Outcomes in severe middle cerebral artery ischemic stroke

Clinical course, causes of worsening, and outcomes of severe ischemic stroke: A prospective multicenter cohort study

BACKGROUND

Severe stroke has high rates of mortality and morbidity. This study aimed to investigate the clinical course, causes of worsening, and outcomes of severe ischemic stroke.

METHODS

This prospective, multicenter cohort study enrolled adult patients admitted ≤30 days after ischemic stroke from nine hospitals in China between September 2017 and December 2019. Severe stroke was defined as a score of ≥15 on the National Institutes of Health Stroke Scale (NIHSS). Clinical worsening was defined as an increase of 4 in the NIHSS score from baseline. Unfavorable functional outcome was defined as a modified Rankin scale score ≥3 at 3 months and 1 year. We per-formed logistic regression to explore baseline features and reperfusion therapies associated with clinical worsening and functional outcomes.

RESULTS

Among 4201 patients enrolled, 854 patients (20.33%) had severe stroke on admission. Of 3347 patients without severe stroke on admission, 142 (4.24%) patients developed severe stroke in hospital. Of 854 patients with severe stroke on admission, 33.95% (290/854) experienced clinical worsening (time from stroke onset median: 43 h, interquartile range [IQR]: 20-88 h), with brain edema (54.83% [159/290]) as the leading cause; 24.59% (210/854) of these patients died by 30 days, and 81.47% (677/831) and 78.44% (633/807) had unfavorable functional outcomes at 3 months and 1 year, respectively. Reperfusion reduced the risk of worsening (adjusted odds ratio [OR]: 0.24, 95% confidence interval [CI]: 0.12-0.49, P <0.01), 30-day death (adjusted OR: 0.22, 95% CI: 0.11-0.41, P <0.01), and unfavorable functional outcomes at 3 months (adjusted OR: 0.24, 95% CI: 0.08-0.68, P <0.01) and 1 year (adjusted OR: 0.17, 95% CI: 0.06-0.50, P <0.01).

CONCLUSIONS

Approximately one-fifth of patients with ischemic stroke had severe neurological deficits on admission. Clinical worsening mainly occurred in the first 3 days after stroke onset, with brain edema as the leading cause of worsening. Reperfusion reduced the risk of clinical worsening and improved functional outcomes.

REGISTRATION

ClinicalTrials.gov, NCT03222024.

Automated quantitative pupillometry as a predictor for transtentorial brain herniation in patients with malignant acute ischemic stroke

Brain herniation can be a life-threatening condition, resulting in poor prognosis and higher fatality rates. We examined whether quantitative characteristics of sequential pupillary light reflex (PLR) could serve as biomarkers for identifying brain herniation in fatal acute stroke cases with anterior circulation involvement admitted to neurological intensive care unit (Neuro-ICU). Automatic pupillometer assessed PLR automatically every 4-6 hours, measuring eight specific features: NPi (Neurological pupil index) score, initial resting and constriction pupil size, constriction change, constriction velocity, constriction latency, and dilation velocity. Generalized estimating equations were used to analyze the main effects of assessment time (3-to-0 hours, just before brain herniation, and 27-to-21 hours, considerably before) and clinical groups. The study involved 59 patients (mean age 68.8 ± 1.6 years, 23 females) divided into herniation (n = 10) and non-herniation (n = 49) groups. The herniation group exhibited significantly lower ipsilateral NPi scores at 3-to-0 hours (1.80 ± 0.44, p < 0.0001) compared to 27-to-21 hours (4.26 ± 2.21). Additionally, the herniation group had a larger ipsilateral pupil size at constriction at 3-to-0 hours (4.01 ± 0.40 mm) compared to 27-to-21 hours (2.11 ± 0.17 mm). Specifically, at 3-to-0 hours, the herniation group had lower NPi scores (1.80 ± 0.44 vs. 3.97 ± 0.13, p < 0.0001) and larger pupil size at constriction (4.01 ± 0.04 mm vs. 2.90 ± 0.10 mm, p = 0.007) compared to the non-herniation group. These findings suggest that evaluating PLR characteristics can aid in the early identification of brain herniation, facilitating timely triage and appropriate surgical management.

Resistin and In-Hospital Mortality in Patients with Acute Ischemic Stroke: A Prospective Study

Background/Objectives: Understanding the prognostic factors of acute ischemic stroke (AIS) is essential for improving patient outcomes. The aim of this study was to establish the predictive role of plasmatic resistin and leptin on short-term mortality in adult patients with a first episode of AIS. Methods: This study enrolled 277 patients who were consecutively hospitalized for AIS. Demographic data, cardiovascular risk, comorbidities, and laboratory tests were collected. Death was noted if it occurred during hospitalization. Results: Death was recorded in 33 (11.9%) patients. Conducting multivariate analysis, the following variables were independent variables associated with in-hospital mortality: a resistin value of >11 ng/mL (OR 10.81 (95%CI 2.31;50.57), p = 0.002), a lesion volume of >18.8 mL (OR 4.87 (95%CI 1.87;12.67), p = 0.001), a NIHSS score of >7 (OR 5.88 (95%CI 2.01;17.16), p = 0.001), and the presence of IHD (OR 4.33 (95%CI 1.66;11.27), p = 0.003). This study has some limitations: single-center design (which may affect the generalizability of the results) and the potential impact of the COVID-19 pandemic on patient outcomes. Conclusions: This study demonstrated that resistin is a significant predictor of in-hospital mortality in AIS patients. Other established factors, such as a high NIHSS score, large lesion volume, and the presence of IHD, were reaffirmed as important predictors.

Automatic segmentation of hemispheric CSF on MRI using deep learning: Quantifying cerebral edema following large hemispheric infarction

Background and objective

Cerebral edema (CED) is a serious complication of acute ischemic stroke (AIS), especially in patients with large hemispheric infarction (LHI). Herein, a deep learning-based approach is implemented to extract CSF from T2-Weighted Imaging (T2WI) and evaluate the relationship between quantified cerebrospinal fluid and outcomes.

Methods

Patients with acute LHI who underwent magnetic resonance imaging (MRI) were included. We used a deep learning algorithm to segment the CSF from T2WI. The hemispheric CSF ratio was calculated to evaluate its relationship with the degree of brain edema and prognosis in patients with LHI.

Results

For the 93 included patients, the left and right cerebrospinal fluid regions were automatically extracted with a mean Dice similarity coefficient of 0.830. Receiver operating characteristic analysis indicated that hemispheric CSF ratio was an accurate marker for qualitative severe cerebral edema (area under receiver-operating-characteristic curve 0.867 [95% CI, 0.781-0.929]). Multivariate logistic regression analysis of functional prognosis showed that previous stroke (OR = 5.229, 95% CI 1.013-26.984), ASPECT≤6 (OR = 13.208, 95% CI 1.136-153.540) and low hemispheric CSF ratio (OR = 0.966, 95% CI 0.937-0.997) were significantly associated with higher chances for unfavorable functional outcome in patients with LHI.

