Stroke is the first cause of disability in industrialized countries. Thus, understanding the mechanisms of poststroke recovery appears to be crucial in improving motor performance and reducing disability in stroke patients. Strategies through which brain restores lost functions after ischemic lesions are numerous. The mechanisms underlying poststroke recovery, known as ...

Brain Computed tomography (CT) scan has been used in the past to exclude a hemorrhagic stroke, to determine a possible cause of the stroke patient symptoms, and to demonstrate a stabilized area of hypoperfusional flow. Several results from CT scan studies suggested that we could have new information on prognosis ...

BACKGROUND AND PURPOSE: The goal of thrombolytic therapy in patients with acute ischemic stroke is early recanalization, but this may result in delayed reperfusion injury. The purpose of this study was to evaluate the neuroprotective effect of agmatine in a transient ischemic cat model by using MR perfusion imaging and ...

Computed tomography (CT) scan remains the most widely technique in the cerebrovascular emergency, as it is largely available, minimally invasive, fast, cheap and reliable. Noncontrast enhanced CT (NeCT) imaging can show early signs of infarction in ischemic stroke; however, it could not show if the ischemic tissue is irreversibly damaged. ...

Generally, a computed tomography scan is conducted for the diagnosis of stroke in the emergency department, because these scans are easier and faster in the detection of stroke. If there are no signs of hemorrhage on computed tomography scan, an ischemic stroke is diagnosed and treated accordingly. A magnetic resonance ...

Ultrasonic perfusion imaging predicts size and localization of acute stroke. It is unclear whether irreversibly damaged tissue can be differentiated from tissue at risk. Thirty-four patients (ischemic stroke <12 h) were included (Phase Inversion Harmonic Perfusion Imaging; bolus kinetic; fitted model function). Three patterns of perfusion were defined in 14 ...

The number of potential patients who are actually treated for acute ischemic stroke is disappointingly low, and effective treatments are making a minor impact on this major public health problem. Imaging is not regularly used to identify the ischemic penumbra, a key concept in stroke physiology, though it is capable ...

AIM: To evaluate the feasibility and impact of diffusion weighted magnetic resonance imaging (DW MRI) as the first line neuroimaging of stroke at a district general hospital. METHODS: Prospective audit of all in-patients admitted with clinically suspected acute stroke and referred for imaging over a consecutive 17 week period. The ...

OBJECTIVE: The objective of this study was to describe leukoencephalopathy, lacunar infarcts, microbleeds and macrobleeds in the context of a collagen IV A1 mutation. METHODS: We examined a family with autosomal dominant porencephaly, in whom a defect in collagen IV A1 was detected recently. The patients underwent neurological, ophthalmological, and ...

Current guidelines on thrombolysis post stroke with recombinant tissue plasminogen activator (rt-PA) exclude its use where time of onset is unknown, thus denying some patients potentially beneficial treatment. Contrast enhanced perfusion computed tomography (pCT) imaging can be used together with plain CT and information on clinical deficits to decide whether ...

In recent years, combined diffusion-weighted imaging (DWI) with perfusion imaging (PI) has become an important investigational tool in the acute phase of ischemic stroke, as it may differentiate reversible from irreversible brain tissue damage. We consecutively examined 20 subjects within 12 h of stroke onset using a multiparametric magnetic resonance ...

INTRODUCTION: Computed tomography (CT) perfusion is a new method to diagnose ischaemic stroke especially in developing countries. It identifies the area and is useful to predict the size of final infarction. The aim of this study was to assess cerebral ischaemia with CT perfusion (CTP) among patients with acute ischaemic ...

Both leukoaraiosis and asymptomatic microbleeds are associated with small-artery diseases. Although an association between hyperhomocysteinemia and leukoaraiosis has been reported, no studies have evaluated the association between total homocysteine (tHcy) level and presence of microbleeds in stroke patients. We evaluated the association between tHcy level and leukoaraiosis or microbleeds in ...

Heat shock proteins (HSPs) are molecular chaperones with essential roles in modulating the proteolytic machinery and accelerating cell repair. Heat shock protein overexpression has been observed in vivo and in vitro under stresses including heat, nutrient deprivation and ischemia. Experiments in in vivo models of stroke indicate that transgenically overexpressed ...

The extent of cerebral infarction correlates with increased risk of intracerebral hemorrhage (ICH) following recombinant tissue plasminogen activator (rt-PA) administration. The Alberta Stroke Program Early CT Score (ASPECTS) is a widely used, validated method which assesses involvement of 10 selected regions of the MCA territory. An ASPECTS score >7 is ...

BACKGROUND: The aim of this study is to describe contrast-enhanced computed tomographic (CT) features of acute omental infarction and to study the evolutionary changes on follow-up CT imaging. METHODS: Fifteen cases of omental infarction were evaluated for their initial CT imaging features. The imaging features evaluated included size of the ...

CT perfusion scanning produces dynamic contrast-enhanced brain images, but to generate and interpret the colour maps of cerebral perfusion from these source images requires specialist neuroimaging knowledge. We hypothesized that physicians without such training might still utilise the CT perfusion source images (CTPSI) to diagnose early ischaemic change. Fifteen patients ...

