Scholars@Duke
William John Powers

William John Powers

Professor of Neurology
Hospital Neurology
william.powers@duke.edu
Duke South, Room 120A, Durham, NC 27710
DUMC Box 3824, Durham, NC 27710

Selected Publications

Utility of Clinical Features in Identifying Electrographic Seizures in Hospitalized Patients Admitted for Non-Neurological Diagnoses

Journal Article Critical Care Explorations · October 21, 2024 IMPORTANCE: Electrographic seizures (ESz) are seizures without prominent motor activity diagnosed with electroencephalogram and are a common complication in critically ill patients with alterations of consciousness. Previous studies suggested clinical sign ... Full text Cite

Comparison of cerebral oxygen extraction fraction using ASE and TRUST methods in patients with sickle cell disease and healthy controls.

Journal Article J Cereb Blood Flow Metab · August 2024 Abnormal oxygen extraction fraction (OEF), a putative biomarker of cerebral metabolic stress, may indicate compromised oxygen delivery and ischemic vulnerability in patients with sickle cell disease (SCD). Elevated OEF was observed at the tissue level acro ... Full text Link to item Cite

Selecting stroke patients for thrombectomy: is CTA+ASPECTS enough?

Journal Article J Neurol Neurosurg Psychiatry · October 2023 Full text Link to item Cite

Extracranial-Intracranial Bypass and Risk of Stroke and Death in Patients With Symptomatic Artery Occlusion: The CMOSS Randomized Clinical Trial.

Journal Article JAMA · August 22, 2023 IMPORTANCE: Prior trials of extracranial-intracranial (EC-IC) bypass surgery showed no benefit for stroke prevention in patients with atherosclerotic occlusion of the internal carotid artery (ICA) or middle cerebral artery (MCA), but there have been subseq ... Full text Link to item Cite

In vivo detection of penetrating arteriole alterations in cerebral white matter in patients with diabetes with 7 T MRI.

Journal Article Magn Reson Imaging · July 2023 Cerebral small vessel disease (SVD) is responsible for primary intracerebral hemorrhages, lacunar infarcts and white matter hyperintensity in T2 weighted images. While the brain lesions attributed to small vessel disease can be characterized by conventiona ... Full text Link to item Cite

Effects of early human immunodeficiency virus infection on cerebral white matter blood flow autoregulation.

Journal Article AIDS · February 1, 2023 Blood flow autoregulation in cerebral white matter was measured before and after acute nicardipine-induced changes in mean arterial pressure of 10-21% in 21 treatment naïve HIV-positive adults and 32 controls. The autoregulatory index (-% cerebral blood fl ... Full text Link to item Cite

Prospective motion correction and automatic segmentation of penetrating arteries in phase contrast MRI at 7 T.

Journal Article Magn Reson Med · November 2022 PURPOSE: To develop a prospective motion correction (MC) method for phase contrast (PC) MRI of penetrating arteries (PAs) in centrum semiovale at 7 T and to evaluate its performance using automatic PA segmentation. METHODS: Head motion was monitored and co ... Full text Link to item Cite

ACR Appropriateness Criteria® Cranial Neuropathy: 2022 Update.

Journal Article J Am Coll Radiol · November 2022 Cranial neuropathy can result from pathology affecting the nerve fibers at any point and requires imaging of the entire course of the nerve from its nucleus to the end organ in order to identify a cause. MRI with and without intravenous contrast is often t ... Full text Link to item Cite

Strokelore: Therapeutic Relevance of Lacunar Infarcts.

Journal Article J Stroke Cerebrovasc Dis · August 2022 Full text Link to item Cite

Comparison of Outcomes of Ischemic Stroke Initially Imaged With Cranial Computed Tomography Alone vs Computed Tomography Plus Magnetic Resonance Imaging.

Journal Article JAMA Netw Open · July 1, 2022 IMPORTANCE: Patients with acute ischemic stroke often undergo magnetic resonance imaging (MRI) in addition to computed tomography (CT), but its association with clinical outcomes is uncertain. OBJECTIVE: To assess whether clinical outcomes of patients with ... Full text Link to item Cite

Strokelore: Outcome of Basilar Artery Occlusion.

Journal Article J Stroke Cerebrovasc Dis · June 2022 Full text Link to item Cite

Strokelore: Antithrombotic therapy and hemorrhagic infarction.

Journal Article J Stroke Cerebrovasc Dis · April 2022 Full text Link to item Cite

Reduction in cerebral oxygen metabolism in subcortical regions may be a biomarker of cognitive decline in people living with human immunodeficiency virus.

Journal Article Eur J Neurol · April 2022 BACKGROUND AND PURPOSE: Regional cerebral blood flow (rCBF) and oxygen metabolism (rCMRO2 ) in whole brain, white matter, gray matter and lenticular nuclei were studied in people living with human immunodeficiency virus (PLHIV) as well as HIV-associated ne ... Full text Link to item Cite

Strokelore: Early Anticoagulation for Large Ischemic Strokes.

Journal Article J Stroke Cerebrovasc Dis · December 2021 Full text Link to item Cite

"Disappearing Infarct" Is Late-Onset MELAS.

Journal Article Ann Neurol · December 2021 Full text Link to item Cite

ACR Appropriateness Criteria® Cerebrovascular Diseases-Aneurysm, Vascular Malformation, and Subarachnoid Hemorrhage.

Journal Article J Am Coll Radiol · November 2021 Cerebrovascular disease is a broad topic. This document focuses on the imaging recommendations for the varied clinical scenarios involving intracranial aneurysms, vascular malformations, and vasculitis, which all carry high risk of morbidity and mortality. ... Full text Link to item Cite

ACR Appropriateness Criteria® Low Back Pain: 2021 Update.

Journal Article J Am Coll Radiol · November 2021 In the United States, acute low back pain, with or without radiculopathy, is the leading cause of years lived with disability and the third ranking cause of disability-adjusted life-years. Uncomplicated acute low back pain and/or radiculopathy is a benign, ... Full text Link to item Cite

ACR Appropriateness Criteria® Syncope.

Journal Article J Am Coll Radiol · May 2021 Syncope and presyncope lead to well over one million emergency room visits in the United States each year. Elucidating the cause of syncope or presyncope, which are grouped together given similar etiologies and outcomes, can be exceedingly difficult given ... Full text Link to item Cite

Clinical utility of echocardiography in secondary ischemic stroke prevention.

Chapter · 2021 Echocardiography employs ultrasound to evaluate cardiac function, structure and pathology. The clinical value in secondary ischemic stroke prevention depends on identification of associated conditions for which a change in treatment from antiplatelet agent ... Full text Link to item Cite

15O PET Imaging: Methods and Applications

Chapter · January 1, 2021 Oxygen metabolism plays a central role in maintaining normal neuronal functions and tissue integrity. The ability to evaluate cerebral blood flow, oxygen extraction fraction, and cerebral metabolic rate of oxygen is critical to understanding neurological d ... Full text Cite

Acute Ischemic Stroke.

Journal Article N Engl J Med · July 16, 2020 Full text Link to item Cite

Recurrent Hemispheric Stroke Syndromes in Symptomatic Atherosclerotic Internal Carotid Artery Occlusions: The Carotid Occlusion Surgery Study Randomized Trial.

Journal Article Neurosurgery · July 1, 2020 BACKGROUND: There are limited data on outcomes of extracranial-intracranial (EC-IC) bypass in patients with recurrent hemispheric syndromes due to atherosclerotic internal carotid artery occlusion (AICAO). OBJECTIVE: To compare clinical outcomes and effica ... Full text Link to item Cite

Diagnostic accuracy of acute infarcts in multiple cerebral circulations for cardioembolic stroke: Literature review and meta-analysis.

Journal Article J Stroke Cerebrovasc Dis · July 2020 OBJECTIVE: To determine the diagnostic value of acute infarcts in multiple cerebral circulations (AIMCC) on MRI diffusion-weighted imaging (DWI) for cardioembolism (CE) stroke subtype in adult patients hospitalized with acute ischemic stroke, we conducted ... Full text Link to item Cite

ACR Appropriateness Criteria® Dementia.

Journal Article J Am Coll Radiol · May 2020 Degenerative disease of the central nervous system is a growing public health concern. The primary role of neuroimaging in the workup of patients with probable or possible Alzheimer disease has typically been to exclude other significant intracranial abnor ... Full text Link to item Cite

ACR Appropriateness Criteria® Movement Disorders and Neurodegenerative Diseases.

Journal Article J Am Coll Radiol · May 2020 Movement disorders and neurodegenerative diseases are a variety of conditions that involve progressive neuronal degeneration, injury, or death. Establishing the correct diagnosis of a movement disorder or neurodegenerative process can be difficult due to t ... Full text Link to item Cite

Guidelines for the Early Management of Patients With Acute Ischemic Stroke: 2019 Update to the 2018 Guidelines for the Early Management of Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association.

Journal Article Stroke · December 2019 Background and Purpose- The purpose of these guidelines is to provide an up-to-date comprehensive set of recommendations in a single document for clinicians caring for adult patients with acute arterial ischemic stroke. The intended audiences are prehospit ... Full text Link to item Cite

ACR Appropriateness Criteria® Headache.

