Prediction of early neurological deterioration using diffusion- and perfusion-weighted imaging in hyperacute middle cerebral artery ischemic stroke

Transient Ischemic Attack (TIA) presenting with isolated anomic aphasia due to ischemia in the posterior cingulate gyrus in a 11-year-old girl

INTRODUCTION

Anomic aphasia, characterized by difficulty in word finding, is a subtype without impairments in fluent speech, comprehension, reading, writing, and repetition. Recognizing pure anomic aphasia in this group is crucial for a comprehensive understanding of localization and brain functions.

CASE REPORT

We present the case of an 11-year-old girl with transient ischemic attack and anomic aphasia. Neuroimaging identified abnormalities in the cingulate gyrus and temporo-occipital regions. No focal neurological findings were observed without aphasia. In terms of etiology, an MTHFR mutation was detected, and aside from this, no hematological or systemic cause could be identified.

CONCLUSION

This case marks the first demonstration of posterior cingulate gyrus involvement in pure anomic aphasia.

The relationship between neurological function trajectory, assessed by repeated NIHSS measurement, and long-term cardiovascular events, recurrent stroke, and mortality after ischemic stroke

BACKGROUND

Clinically significant changes in neurological deficits frequently occur after stroke onset, reflecting further neurological injury or neurological improvement. However, the National Institutes of Health Stroke Scale (NIHSS) score is only evaluated once in most studies, usually at stroke onset. Utilizing repeated measures of NIHSS scores to identify different trajectories of neurological function may be more informative and provide more useful predictive information. We determined the association of neurological function trajectories with long-term clinical outcomes after ischemic stroke.

METHODS

A total of 4025 participants with ischemic stroke from the China Antihypertensive Trial in Acute Ischemic Stroke were included. Patients were recruited from 26 hospitals across China between August 2009 and May 2013. A group-based trajectory model was used to identify distinct neurological function trajectories, as measured by NIHSS at admission, 14 days or hospital discharge, and 3 months. Study outcomes were cardiovascular events, recurrent stroke, and all-cause mortality during 3-24 months after ischemic stroke onset. Cox proportional hazards models were used to examine the associations of neurological function trajectories with outcomes.

RESULTS

We identified three distinct subgroups of NIHSS trajectories: persistent severe (persistent high NIHSS scores during the 3-month follow-up), moderate (NIHSS scores started at around 5 and gradually reduced), and mild (NIHSS scores always below 2). The three trajectory groups had different clinical profiles and different risk of stroke outcomes at 24-month follow-up. Compared to the mild trajectory group, patients in the persistent severe trajectory group had a higher risk of cardiovascular events (multivariable-adjusted hazard ratios (95% confidence intervals) = 1.77 (1.10-2.86)), recurrent stroke (1.82 (1.10-3.00)), and all-cause mortality (5.64 (3.37-9.43)). Those with moderate trajectory had an intermediate risk: 1.45 (1.03-2.04) for cardiovascular events and 1.52 (1.06-2.19) for recurrent stroke.

CONCLUSION

Longitudinal neurological function trajectories derived from repeated NIHSS measurements during the first 3 months after stroke provide additional predictive information and are associated with long-term clinical outcomes. The trajectories characterized by persistent severe and moderate neurological impairment were associated with increased risk of subsequent cardiovascular events.

Impact on collateral flow of devices used for endovascular treatment of stroke: an in-vitro flow model

BACKGROUND

Collateral blood supply of distal vessels has been linked to clinical outcome, infarct volume and recanalization rates in patients with large vessel occlusion. Our study aimed to explore the effects of catheterization during mechanical thrombectomy in collaterals.

METHODS

We quantified the flow diversion effect secondary to arterial occlusions in an in vitro model which was connected in a flow-loop setup with a saline reservoir and a pump supplying pulsatile flow. Clot analogs were embolized to the middle cerebral artery (MCA) M1 or M2 segments. We used the same model with a clamped anterior communicating artery (AComA) to simulate its absence. An ultrasound flow sensor was placed at the vessel of interest. Flow rates and pressures were evaluated according to the following catheter locations: baseline (1) before and (2) after the occlusion; (3) 8F guiding catheter at the internal carotid artery (ICA) bulb; (4) at the cavernous segment; (5) at the cavernous segment a 0.071" distal access catheter at proximal M1; (6) 8F balloon guide catheter inflated.

RESULTS

Collateral blood flow measured at distal anterior cerebral artery (ACA) (M1-MCA occlusion) and M2-MCA (M2-MCA occlusion) was progressively reduced as catheters were advanced through the ICA and MCA. In the lacking AComA model, the flow was further diminished as compared with the model with a patent AComA.

CONCLUSION

Our in vitro study showed a progressive reduction of collateral blood flow due to the advance of catheters during mechanical thrombectomy.

Risk factors of unexplained early neurological deterioration after treatment for ischemic stroke due to large vessel occlusion: a post hoc analysis of the HERMES study

BACKGROUND

Early neurological deterioration (END) after endovascular treatment (EVT) in patients with anterior circulation acute ischemic stroke (AIS) is associated with poor outcome. END may remain unexplained by parenchymal hemorrhage (UnEND). We aim to analyze the risk factors of UnEND in the medical management (MM) and EVT arms of the HERMES study.

METHODS

We conducted a post-hoc analysis of anterior AIS patients who underwent EVT for proximal anterior occlusions. Risk factors of UnEND, defined as a worsening of ≥4 points between baseline National Institutes of Health Stroke Scale (NIHSS) and NIHSS at 24 hours without hemorrhage, were compared between both arms using mixed logistic regression models adjusted for baseline characteristics. An interaction analysis between the EVT and MM arms for risk factors of UnEND was conducted.

RESULTS

Among 1723 patients assessable for UnEND, 160 patients experienced an UnEND (9.3%), including 9.1% (78/854) in the EVT arm and 9.4% (82/869) in the MM arm. There was no significant difference in the incidence of UnEND between the two study arms. In the EVT population, independent risk factors of UnEND were lower baseline NIHSS, higher baseline glucose, and lower collateral grade. In the MM population, the only independent predictor of UnEND was higher baseline glucose. However, we did not demonstrate an interaction between EVT and MM for baseline factors as risk factors of UnEND. UnEND was, similarly in both treatment groups, a significant predictor of unfavorable outcome in both the EVT (p<0.001) and MM (p<0.001) arms.

CONCLUSIONS

UnEND is not an uncommon event, with a similar rate which ever treatment arm is considered. In the clinical scenario of AIS due to large vessel occlusion, no patient-related factor seems to increase the risk for UnEND when treated by EVT compared with MM.

Effect of Argatroban Plus Intravenous Alteplase vs Intravenous Alteplase Alone on Neurologic Function in Patients With Acute Ischemic Stroke: The ARAIS Randomized Clinical Trial

IMPORTANCE

Previous studies suggested a benefit of argatroban plus alteplase (recombinant tissue-type plasminogen activator) in patients with acute ischemic stroke (AIS). However, robust evidence in trials with large sample sizes is lacking.

OBJECTIVE

To assess the efficacy of argatroban plus alteplase for AIS.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter, open-label, blinded end point randomized clinical trial including 808 patients with AIS was conducted at 50 hospitals in China with enrollment from January 18, 2019, through October 30, 2021, and final follow-up on January 24, 2022.

INTERVENTIONS

Eligible patients were randomly assigned within 4.5 hours of symptom onset to the argatroban plus alteplase group (n = 402), which received intravenous argatroban (100 μg/kg bolus over 3-5 minutes followed by an infusion of 1.0 μg/kg per minute for 48 hours) within 1 hour after alteplase (0.9 mg/kg; maximum dose, 90 mg; 10% administered as 1-minute bolus, remaining infused over 1 hour), or alteplase alone group (n = 415), which received intravenous alteplase alone. Both groups received guideline-based treatments.