AIM: To investigate how often early computed tomography (CT) signs are associated with blood-brain barrier (BBB) disruption and result in haemorrhagic transformations. MATERIALS AND METHODS: Serial CT findings were prospectively evaluated in 61 patients with acute middle cerebral artery (MCA) occlusion who underwent initial CT examination within 3h of stroke ...

PURPOSE: To report a method for determining absolute percentage change in cerebral blood flow (measurement of cerebrovascular reserve) before and after acetylazolamide (Diamox) administration in children with sickle cell anemia. MATERIALS AND METHODS: Thirty-six symptomatic sickle cell disease patients (48 studies) were evaluated. After the injection of either Tc-99m bicisate ...

Stroke carries a severe toll in terms of loss of life and disability for patients and their families. Until 10 years ago, physicians, and in particular neurologists, had a conservative, non-aggressive approach to this devastating disease. The advent of thrombolytic therapy not only proved that acute ischemic stroke is treatable, ...

BACKGROUND: We hypothesized that patients with clinically severe strokes but less severe early ischemic changes on brain CT (i.e., clinical-CT mismatch) may respond better to intravenous recombinant tissue plasminogen activator (i.v. rt-PA) within 3 h of symptom onset. METHODS: In this secondary analysis of the CLOTBUST data, patients with middle ...

OBJECTIVE: To assess the benefits of additional computed tomography perfusion (CTP) and computed tomography angiography (CTA) on the detection of early stroke, vessel occlusion, estimated infarct size, and interrater reliability. METHODS: Sixty-seven consecutive patients underwent nonenhanced computed tomography (CT) imaging, CTA, and CTP. The final diagnosis of stroke was made ...

As the overall health of patients with sickle cell anemia (SS) improves and diagnostic techniques become more sensitive, physicians are seeing patients with an increasingly wide range of subtle and not-so-subtle brain injury. The major breakthrough in the field of sickle-related brain injury has been the unprecedented success of transcranial ...

BACKGROUND: To investigate acute stage (<5 days) evolution of the watershed infarction (WI) on diffusion-weighted (DW) magnetic resonance (MR) imaging and to evaluate the role of perfusion MR imaging in predicting the progression of watershed infarction. METHODS: Twenty-eight patients with acute WI within 24 h after symptom onset were selected ...

The development of acute stroke therapies has yielded only limited success and many failures in multiple clinical trials. The target of acute stroke therapy is that portion of the ischemic region that is still potentially salvageable, i.e. the ischemic penumbra. Neuroprotective drugs have the potential to prevent a portion of ...

Although our clinical understanding remains our most important diagnostic tool, acute stroke therapy without neuroimaging is impossible. In most patients, only non-contrast computed tomography is used for diagnosis of acute stroke. However, findings based exclusively on clinical assessment and nonhemorrhagic computed tomography scans may no longer be appropriate for acute ...

PURPOSE: The hyperintense appearance of the middle cerebral artery (HMCA) sign consists of a thickened MCA stem with a blurred intense signal on contrast enhanced T1-weighted magnetic resonance imaging (T1W MRI). In this article, we define it and determine its incidence, diagnostic value, and reliability by comparison with magnetic resonance ...

Thrombolysis has become an approved therapy for acute stroke. However, many stroke patients do not benefit from such treatment, since the presently used criteria are very restrictive, notably with respect to the accepted time window. Even so, a significant rate of intracranial hemorrhage still occurs. Conventional cerebral computed tomography (CT) ...

PURPOSE: To evaluate prospectively with magnetic resonance (MR) imaging the coexistence of microhemorrhages (MHs) in white patients with acute spontaneous intraparenchymal hemorrhage (IPH) and acute ischemic stroke and to study the association with imaging findings of microangiopathy and various clinical data. MATERIALS AND METHODS: Before examinations, informed consents were signed ...

Stroke remains one of the most important clinical diagnoses for which patients are referred to the radiologist for emergent imaging. Timely and accurate imaging guides admission from the emergency department or transfer to a hospital with a dedicated stroke service, triage to the intensive care unit, anticoagulation, thrombolysis, and many ...

Although neuroimaging remains the foundation for the diagnosis of cerebrovascular disease, ongoing technologic advances have now opened up new frontiers for stroke evaluation and treatment. Neuroimaging studies can provide crucial information regarding tissue injury (size, location, and degree of reversibility of ischemic injury as well as presence of hemorrhage), vessel ...

Stroke in the young adult often presents a diagnostic challenge. This report presents a case of a 27-year-old man who developed an abrupt onset of weakness and aphasia. Transesophageal and transthoracic echocardiography were normal. Chest computed tomography (CT) was then performed during the evaluation, and a left ventricular thrombus was ...

INTRODUCTION: Diffusion-weighted (DW) MR imaging enables early identification of ischemic lesions in stroke. Stroke subtype may be related to different lesion patterns. The aim of this study was to analyze the subtype of ischemic lesions as determined by the Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria by ...

