Publications by authors named "Campbell B C"

Importance: Reperfusion is a key factor for clinical outcome in patients with acute ischemic stroke (AIS) treated with endovascular thrombectomy (EVT) for large-vessel intracranial occlusion. However, data are scarce on the association between the time from onset and reperfusion results.

Objective: To analyze the rate of reperfusion after EVT started at different intervals after symptom onset in patients with AIS.

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Importance: The positive treatment effect of endovascular therapy (EVT) is assumed to be caused by the preservation of brain tissue. It remains unclear to what extent the treatment-related reduction in follow-up infarct volume (FIV) explains the improved functional outcome after EVT in patients with acute ischemic stroke.

Objective: To study whether FIV mediates the relationship between EVT and functional outcome in patients with acute ischemic stroke.

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Although dehydroepiandrosterone (DHEA) may exert neuroprotective effects in the developing brain, prolonged or excessive elevations in cortisol may exert neurotoxic effects. The ratio between DHEA and cortisol (DC ratio) has been linked to internalising and externalising disorders, as well as cognitive performance, supporting the clinical relevance of this hormonal ratio during development. However, the brain mechanisms by which these effects may be mediated have not yet been identified.

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Background: EXtending the time for Thrombolysis in Emergency Neurological Deficits (EXTEND) is a randomized, multicenter, double-blinded, placebo-controlled phase 3 trial to test the hypothesis of extending the thrombolysis time window to 9 h from stroke onset and in wake-up stroke (WUS) patients.

Objective: To formulate the detailed statistical analysis plan for the EXTEND trial prior to database lock. This statistical analysis plan is based on the published and registered EXTEND trial protocol and is developed by the blinded steering committee and management team.

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Objective: Spending at least 90% of hospital admission in a stroke unit (SU) is a recommended indicator of receiving high-quality stroke care. However, whether this makes a difference to patient outcomes is unknown. We aimed to investigate outcomes and factors associated with patients with acute stroke spending at least 90% of their admission in an SU, compared with those having less time in the SU.

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Background: CT perfusion (CTP) and diffusion or perfusion MRI might assist patient selection for endovascular thrombectomy. We aimed to establish whether imaging assessments of irreversibly injured ischaemic core and potentially salvageable penumbra volumes were associated with functional outcome and whether they interacted with the treatment effect of endovascular thrombectomy on functional outcome.

Methods: In this systematic review and meta-analysis, the HERMES collaboration pooled patient-level data from all randomised controlled trials that compared endovascular thrombectomy (predominantly using stent retrievers) with standard medical therapy in patients with anterior circulation ischaemic stroke, published in PubMed from Jan 1, 2010, to May 31, 2017.

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Background and Purpose- The volume of estimated ischemic core using computed tomography perfusion (CTP) imaging can identify ischemic stroke patients who are likely to benefit from reperfusion, particularly beyond standard time windows. We assessed the accuracy of pretreatment CTP estimated ischemic core in patients with successful endovascular reperfusion. Methods- Patients from the HERMES (Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke Trials) and EXTEND-IA TNK (Tenecteplase Versus Alteplase Before Endovascular Therapy for Ischemic Stroke) databases who had pretreatment CTP, >50% angiographic reperfusion, and follow-up magnetic resonance imaging at 24 hours were included.

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Even though stroke presents as a variety of clinical syndromes, neuroimaging is the most important biomarker to help differentiate between stroke subtypes and assess treatment eligibility. Therapeutic advances have led to intravenous thrombolysis with tissue-type plasminogen activator and endovascular treatment for proximal vessel occlusion in the anterior cerebral circulation being standard care for acute ischaemic stroke. Providing access to this care has implications for existing systems of care for stroke and their organisation and has reintroduced the possibility of adjuvant and neuroprotective treatment strategies in acute ischaemic stroke.

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Background: Evidence regarding whether imaging can be used effectively to select patients for endovascular thrombectomy (EVT) is scarce. We aimed to investigate the association between baseline imaging features and safety and efficacy of EVT in acute ischaemic stroke caused by anterior large-vessel occlusion.

Methods: In this meta-analysis of individual patient-level data, the HERMES collaboration identified in PubMed seven randomised trials in endovascular stroke that compared EVT with standard medical therapy, published between Jan 1, 2010, and Oct 31, 2017.

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Background: Revascularization after endovascular therapy for acute ischemic stroke is measured by the Thrombolysis In Cerebral Infarction (TICI) scale, yet variability exists in scale definitions. We examined the degree of reperfusion with the expanded TICI (eTICI) scale and association with outcomes in the HERMES collaboration of recent endovascular trials.

