Developing precision stroke imaging.

Stroke experts stand at the cusp of a unique opportunity to advance the care of patients with cerebrovascular disorders across the globe through improved imaging approaches. NIH initiatives including the Stroke Progress Review Group promotion of imaging in stroke research and the newly established NINDS Stroke Trials network converge with the rapidly evolving concept of precision medicine. Precision stroke imaging portends the coming shift to individualized approaches to cerebrovascular disorders where big data may be leveraged to identify and manage stroke risk with specific treatments utilizing an improved neuroimaging infrastructure, data collection, and analysis.

Association of ischemic stroke, hormone therapy, and right to left shunt in postmenopausal women.

Background: Postmenopausal hormone therapy (HT) increases the risk of venous thrombosis and ischemic stroke.

Objectives: We postulated that HT might increase the risk of ischemic stroke by promoting venous clots that travel to the brain through a right to left shunt (RLS).

Methods: A total of 2,389 records were studied.

Data considerations in ischemic stroke trials.

Data drive the analyses of any ischemic stroke trial, culminating in the main results and potential next steps. The distinct purpose of a given trial, advancing a novel treatment or examining routine clinical practice, determines the nature of essential data elements. Information gathering for an effective trial depends on ample data, adequate infrastructure, and properly planned statistical analyses.

Collateral lessons from recent acute ischemic stroke trials.

Numerous acute ischemic stroke trials have recently published detailed results, providing an opportunity to consider the role of collaterals in stroke pathophysiology and their influential effect on patient outcomes. Safety and Efficacy of NeuroFlo Technology in Ischemic Stroke (SENTIS), the largest randomized controlled trial of device therapy to date, tested the potential augmentation of collateral perfusion. SYNTHESIS Expansion, Mechanical Retrieval and Recanalization of Stroke Clots Using Embolectomy (MR RESCUE), and Interventional Management of Stroke (IMS) III chronicled the saga of endovascular therapy trialed against medical treatment for acute ischemic stroke.

Noninvasive fractional flow on MRA predicts stroke risk of intracranial stenosis.

Background And Purpose: Fractional flow may identify hemodynamic effects and ischemic risk beyond percent stenosis of an artery. We hypothesized that diminished TOF-MRA signal intensity distal to an intracranial stenosis predicts stroke risk.

Methods: TOF-MRA was acquired prospectively in the SONIA-WASID trials.

Serial Alberta Stroke Program early CT score from baseline to 24 hours in Solitaire Flow Restoration with the Intention for Thrombectomy study: a novel surrogate end point for revascularization in acute stroke.

Background And Purpose: The Alberta Stroke Program Early CT Score (ASPECTS) on baseline imaging is an established predictor of acute ischemic stroke outcomes. We analyzed change on serial ASPECTS at baseline and 24-hour imaging in the Solitaire Flow Restoration with the Intention for Thrombectomy (SWIFT) study to determine prognostic value and to identify subgroups with extensive injury after intervention.

Methods: ASPECTS at baseline and 24 hours was independently scored in all anterior circulation SWIFT cases, blinded to all other trial data.

Collaterals at angiography and outcomes in the Interventional Management of Stroke (IMS) III trial.

Background And Purpose: Endovascular strategies provide unique opportunity to correlate angiographic measures of collateral circulation at the time of endovascular therapy. We conducted systematic analyses of collaterals at conventional angiography on recanalization, reperfusion, and clinical outcomes in the endovascular treatment arm of the Interventional Management of Stroke (IMS) III trial.

Methods: Prospective evaluation of angiographic collaterals was conducted via central review of subjects treated with endovascular therapy in IMS III (n=331).

Role of statin in atrial fibrillation-related stroke: an angiographic study for collateral flow.

Background: Currently, intensive lipid lowering is recommended in patients with atherosclerotic ischemic stroke or transient ischemic attack. However, the role of statin in cardioembolic stroke is unclear. We investigated the association of statin with pretreatment collateral status in cardioembolic stroke.

Methodology of the Field Administration of Stroke Therapy - Magnesium (FAST-MAG) phase 3 trial: Part 2 - prehospital study methods.

Rationale: In acute stroke, the volume of salvageable brain tissue is maximal at onset and declines rapidly with time. Prehospital start of clinical trial interventions would enable delivery of neuroprotective agents, such as magnesium sulfate, to stroke patients in the hyperacute period when they are potentially most effective.

Aims: A broad aim of the FAST-MAG study is to develop and validate techniques to perform pivotal trials of neuroprotective therapies for acute stroke in the prehospital setting.

Methodology of the Field Administration of Stroke Therapy - Magnesium (FAST-MAG) phase 3 trial: Part 1 - rationale and general methods.

Rationale: Prehospital initiation by paramedics may enable delivery of neuroprotective therapies to stroke patients in the hyperacute period when they are most effective in preclinical studies. Magnesium is neuroprotective in experimental stroke models and has been shown to be safe with signals of potential efficacy when started early after onset of human cerebral ischemia.

Aims: (a) To demonstrate that paramedic initiation of the neuroprotective agent magnesium sulfate in the field is an efficacious and safe treatment for acute stroke; (b) To demonstrate that field enrollment of acute stroke patients is a practical and feasible strategy for phase 3 stroke trials, permitting enrollment of greater numbers of patients in hyperacute time windows.

Predictors and clinical relevance of hemorrhagic transformation after endovascular therapy for anterior circulation large vessel occlusion strokes: a multicenter retrospective analysis of 1122 patients.