Journal Article J Am Coll Radiol · November 2019 Headache is one of the most common human afflictions. In most cases, headaches are benign and idiopathic, and resolve spontaneously or with minor therapeutic measures. Imaging is not required for many types of headaches. However, patients presenting with h ... Full text Link to item Cite

ACR Appropriateness Criteria® Ataxia.

Journal Article J Am Coll Radiol · May 2019 Ataxia can result from an abnormality in the cerebellum, spinal cord, peripheral nerves, and/or vestibular system. Pathology involving the brain, such as infarct or hydrocephalus, can also present with ataxia as part of the symptom constitution, or result ... Full text Link to item Cite

ACR Appropriateness Criteria® Neuroendocrine Imaging.

Journal Article J Am Coll Radiol · May 2019 Neuroendocrine dysfunction includes suspected hyper- and hypofunction of the pituitary gland. Causative lesions may include primary masses of the pituitary such as pituitary microadenomas and macroadenomas, as well as extrinsic masses, typically centered i ... Full text Link to item Cite

Oxygen metabolism in acute ischemic stroke.

Journal Article J Cereb Blood Flow Metab · September 2018 Gaining insights into brain oxygen metabolism has been one of the key areas of research in neurosciences. Extensive efforts have been devoted to developing approaches capable of providing measures of brain oxygen metabolism not only under normal physiologi ... Full text Link to item Cite

ACR Appropriateness Criteria® Orbits Vision and Visual Loss.

Journal Article J Am Coll Radiol · May 2018 Visual loss can be the result of an abnormality anywhere along the visual pathway including the globe, optic nerve, optic chiasm, optic tract, thalamus, optic radiations or primary visual cortex. Appropriate imaging analysis of visual loss is facilitated b ... Full text Link to item Cite

2018 Guidelines for the Early Management of Patients With Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association.

Journal Article Stroke · March 2018 BACKGROUND AND PURPOSE: The purpose of these guidelines is to provide an up-to-date comprehensive set of recommendations for clinicians caring for adult patients with acute arterial ischemic stroke in a single document. The intended audiences are prehospit ... Full text Link to item Cite

Dissociation Between Hormonal Counterregulatory Responses and Cerebral Glucose Metabolism During Hypoglycemia.

Journal Article Diabetes · December 2017 Hypoglycemia is the most common complication of diabetes, causing morbidity and death. Recurrent hypoglycemia alters the cascade of physiological and behavioral responses that maintain euglycemia. The extent to which these responses are normally triggered ... Full text Link to item Cite

Increased Cortical Cerebral Blood Flow in Asymptomatic Human Immunodeficiency Virus-Infected Subjects.

Journal Article J Stroke Cerebrovasc Dis · August 2016 BACKGROUND: Human immunodeficiency virus (HIV)-infected individuals are at high risk for ischemic stroke. To investigate the physiological basis for this risk, we used magnetic resonance imaging (MRI) to measure oxygen extraction fraction (OEF) and cerebra ... Full text Link to item Cite

Effect of High-Dose Simvastatin on Cerebral Blood Flow and Static Autoregulation in Subarachnoid Hemorrhage.

Journal Article Neurocrit Care · August 2016 BACKGROUND: Statins may promote vasodilation following subarachnoid hemorrhage (SAH) and improve the response to blood pressure elevation. We sought to determine whether simvastatin increases cerebral blood flow (CBF) and alters the response to induced hyp ... Full text Link to item Cite

Relative Mean Transit Time Predicts Subsequent Stroke in Symptomatic Carotid Occlusion.

Journal Article J Stroke Cerebrovasc Dis · June 2016 BACKGROUND: Mean transit time (MTT) measurements to assess cerebral hemodynamics are easily obtained by computed tomography and magnetic resonance imaging. We reviewed hemodynamic and clinical outcome data from the St. Louis Carotid Occlusion Study to dete ... Full text Link to item Cite

Pupil-sparing third nerve palsies and hemiataxia: Claude's and reverse Claude's syndrome.

Journal Article J Clin Neurosci · June 2016 We report two patients with midbrain infarction with pupil-sparing third nerve palsies and hemiataxia: one with contralateral ataxia (Claude's syndrome) and one with ipsilateral ataxia (which we refer to as reverse Claude's syndrome). We highlight the impo ... Full text Link to item Cite

Antiplatelet therapy

Chapter · January 1, 2016 Antiplatelet therapy is the first-line antithrombotic drug treatment for secondary ischemic stroke prevention in most situations, with the notable exception of atrial fibrillation. Drugs other than aspirin offer a small additional benefit. Anti-platelet ag ... Full text Cite

Reperfusion Beyond 6 Hours Reduces Infarct Probability in Moderately Ischemic Brain Tissue.

Journal Article Stroke · January 2016 BACKGROUND AND PURPOSE: We aimed to examine perfusion changes between 3 and 6 and 6 and 24 hours after stroke onset and their impact on tissue outcome. METHODS: Acute ischemic stroke patients underwent perfusion magnetic resonance imaging at 3, 6, and 24 h ... Full text Link to item Cite

2015 American Heart Association/American Stroke Association Focused Update of the 2013 Guidelines for the Early Management of Patients With Acute Ischemic Stroke Regarding Endovascular Treatment: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association.

Journal Article Stroke · October 2015 PURPOSE: The aim of this guideline is to provide a focused update of the current recommendations for the endovascular treatment of acute ischemic stroke. When there is overlap, the recommendations made here supersede those of previous guidelines. METHODS: ... Full text Link to item Cite

High-Pressure Transvenous Perfusion of the Upper Extremity in Human Muscular Dystrophy: A Safety Study with 0.9% Saline.

Journal Article Hum Gene Ther · September 2015 We evaluated safety and feasibility of high-pressure transvenous limb perfusion in an upper extremity of adult patients with muscular dystrophy, after completing a similar study in a lower extremity. A dose escalation study of single-limb perfusion with 0. ... Full text Link to item Cite

Primary angiitis of the central nervous system: diagnostic criteria.

Journal Article Neurol Clin · May 2015 Primary angiitis of the central nervous system (PACNS) is a vasculitis of small arteries and veins of unknown cause restricted to the central nervous system (CNS), and controversy and disagreement exist over the means to establish the diagnosis. Cerebral a ... Full text Link to item Cite

Note on levels of clinical efficacy.

Journal Article Neurol Clin · May 2015 Full text Link to item Cite

Defining the ischemic penumbra using magnetic resonance oxygen metabolic index.

Journal Article Stroke · April 2015 BACKGROUND AND PURPOSE: Penumbral biomarkers promise to individualize treatment windows in acute ischemic stroke. We used a novel magnetic resonance imaging approach that measures oxygen metabolic index (OMI), a parameter closely related to positron emissi ... Full text Link to item Cite

Clinically relevant reperfusion in acute ischemic stroke: MTT performs better than Tmax and TTP.

Journal Article Transl Stroke Res · June 2014 While several MRI parameters are used to assess tissue perfusion during hyperacute stroke, it is unclear which is optimal for measuring clinically relevant reperfusion. We directly compared mean transit time (MTT) prolongation (MTTp), time-to-peak (TTP), a ... Full text Link to item Cite

The safety of aeroplane travel in patients with symptomatic carotid occlusion.

Journal Article J Neurol Neurosurg Psychiatry · April 2014 OBJECTIVE: Patients with carotid stenosis or occlusion may be at increased risk for stroke during air travel. Records from the Carotid Occlusion Surgery Study (COSS), a randomised trial of surgical revascularisation for complete carotid artery occlusion an ... Full text Link to item Cite

Lower stroke risk with lower blood pressure in hemodynamic cerebral ischemia.

Journal Article Neurology · March 25, 2014 OBJECTIVE: To determine whether strict blood pressure (BP) control is the best medical management for patients with symptomatic carotid artery occlusion and hemodynamic cerebral ischemia. METHODS: In this prospective observational cohort study, we analyzed ... Full text Link to item Cite

Randomized Evaluation of Carotid Occlusion and Neurocognition (RECON) trial: main results.

Journal Article Neurology · March 4, 2014 OBJECTIVE: To determine whether extracranial-intracranial (EC-IC) bypass can improve cognition over 2 years compared to best medical therapy alone in patients with symptomatic internal carotid artery (ICA) occlusion and increased oxygen extraction fraction ... Full text Link to item Cite

Endovascular (intraarterial) treatment of acute ischemic stroke: efficacy not supported by clinical trials.

