaging. Pooled areas under the curve increased from 0.66 (0.53 to 0.78) for the ABCD 2 score to 0.78 (0.72 to 0.85) for the ABCD 2 I score.

Conclusions— In secondary care, incorporation of brain infarction into the ABCD system (ABCD 2 I score) improves prediction of stroke in the acute phase after transient ischemic attack.

Magnetic resonance imaging in the evaluation of acute stroke

The ability to use physiologic imaging with either magnetic resonance (MR) or computed tomography to help define irreversibly injured brain (the infarct core) and tissue at risk of infarct (reversible ischemic penumbra) holds great promise in the future treatment of stroke. The physiologic principles and concepts underlying the evaluation for mismatch between injured tissue and tissue at risk are similar for the 2 imaging techniques. Multimodal MR imaging (diffusion-weighted imaging/perfusion-weighted imaging/MR angiography) provides a validated penumbral selection criteria based on the results of 2 clinical trials (diffusion and perfusion imaging evaluation for understanding stroke evolution and echoplanar imaging thrombolysis evaluation). Computed tomographic perfusion parameters have also been calculated to optimize final infarct prediction. Both techniques await further study to prove their capability of selecting cases for short-term recanalization/reperfusion therapy.

[Feasibility of percutaneous exclusion of the left atrial appendage: results of 11 cases]

Atrial fibrillation is associated with a risk of cerebral embolism, the only proven effective prevention of which is anticoagulant therapy. There is no known alternative in cases with contra-indications to this treatment. Percutaneous exclusion of the left atrial appendage by the implantation of a prosthesis (PLAATO System, ev3 Inc., Plymouth, Minnesota) is a new approach to the prevention of these complications. The authors report the results observed in a series of 11 consecutive patients (7 men, mean age 72 +/- 9 years) in whom this procedure was proposed. All patients had atrial fibrillation for over 3 months, were at high risk and had contra-indications to oral anticoagulants. The implantation of the prosthesis was performed after treatment with aspirin and clopidogrel, under general anaesthesia radioscopy and transoesophageal echocardiographic guidance with success in 9 cases (1 implantation refused in the catheter laboratory and 1 failure). The only complication observed was transient ST elevation treated by emergency angioplasty. The echographic and angiographic criteria of success of left atrial appendage exclusion were fulfilled in all implanted patients. The hospital course was uncomplicated. One recurrence of stroke was observed at the second month: transoesophageal echocardiography confirmed the absence of thrombosis, of migration of the prosthesis and its impermeability in all the patients. After 7 +/- 5 months' follow-up, no other adverse event was observed. This new procedure is technically feasible. Despite encouraging results, its long-term efficacy in the prevention of thromboembolic complications of atrial fibrillation remains to be demonstrated.

Diffusion weighted imaging of cerebellar lesions in Wernicke’s encephalopathy

We report unusual findings on MR imaging in a 62-year-old woman with Wernicke's encephalopathy (WE). Initial fluid-attenuated inversion recovery (FLAIR) and diffusion weighted MR imaging (DW-MRI) showed hyperintense lesions in the cerebellum and medial thalami, with a decreased apparent diffusion coefficient (ADC) in the cerebellum (reduced by 45%). After thiamine supplementation, the T2 and diffusion hyperintensities disappeared. However, clinical examination at three months showed persistent cerebellar impairment. The importance of the ADC values should be further investigated.

Thrombomodulin prolongs thrombin-induced extracellular signal-regulated kinase phosphorylation and nuclear retention in endothelial cells

On endothelial cells, thrombin binds to thrombomodulin (TM), an integral membrane-bound glycoprotein, and to protease-activated receptors (PARs). Thrombin binding to TM modulates endothelial cell and smooth muscle cell proliferation mediated through PAR1. We studied the phosphorylation and nuclear translocation of extracellular signal-regulated kinases (ERKs) 1 and 2 in human umbilical vein endothelial cells activated by thrombin. Thrombin and thrombin receptor-activating peptide (TRAP)-induced DNA synthesis were significantly inhibited by PD98059, an inhibitor of ERK phosphorylation. Immunoblots of phosphorylated ERKs (pERKs) and immunocytochemical studies of pERK localization revealed differences in the signal generated by thrombin and TRAP. After a short activation (15 minutes), the phosphorylation and the intracellular localization of pERKs were the same with the 2 agonists. After 4 hours, however, pERKs were visualized in the nuclei of thrombin-activated cells but barely detectable in TRAP-activated cells. Moreover, after 4 hours, the pERKs were visualized in the nuclei of cells stimulated by TRAP in the presence of a thrombin mutant that bound to TM, whereas they were around the nuclei in cells stimulated by thrombin in the presence of a monoclonal antibody preventing thrombin binding to TM. The results demonstrate that ERKs are involved in human umbilical vein endothelial cell DNA synthesis mediated by PAR agonists, that the duration of pERK nuclear retention is in inverse ratio to the mitogenic response, and that in addition to its role in the regulation of blood coagulation, TM acts as a thrombin receptor that modulates the duration of pERK nuclear retention and cell proliferation in response to thrombin.