Conclusions

Automated assessment of CSF volume provides an objective biomarker of cerebral edema that can be leveraged to quantify the degree of cerebral edema and confirm its predictive effect on outcomes after LHI.

Task-dependent Alteration in Delta Band Corticomuscular Coherence during Standing in Chronic Stroke Survivors

Balance control is an important indicator of mobility and independence in activities of daily living. How the changes in functional integrity of corticospinal tract due to stroke affects the maintenance of upright stance remains to be known. We investigated the changes in functional coupling between the cortex and lower limb muscles during a challenging balance task over multiple frequency bands in chronic stroke survivors. Eleven stroke patients and nine healthy controls performed a challenging balance task. They stood on a computerized platform with/without somatosensory input distortion created by sway-referencing the support surface, thereby varying the difficulty levels of the task. We computed corticomuscular coherence between Cz (electroencephalography) and leg muscles and assessed balance performance using Berg Balance scale (BBS), Timed-up and go (TUG) and center of pressure (COP) measures. We found lower delta frequency band coherence in stroke patients when compared with healthy controls under medium difficulty condition for distal but not proximal leg muscles. For both groups, we found similar coherence at other frequency bands. On BBS and TUG, stroke patients showed poor balance. However, similar group differences were not consistently observed across COP measures. The presence of distal versus proximal effect suggests differences in the (re)organization of the corticospinal connections across the two muscles groups for balance control. We argue that the observed group difference in the delta coherence might be due to altered mechanisms for the detection of somatosensory modulation resulting from sway-referencing of the support platform for balance control.

Targeting foam cell formation to improve recovery from ischemic stroke

Inflammation is a crucial part of the healing process after an ischemic stroke and is required to restore tissue homeostasis. However, the inflammatory response to stroke also worsens neurodegeneration and creates a tissue environment that is unfavorable to regeneration for several months, thereby postponing recovery. In animal models, inflammation can also contribute to the development of delayed cognitive deficits. Myeloid cells that take on a foamy appearance are one of the most prominent immune cell types within chronic stroke infarcts. Emerging evidence indicates that they form as a result of mechanisms of myelin lipid clearance becoming overwhelmed, and that they are a key driver of the chronic inflammatory response to stroke. Therefore, targeting lipid accumulation in foam cells may be a promising strategy for improving recovery. The aim of this review is to provide an overview of current knowledge regarding inflammation and foam cell formation in the brain in the weeks and months following ischemic stroke and identify targets that may be amenable to therapeutic intervention.

Radiomics analysis for predicting malignant cerebral edema in patients undergoing endovascular treatment for acute ischemic stroke

PURPOSE

Radiomics analysis is a promising image analysis technique. This study aims to extract a radiomics signature from baseline computed tomography (CT) to predict malignant cerebral edema (MCE) in patients with acute anterior circulation infarction after endovascular treatment (EVT).

METHODS

In this retrospective study, 111 patients underwent EVT for acute ischemic stroke caused by middle cerebral artery (MCA) and/or internal carotid artery occlusion. The participants were randomly divided into two datasets: the training set (n = 77) and the test set (n = 34). The clinico-radiological profiles of all patients were collected, including cranial non-contrast-enhanced CT, CT angiography, and CT perfusion. The MCA territory on non-contrast-enhanced CT images was segmented, and the radiomics features associated with MCE were analyzed. The clinico-radiological parameters related to MCE were also identified. In addition, a routine visual radiological model based on radiological factors and a combined model comprising radiomics features and clinico-radiological factors were constructed to predict MCE.

RESULTS

The areas under the curve (AUCs) of the radiomics signature for predicting MCE were 0.870 (P < 0.001) and 0.837 (P = 0.002) in the training and test sets, respectively. The AUCs of the routine visual radiological model were 0.808 (P < 0.001) and 0.813 (P = 0.005) in the training and test sets, respectively. The AUCs of the model combining the radiomics signature and clinico-radiological factors were 0.924 (P < 0.001) and 0.879 (P = 0.001) in the training and test sets, respectively.

CONCLUSION

A CT image-based radiomics signature is a promising tool for predicting MCE in patients with acute anterior circulation infarction after EVT. For clinicians, it may assist in diagnostic decision-making.

Cerebrospinal fluid volume improves prediction of malignant edema after endovascular treatment of stroke

BACKGROUND

The ratio of intracranial cerebrospinal fluid (CSF) volume to intracranial volume (ICV) has been identified as a potential predictor of malignant edema formation in patients with acute ischemic stroke.

AIMS

We aimed to evaluate the added value of the CSF/ICV ratio in a model to predict malignant edema formation in patients who underwent endovascular treatment.

METHODS

We included patients from the MR CLEAN Registry, a prospective national multicenter registry of patients who were treated with endovascular treatment between 2014 and 2017 because of acute ischemic stroke caused by large vessel occlusion. The CSF/ICV ratio was automatically measured on baseline thin-slice noncontrast CT. The primary outcome was the occurrence of malignant edema based on clinical and imaging features. The basic model included the following predictors: age, National Institutes of Health Stroke Scale, Alberta Stroke Program Early CT score, occlusion of the internal carotid artery, collateral score, time between symptom onset and groin puncture, and unsuccessful reperfusion. The extended model included the basic model and the CSF/ICV ratio. The performance of the basic and the extended model was compared with the likelihood ratio test.

RESULTS

Malignant edema occurred in 40 (6%) of 683 patients. In the extended model, a lower CSF/ICV ratio was associated with the occurrence of malignant edema (odds ratio (OR) per percentage point, 1.2; 95% confidence interval (CI) 1.1-1.3, p < 0.001). Age lost predictive value for malignant edema in the extended model (OR 1.1; 95% CI 0.9-1.5, p = 0.372). The performance of the extended model was higher than that of the basic model (p < 0.001).

CONCLUSIONS

Adding the CSF/ICV ratio improves a multimodal prediction model for the occurrence of malignant edema after endovascular treatment.

Investigating the Precise Localization of the Grasping Action in the Mid-Cingulate Cortex and Future Directions

Objective

To prospectively study the cingulate cortex for the localization and role of the grasping action in humans during electrical stimulation of depth electrodes.

Methods

All the patients (n = 23) with intractable focal epilepsy and a depth electrode stereotactically placed in the cingulate cortex, as part of their pre-surgical epilepsy evaluation from 2015 to 2017, were included. Cortical stimulation was performed and examined for grasping actions. Post-implantation volumetric T1 MRIs were co-registered to determine the exact electrode position.

Results

Five patients (male: female 4:1; median age 31) exhibited contralateral grasping actions during electrical stimulation. All patients had electrodes implanted in the ventral bank of the right cingulate sulcus adjacent to the vertical anterior commissure (VAC) line. Stimulation of other electrodes in adjacent regions did not elicit grasping.

Conclusion

Grasping action elicited from a localized region in the mid-cingulate cortex (MCC) directly supports the concept of the cingulate cortex being crucially involved in the grasping network. This opens an opportunity to explore this region with deep brain stimulation as a motor neuromodulation target for treatment in specific movement disorders or neurorehabilitation.