MAIN OUTCOMES AND MEASURES

The primary end point was excellent functional outcome, defined as a modified Rankin Scale score (range, 0 [no symptoms] to 6 [death]) of 0 to 1 at 90 days. All end points had blinded assessment and were analyzed on a full analysis set.

RESULTS

Among 817 eligible patients with AIS who were randomized (median [IQR] age, 65 [57-71] years; 238 [29.1%] women; median [IQR] National Institutes of Health Stroke Scale score, 9 [7-12]), 760 (93.0%) completed the trial. At 90 days, 210 of 329 participants (63.8%) in the argatroban plus alteplase group vs 238 of 367 (64.9%) in the alteplase alone group had an excellent functional outcome (risk difference, -1.0% [95% CI, -8.1% to 6.1%]; risk ratio, 0.98 [95% CI, 0.88-1.10]; P = .78). The percentages of participants with symptomatic intracranial hemorrhage, parenchymal hematoma type 2, and major systemic bleeding were 2.1% (8/383), 2.3% (9/383), and 0.3% (1/383), respectively, in the argatroban plus alteplase group and 1.8% (7/397), 2.5% (10/397), and 0.5% (2/397), respectively, in the alteplase alone group.

CONCLUSIONS AND RELEVANCE

Among patients with acute ischemic stroke, treatment with argatroban plus intravenous alteplase compared with alteplase alone did not result in a significantly greater likelihood of excellent functional outcome at 90 days.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03740958.

Predictors of early neurologic deterioration (END) following stroke thrombectomy

BACKGROUND

Early neurologic deterioration (END) following ischemic stroke is a serious event and is associated with poor outcomes. However, the incidence and predictors of END after stroke thrombectomy for emergent large vessel occlusion are largely unknown.

METHODS

The baseline characteristics of patients enrolled in the COMPASS trial (NCT02466893) were analyzed. The primary outcome was worsening of ≥4 National Institutes of Health Stroke Scale (NIHSS) points 24 hours post thrombectomy (4+ END₂₄) and the secondary outcome was deterioration of ≥2 points (2+ END₂₄).

RESULTS

Among 270 patients, 27 (10%) developed 4+ END₂₄ and 42 (16%) had 2+ END₂₄. Those with 4+ END₂₄ were older (76.4±12.9 vs 70.9±12.9 years; p=0.04), had a higher prevalence of hypertension (96% vs 69%; p=0.003), diabetes (41% vs 27%; p=0.13) and higher pretreatment systolic blood pressure (SBP) (170.4±32.6 vs 157.6±28.1 mmHg; p=0.03). More 4+ END₂₄ patients had failed reperfusion: Thrombolysis in Cerebral Infarction ≤2a (26% vs 8%; p=0.003). In unadjusted analysis, older patients and those with hypertension, diabetes, elevated SBP and failed reperfusion had higher odds of 4+ END₂₄. In adjusted analysis, age increase by 5 years led to an increase in 4+ END₂₄ of 28%, diabetes increased odds of 2.6 and failed reperfusion increased odds of 4.5. In the multivariable analysis for the secondary outcome, age (OR 1.33; 95% CI 1.109 to 1.593), diabetes (OR 2.7; 95% CI 1.247 to 5.764) and failed reperfusion (OR 7.2; 95% CI 0.055 to 0.349) were also significant predictors of 2+ END₂₄.

CONCLUSIONS

Older patients with acute ischemic stroke who have a history of diabetes or hypertension, with elevated pretreatment SBP and failed reperfusion are at a higher risk of END following stroke thrombectomy for emergent large vessel occlusion.

Leveraging Continuous Vital Sign Measurements for Real-Time Assessment of Autonomic Nervous System Dysfunction After Brain Injury: A Narrative Review of Current and Future Applications

Subtle and profound changes in autonomic nervous system (ANS) function affecting sympathetic and parasympathetic homeostasis occur as a result of critical illness. Changes in ANS function are particularly salient in neurocritical illness, when direct structural and functional perturbations to autonomic network pathways occur and may herald impending clinical deterioration or intervenable evolving mechanisms of secondary injury. Sympathetic and parasympathetic balance can be measured quantitatively at the bedside using multiple methods, most readily by extracting data from electrocardiographic or photoplethysmography waveforms. Work from our group and others has demonstrated that data-analytic techniques can identify quantitative physiologic changes that precede clinical detection of meaningful events, and therefore may provide an important window for time-sensitive therapies. Here, we review data-analytic approaches to measuring ANS dysfunction from routine bedside physiologic data streams and integrating this data into multimodal machine learning-based model development to better understand phenotypical expression of pathophysiologic mechanisms and perhaps even serve as early detection signals. Attention will be given to examples from our work in acute traumatic brain injury on detection and monitoring of paroxysmal sympathetic hyperactivity and prediction of neurologic deterioration, and in large hemispheric infarction on prediction of malignant cerebral edema. We also discuss future clinical applications and data-analytic challenges and future directions.

Malnutrition and the Risk of Early Neurological Deterioration in Elderly Patients with Acute Ischemic Stroke

BACKGROUND AND PURPOSE

This study aimed to investigate the relationship between malnutrition and early neurological deterioration (END) in elderly patients with acute ischemic stroke in China.

METHODS

We used the registry data in the Third Affiliated Hospital of Nantong University and Nanjing Brain Hospital from June 2019 to January 2021. Malnutrition risk was evaluated by controlling nutritional status score (CONUT), geriatric nutritional risk index (GNRI) and prognostic nutritional index (PNI) score, respectively. END was defined as an increment of at least two points in the total NIHSS score within three days after admission. We evaluated the relationship between malnutrition and END with multivariable logistic regression models and reclassification indexes.

RESULTS

A total of 732 elderly patients with first-ever acute ischemic stroke were included in the study. 243 patients developed END. 5.7%, 21.4%, 4.6% patients were classified as moderate to severe malnutrition by CONUT, GNRI and PNI, respectively. Malnutrition was associated with the risk of END for CONUT (odds ratio [OR], 1.210; 95% confidence interval [CI] 1.092-1.341; P < 0.001), for GNRI (OR, 0.943; 95% CI, 0.919-0.967; P < 0.001), and for PNI (OR, 0.936; 95% CI, 0.908-0.965; P < 0.001) in multivariable logistic regression models using the back-ward selection method. The discriminative ability was 0.763 (95% CI, 0.727-0.798) for CONUT, 0.769 (95% CI, 0.733-0.805) for GNRI and 0.769 (95% CI, 0.733-0.805) for PNI after adjusting for confounders. Besides, adding malnutrition indexes into models made the prediction of END more accurate.

CONCLUSION

Malnutrition was associated with END in elderly Chinese patients with acute ischemic stroke.

Blood Pressure After Endovascular Thrombectomy and Outcomes in Patients With Acute Ischemic Stroke: An Individual Patient Data Meta-analysis

OBJECTIVE

To explore the association between blood pressure (BP) levels after endovascular thrombectomy (EVT) and the clinical outcomes of acute ischemic stroke (AIS) patients with large vessel occlusion (LVO).

METHODS

A study was eligible if it enrolled AIS patients older than 18 years, with an LVO treated with either successful or unsuccessful EVT, and provided either individual or mean 24-hour systolic BP values after the end of the EVT procedure. Individual patient data from all studies were analyzed using a generalized linear mixed-effects model.