Background And Purpose: Endovascular techniques are frequently employed to treat large artery occlusion in acute ischemic stroke (AIS). We sought to determine the predictors and clinical impact of intracranial hemorrhage (ICH) after endovascular therapy.

Methods: Retrospective analysis of consecutive patients presenting to 13 high volume stroke centers with AIS due to proximal occlusion in the anterior circulation who underwent endovascular treatment within 8 h from symptom onset.

Predicting discharge mortality after acute ischemic stroke using balanced data.

Several models have been developed to predict stroke outcomes (e.g., stroke mortality, patient dependence, etc.

Nephrotic syndrome.

Nephrotic syndrome refers to excessive proteinuria, with associated hypoalbuminemia, edema, and hyperlipidemia. A diverse spectrum of disorders has been associated with nephrotic syndrome and related neurologic complications, although the relative infrequency of these cases limits conclusive associations. Neurologic manifestations of nephrotic syndrome may result from hypoproteinemia, hypercoagulability, hyperlipidemia, hypertension, amyloid deposition, hormonal changes, or electrolyte disorders.

Magnetic resonance angiography signal intensity as a marker of hemodynamic impairment in intracranial arterial stenosis.

Background: Intracranial arterial stenosis (ICAS) is the predominant cause of ischemic stroke and transient ischemic attack in Asia. Change of signal intensities (SI) across an ICAS on magnetic resonance angiography (MRA) may reflect its hemodynamic severity.

Methods: In-patients with a symptomatic single ICAS detected on 3D time-of-flight MRA were recruited from 2 hospitals.

Imaging of cerebral ischemia: from acute stroke to chronic disorders.

Cerebral ischemia manifests widely in patient symptoms. Along with the clinical examination, imaging serves as a powerful tool throughout the course of ischemia-from acute onset to evolution. A thorough understanding of imaging modalities, their strengths and their limitations, is essential for capitalizing on the benefit of this complementary source of information for understanding the mechanism of disease, making therapeutic decisions, and monitoring patient response over time.

Age dependency of successful recanalization in anterior circulation stroke: the ENDOSTROKE study.

Background: Clinical outcome after endovascular stroke therapy (EVT) for proximal anterior circulation stroke is often disappointing despite high recanalization rates. The ENDOSTROKE study aims to determine predictors of clinical outcome in patients undergoing EVT. Here we focus on the impact of age and recanalization on proximal middle cerebral artery (M1-MCA) or carotid T occlusion.

Stroke treatment academic industry roundtable: research priorities in the assessment of neurothrombectomy devices.

Background And Purpose: The goal of the Stroke Treatment Academic Industry Roundtable (STAIR) meetings is to advance the development of stroke therapies. At STAIR VIII, consensus recommendations were developed for clinical trial strategies to demonstrate the benefit of endovascular reperfusion therapies for acute ischemic stroke.

Summary Of Review: Prospects for success with forthcoming endovascular trials are robust, because new neurothrombectomy devices have superior reperfusion efficacy compared with earlier-generation interventions.

Multi-delay multi-parametric arterial spin-labeled perfusion MRI in acute ischemic stroke - Comparison with dynamic susceptibility contrast enhanced perfusion imaging.

The purpose of the present study was to present a multi-delay multi-parametric pseudo-continuous arterial spin labeling (pCASL) protocol with background suppressed 3D GRASE (gradient and spin echo) readout for perfusion imaging in acute ischemic stroke. PCASL data at 4 post-labeling delay times (PLD = 1.5, 2, 2.

The goldilocks dilemma in acute ischemic stroke.

Despite the advent of and exciting advances in novel endovascular therapies, t-PA remains the only proven treatment for acute ischemic stroke to date. Although a variety of reasons likely underlie why past trials of endovascular strategies have been unsuccessful, we address in this perspective piece one critical unknown for which a solution is undoubtedly necessary if future ones are to meet with success: determination and selection of patients that are "just right" for endovascular treatments, or the Goldilocks dilemma. Key clinical criteria highlighted in past trials may help provide a solution to this critical problem.

Interobserver reproducibility of signal intensity ratio on magnetic resonance angiography for hemodynamic impact of intracranial atherosclerosis.

Background: Changes of signal intensities (SIs) across intracranial atherosclerosis (ICAS) on magnetic resonance angiography (MRA) may reflect hemodynamic impact of the lesion. We evaluated the interobserver reproducibility of an index termed signal intensity ratio (SIR), developed in a previous study to represent the changes of SIs across ICAS on MRA.

Methods: Symptomatic ICAS on MRA were retrospectively recruited.

THRIVE score predicts outcomes with a third-generation endovascular stroke treatment device in the TREVO-2 trial.

Background And Purpose: Several outcome prediction scores have been tested in patients receiving acute stroke treatment with previous generations of endovascular stroke treatment devices. The TREVO-2 trial was a randomized controlled trial comparing a novel endovascular stroke treatment device (the Trevo device) to a previous-generation endovascular stroke treatment device (the Merci device).

Methods: We used data from the TREVO-2 trial to validate the Totaled Health Risks in Vascular Events (THRIVE) score in patients receiving treatment with a third-generation endovascular stroke treatment device and to compare THRIVE to other predictive scores.

Elevated thyroid autoantibodies and intracranial stenosis in stroke at an early age.

Background: Previous studies have shown that hyperthyroidism was related to Moyamoya disease and intracranial artery stenosis. However, it is not clear whether thyroid hormone or thyroid autoantibodies was associated with them.

Aims And/or Hypothesis: Thyroid autoimmunity was previously shown to be associated with Moyamoya disease.