Targeting Sensory and Motor Integration for Recovery of Movement After CNS Injury

The central nervous system (CNS) integrates sensory and motor information to acquire skilled movements, known as sensory-motor integration (SMI). The reciprocal interaction of the sensory and motor systems is a prerequisite for learning and performing skilled movement. Injury to various nodes of the sensorimotor network causes impairment in movement execution and learning. Stimulation methods have been developed to directly recruit the sensorimotor system and modulate neural networks to restore movement after CNS injury. Part 1 reviews the main processes and anatomical interactions responsible for SMI in health. Part 2 details the effects of injury on sites critical for SMI, including the spinal cord, cerebellum, and cerebral cortex. Finally, Part 3 reviews the application of activity-dependent plasticity in ways that specifically target integration of sensory and motor systems. Understanding of each of these components is needed to advance strategies targeting SMI to improve rehabilitation in humans after injury.

Long-Term Functionality Prediction for First Time Ischemic Middle Cerebral Artery Stroke Patients Receiving Conventional Medical Treatment

BACKGROUND

Middle cerebral artery (MCA) ischemic stroke poses a major threat to human beings and prompts intravenous thrombolytic and/or thrombectomy management remains the gold standard treatment. However, not all MCA stroke patients fit in the inclusion and exclusion criteria that many patients only receive conventional medical therapy. We attempt to seek the baseline parameters that can effectively predict patients' long-term functionality, as well as hypothesizing that the carotid duplex derived resistance/pulsatility index might be capable of fulfilling this purpose.

METHODS

The 741 MCA ischemic stroke patients have been retrospectively recruited for the project. Under the initial screening, matching the inclusion and exclusion criteria, there are 471 participants to be enrolled in the study. The patients' basic information, along with outcome assessments, pre-admission Barthel index and NIHSS score, and pre- and post-treatment mRS are recorded. All statistical analyses were performed using R for Windows (version 3.6.3). The significance level was set at P < 0.05 for all analyses.

RESULTS

Of the 471 patients, 239 participants show a net mRS improvement, whereas the other 232 show deterioration. Hyperlipidaemia, chronic kidney disease, and dementia are related to long-term functionality improvement. The multivariate logistic regression analysis shows that right common carotid artery (CCA) resistance index (RI) and ischemic heart disease play a significant role in favourable outcome functionality. The ROC and Youden Index models are formulated, and it shows that Barthel Index and the NIHSS are most significant in the outcome measurement group (AUC: 0.675, 0.653; cut-off point: 57.5, 3.5, respectively). The right-side CCA RI is the solely important outcome predictor for the baseline carotid duplex study (AUC: 0.5; cut-off point: 0.785).

CONCLUSION

The favourable long-term functionality of MCA ischemic stroke patients receiving conventional medical treatment seems to correlate fairly with pre-admission NIHSS and Barthel index scores. Underlying hyperlipidaemia, chronic kidney disease, and dementia are conversely associated with favourable long-term capability. Moreover, the value of CCA RI appears to significantly alter the long-term outcomes in this group of patients.

Outcomes and resource use of patients with large hemispheric infarction and cerebral edema: analysis of real-world data

OBJECTIVE

Large hemispheric infarction (LHI) is associated with a high likelihood of the evolution of life-threatening edema. Few studies have assessed real-world clinical outcomes and management strategies among patients with LHI. The objective of this study was to describe the management, in-hospital outcomes, and direct healthcare resource burden of patients with LHI, as well as those of patients with subsequent cerebral edema.

METHODS

This observational, retrospective cohort study analyzed de-identified data from US adult patients using the IBM MarketScan Hospital Drug Database (Q4-2015 to Q4-2017). Patients were included in the "Possible LHI" or the "Other Ischemic Strokes" cohorts using ICD-10 diagnosis codes. Patients with possible LHI were further categorized into "LHI with Edema" and "LHI without Edema" subgroups using diagnosis and procedure codes. Select clinical and economic outcomes were compared between cohorts and subgroups using multivariable regressions.

RESULTS

Of 79,201 eligible encounters with ischemic strokes, 11,772 unique patients were assigned to the Possible LHI cohort while 67,429 were assigned to the Other Ischemic Strokes cohort. Among patients with possible LHI, 869 (7%) were assigned to the LHI with Edema subgroup and 10,903 (93%) were assigned to the LHI without Edema subgroup. Patients in the Possible LHI cohort had longer hospital stays (mean difference [MD] [95%CI] = 2.6 [2.4;2.8] days), higher total facility charges (MD [95%CI] = $28,656 [26,794;30,524]), and higher odds of death (odds ratio [95%CI] = 2.2 [2.0;2.4]) than the Other Ischemic Strokes cohort. Among patients with possible LHI, the incremental clinical and resource burden was further exacerbated in the subgroup of patients with edema (hospital days: MD [95%CI] = 5.0 [3.9;6.2] days; total facility charges: MD [95%CI] = $59,585 [50,816;67,583]; mortality: odds ratio [95%CI] = 10.3 [8.5;12.4]).

CONCLUSIONS

Among patients with ischemic strokes, LHI was associated with increased clinical management and direct healthcare resource burden in real-world hospital settings. The burden was substantially increased among patients who developed cerebral edema.

Exploring the predictive value of lesion topology on motor function outcomes in a porcine ischemic stroke model

Harnessing the maximum diagnostic potential of magnetic resonance imaging (MRI) by including stroke lesion location in relation to specific structures that are associated with particular functions will likely increase the potential to predict functional deficit type, severity, and recovery in stroke patients. This exploratory study aims to identify key structures lesioned by a middle cerebral artery occlusion (MCAO) that impact stroke recovery and to strengthen the predictive capacity of neuroimaging techniques that characterize stroke outcomes in a translational porcine model. Clinically relevant MRI measures showed significant lesion volumes, midline shifts, and decreased white matter integrity post-MCAO. Using a pig brain atlas, damaged brain structures included the insular cortex, somatosensory cortices, temporal gyri, claustrum, and visual cortices, among others. MCAO resulted in severely impaired spatiotemporal gait parameters, decreased voluntary movement in open field testing, and higher modified Rankin Scale scores at acute timepoints. Pearson correlation analyses at acute timepoints between standard MRI metrics (e.g., lesion volume) and functional outcomes displayed moderate R values to functional gait outcomes. Moreover, Pearson correlation analyses showed higher R values between functional gait deficits and increased lesioning of structures associated with motor function, such as the putamen, globus pallidus, and primary somatosensory cortex. This correlation analysis approach helped identify neuroanatomical structures predictive of stroke outcomes and may lead to the translation of this topological analysis approach from preclinical stroke assessment to a clinical biomarker.

Potential Therapies for Cerebral Edema After Ischemic Stroke: A Mini Review

Stroke is the leading cause of global mortality and disability. Cerebral edema and intracranial hypertension are common complications of cerebral infarction and the major causes of mortality. The formation of cerebral edema includes three stages (cytotoxic edema, ionic edema, and vasogenic edema), which involve multiple proteins and ion channels. A range of therapeutic agents that successfully target cerebral edema have been developed in animal studies, some of which have been assessed in clinical trials. Herein, we review the mechanisms of cerebral edema and the research progress of anti-edema therapies for use after ischemic stroke.