RESULTS

A total of 5874 patients (mean age: 69±14 years, 50% women, median NIHSS on admission: 16) from 7 published studies were included. Increasing mean systolic BP levels per 10 mm Hg during the first 24 hours after the end of the EVT were associated with a lower odds of functional improvement (unadjusted common OR=0.82, 95%CI:0.80-0.85; adjusted common OR=0.88, 95%CI:0.84-0.93) and modified Ranking Scale score≤2 (unadjusted OR=0.82, 95%CI:0.79-0.85; adjusted OR=0.87, 95%CI:0.82-0.93), and a higher odds of all-cause mortality (unadjusted OR=1.18, 95%CI:1.13-1.24; adjusted OR=1.15, 95%CI:1.06-1.23) at 3 months. Higher 24-hour mean systolic BP levels were also associated with an increased likelihood of early neurological deterioration (unadjusted OR=1.14, 95%CI:1.07-1.21; adjusted OR=1.14, 95%CI:1.03-1.24) and a higher odds of symptomatic intracranial hemorrhage (unadjusted OR=1.20, 95%CI:1.09-1.29; adjusted OR=1.20, 95%CI:1.03-1.38) after EVT.

CONCLUSION

Increased mean systolic BP levels in the first 24 hours after EVT are independently associated with a higher odds of symptomatic intracranial hemorrhage, early neurological deterioration, three-month mortality, and worse three-month functional outcomes.

Association of cerebral microvascular perfusion and diffusion dynamics detected by intravoxel incoherent motion-diffusion weighted imaging with initial neurological function and clinical outcome in acute ischemic stroke

Background

This work aimed to explore the association of cerebral microvascular perfusion and diffusion dynamics measured by intravoxel incoherent motion (IVIM) imaging with initial neurological function and clinical outcome in acute stroke.

Methods

In total, 39 patients were assessed with admission National Institutes of Health Stroke Scale (NIHSS) and day-90 modified Rankin Scale (mRS). The parametrical maps of IVIM were obtained, including apparent diffusion coefficient (ADC), pseudo-diffusion coefficient (D*), true diffusion coefficient (D) and perfusion fraction (f). The fD* was the product of f and D*. Moreover, the ratios of lesioned/contralateral parameters (rADC, rD, rD*, rf and rfD*) were also obtained. The differences of these parameters between the poor outcome group and good outcome group were evaluated. Partial correlation analysis was used to evaluate the correlations between the admission NIHSS/day-90 mRS and each parameter ratio, with lesion volumes controlled.

Results

The ADC, D, D*, f and fD* values of lesions were significantly reduced than those of the contralateral regions. The rADC and rD were significantly decreased in the poor outcome group than good outcome group (all p < 0.01). With lesion volume controlled, rADC showed a weak negative correlation (r = −0.340, p = 0.037) and a notable negative correlation (r = −0.688, p < 0.001) with admission NIHSS score and day-90 mRS score, respectively. In addition, rD showed a strong negative correlation (r = −0.731, p < 0.001) with day-90 mRS score.

Conclusion

Significant negative correlations were revealed between IVIM derived diffusion dynamics parameters and initial neurological function as well as clinical outcome for patients with acute ischemic stroke. IVIM can be therefore suggested as an effective non-invasive method for evaluating the acute ischemic stroke.

Neurological Instability in Ischemic Stroke: Relation with Outcome, Latency Time, and Molecular Markers

The National Institutes of Health Stroke Scale (NIHSS) is commonly used to evaluate stroke neurological deficits and to predict the patient’s outcome. Neurological instability (NI), defined as the variation of the NIHSS in the first 48 h, is a simple clinical metric that reflects dynamic changes in the area of the brain affected by the ischemia. We hypothesize that NI may represent areas of cerebral instability known as penumbra, which could expand or reduce brain injury and its associated neurological sequels. In this work, our aim was to analyze the association of NI with the functional outcome at 3 months and to study clinical biomarkers associated to NI as surrogate biomarkers of ischemic and inflammatory penumbrae in ischemic stroke (IS) patients. We included 663 IS patients in a retrospective observational study. Neutral NI was defined as a variation in the NI scale between − 5 and 5% (37.1%). Positive NI is attributed to patients with an improvement of > 5% NI after 48 h (48.9%), while negative NI is assigned to patients values lower than − 5% (14.0%). Poor outcome was assigned to patients with mRS ≥ 3 at 3 months. We observed an inverse association of poor outcome with positive NI (OR, 0.35; 95%CI, 0.18–0.67; p = 0.002) and a direct association with negative NI (OR, 6.30; 95%CI, 2.12–18.65; p = 0.001). Negative NI showed a higher association with poor outcome than most clinical markers. Regarding good functional outcome, positive NI was the marker with the higher association (19.31; CI 95%, 9.03–41.28; p < 0.0001) and with the highest percentage of identified patients with good functional outcome (17.6%). Patients with negative NI have higher glutamate levels compared with patients with neutral and positive NI (p < 0.0001). IL6 levels are significantly lower in patients with positive NI compared with neutral NI (p < 0.0001), while patients with negative NI showed the highest IL6 values (p < 0.0001). High glutamate levels were associated with negative NI at short latency times, decreasing at higher latency times. An opposite trend was observed for inflammation, and IL6 levels were similar in patients with positive and negative NI in the first 6 h and then higher in patients with negative NI. These results support NI as a prognosis factor in IS and the hypothesis of the existence of a delayed inflammatory penumbra, opening up the possibility of extending the therapeutic window for IS.

Hypoperfusion Intensity Ratio Predicts Malignant Edema and Functional Outcome in Large-Vessel Occlusive Stroke with Poor Revascularization

BACKGROUND AND OBJECTIVE

Malignant cerebral edema (MCE) is a well-known complication in patients with acute ischemic stroke with core infarcts ≥ 80 mL caused by large-vessel occlusions. MCE can also develop in patients with smaller infarcts with moderate -to-large volume of tissue at risk who do not achieve successful revascularization with endovascular thrombectomy (ET). Features that predict the development of MCE in this population are not well-described. We aim to identify predictors of MCE and 90-day functional outcome in stroke patients with an anterior circulation large vessel occlusion (LVO) and a < 80 mL ischemic core who do not achieve complete reperfusion.

METHODS

We reviewed our institutional stroke registry and included patients who achieved unsuccessful revascularization, mTICI 0-2a, after ET and whose baseline imaging was notable for a core infarct < 80 mL, a T_max > 6 s volume ≥ 80 mL, and a mismatch ratio ≥ 1.8. MCE was defined as ≥ 5 mm of midline shift on follow-up imaging, obtained 6-48 h after the pre-ET perfusion scan.

RESULTS

Thirty-six patients met inclusion criteria. Unadjusted analysis demonstrated that younger age, higher systolic blood pressure, larger core volume, and higher hypoperfusion intensity ratio (HIR) were associated with MCE (all p < 0.02). In multivariate logistic regression analysis, age, HIR, and core infarct volume were independent predictors of MCE. The optimal HIR threshold to predict MCE was ≥ 0.54 (OR 14.7, 95% CI 2.4-78.0, p = 0.003). HIR was also associated with 3-month mRS (HIR ≥ 0.54 for mRS of 3-6: OR 10.8, 95% CI 1.9-44.0, p = 0.02).

CONCLUSIONS

Younger age, larger core infarct volume, and higher HIR are predictive of MCE in patients with anterior circulation LVO, moderate-to-large tissue at risk, and suboptimal revascularization. HIR is correlated with three-month functional outcomes.

Predictors of Unexplained Early Neurological Deterioration After Endovascular Treatment for Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Although the efficacy of endovascular treatment (EVT) in patients with anterior circulation ischemic stroke (AIS) is well documented, early neurological deterioration after EVT remains a serious issue associated with poor outcome. Besides obvious causes, such as lack of reperfusion, procedural complications, or parenchymal hemorrhage, early neurological deterioration may remain unexplained (UnEND). Our aim was to investigate predictors of UnEND after EVT in patients with AIS.

METHODS

Patients who underwent EVT for AIS, with an initial National Institutes of Health Stroke Scale score >5, Alberta Stroke Program Early CT Score ≥6, and included in a multicenter prospective observational registry were analyzed. Predictors of UnEND, defined as ≥4-point increase in the National Institutes of Health Stroke Scale score between baseline and day 1 after EVT, were determined via center-adjusted analyses.

