The ischemic penumbra: From concept to reality

Ermine, Charlotte M.; Bivard, Andrew; Baron, Jean‐Claude

doi:10.1177/1747493020975229

Cited by 52 publications

(39 citation statements)

References 113 publications

(168 reference statements)

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“…All patients received standard therapy, and the 90-day well prognosis rate (mRS score 0–2) was significantly better in the plains than patients in the highlands. The large infarct size and severe functional impairment symptoms in the highlands may be related to the compensatory increase in RBC and HB levels, elevated blood viscosity, severe systemic and vascular inflammatory pathology, and the hypoxic environment that aggravates the cascade of neuronal cell damage after stroke, resulting in a double “hypoxic” injury and promoting the early development of the “ischemic penumbra” to the “infarct focus” ( 44 – 46 ).…”

Section: Discussionmentioning

confidence: 99%

Anterior Circulation Acute Ischemic Stroke in the Plateau of China: Risk Factors and Clinical Characteristics

Yan

Zhang²,

Ren

et al. 2022

Front. Neurol.

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Background and PurposeAcute ischemic stroke has a high incidence in the plateau of China. It has unique characteristics compared to the plains, and the specific relationship with altitude has not yet been appreciated. This study aimed to investigate the specificity of the plateau's anterior circulation acute ischemic stroke in China.MethodsTo retrospectively collect clinical data of patients with first-episode acute ischemic stroke in the anterior circulation in Tianjin and Xining city. The differences in clinical presentation, laboratory, and imaging examinations were compared.ResultsPatients at high altitudes showed a significant trend toward lower age (61.0 ± 10.2 vs. 64.8 ± 8.1, P = 0.010) and had a history of dyslipidemia, higher levels of inflammatory markers, erythrocytosis, and alcohol abuse. The main manifestations were higher diastolic blood pressure (85.5 ± 14.0 mmHg vs. 76.8 ± 11.6 mmHg, P < 0.001), triglycerides [2.0 (1.8) mmol/L vs. 1.3 (0.9) mmol/L, P < 0.001], CRP [4.7 (4.4) mg/L vs. 2.1 (1.9) mg/L, P < 0.001], homocysteine levels [14.5 (11.7) μmol/L vs. 11.2 (5.2) μmol/L, P < 0.001]; larger infarct volume [3.5 (4.8) cm3 vs. 9.0 (6.9) cm3, P < 0.001] and worse prognosis. Patients at high altitudes had higher atherosclerotic indexes in cIMT and plaque than those in plains.ConclusionsThe natural habituation and genetic adaptation of people to the particular geo-climatic environment of the plateau have resulted in significant differences in disease characteristics. Patients with the anterior circulation acute ischemic stroke in the plateau show more unfavorable clinical manifestations and prognosis. This study provides a preliminary interpretation of the effects of altitude and suggests developing preventive and therapeutic protocol measures that are more appropriate for the plateau of China.

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Section: Discussionmentioning

confidence: 99%

Anterior Circulation Acute Ischemic Stroke in the Plateau of China: Risk Factors and Clinical Characteristics

Yan

Zhang²,

Ren

et al. 2022

Front. Neurol.

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“…The shift from a “time-based” to a “tissue-based” approach has significantly improved stroke management by extending therapeutic windows in patients with persistent penumbra, i.e. those with a good collateral status ( 47 , 48 ). CT and MRI are therefore used in daily practice to guide therapy in patients managed beyond the conventional time window.…”

Section: Evolution Of Penumbra Imaging In Clinical Emergency Settingsmentioning

confidence: 99%

Clinical Imaging of the Penumbra in Ischemic Stroke: From the Concept to the Era of Mechanical Thrombectomy

Chalet

Boutelier

Christen

et al. 2022

Front. Cardiovasc. Med.

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The ischemic penumbra is defined as the severely hypoperfused, functionally impaired, at-risk but not yet infarcted tissue that will be progressively recruited into the infarct core. Early reperfusion aims to save the ischemic penumbra by preventing infarct core expansion and is the mainstay of acute ischemic stroke therapy. Intravenous thrombolysis and mechanical thrombectomy for selected patients with large vessel occlusion has been shown to improve functional outcome. Given the varying speed of infarct core progression among individuals, a therapeutic window tailored to each patient has recently been proposed. Recent studies have demonstrated that reperfusion therapies are beneficial in patients with a persistent ischemic penumbra, beyond conventional time windows. As a result, mapping the penumbra has become crucial in emergency settings for guiding personalized therapy. The penumbra was first characterized as an area with a reduced cerebral blood flow, increased oxygen extraction fraction and preserved cerebral metabolic rate of oxygen using positron emission tomography (PET) with radiolabeled O2. Because this imaging method is not feasible in an acute clinical setting, the magnetic resonance imaging (MRI) mismatch between perfusion-weighted imaging and diffusion-weighted imaging, as well as computed tomography perfusion have been proposed as surrogate markers to identify the penumbra in acute ischemic stroke patients. Transversal studies comparing PET and MRI or using longitudinal assessment of a limited sample of patients have been used to define perfusion thresholds. However, in the era of mechanical thrombectomy, these thresholds are debatable. Using various MRI methods, the original penumbra definition has recently gained a significant interest. The aim of this review is to provide an overview of the evolution of the ischemic penumbra imaging methods, including their respective strengths and limitations, as well as to map the current intellectual structure of the field using bibliometric analysis and explore future directions.

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“…In conclusion, we have been fortunate to have been witness to and played a small part in what could be termed the penumbral revolution [106,107]. The prediction of Lindsay Symon that the penumbra could be imaged in real time and form the basis for therapeutic intervention has been thoroughly validated.…”

Section: Intravenous Thrombolysismentioning

confidence: 99%

Ischemic Penumbra: A Personal View

Davis¹,

Donnan²

2021

Cerebrovasc Dis

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The concept of the ischemic penumbra was defined over 40 years ago by Lindsay Symon and his group and is now an established principle of all acute ischemic stroke therapies. These reperfusion treatments rescue threatened, critically hypoperfused brain tissue and have been proven to improve clinical outcomes. We have been fortunate to have observed and played a small part in the penumbral story from its beginnings in the 1970s to its pivotal position today. Over this period, we have witnessed penumbral imaging evolve from positron emission tomography through to magnetic resonance imaging and now predominantly computed tomography perfusion, with the advent of automated imaging facilitating case selection for reperfusion therapies. We and others have conducted clinical trials using penumbral imaging to extend the time window for intravenous thrombolysis and select patients for thrombectomy. Together with the concept of fast- and slow-growing ischemic infarct patterns, this embeds the penumbral principle in everyday clinical management. The opportunity now exists to make penumbral imaging even more portable, affordable, and more widely available using mobile platforms, novel imaging techniques, digital linkage, and artificial intelligence.

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The ischemic penumbra: From concept to reality

Cited by 52 publications

References 113 publications

Anterior Circulation Acute Ischemic Stroke in the Plateau of China: Risk Factors and Clinical Characteristics

Anterior Circulation Acute Ischemic Stroke in the Plateau of China: Risk Factors and Clinical Characteristics

Clinical Imaging of the Penumbra in Ischemic Stroke: From the Concept to the Era of Mechanical Thrombectomy

Ischemic Penumbra: A Personal View

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