Blood pressure variability and outcome in acute severe stroke: A post hoc analysis of CHASE-A randomized controlled trial

The influence of blood pressure variability (BPV) on outcomes in patients with severe stroke is still largely unsettled. Using the data of CHASE trial, the authors calculated the BPV during the acute phase and subacute phase of severe stroke, respectively. The primary outcome was to investigate the relationship between BPV and 90‐day modified Rankin scale (mRS) ≥ 3. The BPV was assessed by eight measurements including standard deviation (SD), mean, maximum, minimum, coefficient of variation (CV), successive variation (SV), functional successive variation (FSV), and average real variability (ARV). Then, the SD of SBP was divided into quintiles and compared the quintile using logistic regression in three models. The acute phase included 442 patients, and the subacute phase included 390 patients. After adjustment, six measurements of BPV during the subacute phase rather than acute phase were strongly correlated with outcomes including minimum (odds ratio [OR]: 0.83, 95% confidence interval [CI]: 0.69‐0.99, p = .037), SD (OR: 1.10, 95% CI: 1.03‐1.17, p = .007), CV (OR: 1.12, 95% CI: 1.03‐1.23, p = .012), ARV (OR: 1.13, 95% CI: 1.05‐1.20, p < .001), SV (OR: 1.09, 95% CI: 1.04‐1.15, p = .001), and FSV (OR: 1.12, 95% CI: 1.05‐1.19, p = .001). In the logistic regression, the highest fifth of SD of SBP predicted poor outcome in all three models. In conclusion, the increased BPV was strongly correlated with poor outcomes in the subacute phase of severe stroke, and the magnitude of association was progressively increased when the SD of BP was above 12.

Middle cerebral artery territory infarction in a COVID-19 patient: a case report

Coronavirus disease 2019 (COVID-19) mainly invades the respiratory system, yet previous reports have shown unusual manifestations of COVID-19, including cerebrovascular events. However, detailed case reports are still lacking. A 57-year-old male presented with sudden unconsciousness and right side lateralization for 6 hours before hospital admission. His test results were positive for severe acute respiratory syndrome coronavirus 2 infection. The head computed tomography (CT) scan showed infarction within the middle cerebral artery region. The scan was repeated 48 hours after admission and showed a massive infarct in the left hemisphere with hemorrhagic transformation. A chest CT showed the appearance of bronchopneumonia with ground-glass opacities in both lungs. The patient's condition was rapidly deteriorating, and he died on the third day after admission. Our findings suggest that ischemic vascular events may simultaneously develop due to the progression of COVID-19. A hypercoagulable state and vascular endothelial dysfunction have been proposed as complications of COVID-19 and are risk factors of thrombotic vascular events.

Simultaneous decompressive craniectomy and caesarean section

A 24-year-old primigravid woman at 29-weeks gestation presented with headache, hypertension and proteinuria. A diagnosis of pre-eclampsia was made. Later that day she developed a left hemiparesis and neuroimaging demonstrated an intracerebral haemorrhage in the right frontal lobe as well as thrombosis of the superior sagittal sinus. She was commenced on an IV heparin infusion to manage the sinus thrombosis, and nifedipine and labetalol to treat the hypertension. GCS remained 15/15. However, 12 hours later, she became progressively agitated. Her GCS decreased to 10/15 (E3V2M5). Repeat imaging demonstrated enlargement of the haematoma, causing significant mass effect and midline shift. A decision was made to perform decompressive hemicraniectomy to save the life of the mother, and caesarean section to protect the foetus as well as providing definitive treatment of pre-eclampsia. Due to further neurological deterioration of the mother it became necessary to perform the two procedures simultaneously. We present the first reported case of decompressive craniectomy and caesarean section performed simultaneously. After discussing the case, we consider why this clinical scenario is rare and why it became necessary in this patient to perform the two procedures simultaneously.

Prediction of Malignant Acute Middle Cerebral Artery Infarction via Computed Tomography Radiomics

Malignant middle cerebral artery infarction (mMCAi) is a serious complication of cerebral infarction usually associated with poor patient prognosis. In this retrospective study, we analyzed clinical information as well as non-contrast computed tomography (NCCT) and computed tomography angiography (CTA) data from patients with cerebral infarction in the middle cerebral artery (MCA) territory acquired within 24 h from symptoms onset. Then, we aimed to develop a model based on the radiomics signature to predict the development of mMCAi in cerebral infarction patients. Patients were divided randomly into training (n = 87) and validation (n = 39) sets. A total of 396 texture features were extracted from each NCCT image from the 126 patients. The least absolute shrinkage and selection operator regression analysis was used to reduce the feature dimension and construct an accurate radiomics signature based on the remaining texture features. Subsequently, we developed a model based on the radiomics signature and Alberta Stroke Program Early CT Score (ASPECTS) based on NCCT to predict mMCAi. Our prediction model showed a good predictive performance with an AUC of 0.917 [95% confidence interval (CI), 0.863-0.972] and 0.913 [95% CI, 0.795-1] in the training and validation sets, respectively. Additionally, the decision curve analysis (DCA) validated the clinical efficacy of the combined risk factors of radiomics signature and ASPECTS based on NCCT in the prediction of mMCAi development in patients with acute stroke across a wide range of threshold probabilities. Our research indicates that radiomics signature can be an instrumental tool to predict the risk of mMCAi.

Controlling Hypertension After Severe Cerebrovascular Event (CHASE): A randomized, multicenter, controlled study

BACKGROUND

The optimal blood pressure lowering target in the acute phase of severe stroke is uncertain. Our aim was to compare the efficacy and safety of individualized blood pressure lowering with standard blood pressure lowering in severe stroke.

METHODS

Five-hundred consecutive patients with acute severe stroke and elevated BP were recruited from 26 Chinese hospitals. Eligible patients were randomized into an individualized blood pressure lowering group (with 10-15% reduction in systolic blood pressure from admission level or standard blood pressure lowering group (with a target SBP of <200 mm Hg in acute ischemic stroke and <180 mm Hg in intracerebral hemorrhage). The primary outcome was the proportion of patients with a poor functional outcome at day 90 of enrolment.

RESULTS

Of 483 participants included in the analysis, 242 received individualized blood pressure lowering treatment and 241 received standard treatment. The primary outcome event was observed in 71.1% of the participants in the individualized treatment group and in 73.4% of the standard treatment group (odds ratio with individualized treatment for primary outcome, 0.75; 95% confidence interval, 0.47 to 1.19; p = 0.222). The rates of serious adverse events in the two groups were similar (27.7% vs. 28.2%).

CONCLUSIONS

In patients with acute severe stoke, individualized blood pressure lowering treatment did not significantly reduce the rate of three-month death or dependence.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT02982655. Registered in 5 December 2016, https://clinicaltrials.gov/ct2/show/NCT02982655.