RESULTS

Among the 1925 included in the analysis, 128 UnEND (6.6%) were recorded. In multivariate analysis, predictors of UnEND were diabetes mellitus (odds ratio [OR], 2.17 [95% CI, 1.32-3.56]), prestroke modified Rankin Scale score ≥2 (OR, 2.22 [95% CI, 1.09-4.55]), general anesthesia (OR, 2.55 [95% CI, 1.51-4.30]), admission systolic blood pressure (OR, 1.10 [95% CI, 1.01-1.20]), age (OR, 1.38 [95% CI, 1.14-1.67]), number of passes (OR, 1.16 [95% CI, 1.04-1.28]), direct admission or not to a comprehensive stroke center (OR, 0.49 [95% CI, 0.30-0.81]), and initial National Institutes of Health Stroke Scale score (OR, 0.65 [95% CI, 0.52-0.81]).

CONCLUSIONS

Severely impaired AIS patients with nonmodifiable factors are more likely to develop UnEND. Some modifiable predictors of UnEND such as the number of EVT passes could be the object of improvement in AIS management.

Asymmetrical cortical vein sign predicts early neurological deterioration in acute ischemic stroke patients with severe intracranial arterial stenosis or occlusion

Background

Susceptibility weighted imaging (SWI) provides an approximate assessment of tissue perfusion and shows prominent hypointense cortical veins in the ischemic territory because of the increased concentration of deoxyhemoglobin. We aimed to evaluate whether asymmetrical prominent cortical vein sign (APCVS) on SWI can predict early neurological deterioration (END) in acute ischemic stroke patients with severe intracranial arterial stenosis or occlusion (SIASO).

Methods

One hundred and nine acute ischemic stroke patients with SIASO who underwent SWI were retrospectively recruited. END was defined as an increase in the National Institutes of Health Stroke Scale score ≧2 points despite standard treatment in the first 72 h after admission. The APCVS was defined as more and/or large vessels with greater signal loss than those in the opposite hemisphere on SWI.

Results

Thirty out of the 109 (27.5%) patients developed END. Sixty (55.0%) patients presented with APCVS on SWI. APCVS occurred in 24 (80%) patients with END, whereas it only occurred in 36 (45.6%) patients without END (P = 0.001). Patients with APCVS were more likely to have END (40.0%, vs. 12.2%, P = 0.001) than those without END. Multivariate logistic regression indicated that APCVS (OR = 4.349, 95% C.I. = 1.580–11.970, P = 0.004) was a significant predictor of END in acute ischemic stroke patients with SIASO, adjusted for previous stroke history and acute infarct volume.

Conclusions

In acute ischemic stroke patients with SIASO, the APCVS might be a useful neuroimaging marker for predicting END, which suggests the importance of evaluation of perfusion status.

The Incidence and Associated Factors of Early Neurological Deterioration After Thrombolysis

Background and purpose:

Early neurological deterioration (END) after stroke onset may predict severe outcomes. Estimated rates of END after intravenous thrombolysis among small patient samples have been reported up to 29.8%. We studied the incidence and factors associated with END among patients following intravenous thrombolysis.

Methods:

We analyzed SITS-International Stroke Thrombolysis registry patients with known outcomes enrolled in 2010 to 2017. END was defined as an increase in National Institutes of Health Stroke Scale score ≥4 or death within 24 hours from baseline National Institutes of Health Stroke Scale. We determined the incidence of END and used logistic regression models to inspect its associated factors. We adjusted for variables found significant in univariate analyses ( P <0.05). Main outcomes were incidence of END, associated predictors of END, ordinal day-90 mRS, and day-90 mortality.

Results:

We excluded 53 539 patients and included 50 726 patients. The incidence of END was 3415/50 726 (6.7% [95% CI, 6.5%–7.0%]). Factors independently associated with END on multivariate analysis were intracerebral hemorrhage (OR, 3.23 [95% CI, 2.96–3.54], P <0.001), large vessel disease (LVD) with carotid stenosis (OR, 2.97 [95% CI, 2.45–3.61], P <0.001), other LVD (OR, 2.41 [95% CI, 2.03–2.88], P <0.001), and ischemic stroke versus transient ischemic attack (TIA)/stroke mimics (OR, 16.14 [95% CI, 3.99–65.3], P <0.001). END was associated with worse outcome on ordinal mRS: adjusted OR 2.48 (95% CI, 2.39–2.57, P <0.001) by day-90 compared with no END. The adjusted OR for day-90 mortality was 9.70 (95% CI, 8.36–11.26, P <0.001).

Conclusions:

The routinely observed rate of END reflected by real-world data is low, but END greatly increases risk of disability and mortality. Readily identifiable factors predict END and may help with understanding causal mechanisms to assist prevention of END.

Multiple hypointense vessels on susceptibility-weighted imaging predict early neurological deterioration in acute ischaemic stroke patients with severe intracranial large artery stenosis or occlusion receiving intravenous thrombolysis

Background and purpose

Early neurological deterioration (END) is a common feature in patients with acute ischaemic stroke (AIS) receiving thrombolysis. This study aimed to investigate whether the presence of multiple hypointense vessels (MHVs) on susceptibility-weighted imaging (SWI) could predict END in patients with the anterior circulation AIS treated with recombinant tissue plasminogen activator (r-tPA).

Methods

This was a retrospective study focusing on AIS patients suffering from symptomatic stenosis or occlusion of the middle cerebral artery or internal carotid artery with r-tPA treatment. We collected clinical variables and initial haematological and neuroimaging findings. MHVs were measured on SWI performed after intravenous thrombosis and were defined as the presence of a greater number of veins or veins of a larger diameter with greater signal loss on SWI than those of the contralesional haemisphere. The degree of hyperintensity of MHVs was classified into four grades: none, subtle, moderate and extensive. END was defined as an increase in the National Institutes of Health Stroke Scale score by 2 points during the first 48 hours after the onset of symptoms. Multivariate logistic regressions were conducted to investigate the predictors of END.

Results

The study included 61 patients (51 males and 10 females) with a mean age of 62.4±12.6 years. Thirty-five (57.4%) patients presented with MHVs: 8 (13.1%) were graded as subtle MHVs, while 23 (37.7%) and 4 (6.6%) were graded as moderate or extensive MHVs, respectively. Twenty patients (32.8%) presented with END. Logistic regression analysis showed that compared with patients without MHVs, moderate MHVs (adjusted OR 5.446, 95% CI 1.360 to 21.800; p=0.017) and extensive MHVs (adjusted OR 15.240, 95% CI 1.200 to 193.544; p=0.036) were significantly associated with END.

Conclusions

MHVs might be a useful predictor of END in AIS patients with symptomatic large artery stenosis or occlusion after r-tPA treatment.

Acute insular infarction: Early outcomes of minor stroke with proximal artery occlusion

BACKGROUND AND PURPOSE

We hypothesized that admission insular infarcts could be associated with early neurological deterioration (END) in acute minor stroke with large vessel occlusion.

METHODS

Using acute and follow-up diffusion-weighted imaging (DWI), we assessed insular involvement including the percent insular ribbon infarction (PIRI) scores and follow-up lesion patterns in acute minor stroke (NIHSS ≤5) with MCA/ICA occlusion. Follow-up lesion patterns were classified as swelling, new lesions, or infarct growth. END was defined as any increase in the NIHSS score.

RESULTS

Among 166 patients (age: 66±12 y, 60.8% male), 82 (49.4%) had insular lesions on baseline DWI, and 64 (38.6%) had PIRI scores ≥2. On follow-up DWI, infarct growths, new lesions, and swelling were observed in 34.9%, 69.9%, and 29.5% of patients. Infarct growths were significantly more frequent in patients with insular infarcts (43.9%), especially those with a PIRI score of 2 (54.8%), than in patients without insular infarcts (p = 0.02). While END was not significantly different in patients with and without insular lesions, insular lesions were independently associated with infarct growths (OR 2.18, 95% CI 1.12-4.26, p = 0.02) and END due to infarct growth (OR 2.54, 95% CI 1.12-5.76, p = 0.03), particularly in those with PIRI scores ≥2.