Since acute stroke is now considered a potentially treatable medical emergency, a rapid and correct diagnosis must be made. The first step is to exclude hemorrhage, then to visualize any early ischemic changes, demonstrate the presence of hypoperfusion and locate the presence of a vascular underlying pathology as well as ...

INTRODUCTION: It is becoming increasingly recognized that CNS immaturity at birth affects ischemic injury and recovery, and that the consequences of neonatal stroke need to be studied using age-appropriate focal stroke models. The inclusion of magnetic resonance imaging (MRI) as a surrogate measure of stroke progression has provided useful information ...

Noncontrast head CT has an important role in the work-up of acute stroke by excluding intracranial hemorrhage and by directly visualizing the parenchymal changes of early infarct. However, noncontrast CT has limited sensitivity and moderate interobserver variability in detecting early infarcts. This article reviews the noncontrast CT appearance and clinical ...

Diffusion and perfusion MRI have contributed to stroke management by identifying patients with tissue "at risk" for further damage in acute stroke. However, the potential usefulness of these imaging modalities, along with diffusion tensor imaging, can be expanded by using these imaging techniques with concurrent assessment of language and other ...

The purpose of our study was to identify the perfusion MRI (pMRI) algorithm which yields a volume of hypoperfused tissue that best correlates with the acute clinical deficit as quantified by the NIH Stroke Scale (NIHSS) and therefore reflects critically hypoperfused tissue. A group of 20 patients with a first ...

We found previously that plasma levels of acrolein (CH2=CHCHO) and spermine oxidase (SMO) were well correlated with the degree of severity of chronic renal failure. The aim of this study was to test whether the levels of these 2 markers and of acetylpolyamine oxidase (AcPAO) were increased in the plasma ...

BACKGROUND AND OBJECTIVES: Controversy exists about the optimal imaging technique in acute stroke. It was hypothesised that CT is comparable with DWI, when both are read systematically using quantitative scoring. METHODS: Ischaemic stroke patients who had CT within six hours and DWI within seven hours of onset were included. Five ...

The incidence and characteristics of microbleeds in hemodialysis (HD) patients were investigated to elucidate the clinical significance with T(2)(*)-weighted gradient-echo magnetic resonance (MR) imaging. The 57 patients with chronic renal failure maintained by HD had no previous history of stroke. The control group consisted of 53 patients without previous history ...

The role of neuro-imaging in the evaluation of acute stroke has changed dramatically in the past decade. Previously, neuro-imaging was used in this setting to provide anatomic imaging that indicated the presence or absence of acute cerebral ischemia and excluded lesions that produce symptoms or signs mimicking those of stroke, ...

OBJECTIVE: To determine the clinical presentation and aetiology of small subcortical infarctions as found on diffusion weighted magnetic resonance imaging (DWI). DWI is both sensitive and specific in the early detection of acute ischaemic brain lesions irrespective of pre-existing vascular damage. METHODS: Ninety three patients were identified showing subcortical or ...

The Alberta Stroke Program Early Computed Tomography Score (ASPECTS) has not been previously applied to perfusion CT (CTP). Five raters assigned ASPECTS to baseline noncontrast CT (NCCT), CT angiography source images (CTA-SI), CTP source images (CTP-SI), and CTP maps of cerebral blood volume (CBV), cerebral blood flow (CBF), and mean ...

Regular, evidence-based assignment of patients to etiologic stroke categories is essential to enable valid comparison among studies. We designed an algorithm (SSS-TOAST) that incorporated recent advances in stroke imaging and epidemiology to identify the most probable TOAST category in the presence of evidence for multiple mechanisms. Based on the weight ...

OBJECTIVES: To assess organisational and patient specific limitations and safety of magnetic resonance imaging (MRI) as the first line investigation for hospital admitted stroke patients. METHODS: Consecutive patients admitted with acute stroke were assessed and an attempt was made to perform MRI in all patients. Oxygen saturation and interventions required ...

BACKGROUND AND PURPOSE: To evaluate the clinical significance of early ischemic change (EIC) on computed tomography (CT), pertinent factors that contribute to the appearance of EIC. METHODS: Both CT and technetium-99m hexamethylpropylene amine oxime were performed on a total of 53 patients (34 men, 19 women, mean 69.7 years old) ...

OBJECTIVE: To establish the validity of visual interpretation of immediately processed perfusion computed tomography (CT) maps in acute stroke for prediction of final infarction. METHODS: Perfusion CT studies acquired prospectively were reprocessed within six hours of stroke onset using standard CT console software. Four contiguous 5 mm thick images were ...

BACKGROUND AND PURPOSE: We report the first case of 2 intravenous thrombolysis treatments within 90 hours in a patient with early recurrent stroke. SUMMARY OF REVIEW: A 50-year-old man had improved significantly after intravenous thrombolysis for acute stroke. On the fourth day, he deteriorated dramatically because of recurrent stroke. Evidence ...

Stroke is a leading cause of disability in the Western world, yet the choices for therapeutic intervention are few. The complex role played by aldosterone in the pathogenesis of stroke is beginning to emerge. Chronic mineralocorticoid receptor (MR) blockade reduces the incidence of hemorrhagic strokes and the severity of damage ...