Direct Versus Indirect Revascularization for Moyamoya: a Large Multicenter Study.

BACKGROUND: Moyamoya is a chronic occlusive cerebrovascular disease of unknown etiology causing neovascularization of the lenticulostriate collaterals at the base of the brain. Although revascularization surgery is the most effective treatment for moyamoya, there is still no consensus on the best surgical treatment modality as different studies provide different outcomes. OBJECTIVE: In this large case series, we compare the outcomes of direct (DR) and indirect revascularisation (IR) and compare our results to the literature in order to reflect on the best revascularization modality for moyamoya. METHODS: We conducted a multicenter retrospective study in accordance with the Strengthening the Reporting of Observational studies in Epidemiology guidelines of moyamoya affected hemispheres treated with DR and IR surgeries across 13 academic institutions predominantly in North America. All patients who underwent surgical revascularization of their moyamoya-affected hemispheres were included in the study. The primary outcome of the study was the rate of symptomatic strokes. RESULTS: The rates of symptomatic strokes across 515 disease-affected hemispheres were comparable between the two cohorts (11.6% in the DR cohort vs 9.6% in the IR cohort, OR 1.238 (95% CI 0.651 to 2.354), p=0.514). The rate of total perioperative strokes was slightly higher in the DR cohort (6.1% for DR vs 2.0% for IR, OR 3.129 (95% CI 0.991 to 9.875), p=0.052). The rate of total follow-up strokes was slightly higher in the IR cohort (8.1% vs 6.6%, OR 0.799 (95% CI 0.374 to 1.709) p=0.563). CONCLUSION: Since both modalities showed comparable rates of overall total strokes, both modalities of revascularization can be performed depending on the patient's risk assessment.

Evolutionary design of magnetic soft continuum robots.

Worldwide cardiovascular diseases such as stroke and heart disease are the leading cause of mortality. While guidewire/catheter-based minimally invasive surgery is used to treat a variety of cardiovascular disorders, existing passive guidewires and catheters suffer from several limitations such as low steerability and vessel access through complex geometry of vasculatures and imaging-related accumulation of radiation to both patients and operating surgeons. To address these limitations, magnetic soft continuum robots (MSCRs) in the form of magnetic field-controllable elastomeric fibers have recently demonstrated enhanced steerability under remotely applied magnetic fields. While the steerability of an MSCR largely relies on its workspace-the set of attainable points by its end effector-existing MSCRs based on embedding permanent magnets or uniformly dispersing magnetic particles in polymer matrices still cannot give optimal workspaces. The design and optimization of MSCRs have been challenging because of the lack of efficient tools. Here, we report a systematic set of model-based evolutionary design, fabrication, and experimental validation of an MSCR with a counterintuitive nonuniform distribution of magnetic particles to achieve an unprecedented workspace. The proposed MSCR design is enabled by integrating a theoretical model and the genetic algorithm. The current work not only achieves the optimal workspace for MSCRs but also provides a powerful tool for the efficient design and optimization of future magnetic soft robots and actuators.

The impact of hypertension on clinical outcomes in moyamoya disease: a multicenter, propensity score-matched analysis.

BACKGROUND: Moyamoya disease (MMD) is a rare cerebrovascular disorder characterized by progressive steno-occlusive changes in the internal carotid arteries, leading to an abnormal vascular network. Hypertension is prevalent among MMD patients, raising concerns about its impact on disease outcomes. This study aims to compare the clinical characteristics and outcomes of MMD patients with and without hypertension. METHODS: We conducted a multicenter, retrospective study involving 598 MMD patients who underwent surgical revascularization across 13 academic institutions in North America. Patients were categorized into hypertensive (n=292) and non-hypertensive (n=306) cohorts. Propensity score matching (PSM) was performed to adjust for baseline differences. RESULTS: The mean age was higher in the hypertension group (46 years vs. 36.8 years, p < 0.001). Hypertensive patients had higher rates of diabetes mellitus (45.2% vs. 10.7%, p < 0.001) and smoking (48.8% vs. 27.1%, p < 0.001). Symptomatic stroke rates were higher in the hypertension group (16% vs. 7.1%; OR: 2.48; 95% CI: 1.39-4.40, p = 0.002) before matching. After PSM, there were no significant differences in symptomatic stroke rates (11.1% vs. 7.7%; OR: 1.5; CI: 0.64-3.47, p = 0.34), perioperative strokes (6.2% vs. 2.1%; OR 3.13; 95% CI: 0.83-11.82, p = 0.09), or good functional outcomes at discharge (93% vs. 92.3%; OR 1.1; 95% CI: 0.45-2.69, p = 0.82). CONCLUSION: No significant differences in symptomatic stroke rates, perioperative strokes, or functional outcomes were observed between hypertensive and non-hypertensive Moyamoya patients. Appropriate management can lead to similar outcomes in both groups. Further prospective studies are required to validate these findings.