CONCLUSION

In acute minor stroke with MCA/ICA occlusion, insular lesions on admission DWI, especially in patients with PIRI scores ≥2, were more likely to exhibit infarct growth and END due to infarct growth. This finding may help identify patients with higher risks of clinical worsening following acute minor stroke with large vessel occlusion.

A Novel Neuroimaging Model to Predict Early Neurological Deterioration After Acute Ischemic Stroke

Objective:

In acute ischemic stroke, early neurological deterioration (END) may occur in up to one-third of patients. However, there is still no satisfying or comprehensive predictive model for all the stroke subtypes. We propose a practical model to predict END using magnetic resonance imaging (MRI).

Method:

Patients with anterior circulation infarct were recruited and they underwent an MRI within 24 hours of stroke onset. END was defined as an elevation of ≥2 points on the National Institute of Health Stroke Scale (NIHSS) within 72 hours of stroke onset. We examined the relationships of END to individual END models, including: A, infarct swelling; B, small subcortical infarct; C, mis-match; and D, recurrence.

Results:

There were 163 patients recruited and 43 (26.4%) of them had END. The END models A, B and C significantly predicted END respectively after adjusting for confounding factors (p=0.022, p=0.007 and p<0.001 respectively). In END model D, we examined all imaging predictors of Recur-rence Risk Estimator (RRE) individually and only the “multiple acute infarcts” pattern was signifi-cantly associated with END (p=0.032). When applying END models A, B, C and D, they success-fully predicted END (p<0.001; odds ratio: 17.5[95% confidence interval: 5.1–60.8]), with 93.0% sensitivity, 60.0% specificity, 45.5% positive predictive value and 96.0% negative predictive value.

Conclusion:

The results demonstrate that the proposed model could predict END in all stroke sub-types of anterior circulation infarction. It provides a practical model for clinical physicians to select high-risk patients for more aggressive treatment to prevent END.

Temporal changes in the neutrophil to lymphocyte ratio and the neurological progression in cryptogenic stroke with active cancer

Background

Ischemic stroke patients with active cancer frequently experience early neurological deterioration (END); however, the predictors of END are not well studied. The neutrophil to lymphocyte ratio (NLR) has recently been described as a predictor of poor outcomes in cancer and stroke. However, its role in cancer-related stroke has not been addressed.

Aim

We aimed to evaluate the association between the NLR and END in cancer-related stroke patients.

Methods

We included 85 cryptogenic stroke patients with active cancer. END was defined as an increase ≥ 4 on the total National Institutes of Health Stroke Scale (NIHSS) score within 72 hours of admission. The NLR was calculated as the ratio of the absolute neutrophil count to the absolute lymphocyte count. We obtained the NLR during the following three periods: at admission, 1–3 days after admission (D 1–3 NLR) and 4–7 days after admission (D 4–7 NLR).

Results

END occurred in 15 (18%) of the 85 patients. END was significantly associated with the initial NIHSS score, infarction volume, and the D 1–3 NLR. In multivariate analysis, a higher D 1–3 NLR, measured before END events, remained an independent predictor of END [adjusted odds ratio = 2.78, 95% confidence interval = 1.09–7.08, P = 0.032]. In terms of temporal changes in the NLR, the END group showed a tendency toward temporal increase in the NLR at D 1–3 (P = 0.061) with subsequent decrements in the D 4–7 NLR (P = 0.088), while the non-END group showed no significant changes in the NLR between periods.

Conclusions

This study demonstrated that a higher NLR could predict END events in cryptogenic stroke patients with active cancer. However, the results should be confirmed in further large prospective studies.

Clinical and Imaging Outcomes of Endovascular Therapy in Patients with Acute Large Vessel Occlusion Stroke and Mild Clinical Symptoms

Background

The minimal stroke severity justifying endovascular intervention remains elusive. However, a significant proportion of patients presenting with large vessel occlusion stroke (LVOS) and mild symptoms go untreated and face poor outcomes. We aimed to evaluate the clinical outcomes of patients presenting with LVOS and low symptom scores (National Institutes of Health Stroke Scale [NIHSS] score ≤8) undergoing endovascular therapy (ET).

Methods

We performed a retrospective analysis of a prospectively collected ET database between September 2010 and March 2016. Endovascularly treated patients with LVOS and a baseline NIHSS score ≤8 were included. Baseline patient characteristics, procedural details, and outcome parameters were collected. Efficacy outcomes were the rate of good outcome (90-day modified Rankin Scale score 0-2) and of successful reperfusion (modified Treatment in Cerebral Infarction [mTICI] score 2b-3). Safety was assessed by the rate of parenchymal hematoma (parenchymal hematoma type 1 [PH-1] and parenchymal hematoma type 2 [PH-2]) and 90-day mortality. Logistic regression was used to identify predictors of good clinical outcomes.

Results

A total of 935 patients were considered; 72 patients with an NIHSS score ≤8 were included. Median [IQR] age was 61.5 years [56.2-73.0]; 39 patients (54%) were men. Mean (SD) baseline NIHSS score, computed tomography perfusion core volume, and ASPECTS were 6.3 (1.5), 7.5 mL (16.1), and 8.5 (1.3), respectively. Twenty-eight patients (39%) received intravenous tissue plasminogen activator. Occlusions locations were as follows: 29 (40%) proximal MCA-M1, 20 (28%) MCA-M2, 6 (8%) ICA terminus, and 9 (13%) vertebrobasilar. Tandem occlusion was documented in 7 patients (10%). Sixty-seven patients (93%) achieved successful reperfusion (mTICI score 2b-3); 52 (72%) had good 90-day outcomes. Mean final infarct volume was 32.2 ± 59.9 mL. Parenchymal hematoma occurred in 4 patients (6%). Ninety-day mortality was 10% (n = 7). Logistic regression showed that only successful reperfusion (OR 27.7, 95% CI 1.1-655.5, p = 0.04) was an independent predictor of good outcomes.

Conclusion

Our findings demonstrate that ET is safe and feasible for LVOS patients presenting with mild clinical syndromes. Future controlled studies are warranted.

Early neurological stability predicts adverse outcome after acute ischemic stroke

Background Deterioration in the National Institutes of Health Stroke Scale (NIHSS) in the early days after stroke is associated with progressive infarction, brain edema, and/or hemorrhage, leading to worse outcome. Aims We sought to determine whether a stable NIHSS score represents an adverse or favorable course. Methods Brain magnetic resonance images from a research cohort of acute ischemic stroke patients were analyzed. Using NIHSS scores at baseline and follow-up (day 3-5), patients were categorized into early neurological deterioration (ΔNIHSS ≥ 4), early neurological recovery (ΔNIHSS ≤ -4) or early neurological stability (ΔNIHSS between -3 and 3). The association between these categories and volume of infarct growth, volume of swelling, parenchymal hemorrhage, and 3-month modified Rankin Scale score were evaluated. Results Patients with early neurological deterioration or early neurological stability were less likely to be independent (modified Rankin Scale = 0-2) at 3 months compared to those with early neurological recovery ( P < 0.001). Patients with early neurological deterioration or early neurological stability were observed to have significantly greater infarct growth and swelling volumes than those with early neurological recovery ( P = 0.03; P < 0.001, respectively). Brain edema was more common than the other imaging markers investigated and was independently associated with a stable or worsening NIHSS score after adjustment for age, baseline stroke volume, infarct growth volume, presence of parenchymal hemorrhage, and reperfusion ( P < 0.0001). Conclusions Stable NIHSS score in the subacute period after ischemic stroke may not be benign and is associated with tissue injury, including infarct growth and brain edema. Early improvement is considerably more likely to occur in the absence of these factors.