Journal Article South Med J · February 2014 Intravenous tissue plasminogen activator (IV tPA, alteplase) provides a statistically and clinically significant improvement in clinical outcome for carefully selected patients with acute ischemic stroke when administered within 4.5 hours of onset; however ... Full text Link to item Cite

Stroke; Overview

Chapter · January 1, 2014 Cerebrovascular diseases can be divided into three categories: ischemia and infarction, intracerebral hemorrhage, and subarachnoid hemorrhage. The initial diagnostic evaluation of the patient with suspected stroke has two purposes: (1) to determine whether ... Full text Cite

Antiplatelet Therapy

Chapter · January 1, 2014 Antiplatelet therapy is the first-line antithrombotic drug treatment for secondary ischemic stroke prevention in most situations, with the notable exception of atrial fibrillation. Drugs other than aspirin offer a small additional benefit. Antiplatelet age ... Full text Cite

Brain Imaging, Physiological

Chapter · January 1, 2014 Physiological brain imaging is the branch of neuroimaging that is concerned with measuring biological processes in the brain and their alteration in disease states. A similar term, functional brain imaging, is often used interchangeably. The two most commo ... Full text Cite

Neuroimaging, Overview

Chapter · January 1, 2014 Neuroimaging refers to the use of radiological and other techniques to create images of the living human nervous system. X-rays were and still are valuable for detecting fractures and other bony abnormalities, but they do not show the soft tissues of the n ... Full text Cite

Migraine, Ischemic Stroke and

Chapter · January 1, 2014 The relationship between migraine and ischemic stroke is complex. Migraine is associated with an increased risk of ischemic stroke. This increased risk is most robust for women with migraine with aura. The cause for this association is not clear and variou ... Full text Cite

Stroke Imaging/Diffusion-Perfusion MRI

Chapter · January 1, 2014 Diffusion-perfusion magnetic resonance imaging (D-P MRI) refers to the use of a pair of different MRI techniques to assess the status of brain tissue in patients with acute ischemic stroke and to guide subsequent therapy. Currently, intravenous tissue plas ... Full text Cite

Cerebral Blood Flow, Measurement of

Chapter · January 1, 2014 Normal brain function requires adequate cerebral blood flow (CBF). Thus, understanding the physiology and pathophysiology of the brain requires accurate measurement of CBF. This article will describe the theory and practice of methods that have been used t ... Full text Cite

Positron Emission Tomography (PET)

Chapter · January 1, 2014 Positron emission tomography (PET) is a technique for physiological imaging of the brain, which employs the physical properties of radioactive atoms that decay by emission of positrons, negatively charged electrons. A PET scanner produces an image represen ... Full text Cite

Cerebral Metabolism and Blood Flow

Chapter · January 1, 2014 Under normal circumstances, the brain relies on energy generated from a continuous supply of oxygen and glucose from the blood. The molar ratio is 5.4 rather than 6.0 as expected for complete oxidation of glucose due to the production of a small amount of ... Full text Cite

Extracranial-intracranial bypass for ischemic cerebrovascular disease: what have we learned from the Carotid Occlusion Surgery Study?

Journal Article Neurosurg Focus · January 2014 Extracranial-intracranial (EC-IC) arterial bypass has been used in the treatment of various neurosurgical pathologies including skull base tumors requiring sacrifice of a large intracranial artery; complex intracranial aneurysms requiring trapping; and dis ... Full text Link to item Cite

Investigating the mechanisms of perioperative ischemic stroke in the Carotid Occlusion Surgery Study.

Journal Article J Neurosurg · October 2013 OBJECT: The Carotid Occlusion Surgery Study (COSS) was a large, prospective clinical trial that examined whether superficial temporal artery-middle cerebral artery (STA-MCA) bypass, in addition to best medical therapy, reduced the risk of ipsilateral ische ... Full text Link to item Cite

Comments

Journal Article Neurosurgical Review · October 1, 2013 Full text Cite

The Kety-Schmidt technique for quantitative perfusion and oxygen metabolism measurements in the MR imaging environment.

Journal Article AJNR Am J Neuroradiol · September 2013 The Kety-Schmidt technique provides quantitative measurement of whole-brain CBF. CBF is measured as the area between the arterial and venous washout curves of a diffusible tracer. Oxygen extraction and metabolism may be calculated from arterial and venous ... Full text Link to item Cite

Surgical results of the Carotid Occlusion Surgery Study.

Journal Article J Neurosurg · January 2013 OBJECT: The Carotid Occlusion Surgery Study (COSS) was conducted to determine if superficial temporal artery-middle cerebral artery (STA-MCA) bypass, when added to the best medical therapy, would reduce subsequent ipsilateral stroke in patients with comple ... Full text Link to item Cite

Response

Journal Article Journal of Neurosurgery · January 1, 2013 Full text Cite

Thalamic activation during slightly subphysiological glycemia in humans.

Journal Article Diabetes Care · December 2012 OBJECTIVE: The central nervous system mechanisms of defenses against falling plasma glucose concentrations, and how they go awry and result in iatrogenic hypoglycemia in diabetes, are not known. Hypoglycemic plasma glucose concentrations of 55 mg/dL (3.0 m ... Full text Link to item Cite

Cerebral autoregulation and acute ischemic stroke.

Journal Article Am J Hypertens · September 2012 Cerebral autoregulation tightly controls blood flow to the brain by coupling cerebral metabolic demand to cerebral perfusion. In the setting of acute brain injury, such as that caused by ischemic stroke, the continued precise control of cerebral blood flow ... Full text Link to item Cite

Thromobolysis for acute ischemic stroke: is intra-arterial better than intravenous? A treatment effects model.

Journal Article J Stroke Cerebrovasc Dis · July 2012 BACKGROUND: Three randomized trials of intra-arterial thrombolysis (IAT) for acute ischemic stroke ≤ 6 hours were conducted without intravenous tissue plasminogen activator (IV-tPA) treatment of patients in the control groups now known to benefit. METHODS: ... Full text Link to item Cite

Effect of mannitol on cerebral blood volume in patients with head injury.

Journal Article Neurosurgery · May 2012 BACKGROUND: Mannitol has traditionally been the mainstay of medical therapy for intracranial hypertension in patients with head injury. We previously demonstrated that mannitol reduces brain volume in patients with cerebral edema, although whether this occ ... Full text Link to item Cite

Safety and feasibility of high-pressure transvenous limb perfusion with 0.9% saline in human muscular dystrophy.

Journal Article Mol Ther · February 2012 We evaluated safety and feasibility of the transvenous limb perfusion gene delivery method in muscular dystrophy. A dose escalation study of single limb perfusion with 0.9% saline starting with 5% of limb volume was carried out in adults with muscular dyst ... Full text Link to item Cite

Cerebral hemodynamics and cognitive impairment: baseline data from the RECON trial.

Journal Article Neurology · January 24, 2012 OBJECTIVE: To determine whether unihemispheral hemodynamic failure is independently associated with cognitive impairment among participants in the National Institute of Neurological Disorders and Stroke-sponsored, multicenter, randomized clinical trial, Ra ... Full text Link to item Cite

Editorial

Journal Article Translational Stroke Research · January 1, 2012 Full text Cite

Noninvasive Measurements of Cerebral Blood Flow, Oxygen Extraction Fraction, and Oxygen Metabolic Index in Human with Inhalation of Air and Carbogen using Magnetic Resonance Imaging

Journal Article Translational Stroke Research · January 1, 2012 Noninvasive magnetic resonance (MR) methods have been explored to provide quantitative measurements of cerebral blood flow (CBF), oxygen extraction fraction (OEF), and oxygen metabolic index (OMI = CBF × OEF). In this study, we sought to evaluate whether M ... Full text Cite

Perfusion-Diffusion Mismatch: Does It Identify Who Will Benefit from Reperfusion Therapy?

Journal Article Translational Stroke Research · January 1, 2012 A method to determine which patients would benefit from reperfusion therapies after 4.5 h would greatly add to our ability to reduce the disability caused by stroke. The goal of magnetic resonance perfusion-diffusion imaging in hyperacute ischemic stroke i ... Full text Cite

Recent developments regarding human immunodeficiency virus infection and stroke.

Journal Article Cerebrovasc Dis · 2012 Human immunodeficiency virus (HIV) infection is strongly associated with ischemic stroke in the young. Data obtained from the Nationwide Inpatient Sample in the United States show an increase in the number of stroke hospitalizations in the HIV-infected pop ... Full text Link to item Cite

Poor correlation between perihematomal MRI hyperintensity and brain swelling after intracerebral hemorrhage.

Journal Article Neurocrit Care · December 2011 BACKGROUND AND PURPOSE: The perihematomal hyperintensity (PHH) is commonly interpreted to represent cerebral edema following intracerebral hemorrhage (ICH), but the accuracy of this interpretation is unknown. We therefore investigated the relationship betw ... Full text Link to item Cite

Management of patients with atherosclerotic carotid occlusion

Journal Article Current Treatment Options in Neurology · December 1, 2011 Opinion statement: • Patients with acute ischemic stroke due to atherosclerotic carotid artery occlusion (ACAO) should receive intravenous tissue plasminogen activator (alteplase) if they meet eligibility criteria of the National Institute of Neurological ... Full text Cite

Extracranial-intracranial bypass surgery for stroke prevention in hemodynamic cerebral ischemia: the Carotid Occlusion Surgery Study randomized trial.