Methods: The HERMES Imaging Core, blind to all other data, evaluated angiography after endovascular therapy in HERMES.

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Background And Purpose: Degeneration of gray matter and subcortical structures after ischemic stroke has been well described. However, little is known about white matter degeneration after stroke. It is unclear whether white matter degeneration occurs throughout the whole brain, or whether patterns of degeneration occur more in specific brain areas.

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Goal: Epilepsy is a major complication of stroke. There have been suggestions that patients with cardioembolic stroke are at a greater risk of developing seizures than other stroke subtypes. However, the incidence of atrial fibrillation (AF) and cardioembolic stroke varies considerably across countries, generally higher in Western populations than in Asian populations.

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Alteplase has been the mainstay of thrombolytic treatment since the National Institutes of Neurological Disorders and Stroke trial was published in 1995. Over recent years, several trials have investigated alternative thrombolytic agents. Tenecteplase, a genetically engineered mutant tissue plasminogen activator, has a longer half-life, allowing single intravenous bolus administration without infusion, is more fibrin specific, produces less systemic depletion of circulating fibrinogen, and is more resistant to plasminogen activator inhibitor compared to alteplase.

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Background: Administration of intravenous idarucizumab to reverse dabigatran anticoagulation prior to thrombolysis for patients with acute ischemic stroke has been previously described, but not in the prehospital setting. The speed and predictability of idarucizumab reversal is well suited to prehospital treatment in a mobile stroke unit and allows patients with recent dabigatran intake to access reperfusion therapy.

Aims: To describe feasibility of prehospital idarucizumab administration prior to thrombolysis on the Melbourne mobile stroke unit.

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Mitochondria are a major target for aging and are instrumental in the age-dependent deterioration of the human brain, but studying mitochondria in aging human neurons has been challenging. Direct fibroblast-to-induced neuron (iN) conversion yields functional neurons that retain important signs of aging, in contrast to iPSC differentiation. Here, we analyzed mitochondrial features in iNs from individuals of different ages.

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Background And Purpose: Midline shift determined on magnetic resonance imaging (MRI) or computed tomography (CT) images is a well-validated marker of mass effect after large hemispheric infarction and associated with mortality. In this study, we targeted a population with moderately sized strokes. We compared midline shift to other imaging markers and determined their ability to predict long-term outcome.

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Background: Epilepsy is a major complication of stroke. We aimed to establish whether there is an association between intravenous thrombolysis, intra-arterial thrombolysis and post stroke seizure (PSS) development. Improved understanding of the relationship between reperfusion therapies and seizure development may improve post-stroke monitoring and follow-up.

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Background: Intravenous infusion of alteplase is used for thrombolysis before endovascular thrombectomy for ischemic stroke. Tenecteplase, which is more fibrin-specific and has longer activity than alteplase, is given as a bolus and may increase the incidence of vascular reperfusion.

Methods: We randomly assigned patients with ischemic stroke who had occlusion of the internal carotid, basilar, or middle cerebral artery and who were eligible to undergo thrombectomy to receive tenecteplase (at a dose of 0.

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Background: Follow-up infarct volume (FIV) has been recommended as an early indicator of treatment efficacy in patients with acute ischemic stroke. Questions remain about the optimal imaging approach for FIV measurement.

Objective: To examine the association of FIV with 90-day modified Rankin Scale (mRS) score and investigate its dependency on acquisition time and modality.

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Background Several stroke outcome and quality control projects have demonstrated the success in stroke care quality improvement through structured process. However, Chinese health-care systems are challenged with its overwhelming numbers of patients, limited resources, and large regional disparities. Aim To improve quality of stroke care to address regional disparities through process improvement.

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This review summarizes the current state of knowledge regarding the use of imaging to guide stroke treatment. Brain imaging plays a central role in the diagnosis of stroke and identification of the mechanism of stroke, which is relevant to acute treatment, prognosis, and secondary prevention. The chief potential modalities are computed tomography (CT) and magnetic resonance imaging (MRI).

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Background And Purpose: Clinical triage scales for prehospital recognition of large vessel occlusion (LVO) are limited by low specificity when applied by paramedics. We created the 3-step ambulance clinical triage for acute stroke treatment (ACT-FAST) as the first algorithmic LVO identification tool, designed to improve specificity by recognizing only severe clinical syndromes and optimizing paramedic usability and reliability.

Methods: The ACT-FAST algorithm consists of (1) unilateral arm drift to stretcher <10 seconds, (2) severe language deficit (if right arm is weak) or gaze deviation/hemineglect assessed by simple shoulder tap test (if left arm is weak), and (3) eligibility and stroke mimic screen.

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