Lesions on DWI and the Outcome in Hyperacute Posterior Circulation Stroke

BACKGROUND

few studies have addressed the association between the characteristics of ischemic lesions detected by diffusion-weighted imaging (dWi) and the clinical outcome in patients with hyperacute posterior circulation ischemic stroke. this study demonstrates a relationship between the findings assessed by dWi and the outcome in patients with hyperacute posterior circulation ischemic stroke.

METHODS

We reviewed data from 118 patients who had posterior circulation ischemic stroke within six hours from the onset of their symptoms. the clinical outcome included early neurological deterioration (end) and a favorable outcome at three months after the onset of symptoms. using dWi, the lesion volume and the number and location of injured anatomical regions were analyzed to evaluate whether the results correlated with the clinical outcome measures.

RESULTS

the number of injured anatomical regions assessed by dWi was associated with the initial and delayed neurological status. Both the total volume and the number of injured anatomical regions associated with end and a favorable outcome. analysis of the location of the injured regions determined that only a pontine lesion independently associated with end. interestingly, four out of five patients who underwent decompressive craniectomy exhibited a large infarction volume but minor symptoms.

CONCLUSIONS

in patients with hyperacute posterior circulation ischemic strokes, the lesions assessed by dWi were associated with the clinical outcome, regardless of the initial neurological status. dWi is an effective initial imaging tool for assessing the extent of lesions and clinical outcomes in patients with hyperacute posterior circulation ischemic stroke.

Stroke Damage Is Exacerbated by Nano-Size Particulate Matter in a Mouse Model

This study examines the effects of nano-size particulate matter (nPM) exposure in the setting of murine reperfused stroke. Particulate matter is a potent source of inflammation and oxidative stress. These processes are known to influence stroke progression through recruitment of marginally viable penumbral tissue into the ischemic core. nPM was collected in an urban area in central Los Angeles, impacted primarily by traffic emissions. Re-aerosolized nPM or filtered air was then administered to mice through whole body exposure chambers for forty-five cumulative hours. Exposed mice then underwent middle cerebral artery occlusion/ reperfusion. Following cerebral ischemia/ reperfusion, mice exposed to nPM exhibited significantly larger infarct volumes and less favorable neurological deficit scores when compared to mice exposed to filtered air. Mice exposed to nPM also demonstrated increases in markers of inflammation and oxidative stress in the region of the ischemic core. The findings suggest a detrimental effect of urban airborne particulate matter exposure in the setting of acute ischemic stroke.

Metabolic Syndrome Augments the Risk of Early Neurological Deterioration in Acute Ischemic Stroke Patients Independent of Inflammatory Mediators: A Hospital-Based Prospective Study

Background and Aims. Metabolic syndrome (MetS) has been associated with occurrence and prognosis of ischemic stroke. This study aimed to evaluate whether an association exists between MetS and early neurological deterioration (END) following acute ischemic stroke and the possible role inflammatory biomarkers play. Methods and Results. We conducted a prospective cohort investigation that involved 208 stroke patients within 48 hours from symptom onset. MetS was determined by the modified National Cholesterol Education Program/Adult Treatment Panel III criteria. END was defined as an increase of ⩾1 point in motor power or ⩾2 points in the total National Institutes of Health Stroke Scale (NIHSS) score within 7 days. Univariate logistic regression analysis showed that patients with MetS had a 125% increased risk of END (OR 2.25; 95% CI 1.71–4.86, P = 0.005). After adjustment for fibrinogen and high-sensitivity C-reactive protein, MetS remained significantly correlated to END (OR 2.20; 95% CI 1.10–4.04, P = 0.026) with a 77% elevated risk per additional MetS trait (OR 1.77; 95% CI 1.23–2.58, P = 0.002). Conclusions. This study demonstrated that MetS may be a potential predictor for END after ischemic stroke, which was independent of raised inflammatory mediators.

A Simple Geometric Assessment of Perfusion Lesion Volume at Hyperacute Stage of Ischemic Stroke in Patients with Symptomatic Steno-Occlusion of Major Cerebral Arteries and Risk of Subsequent Cerebral Ischemic Events

Our objective is to elucidate the association of baseline perfusion lesion volume on perfusion-weighted magnetic resonance imaging (PWI) obtained at hyperacute stage of ischemic stroke with subsequent cerebral ischemic events (SIEs) in patients with symptomatic steno-occlusion of major cerebral arteries. Using a prospective stroke registry database, patients arriving within 24 hours of onset with symptomatic steno-occlusion of major supratentorial cerebral arteries were identified. On baseline PWI, time-to-peak lesion volume (TTP-LV) was determined by a simple geometric method and dichotomized into the highest tertile (large) and the other tertiles (small to medium) according to the vascular territory of occluded arteries. Primary outcome was a time to SIE up to 1 year after stroke onset. A total of 385 patients (a median time delay from onset to arrival, 2.2 hours) were enrolled. During the first year of stroke, the SIE rate of the large TTP-LV group was twice that of the small-to-medium TTP-LV group (35.7% versus 17.4%; P < .001). Large TTP-LV independently raised the hazard of SIE (hazard ratio, 2.24; 95% confidence interval, 1.45-3.44). This study demonstrates that TTP-LV on PWI measured through a simple geometric method at an emergency setting can be used to predict progression or recurrence of ischemic stroke in patients with symptomatic steno-occlusion of major cerebral arteries.

Recommendations for management of large hemispheric infarction

PURPOSE OF REVIEW

Large hemispheric infarction is a devastating disease that continues to be associated with significant mortality and morbidity. Most often these patients are admitted to the ICU requiring significant physician and nursing resources. This review will address some of the ICU management issues and review the evidence supporting medical and surgical management of malignant cerebral edema.

RECENT FINDINGS

The most recent changes in management of large hemispheric infarct include the American Heart Association and Neurocritical Care Guidelines. These guidelines address airway management and mechanical ventilation, blood pressure control, fluid management, and glucose and temperature control. In addition, they addressed the indication for surgical management of cerebral edema. We review the recent guidelines updates and trials of surgical management of large hemispheric infarcts.

SUMMARY

Large hemispheric infarcts continue to have significant morbidity and mortality. Recent guidelines have provided an excellent framework to help intensivists manage these complicated patients. Recent surgical data continue to support early hemicraniectomy even in elderly patients.

[Neurovisualisation predictors of malignant cerebral infarction and hemorrhagic transformation]

Neuroimaging plays a central role in the assessment of patients with acute ischemic stroke. Within a few minutes, modern multimodal imaging protocols can provide one with comprehensive information about prognosis, management, and outcome of the disease, and may detect changes in the intracranial structures reflecting severity of the ischemic injury depicted by four Ps: parenchyma (of the brain), pipes (i.e., the cerebral blood vessels), penumbra, and permeability (of the blood brain barrier). In this article, we have reviewed neuroradiological predictors of malignant middle cerebral artery infarction and hemorrhagic transformation in light of the aforementioned four Ps.

Validity of shape as a predictive biomarker of final infarct volume in acute ischemic stroke

BACKGROUND AND PURPOSE

This study examines whether lesion shape documented on magnetic resonance diffusion-weighted imaging during acute stroke improves the prediction of the final infarct volume compared with lesion volume only.

METHODS

Diffusion-weighted imaging data and clinical information were retrospectively reviewed in 110 consecutive patients who underwent (n=67) or not (n=43) thrombolytic therapy for acute ischemic stroke. Three-dimensional shape analysis was performed on admission diffusion-weighted imaging data and 5 shape descriptors were developed. Final infarct volume was measured on T2-fluid-attenuated inversion recovery imaging data performed 30 days after stroke.