Journal Article JAMA · November 9, 2011 CONTEXT: Patients with symptomatic atherosclerotic internal carotid artery occlusion (AICAO) and hemodynamic cerebral ischemia are at high risk for subsequent stroke when treated medically. OBJECTIVE: To test the hypothesis that extracranial-intracranial ( ... Full text Link to item Cite

Signal evolution and infarction risk for apparent diffusion coefficient lesions in acute ischemic stroke are both time- and perfusion-dependent.

Journal Article Stroke · May 2011 BACKGROUND AND PURPOSE: This study aimed to examine the temporal relationship between tissue perfusion and apparent diffusion coefficient (ADC) changes within 6 hours of ischemic stroke onset and how different reperfusion patterns may affect tissue outcome ... Full text Link to item Cite

Preexisting statin use is associated with greater reperfusion in hyperacute ischemic stroke.

Journal Article Stroke · May 2011 BACKGROUND AND PURPOSE: Statin pretreatment has been associated with improved outcomes in patients with ischemic stroke. Although several mechanisms have been examined in animal models, few have been examined in patients. We hypothesized that patients usin ... Full text Link to item Cite

Metabolic control of resting hemispheric cerebral blood flow is oxidative, not glycolytic.

Journal Article J Cereb Blood Flow Metab · May 2011 Although the close regional coupling of resting cerebral blood flow (CBF) with both cerebral metabolic rate of oxygen (CMRO(2)) and cerebral metabolic rate of glucose (CMRglc) within individuals is well documented, there are few data regarding the coupling ... Full text Link to item Cite

Platelet mitochondrial complex I and I+III activities do not correlate with cerebral mitochondrial oxidative metabolism.

Journal Article J Cereb Blood Flow Metab · January 2011 Assays of mitochondrial electron transport system (ETS) activity in circulating blood platelets have been used to investigate the cause of neurodegenerative diseases. However, the correspondence between platelet ETS function and cerebral mitochondrial meta ... Full text Link to item Cite

Does Ischemia Contribute to Energy Failure in Severe TBI?

Journal Article Translational Stroke Research · January 1, 2011 Ischemia has long been regarded as a cause of secondary brain injury following severe traumatic brain injury (TBI). This manuscript will present the viewpoint that, except for cases of extremely low cerebral perfusion pressure, efforts to establish the pre ... Full text Cite

Early changes of tissue perfusion after tissue plasminogen activator in hyperacute ischemic stroke.

Journal Article Stroke · January 2011 BACKGROUND AND PURPOSE: it is hypothesized that tissue plasminogen activator rescues brain tissue by improving perfusion. In this study, we aimed to examine acute regional perfusion changes and how they influence infarction and clinical outcome. METHODS: t ... Full text Link to item Cite

Autoregulation of cerebral blood flow to changes in arterial pressure in mild Alzheimer's disease.

Journal Article J Cereb Blood Flow Metab · November 2010 Studies in transgenic mice overexpressing amyloid precursor protein (APP) demonstrate impaired autoregulation of cerebral blood flow (CBF) to changes in arterial pressure and suggest that cerebrovascular dysfunction may be critically important in the devel ... Full text Link to item Cite

Intracerebral hemorrhage and head trauma: common effects and common mechanisms of injury.

Conference Stroke · October 2010 Nontraumatic intracerebral hemorrhage (ICH) remains a devastating condition with 30-day mortality rates of 35% to 52%. Until the pathophysiology of this condition is better understood, it will not be possible to develop effective therapies. Studies of cere ... Full text Link to item Cite

Cerebellum as the normal reference for the detection of increased cerebral oxygen extraction.

Journal Article J Cereb Blood Flow Metab · October 2010 Hemispheric ratios of oxygen extraction fraction (OEF), a proven methodology for the detection of severe hemodynamic impairment and stroke risk, are not sensitive for detecting bilateral hemispheric increases in OEF. The aim of this study was to investigat ... Full text Link to item Cite

Dynamic susceptibility contrast MRI with localized arterial input functions.

Journal Article Magn Reson Med · May 2010 Compared to gold-standard measurements of cerebral perfusion with positron emission tomography using H(2)[(15)O] tracers, measurements with dynamic susceptibility contrast MR are more accessible, less expensive, and less invasive. However, existing methods ... Full text Link to item Cite

PET in cerebrovascular disease

Journal Article PET Clinics · January 1, 2010 Investigation of the interplay between the cerebral circulation and brain cellular function is fundamental to understanding both the pathophysiology and treatment of stroke. At present, PET is the only technique that provides accurate, quantitative in vivo ... Full text Cite

PET studies of cerebral metabolism in Parkinson disease.

Journal Article J Bioenerg Biomembr · December 2009 A defect in cerebral energy production due to dysfunction of the mitochondrial electron transport system (ETS) has been postulated to be important in the pathogenesis of Parkinson Disease (PD). However, direct in vivo measurements of cerebral mitochondrial ... Full text Link to item Cite

Autoregulation after ischaemic stroke.

Journal Article J Hypertens · November 2009 OBJECTIVES: Absent outcome data from randomized clinical trials, management of hypertension in acute ischaemic stroke remains controversial. Data from human participants have failed to resolve the question whether cerebral blood flow (CBF) in the peri-infa ... Full text Link to item Cite

Very Early Constraint-Induced Movement during Stroke Rehabilitation (VECTORS): A single-center RCT.

Journal Article Neurology · July 21, 2009 BACKGROUND: Constraint-induced movement therapy (CIMT) is among the most developed training approaches for motor restoration of the upper extremity (UE). METHODS: Very Early Constraint-Induced Movement during Stroke Rehabilitation (VECTORS) was a single-bl ... Full text Link to item Cite

Transient focal increase in perihematomal glucose metabolism after acute human intracerebral hemorrhage.

Journal Article Stroke · May 2009 BACKGROUND AND PURPOSE: Progressive perihematomal cell death over 3 to 4 days has been described after experimental intracerebral hemorrhage (ICH). We investigated whether progressive perihematomal damage occurs in human subjects by measuring relative chan ... Full text Link to item Cite

Response

Journal Article Journal of Neurosurgery · March 1, 2009 Full text Cite

Imaging preventable infarction in patients with acute ischemic stroke.

Journal Article AJNR Am J Neuroradiol · November 2008 One of the goals of neuroimaging in acute ischemic stroke is to identify those patients whose outcome will be improved by therapeutic intervention. This article will discuss the design, analysis, and interpretation of clinical research studies carried out ... Full text Link to item Cite

Cerebral mitochondrial metabolism in early Parkinson's disease.

Journal Article J Cereb Blood Flow Metab · October 2008 Abnormal cerebral energy metabolism owing to dysfunction of mitochondrial electron transport has been implicated in the pathogenesis of Parkinson's disease (PD). However, in vivo data of mitochondrial dysfunction have been inconsistent. We directly investi ... Full text Link to item Cite

Perfusion CT compared to H(2) (15)O/O (15)O PET in patients with chronic cervical carotid artery occlusion.

Journal Article Neuroradiology · September 2008 INTRODUCTION: The purpose of this study was to compare the results of perfusion computed tomography (PCT) with those of (15)O(2)/H(2) (15)O positron emission tomography (PET) in a subset of Carotid Occlusion Surgery Study (COSS) patients. MATERIALS AND MET ... Full text Link to item Cite

Acute stroke imaging research roadmap.

Journal Article AJNR Am J Neuroradiol · May 2008 The recent "Advanced Neuroimaging for Acute Stroke Treatment" meeting on September 7 and 8, 2007 in Washington DC, brought together stroke neurologists, neuroradiologists, emergency physicians, neuroimaging research scientists, members of the National Inst ... Full text Link to item Cite

Attenuation of counterregulatory responses to recurrent hypoglycemia by active thalamic inhibition: a mechanism for hypoglycemia-associated autonomic failure.

Journal Article Diabetes · February 2008 OBJECTIVE: Hypoglycemia, the limiting factor in the glycemic management of diabetes, is the result of the interplay of therapeutic insulin excess and compromised glycemic defenses. The key feature of the latter is an attenuated sympathoadrenal response to ... Full text Link to item Cite

No effect of low-dose statins treatment on cerebral blood flow in humans with atherosclerotic cerebrovascular disease.

Journal Article J Cereb Blood Flow Metab · September 2007 Animal studies have suggested that the reduction in stroke risk observed with 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) therapy is owing to an increase in basal cerebral blood flow (CBF). The purpose of the study was to ... Full text Link to item Cite

Reply from the authors [2]

Journal Article Neurology · July 1, 2007 Full text Cite

Normal platelet mitochondrial complex I activity in Huntington's disease.

Journal Article Neurobiol Dis · July 2007 Two small case series of platelet mitochondrial complex I activity assays in Huntington's Disease (HD) report discrepant results. We measured platelet complex I and complex I/III activity in 21 subjects with early gene-positive HD and 14 age-matched contro ... Full text Link to item Cite

Effect of hyperoxia on cerebral metabolic rate for oxygen measured using positron emission tomography in patients with acute severe head injury.

Journal Article J Neurosurg · April 2007 OBJECT: Recent observations indicate that traumatic brain injury (TBI) may be associated with mitochondrial dysfunction. This, along with growing use of brain tissue PO2 monitors, has led to considerable interest in the potential use of ventilation with 10 ... Full text Link to item Cite

Selective defect of in vivo glycolysis in early Huntington's disease striatum.