Predictors of outcome in 1-month survivors of large middle cerebral artery infarcts treated by decompressive hemicraniectomy

BACKGROUND

Decompressive hemicraniectomy (DH) increases survival without severe dependency in patients with large middle cerebral artery (LMCA) infarcts. The objective was to identify predictors of 1-year outcome after DH for LMCA infarct.

METHODS

We conducted this study in consecutive patients who underwent DH for LMCA infarcts, in a tertiary stroke centre. Using multivariable logistic regression analyses, we evaluated predictors of (1) 30-day mortality and (2) poor outcome after 1 year (defined as a modified Rankin Scale score of 4-6) in 30-day survivors.

RESULTS

Of 212 patients (133 men, 63%; median age 51 years), 35 (16.5%) died within 30 days. Independent predictors of mortality were infarct volume before DH (OR 1.10 per 10 mL increase, 95% CI 1.04 to 1.16), delay between symptom onset and DH (OR 0.41, 95% CI 0.23 to 0.73 per 12 hours increase) and midline shift after DH (OR 2.59, 95% CI 1.09 to 6.14). The optimal infarct volume cut-off to predict death was 210 mL or more. Among the 177 survivors, 77 (43.5%) had a poor outcome at 1 year. Independent predictors of poor outcome were age (OR 1.08 per 1 year increase, 95% CI 1.03 to 1.12) and weekly alcohol consumption of 300 g or more (OR 5.30, 95% CI 2.20 to 12.76), but not infarct volume.

CONCLUSION

In patients with LMCA infarcts treated by DH, stroke characteristics (infarct volume before DH, midline shift after DH and early DH) predict 30-day mortality, while patients' characteristics (age and excessive alcohol intake) predict 1-year outcome survivors.

Second-look strokectomy of cerebral infarction areas in patients with severe herniation

OBJECTIVE

Decompressive craniectomies (DCs) are performed on patients suffering large cerebral infarctions. The efficacy of this procedure has been demonstrated in several trials. In some cases, however, this procedure alone is not sufficient and patients still suffer refractory elevations of intracranial pressure (ICP). The goal of this study was to determine whether resection of infarcted tissue, termed strokectomy, performed as a second-look procedure after DC, improves outcome in selected cases.

METHODS

The authors retrospectively evaluated data of patients who underwent a DC due to a cerebral infarction at their institution from 2009 to 2016, including patients who underwent a strokectomy procedure after DC. Clinical records, imaging data, outcome scores, and neurological symptoms were analyzed, and clinical outcomes and mortality rates in the strokectomy group were compared to those for similar patients in recently published randomized controlled trials.

RESULTS

Of 198 patients who underwent DC due to cerebral infarction, 12 patients underwent strokectomy as a second surgical procedure, with a median National Institutes of Health Stroke Scale (NIHSS) score of 19 for patients with versus 16 for those without secondary strokectomy (p = 0.029). Either refractory increases of ICP > 20 mm Hg or dilated pupils in addition to herniation visible on CT images were triggers for strokectomy surgery. Ten of 12 (83%) patients had infarctions in more than one territory (p < 0.001). After 12 months, 43% of patients had a good outcome according to the modified Rankin Scale (mRS) score (≤ 3). In the subgroup of patients suffering infarctions in more than one vascular territory, functional outcome after 12 months was better (mRS ≤ 3 in 40% of patients in comparison to 9%; p = 0.027). A 1:3 case-control analysis matched to age, side of infarction, sex, and vascular territory confirmed these results (mRS ≤ 3, 42% in comparison to 11%; p = 0.032). Age, NIHSS score on admission, and number of vascular territories involved were identified as risk factors in multivariate analysis (p < 0.05). Patients in the strokectomy group had more infections (p < 0.001). According to these results, the authors developed a scale (Münster Stroke Score, 0-6 points) to predict whether patients might benefit from additional strokectomy. Receiver-operating characteristic (ROC) curve analysis revealed an area under the curve (AUC) of 0.86 (p < 0.001). The authors recommend a Münster Stroke Score of ≥ 3 as a cutoff, with a sensitivity of 92% and specificity of 66%, for predicting benefit from strokectomy.

CONCLUSIONS

In this study in comparison to former studies, mortality rates were lower and clinical outcome was comparable to that of previously published trials regarding large cerebral infarctions. Second surgery including strokectomy may help achieve better outcomes, especially in cases of infarction of more than one vascular territory.

Neural Stem Cell Extracellular Vesicles Disrupt Midline Shift Predictive Outcomes in Porcine Ischemic Stroke Model

Magnetic resonance imaging (MRI) is a clinically relevant non-invasive imaging tool commonly utilized to assess stroke progression in real time. This study investigated the utility of MRI as a predictive measure of clinical and functional outcomes when a stroke intervention is withheld or provided, in order to identify biomarkers for stroke functional outcome under these conditions. Fifteen MRI and ninety functional parameters were measured in a middle cerebral artery occlusion (MCAO) porcine ischemic stroke model. Multiparametric analysis of correlations between MRI measurements and functional outcome was conducted. Acute axial and coronal midline shift (MLS) at 24 h post-stroke were associated with decreased survival and recovery measured by modified Rankin scale (mRS) and were significantly correlated with 52 measured acute (day 1 post) and chronic (day 84 post) gait and behavior impairments in non-treated stroked animals. These results suggest that MLS may be an important non-invasive biomarker that can be used to predict patient outcomes and prognosis as well as guide therapeutic intervention and rehabilitation in non-treated animals and potentially human patients that do not receive interventional treatments. Neural stem cell–derived extracellular vesicle (NSC EV) was a disruptive therapy because NSC EV administration post-stroke disrupted MLS correlations observed in non-treated stroked animals. MLS was not associated with survival and functional outcomes in NSC EV–treated animals. In contrast to untreated animals, NSC EVs improved stroked animal outcomes regardless of MLS severity.

Decompressive hemicraniectomy for malignant middle cerebral artery infarction. Experience from the Western Province of Saudi Arabia

Objective:

To describe our experience implementing decompressive hemicraniectomy (DH) for eligible patients with malignant middle cerebral artery (MCA) infarcts.

Methods:

We retrospectively collected data of malignant MCA infarction patients requiring DH at King Abdulaziz University Hospital & King Faisal Specialist Hospital & Research Center, Jeddah, Kingdom of Saudi Arabia between October 2010 and July 2015. Clinical outcome was assessed immediately postoperatively using Glasgow Coma Score (GCS), and at 12 months using the modified Rankin scale (mRS) and Barthel index. Survival was evaluated at thirty-days and one year after surgery.

Results:

Six out of 10 patients diagnosed with malignant MCA infarction underwent DH. Among the surgically treated patients (n=6), 4 were males (66%), and the median age was 22.5 years. The median time from admission to surgery was 35.5 hours. The median post-operative GCS was 6.5. Three patients (50%) died within 30 days of DH. In those who survived, the median mRS was 4.5 and BI was 7.5.

Conclusion:

Decompressive hemicraniectomy saves life and has the potential of improving survival functional outcome when done fast and in carefully selected patients. We call for national awareness of the management of such cases and early intervention.