RESULTS

Shape analysis of acute ischemic lesion and more specifically the ratio of the bounding box volume to the lesion volume before thrombolytic treatment improved the prediction of the final infarct for patients undergoing thrombolysis (R(2)=0.86 in model with volume; R(2)=0.98 in model with volume and shape).

CONCLUSIONS

Our findings suggest that lesion shape contains important predictive information and reflects important environmental factors that might determine the progression of ischemia from the core.

Incidence, causes and predictors of neurological deterioration occurring within 24 h following acute ischaemic stroke: a systematic review with pathophysiological implications

Early neurological deterioration (END) following ischaemic stroke is a serious event with manageable causes in only a fraction of patients. The incidence, causes and predictors of END occurring within 24 h of acute ischaemic stroke (END24) have not been systematically reviewed. We systematically reviewed Medline and Embase from January 1990 to April 2013 for all studies on END24 following acute ischaemic stroke (<8 h from onset). We recorded the incidence and presumed causes of and factors associated with END24. Thirty-six studies were included. Depending on the definition used, the incidence of END24 markedly varied among studies. Using the most widely used change in National Institutes of Health Stroke Scale ≥4 definition, the pooled incidence was 13.8% following thrombolysis, ascribed to intracranial haemorrhage and malignant oedema each in ∼20% of these. As other mechanisms were rarely reported, in the majority no clear cause was identified. Few data on END24 occurring in non-thrombolysed patients were available. Across thrombolysed and non-thrombolysed samples, the strongest and most consistent admission predictors were hyperglycaemia, no prior aspirin use, prior transient ischaemic attacks, proximal arterial occlusion and presence of early CT changes, and the most consistent 24 h follow-up associated factors were no recanalisation/reocclusion, large infarcts and intracranial haemorrhage. Finally, END24 was strongly predictive of poor outcome. The above findings are discussed with emphasis on END without a clear mechanism. Data on incidence and predictors of the latter subtype is scarce, and future studies using systematic imaging protocols should address its underlying pathophysiology. This may in turn lead to rational preventative and therapeutic measures for this ominous event.

Hemodynamic factors may play a critical role in neurological deterioration occurring within 72 hrs after lacunar stroke

Background

Whether a perfusion defect exists in lacunar infarct and whether it is related to early neurological deterioration (END) is still under debate. The aim of this study was to evaluate whether END in lacunar infarct is related to a perfusion defect using diffusion-weighted imaging (DWI), diffusion tensor imaging (DTI) and perfusion MR imaging.

Methods

One hundred and forty-one consecutive patients had an MRI scan within 30 hours after onset of symptoms and 43 patients with acute lacunar infarct and classic lacunar syndrome were recruited. The MRI sequences included DWI, DTI and cerebral blood flow (CBF) maps to respectively represent the topographic locations of acute infarcts, the corticospinal tract and perfusion defects. The END was defined in reference to the National Institute of Health Stroke Scale (NIHSS) as an increase ≧2 within 72 hours. Cohen's Kappa coefficient was used to examine the reliability between the 2 image readers. A multivariate logistic regression model was constructed adjusting for baseline variables.

Results

Ten out of the 43 patients had END. Patients having END was significantly associated with lower chances of favorable and good outcomes at 3 months (p = 0.01 and p = 0.002, respectively). END was predicted when the non-core hypoperfused area overlapped on the corticospinal tract, which is defined as the expected END profile. Cohen's Kappa coefficient between the 2 image readers to define images of expected END profiles was 0.74. In 15 patients with expected END profile, 9 had END clinically, whereas 28 patients had no expected END profile, and only 1 patient had END (p<0.0001). After adjusting for sex, the expected END profile was still associated with END (odds ratio, 42.2; p = 0.002).

Conclusion

Our study demonstrated that the END in acute lacunar stroke is likely related to the transformation of non-core hypoperfused area into infarction in the anatomy of corticospinal tracts.

Multimodal CT versus MRI in Selecting Acute Stroke Patients for Endovascular Treatment

Arterial revascularization is the most effective therapy for acute stroke patients. Systemic thrombolysis with recombinant tissue plasminogen activator based on baseline non-contrast CT (NCCT) imaging criteria is the only treatment approved to date, which is limited by severe timing and medical restrictions, and a narrow efficacy. The simple imaging methodology required contrast with the current wide range of imaging modalities available, which permits the physician to rapidly obtain an estimation of the most relevant pathophysiological factors involved in an acute stroke, overcoming the limited capability of NCCT. Multimodal CT and MRI combine techniques that aim to depict the neurovasculature and the status of the brain parenchyma, including the presence of hemorrhage and infarction, as well as the viability of the cerebral ischemic areas involved. These additional imaging procedures have been explored in clinical studies and trials to guide intravenous thrombolysis in acute stroke patients beyond the currently established time windows, with inconclusive results. However, emergent endovascular materials and techniques are evolving, showing promising results with increasing rates of arterial recanalization with an acceptable safety profile, therefore becoming a potential alternative and complimentary treatment, although the current lack of a high level of evidence is limiting their use in routine clinical practice. Nevertheless, these advanced neuroimaging methods can be used to improve the selection of candidates for these novel invasive therapies and, moreover, to help the interventionist to design a faster and safer procedure. In this article, we review the basic aspects of both CT and MRI modalities and the state of the evidence of these imaging tools to guide endovascular therapy, as well as the advantages and disadvantages of each method.

Infarct volume prediction using apparent diffusion coefficient maps during middle cerebral artery occlusion and soon after reperfusion in the rat

Middle cerebral artery occlusion (MCAO) in rodents causes brain infarctions of variable sizes that depend on multiple factors, particularly in models of ischemia/reperfusion. This is a major problem for infarct volume comparisons between different experimental groups since unavoidable variability can induce biases in the results and imposes the use of large number of subjects. MRI can help to minimize these difficulties by ensuring that the severity of ischemia is comparable between groups. Furthermore, several studies showed that infarct volumes can be predicted with MRI data obtained soon after ischemia onset. However, such predictive studies require multiparametric MRI acquisitions that cannot be routinely performed, and data processing using complex algorithms that are often not available. The aim here was to provide a simplified method for infarct volume prediction using apparent diffusion coefficient (ADC) data in a model of transient MCAO in rats. ADC images were obtained before, during MCAO and after 60 min of reperfusion. Probability histograms were generated using ADC data obtained either during MCAO, after reperfusion, or both combined. The results were compared to real infarct volumes, i.e.T2 maps obtained at day 7. Assessment of the performance of the estimations showed better results combining ADC data obtained during occlusion and at reperfusion. Therefore, ADC data alone can provide sufficient information for a reasonable prediction of infarct volume if the MRI information is obtained both during the occlusion and soon after reperfusion. This approach can be used to check whether drug administration after MRI acquisition can change infarct volume prediction.

Unexplained Early Neurological Deterioration After Intravenous Thrombolysis

Background and Purpose—

Early neurological deterioration (END) after anterior circulation stroke is a serious clinical event strongly associated with poor outcome. Regarding specifically END occurring within 24 hours of intravenous recombinant tissue-type plasminogen activator, apart from definite causes such as symptomatic intracranial hemorrhage and malignant edema whose incidence, predictors, and clinical management are well established, little is known about END without clear mechanism (END unexplained ).

Methods—

We analyzed 309 consecutive patients thrombolysed intravenously ≤4.5 hours from onset of anterior circulation stroke. END unexplained was defined as a ≥4-point deterioration on 24-hour National Institutes of Health Stroke Scale, without definite mechanism on concomitant imaging. END unexplained and no-END patients were compared for pretreatment clinical and imaging (including magnetic resonance diffusion and diffusion/perfusion mismatch volumes) data and 24-hour post-treatment clinical (including blood pressure and glycemic changes) and imaging (24-hour recanalization) data, using univariate logistic regression. Exploratory multivariate analysis was also performed after variable reduction, with bootstrap analysis for internal validation.