Journal Article Proc Natl Acad Sci U S A · February 20, 2007 Activity of complexes II, III, and IV of the mitochondrial electron transport system (ETS) is reduced in postmortem Huntington's disease (HD) striatum, suggesting that reduced cerebral oxidative phosphorylation may be important in the pathogenesis of neuro ... Full text Link to item Cite

Intra-arterial thrombolysis for basilar artery thrombosis: trial it.

Conference Stroke · February 2007 The poor prognosis for recovery of basilar artery thrombosis has led to the adoption at many institutions of intra-arterial thrombolysis as part of clinical care. However, because neither randomized clinical trials nor observational data provide evidence f ... Full text Link to item Cite

Patterns of infarction in hemodynamic failure.

Journal Article Cerebrovasc Dis · 2007 BACKGROUND AND PURPOSE: The mechanism of stroke in patients with atherosclerotic occlusive disease and hemodynamic failure may be primarily hemodynamic or a combination of hemodynamic and embolic factors. The purpose of this study was to investigate the cl ... Full text Link to item Cite

National Institute of Neurological Disorders and Stroke-Canadian Stroke Network vascular cognitive impairment harmonization standards.

Journal Article Stroke · September 2006 BACKGROUND AND PURPOSE: One in 3 individuals will experience a stroke, dementia or both. Moreover, twice as many individuals will have cognitive impairment short of dementia as either stroke or dementia. The commonly used stroke scales do not measure cogni ... Full text Link to item Cite

Effect of normal saline bolus on cerebral blood flow in regions with low baseline flow in patients with vasospasm following subarachnoid hemorrhage.

Journal Article J Neurosurg · July 2005 OBJECT: Arterial vasospasm is the most common cause of delayed ischemic neurological deficits (DINDs) and one of the major causes of disability following subarachnoid hemorrhage (SAH). Current management of vasospasm involves intravascular volume expansion ... Full text Link to item Cite

Indications for cerebral revascularization for patients with atherosclerotic carotid occlusion

Journal Article Skull Base · February 1, 2005 Patients with complete carotid occlusion and recent ischemic symptoms are at high risk for subsequent stroke, particularly those with evidence of severe hemodynamic impairment due to poor collateral flow. Treatment options for these patients include direct ... Full text Cite

The role of radiotracer imaging in Parkinson disease

Journal Article Neurology · January 25, 2005 Radiotracer imaging (RTI) of the nigrostriatal dopaminergic system is a widely used but controversial biomarker in Parkinson disease (PD). Here the authors review the concepts of biomarker development and the evidence to support the use of four radiotracer ... Full text Cite

Primary angiitis of the central nervous system at conventional angiography.

Journal Article Radiology · December 2004 PURPOSE: To retrospectively determine the sensitivity and specificity of cerebral angiography for the diagnosis of primary angiitis of the central nervous system (CNS). MATERIALS AND METHODS: Institutional review board approval was obtained, and informed c ... Full text Link to item Cite

Activation of human medial prefrontal cortex during autonomic responses to hypoglycemia.

Journal Article Proc Natl Acad Sci U S A · April 20, 2004 Studies in humans implicate the medial prefrontal cortex (MPFC) in complex cognitive and emotional states. We measured regional cerebral blood flow (CBF) four times each during euglycemia (5.2 +/- 0.2 mmol/liter) and hypoglycemia (3.0 +/- 0.3 mmol/liter) i ... Full text Link to item Cite

The use of positron emission tomography in cerebrovascular disease.

Journal Article Neuroimaging Clin N Am · November 2003 Even with rapid development of other neuroimaging modalities such as MR imaging and CT, PET is the only technique that provides accurate, quantitative measurements of regional hemodynamics and metabolism in human subjects. Through the use of these combined ... Full text Link to item Cite

Prognosis of patients with suspected primary CNS angiitis and negative brain biopsy.

Journal Article Neurology · September 23, 2003 The authors retrospectively analyzed 25 patients who had a nondiagnostic brain biopsy for clinically suspected primary CNS angiitis to determine the effect of immunosuppressive therapy on 1-year outcome. Good outcome was seen in 6 of 10 treated patients an ... Full text Link to item Cite

Measurement of cerebral blood flow in chronic carotid occlusive disease: comparison of dynamic susceptibility contrast perfusion MR imaging with positron emission tomography.

Journal Article AJNR Am J Neuroradiol · May 2003 BACKGROUND AND PURPOSE: Our purpose was to evaluate the accuracy of cerebral blood flow (CBF) measurements obtained by using dynamic susceptibility contrast-enhanced MR imaging, including the influence of arterial input function (AIF) selection, compared w ... Link to item Cite

The Carotid Occlusion Surgery Study.

Journal Article Neurosurg Focus · March 15, 2003 The St. Louis Carotid Occlusion Study demonstrated that ipsilateral increased O2 extraction fraction (OEF) (Stage II hemodynamic failure) measured by positron emission tomography (PET) is a powerful independent risk factor for subsequent stroke in patients ... Full text Link to item Cite

Neuroimaging, Overview

Chapter · January 1, 2003 Full text Cite

Warfarin or aspirin for recurrent ischemic stroke.

Journal Article N Engl J Med · April 11, 2002 Link to item Cite

Variability of cerebral blood volume and oxygen extraction: stages of cerebral haemodynamic impairment revisited.

Journal Article Brain · March 2002 The presence or degree of haemodynamic impairment due to occlusive cerebrovascular disease is often inferred from measurements of cerebral blood flow (CBF), cerebral blood volume (CBV), oxygen extraction fraction (OEF) and the cerebral rate for oxygen meta ... Full text Link to item Cite

Hyperventilation.

Journal Article J Neurosurg · January 2002 Link to item Cite

Regional cerebrovascular and metabolic effects of hyperventilation after severe traumatic brain injury.

Journal Article J Neurosurg · January 2002 OBJECT: Recently, concern has been raised that hyperventilation following severe traumatic brain injury (TBI) could lead to cerebral ischemia. In acute ischemic stroke, in which the baseline metabolic rate is normal, reduction in cerebral blood flow (CBF) ... Full text Link to item Cite

Mannitol bolus preferentially shrinks non-infarcted brain in patients with ischemic stroke.

Journal Article Neurology · December 11, 2001 Changes in brain tissue volume in six patients who had acute complete middle cerebral artery (MCA) infarctions and CT evidence of midline shift were measured using the brain boundary shift integral (BBSI) on sequential T1-weighted MR images acquired before ... Full text Link to item Cite

Quantitative measurements of cerebral blood flow in patients with unilateral carotid artery occlusion: a PET and MR study.

Journal Article J Magn Reson Imaging · December 2001 Although it has been demonstrated that quantitative measures of cerebral blood flow (CBF) can be obtained with the singular value decomposition (SVD) algorithm, the extent to which quantitative CBF measurements can be utilized under pathophysiological cond ... Full text Link to item Cite

Workshop on hypoglycemia and the brain

Conference Diabetes Technology and Therapeutics · November 15, 2001 Full text Cite

Blood-to-brain glucose transport, cerebral glucose metabolism, and cerebral blood flow are not increased after hypoglycemia.

Journal Article Diabetes · August 2001 Recent antecedent hypoglycemia has been found to shift glycemic thresholds for autonomic (including adrenomedullary epinephrine), symptomatic, and other responses to subsequent hypoglycemia to lower plasma glucose concentrations. This change in threshold i ... Full text Link to item Cite

Comparison of PET oxygen extraction fraction methods for the prediction of stroke risk.

Journal Article J Nucl Med · August 2001 UNLABELLED: PET measurement of increased oxygen extraction fraction (OEF) identifies patients at high risk for subsequent stroke. OEF methodology remains controversial. In this study we compare the sensitivity and specificity of absolute OEF measurements w ... Link to item Cite

Autoregulation of cerebral blood flow surrounding acute (6 to 22 hours) intracerebral hemorrhage.

Journal Article Neurology · July 10, 2001 BACKGROUND: Arterial hypertension is common in the first 24 hours after acute intracerebral hemorrhage (ICH). Although increased blood pressure usually declines to baseline values within several days, the appropriate treatment during the acute period has r ... Full text Link to item Cite

Hypoperfusion without ischemia surrounding acute intracerebral hemorrhage.

Journal Article J Cereb Blood Flow Metab · July 2001 A zone of hypoperfusion surrounding acute intracerebral hemorrhage (ICH) has been interpreted as regional ischemia. To determine if ischemia is present in the periclot area, the authors measured cerebral blood flow (CBF), cerebral metabolic rate of oxygen ... Full text Link to item Cite

Severe hemodynamic impairment and border zone--region infarction.

Journal Article Radiology · July 2001 PURPOSE: To investigate the relationship between the patterns of cerebral infarction that have been associated with hemodynamic impairment and the presence of severe chronic hemodynamic compromise (increased oxygen extraction fraction) in a large prospecti ... Full text Link to item Cite

Risks of stroke and current indications for cerebral revascularization in patients with carotid occlusion.