Cerebroprotection in the endovascular era: an update.

Despite advances in clinical diagnosis and increasing numbers of patients eligible for revascularisation, ischaemic stroke remains a significant public health concern accounting for 3.3 million deaths annually. In addition to recanalisation therapy, patient outcomes could be improved through cerebroprotection, but all translational attempts have remained unsuccessful. In this narrative review, we discuss potential reasons for those failures. We then outline the diverse, multicellular effects of ischaemic stroke and the complex temporal sequences of the pathophysiological cascade during and following ischaemia, reperfusion, and recovery. This evidence is linked with findings from prior cerebroprotective trials and interpreted for the modern endovascular era. Future cerebroprotective agents that are multimodal and multicellular, promoting cellular and metabolic health to different targets at time points that are most responsive to treatment, might prove more successful.

The Impact of Dual Antiplatelet Therapy Duration on Unruptured Aneurysm Occlusion After Flow Diversion: A Multicenter Study.

OBJECTIVE: Endoluminal flow diversion reduces blood flow into intracranial aneurysms, promoting thrombosis. Postprocedural dual antiplatelet therapy (DAPT) is necessary for the prevention of thromboembolic complications. The purpose of this study is to therefore assess the impact that the type and duration of DAPT has on aneurysm occlusion rates and iatrogenic complications after flow diversion. METHODS: A retrospective review of a multicenter aneurysm database was performed from 2012 to 2020 to identify unruptured intracranial aneurysms treated with single device flow diversion and ≥12-month follow-up. Clinical and radiologic data were analyzed with aneurysm occlusion as a function of DAPT duration serving as a primary outcome measure. RESULTS: Two hundred five patients underwent flow diversion with a single pipeline embolization device with 12.7% of treated aneurysms remaining nonoccluded during the study period. There were no significant differences in aneurysm morphology or type of DAPT used between occluded and nonoccluded groups. Nonoccluded aneurysms received a longer mean duration of DAPT (9.4 vs 7.1 months, P = 0.016) with a significant effect of DAPT duration on the observed aneurysm occlusion rate (F(2, 202) = 4.2, P = 0.016). There was no significant difference in the rate of complications, including delayed ischemic strokes, observed between patients receiving short (≤6 months) and prolonged duration (>6 months) DAPT (7.9% vs 9.3%, P = 0.76). CONCLUSIONS: After flow diversion, an abbreviated duration of DAPT lasting 6 months may be most appropriate before transitioning to low-dose aspirin monotherapy to promote timely aneurysm occlusion while minimizing thromboembolic complications.

FRED Jr stent for acute flow diversion in ruptured cerebral aneurysms arising from small-caliber vessels: a clinical case series.

OBJECTIVE: Treatment of ruptured aneurysms arising from small-caliber (< 2.5 mm) or distal vessels beyond the circle of Willis is considered challenging with all treatment modalities. Recently, the Flow Re-Direction Endoluminal Device Junior (FRED Jr) stent, designed for flow diversion in small arteries, was approved in the United States for the treatment of nonruptured aneurysms. Here, the authors report their experience using this device in the setting of subarachnoid hemorrhage (SAH). METHODS: Clinical and radiological records of patients sustaining SAH treated with a FRED Jr stent between June 2020 and October 2022 were reviewed. Treatment course, including antiplatelet therapy, external ventricular drain (EVD) management, and vasospasm, and clinical outcomes were analyzed. Angiographic results were assessed according to the O'Kelly-Marotta (OKM) grading scale. RESULTS: Nine patients at a median age of 62 (range 27-75) years were included. The median Hunt and Hess grade was II (IQR I) and the median modified Fisher grade was 4 (IQR 1). Aneurysm morphology types included saccular (6 patients), blister (1 patient), and dissecting (2 patients), and the aneurysms were located at the anterior communicating artery complex (n = 3) at the A2/A3 (n = 3), M2/M3 (n = 1), V4 (n = 1), and P2 (n = 1) arterial segments. All stents were deployed successfully with no intraprocedural complications. Postoperatively, no rebleeding events were encountered. Vasospasm therapy was initiated in 6 patients, and no symptomatic EVD-related hematomas were observed. Postoperative ischemic events were encountered in 2 patients. The median 3-month modified Rankin Scale score was 2 (IQR 1) for the 7 surviving patients, and 3-month radiographic follow-up revealed OKM grade D in 4 of 7 patients. CONCLUSIONS: Flow diversion using the FRED Jr stent is feasible as a potential treatment strategy for acutely ruptured aneurysms arising from small-caliber vessels. The complication profile reported in this series is comparable to those of historical microsurgical cohorts, and effective protection was conferred by this treatment modality. Therefore, our small cohort provides a glimpse into a new tool for successfully achieving acute flow diversion for this subset of difficult-to-treat aneurysms.