Intracranial Cerebrospinal Fluid Volume as a Predictor of Malignant Middle Cerebral Artery Infarction

Background and Purpose- Predicting malignant middle cerebral artery (MCA) infarction can help to identify patients who may benefit from preventive decompressive surgery. We aimed to investigate the association between the ratio of intracranial cerebrospinal fluid (CSF) volume to intracranial volume (ICV) and malignant MCA infarction. Methods- Patients with an occlusion proximal to the M3 segment of the MCA were selected from the DUST (Dutch Acute Stroke Study). Admission imaging included noncontrast computed tomography (CT), CT perfusion, and CT angiography. Patient characteristics and CT findings were collected. The ratio of intracranial CSF volume to ICV (CSF/ICV) was quantified on admission thin-slice noncontrast CT. Malignant MCA infarction was defined as a midline shift of >5 mm on follow-up noncontrast CT, which was performed 3 days after the stroke or in case of clinical deterioration. To test the association between CSF/ICV and malignant MCA infarction, odds ratios and 95% CIs were calculated for 3 multivariable models by using binary logistic regression. Model performances were compared by using the likelihood ratio test. Results- Of the 286 included patients, 35 (12%) developed malignant MCA infarction. CSF/ICV was independently associated with malignant MCA infarction in 3 multivariable models: (1) with age and admission National Institutes of Health Stroke Scale (odds ratio, 3.3; 95% CI, 1.1-11.1), (2) with admission National Institutes of Health Stroke Scale and poor collateral score (odds ratio, 7.0; 95% CI, 2.6-21.3), and (3) with terminal internal carotid artery or proximal M1 occlusion and poor collateral score (odds ratio, 7.7; 95% CI, 2.8-23.9). The performance of model 1 (areas under the receiver operating characteristic curves, 0.795 versus 0.824; P=0.033), model 2 (areas under the receiver operating characteristic curves, 0.813 versus 0.850; P<0.001), and model 3 (areas under the receiver operating characteristic curves, 0.811 versus 0.856; P<0.001) improved significantly after adding CSF/ICV. Conclusions- The CSF/ICV ratio is associated with malignant MCA infarction and has added value to clinical and imaging prediction models in limited numbers of patients.

Putting the "Sensory" Into Sensorimotor Control: The Role of Sensorimotor Integration in Goal-Directed Hand Movements After Stroke

Integration of sensory and motor information is one-step, among others, that underlies the successful production of goal-directed hand movements necessary for interacting with our environment. Disruption of sensorimotor integration is prevalent in many neurologic disorders, including stroke. In most stroke survivors, persistent paresis of the hand reduces function and overall quality of life. Current rehabilitative methods are based on neuroplastic principles to promote motor learning that focuses on regaining motor function lost due to paresis, but the sensory contributions to motor control and learning are often overlooked and currently understudied. There is a need to evaluate and understand the contribution of both sensory and motor function in the rehabilitation of skilled hand movements after stroke. Here, we will highlight the importance of integration of sensory and motor information to produce skilled hand movements in healthy individuals and individuals after stroke. We will then discuss how compromised sensorimotor integration influences relearning of skilled hand movements after stroke. Finally, we will propose an approach to target sensorimotor integration through manipulation of sensory input and motor output that may have therapeutic implications.

Computed Tomography-Based Imaging of Voxel-Wise Lesion Water Uptake in Ischemic Brain: Relationship Between Density and Direct Volumetry

OBJECTIVES

Net water uptake per volume of brain tissue may be calculated by computed tomography (CT) density, and this imaging biomarker has recently been investigated as a predictor of lesion age in acute stroke. However, the hypothesis that measurements of CT density may be used to quantify net water uptake per volume of infarct lesion has not been validated by direct volumetric measurements so far. The purpose of this study was to (1) develop a theoretical relationship between CT density reduction and net water uptake per volume of ischemic lesions and (2) confirm this relationship by quantitative in vitro and in vivo CT image analysis using direct volumetric measurements.

MATERIALS AND METHODS

We developed a theoretical rationale for a linear relationship between net water uptake per volume of ischemic lesions and CT attenuation. The derived relationship between water uptake and CT density was tested in vitro in a set of increasingly diluted iodine solutions with successive CT measurements. Furthermore, the consistency of this relationship was evaluated using human in vivo CT images in a retrospective multicentric cohort. In 50 edematous infarct lesions, net water uptake was determined by direct measurement of the volumetric difference between the ischemic and normal hemisphere and was correlated with net water uptake calculated by ischemic density measurements.

RESULTS

With regard to in vitro data, water uptake by density measurement was equivalent to direct volumetric measurement (r = 0.99, P < 0.0001; mean ± SD difference, -0.29% ± 0.39%, not different from 0, P < 0.0001). In the study cohort, the mean ± SD uptake of water within infarct measured by volumetry was 44.7 ± 26.8 mL and the mean percent water uptake per lesion volume was 22.7% ± 7.4%. This was equivalent to percent water uptake obtained from density measurements: 21.4% ± 6.4%. The mean difference between percent water uptake by direct volumetry and percent water uptake by CT density was -1.79% ± 3.40%, which was not significantly different from 0 (P < 0.0001).

CONCLUSIONS

Volume of water uptake in infarct lesions can be calculated quantitatively by relative CT density measurements. Voxel-wise imaging of water uptake depicts lesion pathophysiology and could serve as a quantitative imaging biomarker of acute infarct lesions.

Predictors of malignant brain edema after mechanical thrombectomy for acute ischemic stroke

BACKGROUND

Malignant brain edema (MBE) is a devastating complication in ischemic stroke. Data on MBE in patients who have had mechanical thrombectomy (MT) are relatively scarce.

OBJECTIVE

To investigate the incidence, predictors, and clinical outcomes of MBE in patients after MT.

METHODS

We included 130 consecutive patients after MT caused by anterior circulation large vessel occlusion stroke, treated with MT. MBE was defined as a midline shift of ≥5 mm on the follow-up imaging within 72 hours after MT. Characteristics of patients at admission and details of treatment were collected. The 90-day modified Rankin scale score was used as a measure of functional outcomes.

RESULTS

Of the 130 patients (age, 68.6±10.9 years; male, 50%), 35 (26.9%) patients developed MBE. The patients with MBE had a lower rate of functional independence (OR=7.831; 95% CI 1.731 to 35.427; p=0.008) and significantly higher mortality at 90 days (OR=7.958; 95% CI 2.274 to 27.848; p=0.001) than patients without MBE. In 104 (80%) patients with successful recanalization (modified Thrombolysis in Cerebral Infarction score of 2b-3), 24 (23.1%) patients exhibited MBE. After adjustment for confounding, ICA occlusion (OR=3.746; 95% CI 1.169 to 12.006; p=0.026) and worse collateral score (grade 1 vs grade 0: OR=0.727; 95% CI 0.192 to 2.753; p=0.638; grade 2 vs grade 0: OR=0.130; 95% CI 0.021 to 0.819; p=0.030) were significantly associated with the development of MBE, despite successful recanalization.

CONCLUSIONS

MBE after MT is not uncommon and was related to poor functional outcomes. Localization of a vessel occlusion and collateral status may play a role in the development of MBE.