Journal Article Neurosurg Clin N Am · July 2001 Preventing further stroke in patients with complete carotid artery occlusion remains a difficult challenge because there is no therapy proven effective for this prevention. These patients comprise approximately 15% of patients with carotid artery territory ... Link to item Cite

Preview of a new trial of extracranial-to-intracranial arterial anastomosis: the carotid occlusion surgery study.

Journal Article Neurosurg Clin N Am · July 2001 In 1985, the International Study of Extracranial-to-Intracranial Arterial Anastomosis demonstrated no benefit from extracranial-to-intracranial arterial bypass operations in treatment of patients with extensive cerebrovascular disease including those with ... Link to item Cite

A default mode of brain function.

Journal Article Proc Natl Acad Sci U S A · January 16, 2001 A baseline or control state is fundamental to the understanding of most complex systems. Defining a baseline state in the human brain, arguably our most complex system, poses a particular challenge. Many suspect that left unconstrained, its activity will v ... Full text Link to item Cite

PET screening of carotid occlusion.

Journal Article Adm Radiol J · 2001 Link to item Cite

Comparing MRS and PET.

Journal Article J Nucl Med · August 2000 Link to item Cite

Cost-effectiveness analysis of therapy for symptomatic carotid occlusion: PET screening before selective extracranial-to-intracranial bypass versus medical treatment.

Journal Article J Nucl Med · May 2000 UNLABELLED: The St. Louis Carotid Occlusion Study (STLCOS) demonstrated that increased cerebral oxygen extraction fraction (OEF) detected by PET scanning predicted stroke in patients with symptomatic carotid occlusion. Consequently, a trial of extracranial ... Link to item Cite

Absence of selective deep white matter ischemia in chronic carotid disease: a positron emission tomographic study of regional oxygen extraction.

Journal Article AJNR Am J Neuroradiol · April 2000 BACKGROUND AND PURPOSE: Deep white matter may be the location of an internal arterial border zone. The purpose of this study was to determine whether the deep white matter was subject to a greater degree of ischemia than was the cortex among patients with ... Link to item Cite

Benign prognosis of never-symptomatic carotid occlusion.

Journal Article Neurology · February 22, 2000 OBJECTIVE: To determine the prognosis of asymptomatic carotid artery occlusion. BACKGROUND: As opposed to symptomatic carotid occlusion, little information is available on the prognosis of asymptomatic carotid occlusion. METHOD: Thirty never-symptomatic an ... Full text Link to item Cite

No reduction in cerebral metabolism as a result of early moderate hyperventilation following severe traumatic brain injury.

Journal Article J Neurosurg · January 2000 OBJECT: Hyperventilation has been used for many years in the management of patients with traumatic brain injury (TBI). Concern has been raised that hyperventilation could lead to cerebral ischemia; these concerns have been magnified by reports of reduced c ... Full text Link to item Cite

Absolute measurements of water content using magnetic resonance imaging: preliminary findings in an in vivo focal ischemic rat model.

Journal Article Magn Reson Med · January 2000 Using a magnetic resonance (MR) imaging method, absolute measurements of in vivo brain water content were obtained in 15 male Long Evans rats that underwent a 90-min focal cerebral ischemia. A strong linear relationship (r = 0.80) with a slope of 1 was obs ... Full text Link to item Cite

An absolute measurement of brain water content using magnetic resonance imaging in two focal cerebral ischemic rat models.

Journal Article J Cereb Blood Flow Metab · January 2000 Magnetic resonance imaging (MRI) was utilized to obtain absolute estimates of regional brain water content (W), and results were compared with those obtained with conventional wet/dry measurements. In total, 31 male Long-Evans rats were studied and divided ... Full text Link to item Cite

Mirror movements complicate interpretation of cerebral activation changes during recovery from subcortical infarction.

Journal Article Neurorehabil Neural Repair · 2000 In recovered stroke patients, performance of motor tasks with the affected limb has been reported to activate cortical areas ipsilateral to the affected side. The better to determine the causal role these areas play in recovery of motor function, we assess ... Full text Link to item Cite

Count-based PET method for predicting ischemic stroke in patients with symptomatic carotid arterial occlusion.

Journal Article Radiology · August 1999 PURPOSE: To test the ability of a count-based positron emission tomographic (PET) method, without arterial sampling, for the measurement of regional cerebral oxygen extraction fraction (OEF) to predict ischemic stroke in patients with symptomatic carotid a ... Full text Link to item Cite

Quantitative magnetic resonance imaging in experimental hypercapnia: improvement in the relation between changes in brain R2 and the oxygen saturation of venous blood after correction for changes in cerebral blood volume.

Journal Article J Cereb Blood Flow Metab · August 1999 Acute hypercapnia simultaneously induces increases in regional cerebral blood volume (rCBV) and the oxygen saturation of cerebral venous blood (Yv). Changes in both physiologic parameters may influence the changes in R2 (deltaR2) that can be measured in th ... Full text Link to item Cite

Cerebral hemodynamic impairment: methods of measurement and association with stroke risk.

Journal Article Neurology · July 22, 1999 Stenosis or occlusion of the major arteries of the head and neck may cause hemodynamic impairment of the distal cerebral circulation. Hemodynamic factors may play an important role in the pathogenesis of ischemic stroke for patients with cerebrovascular di ... Full text Link to item Cite

Progression of mass effect after intracerebral hemorrhage.

Journal Article Stroke · June 1999 BACKGROUND AND PURPOSE: While the evolution of mass effect after cerebral infarction is well characterized, similar data regarding intracerebral hemorrhage (ICH) are scant. Our goal was to determine the time course and cause for progression of mass effect ... Full text Link to item Cite

Lack of correlation between pattern of collateralization and misery perfusion in patients with carotid occlusion.

Journal Article Stroke · May 1999 BACKGROUND AND PURPOSE: Misery perfusion, identified by increased oxygen extraction fraction (OEF), predicts subsequent stroke in patients with carotid occlusion. The purpose of this investigation was to determine the relationship of angiographic findings ... Full text Link to item Cite

Compensatory mechanisms for chronic cerebral hypoperfusion in patients with carotid occlusion.

Journal Article Stroke · May 1999 BACKGROUND AND PURPOSE: The purpose of this experiment was to assess long-term cerebral hemodynamic and metabolic changes in patients with increased oxygen extraction fraction (OEF) in the hemisphere distal to an occluded carotid artery who remain free of ... Full text Link to item Cite

The effects of mannitol on cerebral edema after large hemispheric cerebral infarct.

Journal Article Neurology · February 1999 OBJECTIVE: To evaluate the effect of a single large dose of mannitol on midline tissue shifts after a large cerebral infarction. BACKGROUND: Theoretically, mannitol use in the largest cerebral infarctions may preferentially shrink noninfarcted cerebral tis ... Full text Link to item Cite

Correction for partial volume effects in regional blood flow measurements adjacent to hematomas in humans with intracerebral hemorrhage: implementation and validation.

Journal Article J Comput Assist Tomogr · 1999 PURPOSE: Reduced blood flow measured with PET and SPECT has been reported in brain surrounding intracerebral hemorrhage (ICH). These studies have not corrected for partial volume effects from adjacent hematomas or ventricles. We have implemented a method t ... Full text Link to item Cite

Temporal stability of hemodynamic status in patients with carotid occlusion

Journal Article Journal of Neurosurgery · December 1, 1998 The purpose of our investigation was to assess cerebral hemodynamic status longitudinally with serial positron-emission tomogra phy (PET) studies in patients with carotid artery occlusion. We obtained regional measurements of cerebral blood flow (CBF), vol ... Cite

Effects of acute normovolemic hemodilution on T2*-weighted images of rat brain.

Journal Article Magn Reson Med · December 1998 Acute normovolemic hemodilution (HD) was induced in anesthetized rats to assess the effect of changes in hematocrit (Hct) on signal intensity in T2*-weighted magnetic resonance (MR) images. Other relevant physiological parameters were maintained invariant. ... Full text Link to item Cite

Importance of hemodynamic factors in the prognosis of symptomatic carotid occlusion.

Journal Article JAMA · September 23, 1998 CONTEXT: The relative importance of hemodynamic factors in the pathogenesis and treatment of stroke in patients with carotid artery occlusion remains controversial. OBJECTIVE: To test the hypothesis that stage II cerebral hemodynamic failure (increased oxy ... Full text Link to item Cite

Blood-to-brain glucose transport and cerebral glucose metabolism are not reduced in poorly controlled type 1 diabetes.

Journal Article Diabetes · September 1998 To test the hypothesis that blood-to-brain glucose transport is reduced in poorly controlled type 1 diabetes, we studied seven patients with a mean (+/- SD) HbA1c level of 10.1 +/- 1.2% and nine nondiabetic subjects during hyperinsulinemic, mildly hypoglyc ... Full text Link to item Cite

Hemodynamic effects of middle cerebral artery stenosis and occlusion.