Carotid Stenting Versus Endarterectomy for Asymptomatic Carotid Artery Stenosis: A Systematic Review and Meta-Analysis.

BACKGROUND: To compare safety and efficacy between carotid artery stenting (CAS) and carotid endarterectomy (CEA) in treating asymptomatic carotid artery stenosis based on results from randomized controlled trials. METHODS: Randomized controlled trials comparing CAS and CEA in treating asymptomatic carotid artery stenosis were searched from databases of the EMBASE, PubMed, MEDLINE, and Cochrane libraries. Two independent reviewers identified eligible studies, extracted relevant data, and used the Cochrane risk of bias tool to assess quality. Mantel-Haenszel method random-effects models were used to estimate odds ratio (OR) regarding perioperative risks between CAS and CEA. Kaplan-Meier curve data were extracted and analyzed through Exp[(O-E)/Var] fixed-effect models to calculate the Peto odds ratio (OR) regarding long-term outcomes. RESULTS: Sixteen articles from 7 randomized controlled trials were included, reporting relevant outcomes for 7230 asymptomatic carotid artery stenosis patients (CAS: n=3920; CEA: n=3198). Compared with the CEA group, CAS group had no difference in perioperative composite end point events including stroke, death, and myocardial infarction (MI; OR, 1.13 [95% CI, 0.87-1.47]; P=0.37, I2=0%). Compared with CEA, CAS had a higher risk of any stroke during the perioperative period (OR, 1.62 [95% CI, 1.16-2.24]; P=0.004, I2=0%) and an increased risk of nondisabling stroke (OR, 1.81 [95% CI, 1.23-2.65]; P=0.003, I2=0%), but there was no significant difference in disabling stroke and death between groups (OR, 0.91 [95% CI, 0.50-1.65]; P=0.76, I2=0%). For long-term outcomes, no difference regarding the composite outcome of any stroke, death, and myocardial infarction existed between CEA and CAS (Peto OR, 1.18 [95% CI, 0.94-1.48]; P=0.14, I2=0%). Individual-level patient data would be important to verify the long-term outcome results. CONCLUSIONS: When treating asymptomatic carotid artery stenosis, CAS has comparable perioperative and long-term composite outcomes compared with CEA. However, CAS may have a higher risk of any stroke and nondisabling stroke in the perioperative period.

Cortical Spreading Depolarizations and Clinically Measured Scalp EEG Activity After Aneurysmal Subarachnoid Hemorrhage and Traumatic Brain Injury.

BACKGROUND: Spreading depolarizations (SDs) are associated with worse outcome following subarachnoid hemorrhage (SAH) and traumatic brain injury (TBI), but gold standard detection requires electrocorticography with a subdural strip electrode. Electroencephalography (EEG) ictal-interictal continuum abnormalities are associated with poor outcomes after TBI and with both delayed cerebral ischemia (DCI) and poor outcomes after SAH. We examined rates of SD detection in patients with SAH and TBI with intraparenchymal and subdural strip electrodes and assessed which continuous EEG (cEEG) measures were associated with intracranially quantified SDs. METHODS: In this single-center cohort, we included patients with SAH and TBI undergoing ≥ 24 h of interpretable intracranial monitoring via eight-contact intraparenchymal or six-contact subdural strip platinum electrodes or both. SDs were rated according to established consensus criteria and compared with cEEG findings rated according to the American Clinical Neurophysiology Society critical care EEG monitoring consensus criteria: lateralized rhythmic delta activity, generalized rhythmic delta activity, lateralized periodic discharges, generalized periodic discharges, any ictal-interictal continuum, or a composite scalp EEG tool for seizure risk estimation: the 2HELPS2B score. Among patients with SAH, cEEG was assessed for validated DCI biomarkers: new or worsening epileptiform abnormalities and new background deterioration. RESULTS: Over 6 years, SDs were recorded in 5 (18%) of 28 patients recorded with intraparenchymal electrodes and 4 (40%) of 10 patients recorded with subdural strip electrodes. There was no significant association between occurrence of SDs and day 1 cEEG findings (American Clinical Neurophysiology Society main terms lateralized periodic discharges, generalized periodic discharges, lateralized rhythmic delta activity, or seizures, individually or in combination). After SAH, established cEEG DCI predictors were not associated with SDs. CONCLUSIONS: Intraparenchymal recordings yielded low rates of SD, and documented SDs were not associated with ictal-interictal continuum abnormalities or other cEEG DCI predictors. Identifying scalp EEG correlates of SD may require training computational EEG analytics and use of gold standard subdural strip electrocorticography recordings.