Infarct Volume Predicts Hospitalization Costs in Anterior Circulation Large-Vessel Occlusion Stroke

BACKGROUND AND PURPOSE

Anterior circulation large-vessel occlusion stroke, one of the most devastating stroke subtypes, is associated with substantial economic burden. We aimed to identify predictors of increased acute care hospitalization costs associated with anterior circulation large-vessel occlusion stroke.

MATERIALS AND METHODS

Comprehensive cost-tracking software was used to calculate acute care hospitalization costs for patients with anterior circulation large-vessel occlusion stroke admitted July 2012 to October 2014. Patient demographics and stroke characteristics were analyzed, including final infarct volume on follow-up neuroimaging. Predictors of hospitalization costs were determined using multivariable linear regression including subgroup cost analyses by treatment technique (endovascular, IV tPA-only, and no reperfusion therapy) and sensitivity analyses incorporating patients initially excluded due to early withdrawal of care.

RESULTS

Three hundred forty-one patients (median age, 69 years; interquartile range, 57-80 years; median NIHSS score, 16; interquartile range, 13-21) were included in our primary analysis. Final infarct volume, parenchymal hematoma, baseline NIHSS score, ipsilateral carotid stenosis, age, and obstructive sleep apnea were significant predictors of acute care hospitalization costs. Final infarct volume alone accounted for 20.87% of the total cost variance. Additionally, final infarct volume was consistently the strongest predictor of increased cost in primary, subgroup, and sensitivity analyses.

CONCLUSIONS

Final infarct volume was the strongest predictor of increased hospitalization costs in anterior circulation large-vessel occlusion stroke. Acute stroke therapies that reduce final infarct volume may not only improve clinical outcomes but may also prove cost-effective.

Infarct volume predicts outcome after decompressive hemicraniectomy for malignant hemispheric stroke

The decision to perform decompressive hemicraniectomy (DHC) by default in malignant hemispheric stroke (MHS) remains controversial. Even under ideal conditions, DHC usually results in moderate to severe disability. The present study for the first time uses neuroimaging to identify independent outcome predictors in a prospective cohort of 96 MHS patients undergoing DHC. The primary outcome was functional status according to the modified Rankin Scale (mRS) at 12 months and categorized as favorable (mRS 0-3) or unfavorable (mRS 4-6). At 12 months, 19 patients (20%) reached favorable and 77 patients (80%) unfavorable outcome. The overall mean infarct volume was 328 ± 114 ml. Multivariable logistic regression identified age per year (OR 1.14, 95% CI 1.04-1.24; p = 0.005), infarct volume per cm³ (OR 1.012, 95% CI 1.003-1.022; p = 0.013), thalamic involvement (OR 8.65, 95% CI 1.04-72.15; p = 0.046) and postoperative pneumonia (OR 5.52, 95% CI 1.03-29.57; p = 0.046) as independent outcome predictors, which was confirmed by multivariable ordinal regression for age ( p = 0.004) and infarct volume ( p = 0.015). The infarct volume threshold for reasonable prediction of unfavorable outcome in our patients was 270 cm³, which in the future may help prognostication and development of clinical trials on DHC and outcome in MHS.

Neuroprotective delivery platforms as an adjunct to mechanical thrombectomy

Despite the success of numerous neuroprotective strategies in animal and preclinical stroke models, none have effectively translated to clinical medicine. A multitude of influences are likely responsible. Two such factors are inefficient recanalization strategies for large vessel occlusions and suboptimal delivery methods/platforms for neuroprotective agents. The recent endovascular stroke trials have established a new paradigm for large vessel stroke treatment. The associated advent of advanced mechanical revascularization devices and new stroke technologies help address each of these existing gaps. A strategy combining effective endovascular revascularization with administration of neuroprotective therapies is now practical and could have additive, if not synergistic, effects. This review outlines past and current neuroprotective strategies assessed in acute stroke trials. The discussion focuses on delivery platforms and their potential applicability to endovascular stoke treatment.

The cerebral circulation and cerebrovascular disease I: Anatomy

In this paper, which is the first in a three-part series that reviews cerebrovascular anatomy, pathogenesis, and stroke, we lay the anatomical foundation for the rest of the series. Beginning with its origin in the branches of the aorta, we start by describing the arterial system. This system is partitioned into two major divisions (anterior and posterior circulations) that differ significantly in features and pathogenic potential. The systems, and the major branches that comprise them, are described. Description of the arterial system proceeds to the point of the fulfillment of its function. This function, the exchange of gases and nutrients with the cerebral parenchyma, is the subject of a subsequent section on the microcirculation and blood-brain barrier. Finally, the cerebral venous system, which is composed of cerebral veins and dural venous sinuses, is described. Thus, an anatomical context is supplied for the discussion of cerebrovascular disease pathogenesis provided by our second paper.

Predictors of early in-hospital death after decompressive craniectomy in swollen middle cerebral artery infarction

BACKGROUND

Swollen middle cerebral artery infarction is a life-threatening disease and decompressive craniectomy is improving survival significantly. Despite decompressive surgery, however, many patients are not discharged from the hospital alive. We therefore wanted to search for predictors of early in-hospital death after craniectomy in swollen middle cerebral artery infarction.

METHODS

All patients operated with decompressive craniectomy due to swollen middle cerebral artery infarction at the Department of Neurosurgery, Oslo University Hospital Rikshospitalet, Oslo, Norway, between May 1998 and October 2010, were included. Binary logistic regression analyses were performed and candidate variables were age, sex, time from stroke onset to decompressive craniectomy, NIHSS on admission, infarction territory, pineal gland displacement, reduction of pineal gland displacement after surgery, and craniectomy size.

RESULTS

Fourteen out of 45 patients (31%) died during the primary hospitalization (range, 3-44 days). In the multivariate logistic regression model, middle cerebral artery infarction with additional anterior and/or posterior cerebral artery territory involvement was found as the only significant predictor of early in-hospital death (OR, 12.7; 95% CI, 0.01-0.77; p = 0.029).

CONCLUSIONS

The present study identified additional territory infarction as a significant predictor of early in-hospital death. The relatively small sample size precludes firm conclusions.

SUR1-Associated Mechanisms Are Not Involved in Ischemic Optic Neuropathy 1 Day Post-Injury

Ischemia-reperfusion injury after central nervous system (CNS) injury presents a major health care challenge with few promising treatments. Recently, it has become possible to reduce edema after CNS injury by antagonizing a sulfonylurea receptor 1 (SUR1) regulated ion channel expressed after injury. SUR1 upregulation after injury is a necessary precondition for the formation of this channel, and has been implicated in white matter injury after clinical spinal cord trauma. Glibenclamide, an SUR1 antagonist, appears to have neuroprotective effect against cerebral stroke in an open-label small clinical trial and great effectiveness in reducing damage after varied experimental CNS injury models. Despite its importance in CNS injuries, SUR1 upregulation appears to play no part in rodent anterior ischemic optic neuropathy (rAION) injury as tested by real-time PCR and immunohistochemical staining of rAION-injured rat optic nerve (ON). Furthermore, the SUR1 antagonist glibenclamide administered immediately after rAION injury provided no protection to proximal ON microvasculature 1 day post-injury but may reduce optic nerve head edema in a manner unrelated to ON SUR1 expression. Our results suggest that there may be fundamental differences between rAION optic nerve ischemia and other CNS white matter injuries where SUR1 appears to play a role.