Journal Article AJNR Am J Neuroradiol · September 1998 BACKGROUND AND PURPOSE: Middle cerebral artery (MCA) stenosis and occlusion may cause ischemic symptoms through both hemodynamic and embolic mechanisms. The purpose of this investigation was to determine the hemodynamic effects of these lesions. METHODS: T ... Link to item Cite

Experimental hypoxemic hypoxia: effects of variation in hematocrit on magnetic resonance T2*-weighted brain images.

Journal Article J Cereb Blood Flow Metab · September 1998 T2*-weighted gradient echo magnetic resonance images of rat brain were obtained dynamically during acute hypoxemic hypoxia to investigate the relations between changes in cerebral blood oxygen saturation (deltaYb), blood hematocrit (Hct), and R2* (deltaR2* ... Full text Link to item Cite

Hemodynamic effects of STA-MCA bypass surgery revisited

Journal Article Journal of Stroke and Cerebrovascular Diseases · September 1, 1998 Full text Cite

Cerebral glucose transport and metabolism in preterm human infants.

Journal Article J Cereb Blood Flow Metab · June 1998 Few data regarding early developmental changes in cerebral (blood-to-brain) glucose transport (CTXglc) and CMRglc are available for humans. We measured CBF, CTXglc, and CMRglc with positron emission tomography at 4 to 7 days of life in six preterm human in ... Full text Link to item Cite

Increased oxygen extraction fraction is associated with prior ischemic events in patients with carotid occlusion.

Journal Article Stroke · April 1998 BACKGROUND AND PURPOSE: The purpose of our study was to investigate the relationship between misery perfusion (increased oxygen extraction fraction, OEF) and baseline risk factors in patients with carotid occlusion. METHODS: One-hundred seventeen patients ... Full text Link to item Cite

Isolated cortical venous thrombosis and ulcerative colitis.

Journal Article AJNR Am J Neuroradiol · March 1998 Aseptic cortical venous thrombosis is rare without concomitant dural sinus thrombosis. Ulcerative colitis is associated with both dural sinus thrombosis and isolated cortical venous thrombosis. We describe a 26-year-old woman with ulcerative colitis who ha ... Link to item Cite

Experimental hypoxemic hypoxia: changes in R2* of brain parenchyma accurately reflect the combined effects of changes in arterial and cerebral venous oxygen saturation.

Journal Article Magn Reson Med · March 1998 A two-dimensional T2*-weighted gradient-echo sequence was used to image the rat brain before and during graded hypoxemia. Changes in R2* (deltaR2*) with respect to the control state were calculated for brain parenchyma and were compared with changes in hem ... Full text Link to item Cite

Temporal stability of hemodynamic stage in patients with carotid artery occlusion

Conference Rivista di Neuroradiologia · January 1, 1998 We assessed cerebral hemodynamic status longitudinally with serial positron emission tomography (PET) studies in patients with carotid occlusion and no interval stroke. Regional measurements of cerebral blood flow (CBF), cerebral blood volume (CBV), cerebr ... Full text Cite

Hemodynamic effects of middle cerebral artery stenosis and occlusion

Conference Rivista di Neuroradiologia · January 1, 1998 Middle cerebral artery (MCA) stenosis and occlusion may cause ischemic symptoms through both hemodynamic and embolic mechanisms. The purpose of this investigation was to determine the hemodynamic effects of these lesions. Ten patients with angiographically ... Full text Cite

A nonlinear quasi-static model of intracranial aneurysms.

Journal Article Neurol Res · October 1997 Biomathematical models of intracranial aneurysms can provide qualitative and quantitative information on stages of aneurysm development through elucidation of biophysical interactions and phenomena. However, most current aneurysm models, based on Laplace's ... Full text Link to item Cite

Quantitative regional brain water measurement with magnetic resonance imaging in a focal ischemia model.

Journal Article Magn Reson Med · August 1997 Therapeutic approaches to cerebral edema require an understanding of both the magnitude and location of changes in brain water content. It is desirable to have a sensitive, accurate means of measuring brain water noninvasively so that effective therapies f ... Full text Link to item Cite

Cerebral hemodynamic and metabolic changes caused by brain retraction after aneurysmal subarachnoid hemorrhage.

Journal Article Neurosurgery · March 1997 OBJECTIVE: The cerebral hemodynamic and metabolic effects of aneurysmal subarachnoid hemorrhage are complex. To investigate the impact of surgical retraction, we analyzed position emission tomography (PET) studies that measured the regional cerebral metabo ... Full text Link to item Cite

Management of hypertension in acute intracerebral hemorrhage.

Journal Article Crit Care Clin · January 1997 Hypertension commonly occurs in the acute period following spontaneous intracerebral hemorrhage. Management of this hypertension is controversial. Some advocate lowering blood pressure to reduce the risk of bleeding, edema formation, and systemic hypertens ... Full text Link to item Cite

Cost-effectiveness of screening for asymptomatic carotid atherosclerotic disease.

Journal Article Stroke · November 1996 BACKGROUND AND PURPOSE: The value of screening for asymptomatic carotid stenosis has become an important issue with the recently reported beneficial effect of endarterectomy. The purpose of this study is to evaluate the cost-effectiveness of using Doppler ... Full text Link to item Cite

Radiation absorbed dose estimates for [1-carbon-11]-glucose in adults: the effects of hyperinsulinemia.

Journal Article J Nucl Med · October 1996 UNLABELLED: As preparation for studies of blood-brain glucose transport in diabetes mellitus, radiation absorbed dose estimates from intravenous administration of [1-(11)C]-glucose for 24 internal organs, lens, blood and total body were calculated for thre ... Link to item Cite

Effect of stepped hypoglycemia on regional cerebral blood flow response to physiological brain activation.

Journal Article Am J Physiol · February 1996 The effect of vasoactive stimuli on cerebral blood flow (CBF) has been variously reported as normal or impaired by hypoglycemia. We measured regional CBF (rCBF) in contralateral somato-sensory cortex at rest and during vibrotactile stimulation of one hand ... Full text Link to item Cite

Role of Doppler US in screening for carotid atherosclerotic disease.

Journal Article Radiology · December 1995 PURPOSE: To evaluate Doppler ultrasound (US) as a screening modality before arteriography for extracranial carotid artery disease. MATERIALS AND METHODS: The net benefit in stroke reduction from screening with Doppler US was calculated on the basis of lite ... Full text Link to item Cite

Hemodynamic assessment of the development and rupture of intracranial aneurysms using computational simulations.

Journal Article Neurol Res · December 1995 Intracranial aneurysms manifest themselves as sacculations within a weakened region of the vessel wall and pose substantial neurological risks upon rupture. A primary factor in the development and rupture stages of an aneurysm is hemodynamics and its degra ... Link to item Cite

Cerebral transport and metabolism of 1-11C-D-glucose during stepped hypoglycemia.

Journal Article Ann Neurol · October 1995 Attempts to measure blood-to-brain glucose transport and cerebral glucose metabolism with 11C-glucose have been hampered by methods that require jugular venous sampling or do not adequately account for the efflux of labeled metabolites from the brain. We p ... Full text Link to item Cite

Unaltered cerebral blood flow during hypoglycemic activation of the sympathochromaffin system in humans.

Journal Article Am J Physiol · October 1993 To determine if increases in plasma epinephrine and norepinephrine caused by hypoglycemia are associated with increments in cerebral blood flow (CBF), we measured CBF with positron emission tomography in normal humans at ambient fasting arterial plasma glu ... Full text Link to item Cite

Cerebral oxygen metabolism in newborns.

Journal Article Pediatrics · July 1993 OBJECTIVE: A better understanding of the developmental changes in brain energy metabolism that occur in human neonates is critically important for designing rational treatment strategies that ensure an adequate supply of nutrients to the brain and minimize ... Link to item Cite

Improved synthesis of 1-[11C]D-glucose.

Journal Article Appl Radiat Isot · June 1993 An improved synthesis of 1-[11C]D-glucose is described. The major improvement is achieved when a 0.033 M borate buffer at pH 8.1 is used to effect the condensation of d-arabinose with NH4(11)CN. Subsequent reduction of the 1-[11C]D-aldonitriles gives the e ... Full text Link to item Cite

Role of cerebral hemodynamics in ischemic atherosclerotic cerebrovascular disease

Journal Article Neurosurgery Quarterly · January 1, 1993 It is now possible to evaluate regional cerebral hemodynamics in patients with atherosclerotic occlusive cerebrovascular disease using noninvasive techniques to study the cerebral circulation and metabolism. The degree of carotid stenosis and the presence ... Cite

Blinded clinical evaluation of positron emission tomography for diagnosis of probable Alzheimer's disease.

Journal Article Neurology · April 1992 We evaluated the sensitivity and specificity of positron emission tomography for diagnosis of probable Alzheimer's disease under conditions similar to those encountered in the routine clinical practice of nuclear medicine. We obtained tomographic images of ... Full text Link to item Cite

Hemodynamics and metabolism in ischemic cerebrovascular disease.