Association of External Ventricular Drain Wean Strategy with Shunt Placement and Length of Stay in Subarachnoid Hemorrhage: A Prospective Multicenter Study.

BACKGROUND: Survivors of aneurysmal subarachnoid hemorrhage (SAH) face a protracted intensive care unit (ICU) course and are at risk for developing refractory hydrocephalus with the need for a permanent ventriculoperitoneal shunt (VPS). Management of the external ventricular drain (EVD) used to provide temporary cerebrospinal fluid diversion may influence the need for a VPS, ICU length of stay (LOS), and drain complications, but the optimal EVD management approach is unknown. Therefore, we sought to determine the effect of EVD discontinuation strategy on VPS rate. METHODS: This was a prospective multicenter observational study at six neurocritical care units in the United States. The target population included adults with suspected aneurysmal SAH who required an EVD. Patients were preassigned to rapid or gradual EVD weans based on their treating center. The primary outcome was the rate of VPS placement. Secondary outcomes were EVD duration, ICU LOS, hospital LOS, and drain complications. RESULTS: A rapid EVD wean protocol was associated with a lower rate of VPS placement, including a delayed posthospitalization shunt, in an adjusted Cox proportional analysis (hazard ratio 0.52 [p = 0.041]) and adjusted logistic regression model (odds ratio 0.43 [95% confidence interval 0.18-1.03], p = 0.057). A rapid wean was also associated with 2.1 fewer EVD days (p = 0.007) and saved an estimated 2.5 ICU days (p = 0.049), as compared with a gradual wean protocol. There were fewer nonfunctioning EVDs in the rapid group (odds ratio 0.32 [95% confidence interval 0.11-0.92]). Furthermore, we found that the time to first wean and the number of weaning attempts were important independent covariates that affected the likelihood of receiving a VPS and the duration of ICU admission. CONCLUSIONS: A rapid EVD wean was associated with decreased rates of VPS placement, decreased ICU LOS, and decreased drain complications in survivors of aneurysmal SAH. These findings suggest that a randomized multicentered controlled study comparing rapid vs. gradual EVD weaning protocols is justified.

Antiseizure Medication Treatment and Outcomes in Patients with Subarachnoid Hemorrhage Undergoing Continuous EEG Monitoring.

BACKGROUND: Patients with aneurysmal subarachnoid hemorrhage (aSAH) with electroencephalographic epileptiform activity (seizures, periodic and rhythmic patterns, and sporadic discharges) are frequently treated with antiseizure medications (ASMs). However, the safety and effectiveness of ASM treatment for epileptiform activity has not been established. We used observational data to investigate the effectiveness of ASM treatment in patients with aSAH undergoing continuous electroencephalography (cEEG) to develop a causal hypothesis for testing in prospective trials. METHODS: This was a retrospective single-center cohort study of patients with aSAH admitted between 2011 and 2016. Patients underwent ≥ 24 h of cEEG within 4 days of admission. All patients received primary ASM prophylaxis until aneurysm treatment (typically within 24 h of admission). Treatment exposure was defined as reinitiation of ASMs after aneurysm treatment and cEEG initiation. We excluded patients with non-cEEG indications for ASMs (e.g., epilepsy, acute symptomatic seizures). Outcomes measures were 90-day mortality and good functional outcome (modified Rankin Scale scores 0-3). Propensity scores were used to adjust for baseline covariates and disease severity. RESULTS: Ninety-four patients were eligible (40 continued ASM treatment; 54 received prophylaxis only). ASM continuation was not significantly associated with higher 90-day mortality (propensity-adjusted hazard ratio [HR] = 2.01 [95% confidence interval (CI) 0.57-7.02]). ASM continuation was associated with lower likelihood for 90-day good functional outcome (propensity-adjusted HR = 0.39 [95% CI 0.18-0.81]). In a secondary analysis, low-intensity treatment (low-dose single ASM) was not significantly associated with mortality (propensity-adjusted HR = 0.60 [95% CI 0.10-3.59]), although it was associated with a lower likelihood of good outcome (propensity-adjusted HR = 0.37 [95% CI 0.15-0.91]), compared with prophylaxis. High-intensity treatment (high-dose single ASM, multiple ASMs, or anesthetics) was associated with higher mortality (propensity-adjusted HR = 6.80 [95% CI 1.67-27.65]) and lower likelihood for good outcomes (propensity-adjusted HR = 0.30 [95% CI 0.10-0.94]) compared with prophylaxis only. CONCLUSIONS: Our findings suggest the testable hypothesis that continuing ASMs in patients with aSAH with cEEG abnormalities does not improve functional outcomes. This hypothesis should be tested in prospective randomized studies.