Results—

Among 33 END patients, 23 (7% of whole sample) had END unexplained . END unexplained was associated with poor 3-month outcome ( P <0.01). In univariate analysis, admission predictors of END unexplained included no prior use of antiplatelets ( P =0.02), lower National Institutes of Health Stroke Scale score ( P <0.01), higher glycemia ( P =0.03), larger mismatch volume ( P =0.03), and proximal occlusion ( P =0.01), with consistent results from the multivariate analysis. Among factors recorded during the first 24 hours, only no recanalization was associated with END unexplained in multivariate analysis ( P =0.02).

Conclusions—

END unexplained affected 7% of patients and accounted for most cases of END. Several predictors and associated factors were identified, with important implications regarding underlying mechanisms and potential prevention of this ominous event.

Imaging predictors of outcome following intravenous thrombolysis in acute stroke

Intravenous tissue plasminogen activator is the only approved medical treatment for patients with acute ischemic stroke. While it is associated with excellent clinical outcome in about 30 %, even with timely thrombolysis administration, certain strokes continue to evolve and lead to poor outcomes. Several studies have attempted to identify predictors of outcome despite timely thrombolysis. Persistence of a proximal clot burden and large vessel occlusion following thrombolysis are markers for patients who may potentially benefit from advanced treatment modalities like intra-arterial thrombolysis and thrombectomy. Timely brain imaging and interpretation play a crucial role in providing these treatment decisions. In this review, various imaging predictors of poor outcome among patients with acute ischemic stroke treated with intravenous thrombolysis are outlined. Despite identification of these imaging predictors, thrombolysis should not be withheld, as it may still be beneficial in a subset of patients. Knowledge of these predictors may set benchmarks for selecting candidates who may potentially benefit from advanced management strategies in future trials.

Recommendations for the management of cerebral and cerebellar infarction with swelling: a statement for healthcare professionals from the American Heart Association/American Stroke Association

BACKGROUND AND PURPOSE

There are uncertainties surrounding the optimal management of patients with brain swelling after an ischemic stroke. Guidelines are needed on how to manage this major complication, how to provide the best comprehensive neurological and medical care, and how to best inform families facing complex decisions on surgical intervention in deteriorating patients. This scientific statement addresses the early approach to the patient with a swollen ischemic stroke in a cerebral or cerebellar hemisphere.

METHODS

The writing group used systematic literature reviews, references to published clinical and epidemiology studies, morbidity and mortality reports, clinical and public health guidelines, authoritative statements, personal files, and expert opinion to summarize existing evidence and to indicate gaps in current knowledge. The panel reviewed the most relevant articles on adults through computerized searches of the medical literature using MEDLINE, EMBASE, and Web of Science through March 2013. The evidence is organized within the context of the American Heart Association framework and is classified according to the joint American Heart Association/American College of Cardiology Foundation and supplementary American Heart Association Stroke Council methods of classifying the level of certainty and the class and level of evidence. The document underwent extensive American Heart Association internal peer review.

RESULTS

Clinical criteria are available for hemispheric (involving the entire middle cerebral artery territory or more) and cerebellar (involving the posterior inferior cerebellar artery or superior cerebellar artery) swelling caused by ischemic infarction. Clinical signs that signify deterioration in swollen supratentorial hemispheric ischemic stroke include new or further impairment of consciousness, cerebral ptosis, and changes in pupillary size. In swollen cerebellar infarction, a decrease in level of consciousness occurs as a result of brainstem compression and therefore may include early loss of corneal reflexes and the development of miosis. Standardized definitions should be established to facilitate multicenter and population-based studies of incidence, prevalence, risk factors, and outcomes. Identification of patients at high risk for brain swelling should include clinical and neuroimaging data. If a full resuscitative status is warranted in a patient with a large territorial stroke, admission to a unit with neurological monitoring capabilities is needed. These patients are best admitted to intensive care or stroke units attended by skilled and experienced physicians such as neurointensivists or vascular neurologists. Complex medical care includes airway management and mechanical ventilation, blood pressure control, fluid management, and glucose and temperature control. In swollen supratentorial hemispheric ischemic stroke, routine intracranial pressure monitoring or cerebrospinal fluid diversion is not indicated, but decompressive craniectomy with dural expansion should be considered in patients who continue to deteriorate neurologically. There is uncertainty about the efficacy of decompressive craniectomy in patients ≥60 years of age. In swollen cerebellar stroke, suboccipital craniectomy with dural expansion should be performed in patients who deteriorate neurologically. Ventriculostomy to relieve obstructive hydrocephalus after a cerebellar infarct should be accompanied by decompressive suboccipital craniectomy to avoid deterioration from upward cerebellar displacement. In swollen hemispheric supratentorial infarcts, outcome can be satisfactory, but one should anticipate that one third of patients will be severely disabled and fully dependent on care even after decompressive craniectomy. Surgery after a cerebellar infarct leads to acceptable functional outcome in most patients.

CONCLUSIONS

Swollen cerebral and cerebellar infarcts are critical conditions that warrant immediate, specialized neurointensive care and often neurosurgical intervention. Decompressive craniectomy is a necessary option in many patients. Selected patients may benefit greatly from such an approach, and although disabled, they may be functionally independent.

Collateral therapeutics for cerebral ischemia

Current therapeutic strategies for acute ischemic stroke focus on vessel recanalization or penumbral neuroprotection without consideration of collaterals. Collateral circulation defines the extent of the ischemic penumbra, providing blood flow to tissues at risk of infarction downstream from an occluded artery. Therefore, leptomeningeal collaterals are a principal delivery route for oxygen, nutrients and potential therapeutic agents. Understanding of collateral anatomy and physiology is essential for the development of effective stroke treatments. Diagnostic imaging modalities may illustrate the penumbra from the collateral perspective, defining regions of relative ischemic vulnerability. Although specific collateral therapeutics are unrealized, insight may be gleaned from subtle details of prior stroke studies. Future advances will result from nascent research in therapeutic arteriogenesis and gene therapy adapted to the specific features of the cerebral circulation.

[Multimodal imaging protocols and their predictive role in acute stroke functional outcome]

Brain imaging plays a central role in the assessment of patients with acute ischemic stroke. Within a few minutes, modern multimodal imaging protocols can provide one with comprehensive information about prognosis, management, and outcome of the disease, and may detect changes in the intracranial structures reflecting severity of the ischemic injury depicted by four Ps: parenchyma (of the brain), pipes (i.e., the cerebral blood vessels), penumbra, and permeability (of the blood brain barrier). In this article, we have reviewed neuroradiological predictors of stroke functional outcome in the light of the aforementioned four Ps.

The role of citicoline in neuroprotection and neurorepair in ischemic stroke

Advances in acute stroke therapy resulting from thrombolytic treatment, endovascular procedures, and stroke units have improved significantly stroke survival and prognosis; however, for the large majority of patients lacking access to advanced therapies stroke mortality and residual morbidity remain high and many patients become incapacitated by motor and cognitive deficits, with loss of independence in activities of daily living. Therefore, over the past several years, research has been directed to limit the brain lesions produced by acute ischemia (neuroprotection) and to increase the recovery, plasticity and neuroregenerative processes that complement rehabilitation and enhance the possibility of recovery and return to normal functions (neurorepair). Citicoline has therapeutic effects at several stages of the ischemic cascade in acute ischemic stroke and has demonstrated efficiency in a multiplicity of animal models of acute stroke. Long-term treatment with citicoline is safe and effective, improving post-stroke cognitive decline and enhancing patients' functional recovery. Prolonged citicoline administration at optimal doses has been demonstrated to be remarkably well tolerated and to enhance endogenous mechanisms of neurogenesis and neurorepair contributing to physical therapy and rehabilitation.