Imaging Findings Associated with Space-Occupying Edema in Patients with Large Middle Cerebral Artery Infarcts

BACKGROUND AND PURPOSE

Prominent space-occupying cerebral edema is a devastating complication occurring in some but not all patients with large MCA infarcts. It is unclear why differences in the extent of edema exist. Better knowledge of factors related to prominent edema formation could aid treatment strategies. This study aimed to identify variables associated with the development of prominent edema in patients with large MCA infarcts.

MATERIALS AND METHODS

From the Dutch Acute Stroke Study (DUST), 137 patients were selected with large MCA infarcts on follow-up NCCT (3 ± 2 days after stroke onset), defined as ASPECTS ≤4. Prominent edema was defined as a midline shift of ≥5 mm on follow-up. Admission patient and treatment characteristics were collected. Admission CT parameters used were ASPECTS on NCCT and CBV and MTT maps, and occlusion site, clot burden, and collaterals on CTA. Permeability on admission CTP, and day 3 recanalization and reperfusion statuses were obtained if available. Unadjusted and adjusted (age and NIHSS) odds ratios were calculated for all variables in relation to prominent edema.

RESULTS

Prominent edema developed in 51 patients (37%). Adjusted odds ratios for prominent edema were higher with lower ASPECTS on NCCT (adjusted odds ratio, 1.32; 95% CI, 1.13-1.55) and CBV (adjusted odds ratio, 1.26; 95% CI, 1.07-1.49), higher permeability (adjusted odds ratio, 2.35; 95% CI, 1.30-4.24), more proximal thrombus location (adjusted odds ratio, 3.40; 95% CI, 1.57-7.37), higher clot burden (adjusted odds ratio, 2.88; 95% CI, 1.11-7.45), and poor collaterals (adjusted odds ratio, 3.93; 95% CI, 1.78-8.69).

CONCLUSIONS

Extensive proximal occlusion, poor collaterals, and larger ischemic deficits with higher permeability play a role in the development of prominent edema in large MCA infarcts.

Hemispheric differences in malignant middle cerebral artery stroke

BACKGROUND

We recently reported that left versus right hemisphere cerebral infarctions patients more frequently have worse outcomes. However our clinical experience led us to suspect that the incidence of malignant middle cerebral artery infarctions (MMCA) was higher in the right compared to the left hemispheric strokes.

OBJECTIVE

To determine whether laterality in MMCA stroke is an important determinant of stroke sequelae.

METHODS

A systematic search was performed for publications in PubMed using "malignant middle cerebral artery and infarction". A total of 73 relevant studies were abstracted.

RESULTS

MMCA laterality data were available for 2673 patients, with 1687 (63%) right hemispheric involvement, thus right being more commonly associated with MMCA (binomial test, p<0.05). While mortality rates were similar, right hemispheric MMCA (n=271) had mortality of 31% (n=85) whereas left hemispheric MMCA (n=144) had mortality of 36% (n=53), morbidity rates were worse on the right.

CONCLUSION

MMCA stroke appears to be more common on the right, and this laterality is also associated with significantly higher morbidity. Further prospective studies are needed to more completely understand the nature of this laterality as well as test possible new treatments to reduce mortality and morbidity associated with MMCA.

Treatment of malignant brain edema and increased intracranial pressure after stroke

OPINION STATEMENT

The management of patients with large territory ischemic strokes and the subsequent development of malignant brain edema and increased intracranial pressure is a significant challenge in modern neurology and neurocritical care. These patients are at high risk of subsequent neurologic decline and are best cared for in an intensive care unit or a comprehensive stroke center with access to neurosurgical support. Risks include hemorrhagic conversion, herniation, poor functional outcome, and death. This review discusses recent advances in understanding the pathophysiology of edema formation, identifying patients at risk, current management strategies, and emerging therapies.

Effect of glibenclamide on the prevention of secondary brain injury following ischemic stroke in humans

Cerebral edema and hemorrhagic conversion are common, potentially devastating complications of ischemic stroke and are associated with high rates of mortality and poor functional outcomes. Recent work exploring the molecular pathophysiology of the neurogliovascular unit in ischemic stroke suggests that deranged cellular ion homeostasis due to altered function and regulation of ion pumps, channels, and secondary active transporters plays an integral role in the development of cytotoxic and vasogenic edema and hemorrhagic conversion. Among these proteins involved in ion homeostasis, the ischemia-induced, nonselective cation conductance formed by the SUR1-TRPM4 protein complex appears to play a prominent role and is potently inhibited by glibenclamide, an FDA-approved drug commonly used in patients with Type 2 diabetes. Several robust preclinical studies have demonstrated the efficacy of glibenclamide blockade of SUR1-TRPM4 activity in reducing edema and hemorrhagic conversion in rodent models of ischemic stroke, prompting the study of the potential protective effects of glibenclamide in humans in an ongoing prospective phase II clinical trial. Preliminary data suggest glibenclamide significantly reduces cerebral edema and lowers the rate of hemorrhagic conversion following ischemic stroke, suggesting the potential use of glibenclamide to improve outcomes in humans.

Tracheostomy after severe ischemic stroke: a population-based study

BACKGROUND

Stroke can result in varying degrees of respiratory failure. Some patients require tracheostomy in order to facilitate weaning from mechanical ventilation, long-term airway protection, or a combination of the two. Little is known about the rate and predictors of this outcome in patients with severe stroke. We aim to determine the rate of tracheostomy after severe ischemic stroke.

METHODS

Using the Nationwide Inpatient Sample database from 2007 to 2009, patients hospitalized with ischemic stroke were identified based on validated International Classification of Diseases, 9th revision, Clinical Modification codes. Next, patients with stroke were stratified based on whether they were treated with or without decompressive craniectomy, and the rate of tracheostomy for each group was determined. A logistic regression analysis was used to identify predictors of tracheostomy after decompressive craniectomy. Survey weights were used to obtain nationally representative estimates.

RESULTS

In 1,550,000 patients discharged with ischemic stroke nationwide, the rate of tracheostomy was 1.3% (95% confidence interval [CI], 1.2-1.4%), with a 1.3% (95% CI, 1.1-1.4%) rate in patients without decompressive craniectomy and a 33% (95% CI, 26-39%) rate in the surgical treatment group. Logistic regression analysis identified pneumonia as being significantly associated with tracheostomy after decompressive craniectomy (odds ratio, 3.95; 95% CI, 1.95-6.91).

CONCLUSIONS

Tracheostomy is common after decompressive craniectomy and is strongly associated with the development of pneumonia. Given its impact on patient function and potentially modifiable associated factors, tracheostomy may warrant further study as an important patient-centered outcome among patients with stroke.