Flow diversion in direct carotid-cavernous fistula refractory to multiple coil embolizations: case report and review of the literature.

OBJECTIVES: Direct carotid-cavernous fistulas are high-flow abnormal connections between the carotid artery and cavernous sinus, which are associated with significant morbidity and mortality if left untreated. In addition to endovascular coil embolization, there is an evolving role for alternative stand-alone or adjunctive treatment approaches. We describe a case of flow diversion as an adjunctive treatment approach in a treatment-resistant direct carotid-cavernous fistula and review the literature on the use of flow diversion in this clinical context. MATERIALS AND METHODS: We describe the clinical course, imaging findings, and outcome of a patient who developed a traumatic carotid-cavernous fistula requiring multiple interventions. We also performed an updated literature review of all published cases of flow diversion use in the treatment of direct CCFs. RESULTS: Our patient achieved angiographic cure and significant improvement in symptoms at 6-month follow-up. A total of 53 cases of flow diversion use in direct carotid-cavernous fistulas were identified from a literature search. In one third of cases, flow diversion was used as a stand-alone treatment modality. Angiographic resolution was achieved in 90% of cases at a median follow-up duration of 6 months. One half of reported cases had complete resolution of symptoms and a further third noted clinical improvement in at least some of their symptoms. CONCLUSIONS: There is an emerging role for flow diversion as a safe and effective stand-alone or adjunctive treatment option for direct carotid-cavernous fistulas. Our case further supports a role for flow diversion in treatment-resistant fistulas with high-risk features. As treatment approaches continue to evolve, prospective, randomized data will be needed to establish the role of flow divertors in the hierarchy of available treatments for carotid-cavernous fistulas.

Early Brain Injury and Soluble ST2 After Nontraumatic Subarachnoid Hemorrhage.

[Figure: see text].

The Woven EndoBridge device for ruptured intracranial aneurysms: international multicenter experience and updated meta-analysis.

PURPOSE: The Woven EndoBridge (WEB) can be used to treat wide-necked aneurysms without antiplatelet medications, suggesting it may have advantages in the setting of aneurysmal subarachnoid hemorrhage (aSAH). The goal was assessment of safety and efficacy of WEB in aSAH given the delayed nature of aneurysmal thrombosis. METHODS: An international retrospective analysis of patients with aSAH treated with WEB was conducted at 7 tertiary centers from 2016 to 2020. Outcomes included rates of rebleeding, retreatment, complications, and complete occlusion. Furthermore, a systematic review and meta-analysis was conducted from 2011 to 2020 assessing the same outcomes. All pooled event rates were calculated using a random effect model. RESULTS: Consecutive patients with aSAH harbored 25 aneurysms that were treated with 29 WEB devices. The mean age was 53 years, and 65% were female. Zero experienced rebleeding, 2 were retreated, 2 experienced complications, 16 were completely occluded at 3 months, and 21 were completed occluded at 9-12 months. Meta-analysis of 309 WEB treatments for aSAH from 7 case series revealed 2.5% (95% CI 1-5%) had rebleeding, 9% (95% CI 4-17%) were retreated, 17% (95% CI 10-30%) had complications, and 61% (95% CI 51-71%) were completely occluded at 3-6 months. CONCLUSION: WEB embolization in the setting of aSAH provides similar protection against rebleeding with comparable retreatment rates to traditional approaches. However, there is a higher rate of incomplete radiographic occlusion and operative complications compared to WEB embolization of unruptured aneurysms. Long-term prospective studies are needed to fully delineate the role of WEB embolization in aSAH.

Electroencephalography, Hospital Complications, and Longitudinal Outcomes After Subarachnoid Hemorrhage.

BACKGROUND: Following non-traumatic subarachnoid hemorrhage (SAH), in-hospital delayed cerebral ischemia is predicted by two chief events on continuous EEG (cEEG): new or worsening epileptiform abnormalities (EAs) and deterioration of cEEG background frequencies. We evaluated the association between longitudinal outcomes and these cEEG biomarkers. We additionally evaluated the association between longitudinal outcomes and other in-hospital complications. METHODS: Patients with nontraumatic SAH undergoing ≥ 3 days of cEEG monitoring were enrolled in a prospective study evaluating longitudinal outcomes. Modified Rankin Scale (mRS) was assessed at discharge, and at 3- and 6-month follow-up time points. Adjusting for baseline severity in a cumulative proportional odds model, we modeled the mRS ordinally and measured the association between mRS and two forms of in-hospital cEEG deterioration: (1) cEEG evidence of new or worsening epileptiform abnormalities and (2) cEEG evidence of new background deterioration. We compared the magnitude of these associations at each time point with the association between mRS and other in-hospital complications: (1) delayed cerebral ischemia (DCI), (2) hospital-acquired infections (HAI), and (3) hydrocephalus. In a secondary analysis, we employed a linear mixed effects model to examine the association of mRS over time (dichotomized as 0-3 vs. 4-6) with both biomarkers of cEEG deterioration and with other in-hospital complications. RESULTS: In total, 175 mRS assessments were performed in 59 patients. New or worsening EAs developed in 23 (39%) patients, and new background deterioration developed in 24 (41%). Among cEEG biomarkers, new or worsening EAs were independently associated with mRS at discharge, 3, and 6 months, respectively (adjusted cumulative proportional odds 4.99, 95% CI 1.60-15.6; 3.28, 95% CI 1.14-9.5; and 2.71, 95% CI 0.95-7.76), but cEEG background deterioration lacked an association. Among hospital complications, DCI was associated with discharge, 3-, and 6-month outcomes (adjusted cumulative proportional odds 4.75, 95% CI 1.64-13.8; 3.4; 95% CI 1.24-9.01; and 2.45, 95% CI 0.94-6.6), but HAI and hydrocephalus lacked an association. The mixed effects model demonstrated that these associations were sustained over longitudinal assessments without an interaction with time. CONCLUSION: Although new or worsening EAs and cEEG background deterioration have both been shown to predict DCI, only new or worsening EAs are associated with a sustained impairment in functional outcome. This novel finding raises the potential for identifying therapeutic targets that may also influence outcomes.

White Matter Acute Infarct Volume After Thrombectomy for Anterior Circulation Large Vessel Occlusion Stroke is Associated with Long Term Outcomes.

OBJECTIVES: Despite the proven efficacy of endovascular thrombectomy (EVT) for large vessel occlusion stroke, over half treated remain functionally disabled or die. Infarct topography may have implications for prognostication, patient selection, and the development of tissue-specific neuroprotective agents. We sought to quantify white matter injury in anterior circulation acute infarcts post-EVT to understand its significance and identify its determinants. MATERIALS AND METHODS: Demographics, history, presentations, and outcomes for consecutive patients treated with EVT were recorded in a prospectively maintained database at a single center. Acute infarct masks were coregistered to standard space. Standard atlases of white matter, cortex, and basal ganglia were used to determine region-specific infarct volumes. RESULTS: 167 individuals were identified with median age 69 years and 53% women. 85% achieved adequate reperfusion (TICI 2b-3) after EVT; 43% achieved 90-day functional independence (mRS 0-2). Median infarct volumes were 45cc (IQR 18-122) for total, 17cc (6-49) for white matter, 21cc (4-53) for cortex, and 5cc (1-8) for basal ganglia. The odds of 90-day mRS 0-2 were reduced in patients with larger white matter infarct volume (cc, OR=0.89, 95%CI=0.81-0.96), independent of cortex infarct volume, basal ganglia infarct volume, age, NIHSS, and TICI 2b-3 reperfusion. Reperfusion-to-MRI time was associated with white matter infarct volume (hr, ß=0.119, p=0.017), but not cortical or basal ganglia infarct volume. CONCLUSIONS: These data quantitatively describe region-specific infarct volumes after EVT and suggest the clinical relevance of white matter infarct volume as a predictor of long-term outcomes. Further study is warranted to examine delayed white matter infarction and the significance of specific white matter tracts.

Treatment Approaches and Outcomes for Acute Anterior Circulation Stroke Patients with Tandem Lesions.

OBJECTIVES: Endovascular thrombectomy (EVT) has revolutionized stroke care for large vessel occlusions (LVOs). However, over half treated remain functionally disabled or die. Patients with tandem lesions, or severe stenosis/occlusion of the cervical internal carotid artery (ICA) with intracranial LVO, may have technical EVT challenges and worse outcomes. We sought to compare treatments and outcomes for patients with anterior circulation tandem lesions versus isolated LVOs. MATERIALS AND METHODS: Consecutive tandem lesion and isolated intracranial LVO patients were identified at a single center. Demographics, medical history, presentations, treatments, and outcomes were collected and analyzed. RESULTS: From 381 EVT patients, 62 had tandem lesions related to atherosclerosis (74%) or dissection (26%). Compared to isolated intracranial LVOs, they were younger (63 vs 70, p = 0.003), had less atrial fibrillation (13% vs 40%, p < 0.0001), less adequate reperfusion (TICI 2b-3, 58% vs 82%, p < 0.0001), more intracranial hemorrhage (ICH, 13% vs 5%, p = 0.037), but similar 90-day functional independence (mRS 0-2, 34% vs 43%, p = 0.181). The cervical ICA was treated before intracranial EVT (57%), after (13%), not acutely (22%), or was inaccessible (8%). Acute cervical ICA treatments were stenting (57%) or angioplasty alone (13%). Neither acute stenting nor order of treatment was associated with outcomes (TICI 2b-3, ICH, or 90-day mRS 0-2). Among acutely stented, neither alteplase nor antiplatelets were associated with outcomes or stent patency. CONCLUSIONS: Tandem lesions were associated with less reperfusion, more ICH, but similar 90-day functional independence. No treatment approach was associated with outcomes. These data illustrate the technical challenges of tandem lesion treatment and underscore the importance of developing new approaches.

Soluble ST2 Is Associated With New Epileptiform Abnormalities Following Nontraumatic Subarachnoid Hemorrhage.

Background and Purpose- We evaluated the association between 2 types of predictors of delayed cerebral ischemia after nontraumatic subarachnoid hemorrhage, including biomarkers of the innate immune response and neurophysiologic changes on continuous electroencephalography. Methods- We studied subarachnoid hemorrhage patients that had at least 72 hours of continuous electroencephalography and blood samples collected within the first 5 days of symptom onset. We measured inflammatory biomarkers previously associated with delayed cerebral ischemia and functional outcome, including soluble ST2 (sST2), IL-6 (interleukin-6), and CRP (C-reactive protein). Serial plasma samples and cerebrospinal fluid sST2 levels were available in a subgroup of patients. Neurophysiologic changes were categorized into new or worsening epileptiform abnormalities (EAs) or new background deterioration. The association of biomarkers with neurophysiologic changes were evaluated using the Wilcoxon rank-sum test. Plasma and cerebrospinal fluid sST2 were further examined longitudinally using repeated measures mixed-effects models. Results- Forty-six patients met inclusion criteria. Seventeen (37%) patients developed new or worsening EAs, 21 (46%) developed new background deterioration, and 8 (17%) developed neither. Early (day, 0-5) plasma sST2 levels were higher among patients with new or worsening EAs (median 115 ng/mL [interquartile range, 73.8-197]) versus those without (74.7 ng/mL [interquartile range, 44.8-102]; P=0.024). Plasma sST2 levels were similar between patients with or without new background deterioration. Repeated measures mixed-effects modeling that adjusted for admission risk factors showed that the association with new or worsening EAs remained independent for both plasma sST2 (ß=0.41 [95% CI, 0.09-0.73]; P=0.01) and cerebrospinal fluid sST2 (ß=0.97 [95% CI, 0.14-1.8]; P=0.021). IL-6 and CRP were not associated with new background deterioration or with new or worsening EAs. Conclusions- In patients admitted with subarachnoid hemorrhage, sST2 level was associated with new or worsening EAs but not new background deterioration. This association may identify a link between a specific innate immune response pathway and continuous electroencephalography abnormalities in the pathogenesis of secondary brain injury after subarachnoid hemorrhage.

Sex and Genetic Background Effects on the Outcome of Experimental Intracranial Aneurysms.

BACKGROUND AND PURPOSE: Intracranial aneurysm formation and rupture risk are, in part, determined by genetic factors and sex. To examine their role, we compared 3 mouse strains commonly used in cerebrovascular studies in a model of intracranial aneurysm formation and rupture. METHODS: Intracranial aneurysms were induced in male CD1 (Crl:CD1[ICR]), male and female C57 (C57BL/6NCrl), and male 129Sv (129S2/SvPasCrl or 129S1/SvImJ) mice by stereotaxic injection of elastase at the skull base, combined with systemic deoxycorticosterone acetate-salt hypertension. Neurological deficits and mortality were recorded. Aneurysms and subarachnoid hemorrhage grades were quantified postmortem, either after spontaneous mortality or at 7 to 21 days if the animals survived. In separate cohorts, we examined proinflammatory mediators by quantitative reverse transcriptase-polymerase chain reaction, arterial blood pressure via the femoral artery, and the circle of Willis by intravascular latex casting. RESULTS: We found striking differences in aneurysm formation, rupture, and postrupture survival rates among the groups. 129Sv mice showed the highest rates of aneurysm rupture (80%), followed by C57 female (36%), C57 male (27%), and CD1 (21%). The risk of aneurysm rupture and the presence of unruptured aneurysms significantly differed among all 3 strains, as well as between male and female C57. The same hierarchy was observed upon Kaplan-Meier analysis of both overall survival and deficit-free survival. Subarachnoid hemorrhage grades were also more severe in 129Sv. CD1 mice showed the highest resistance to aneurysm rupture and the mildest outcomes. Higher mean blood pressures and the major phenotypic difference in the circle of Willis anatomy in 129Sv provided an explanation for the higher incidence of and more severe aneurysm ruptures. TNFα (tumor necrosis factor-alpha), IL-1ß (interleukin-1-beta), and CCL2 (chemokine C-C motif ligand 2) expressions did not differ among the groups. CONCLUSIONS: The outcome of elastase-induced intracranial aneurysm formation and rupture in mice depends on genetic background and shows sexual dimorphism.

Soluble ST2 links inflammation to outcome after subarachnoid hemorrhage.

OBJECTIVE: To investigate whether soluble growth stimulation expressed gene 2 (sST2), a prognostic marker in cardiovascular and inflammatory disorders, is associated with neurological injury after aneurysmal subarachnoid hemorrhage (SAH). METHODS: We studied SAH patients from 2 independent cohorts. Outcome assessments included functional status at 90 days using the modified Rankin Scale (mRS), mortality, and delayed cerebral ischemia (DCI). The relationships between sST2 plasma level and outcome measures were assessed in both cross-sectional and longitudinal analysis. Primary blood mononuclear cells from SAH patients and elective aneurysm controls were analyzed by multiparameter flow cytometry. RESULTS: In the discovery cohort, sST2 predicted 90-day mRS 3-6 (C index = 0.724, p < 0.001) and mortality in Kaplan-Meier analysis (p < 0.001). The association with functional status was independent of age, sex, World Federation of Neurosurgical Societies score, modified Fisher score, treatment modality, and cardiac comorbidities (adjusted odds ratio = 2.28, 95% confidence interval = 1.04-5.00, p = 0.039). Higher sST2 concentration was observed in those patients with DCI (90.8 vs 53.7ng/ml, p = 0.003). These associations were confirmed in a replication cohort. In patients with high sST2, flow cytometry identified decreased expression of CD14 (4.27 × 105 ± 2,950 arbitrary unit (AU) vs 5.64 × 105 ± 1,290 AU, p < 0.001), and increased expression of CD16 (39,960 ± 272 AU vs 34,869 ± 183 AU, p < 0.001). INTERPRETATION: Plasma sST2 predicts DCI, functional outcome, and mortality after SAH, independent of clinical and radiographic markers. Elevated sST2 is also associated with changes in CD14+ CD16+ monocytes. ANN NEUROL 2019;86:384-394.

Noninvasive Vagus Nerve Stimulation Prevents Ruptures and Improves Outcomes in a Model of Intracranial Aneurysm in Mice.

Background and Purpose- Inflammation is a critical determinant of aneurysmal wall destabilization, growth, and rupture risk. Targeting inflammation may suppress aneurysm rupture. Vagus nerve stimulation (VNS) has been shown to suppress inflammation both systemically and in the central nervous system. Therefore, we tested the effect of a novel noninvasive transcutaneous VNS approach on aneurysm rupture and outcome in a mouse model of intracranial aneurysm formation with wall inflammation. Methods- Aneurysms were induced by a single stereotaxic injection of elastase into the cerebrospinal fluid at the skull base, combined with systemic deoxycorticosterone-salt hypertension, without or with high-salt diet, for mild or severe outcomes, respectively. Cervical VNS (two 2-minute stimulations 5 minutes apart) was delivered once a day starting from the day after elastase injection for the duration of follow-up. Transcutaneous stimulation of the femoral nerve (FNS) served as control. Multiple aneurysms developed in the circle of Willis and its major branches, resulting in spontaneous ruptures and subarachnoid hemorrhage, neurological deficits, and mortality. Results- In the milder model, VNS significantly reduced aneurysm rupture rate compared with FNS (29% versus 80%, respectively). Subarachnoid hemorrhage grades were also lower in the VNS group. In the more severe model, both VNS and FNS arms developed very high rupture rates (77% and 85%, respectively). However, VNS significantly improved the survival rate compared with FNS after rupture (median survival 13 versus 6 days, respectively), without diminishing the subarachnoid hemorrhage grades. Chronic daily VNS reduced MMP-9 (matrix metalloproteinase-9) expression compared with FNS, providing a potential mechanism of action. As an important control, chronic daily VNS did not alter systemic arterial blood pressure compared with FNS. Conclusions- VNS can reduce aneurysm rupture rates and improve the outcome from ruptured aneurysms.