Journal Article Neurol Clin · February 1992 Measurements of CBF and CMR in human ischemia and infarction have provided valuable insight into the pathophysiology of stroke and important guidance to the development of therapeutic strategies. Further research combing therapeutic manipulation with CBF a ... Link to item Cite

Cerebral oxygen metabolism after aneurysmal subarachnoid hemorrhage.

Journal Article J Cereb Blood Flow Metab · September 1991 Previous studies of cerebral oxygen metabolism and extraction in patients with subarachnoid hemorrhage (SAH) have yielded conflicting results. We used positron emission tomography (PET) to measure the regional cerebral metabolic rate for oxygen (rCMRO2), o ... Full text Link to item Cite

Brief inhalation method to measure cerebral oxygen extraction fraction with PET: accuracy determination under pathologic conditions.

Journal Article J Nucl Med · September 1991 The initial validation of the brief inhalation method to measure cerebral oxygen extraction fraction (OEF) with positron emission tomography (PET) was performed in non-human primates with predominantly normal cerebral oxygen metabolism (CMRO2). Sensitivity ... Link to item Cite

Cerebral hemodynamics in ischemic cerebrovascular disease.

Journal Article Ann Neurol · March 1991 During the past decade, technological advances have made it possible to measure regional cerebral hemodynamics in individual patients. Studies performed with these techniques have demonstrated that the degree of carotid stenosis correlates poorly with the ... Full text Link to item Cite

Borderzone hemodynamics in cerebrovascular disease.

Journal Article Neurology · October 1990 To investigate the possible existence of chronic selective hemodynamic impairment in the arterial borderzone regions of the brain, we used positron emission tomography (PET) to measure regional mean vascular transit time (rt, equal to the ratio of regional ... Full text Link to item Cite

Influence of cerebral hemodynamics on stroke risk: one-year follow-up of 30 medically treated patients.

Journal Article Ann Neurol · April 1989 The importance of hemodynamic factors in the pathogenesis and treatment of ischemic cerebrovascular disease is not clear. We have investigated the relationship between cerebral hemodynamics and the subsequent risk of stroke in 30 medically treated patients ... Full text Link to item Cite

Clinical results of extracranial-intracranial bypass surgery in patients with hemodynamic cerebrovascular disease.

Journal Article J Neurosurg · January 1989 The importance of hemodynamic factors in the pathogenesis and treatment of cerebrovascular disease remains uncertain. The extracranial-intracranial (EC-IC) bypass trial has been criticized for failing to identify and separately analyze those patients with ... Full text Link to item Cite

Radiation absorbed dose estimates for oxygen-15 radiopharmaceuticals (H2(15)O, C15O, O15O) in newborn infants.

Journal Article J Nucl Med · December 1988 In preparation for measurement of regional cerebral oxygen metabolism by positron emission tomography, radiation absorbed dose estimates for 19 internal organs, blood, and total body were calculated for newborn infants following bolus intravenous administr ... Link to item Cite

The effect of carotid artery disease on the cerebrovascular response to physiologic stimulation.

Journal Article Neurology · September 1988 Eight of 16 patients with severe carotid artery disease, but no evidence of functional or structural brain damage, had abnormal regional cerebral blood flow (rCBF) responses to physiologic stimulation of sensorimotor cortex (unilateral reduction in six, ab ... Full text Link to item Cite

Cerebral blood flow requirement for brain viability in newborn infants is lower than in adults.

Journal Article Ann Neurol · August 1988 Measurements of regional cerebral blood flow (CBF) with positron emission tomography in adult humans with cerebrovascular disease have demonstrated consistently that values below 10 ml/(100 gm.min) occur only in infarcted brain. Although experimental data ... Full text Link to item Cite

Cerebral blood volume measured with inhaled C15O and positron emission tomography.

Journal Article J Cereb Blood Flow Metab · August 1987 Local cerebral blood volume (CBV) has been measured previously with inhaled 11CO and positron emission tomography (PET). The model used assumes that equilibrium in tracer concentration has occurred between arterial and systemic venous blood before the PET ... Full text Link to item Cite

The effect of hemodynamically significant carotid artery disease on the hemodynamic status of the cerebral circulation

Journal Article Annals of Internal Medicine · January 1, 1987 Although the presence of a hemodynamically significant carotid artery lesion is commonly used as an indicator of impaired cerebral circulation, the effect of such lesions on cerebral perfusion pressure and cerebral blood flow has never been determined accu ... Full text Cite

Regional asymmetries of cerebral blood flow, blood volume, and oxygen utilization and extraction in normal subjects

Journal Article Journal of Cerebral Blood Flow and Metabolism · January 1, 1987 Positron emission tomography (PET) and 15O-labeled radiotracers were used to measure regional CBF, cerebral blood volume (CBV), CMRO2, and oxygen extraction in 32 right-handed subjects at rest. Mean left hemispheric CBF (46.2 ± 6.8 ml/100 g/min) and CMRO2 ... Full text Cite

PET: the new focus of nuclear medicine?

Journal Article J Nucl Med · December 1985 Link to item Cite

Cerebral blood flow and cerebral metabolic rate of oxygen requirements for cerebral function and viability in humans.

Journal Article J Cereb Blood Flow Metab · December 1985 This study was undertaken to determine the minimum CBF and CMRO2 required by the human brain to maintain normal function and viability for more than a few hours. Positron emission tomography (PET) was used to perform regional measurements in 50 subjects wi ... Full text Link to item Cite

Cerebrospinal fluid lymphocytosis in acute bacterial meningitis.

Journal Article Am J Med · August 1985 Cerebrospinal fluid lymphocytosis (more than 50 percent lymphocytes or mononuclear cells) occurred in 14 of 103 cases of bacteriologically proved acute bacterial meningitis. Patients with cerebrospinal fluid lymphocytosis accounted for 32 percent (13 of 41 ... Full text Link to item Cite

Standardized mean regional method for calculating global positron emission tomographic measurements

Journal Article Journal of Cerebral Blood Flow and Metabolism · January 1, 1985 A new 'mean regional' method for calculating global hemispheric values of blood flow, blood volume, and metabolism with positron emission tomography is presented. It is based on a standardized set of regions defined according to coordinates in a stereotact ... Full text Cite

Regional cerebral blood flow and metabolism in reversible ischemia due to vasospasm. Determination by positron emission tomography

Journal Article Journal of Neurosurgery · January 1, 1985 Regional cerebral blood flow (rCBF) and regional cerebral metabolic rate of oxygen (rCMRO2) were measured by positron emission tomography (PET) in four patients with subarachnoid hemorrhage and hemiparesis due to cerebral vasospasm. With resolution of the ... Full text Cite

Physiological responses to focal cerebral ischemia in humans.

Journal Article Ann Neurol · November 1984 Positron emission tomography (PET) was used to investigate the regional hemodynamic and metabolic changes that accompany focal reductions in cerebral blood flow to ischemic but uninfarcted regions of the brain. Studies were performed on 7 patients chosen f ... Full text Link to item Cite

Extracranial-intracranial bypass surgery: hemodynamic and metabolic effects.

Journal Article Neurology · September 1984 After superficial temporal artery-middle cerebral artery bypass, cerebral blood flow (CBF) in the operated hemisphere increased in 6 of 17 patients. Preoperatively, the symptomatic hemisphere showed lower CBF in all six, lower oxygen metabolism in five, hi ... Full text Link to item Cite

Validation of the dual radiotracer method for quantitative In-111 platelet scintigraphy.

Journal Article Thromb Res · April 15, 1984 We have developed a simple in vivo scintigraphic technique that permits accurate quantitative comparison of intravascular platelet deposition in blood vessels of similar size. Regional count information from scintigraphic images of In-111 platelets and Tc- ... Full text Link to item Cite

Scintigraphic detection of coronary artery thrombi in patients with acute myocardial infarction

Journal Article Journal of the American College of Cardiology · January 1, 1984 To determine whether coronary thrombi can be detected scintigraphically after acute myocardial infarction, 24 patients were studied with a new method employing indium-111-labeled platelets and technetium-99m-labeled red blood cells. Nine patients with susp ... Full text Cite

Hyperglycemia is not associated with mortality in bacterial meningitis.

Journal Article Ann Neurol · July 1983 An association between hyperglycemia and mortality from cerebral ischemia has been reported in both animals and man. Recently, a similar observation has been made in animals with bacterial meningitis. The present study of 83 patients with bacterial meningi ... Full text Link to item Cite

Thrombus imaging with indium-111 platelets.

Journal Article Semin Thromb Hemost · April 1983 Full text Link to item Cite

Indium-111 platelet scintigraphy in cerebrovascular disease.

Journal Article Neurology · September 1982 We obtained scintigraphic images of the neck from 100 patients with suspected cerebrovascular disease after injecting indium-111-labeled autologous platelets. One or more focuses of increased activity, implying local platelet accumulation, were seen along ... Full text Link to item Cite

Improved scintigraphic detection of intravascular thrombi by a double radioisotope technique

Journal Article Journal of Cerebral Blood Flow and Metabolism · January 1, 1982 Cite

Cerebrospinal fluid to serum glucose ratios in diabetes mellitus and bacterial meningitis.

Journal Article Am J Med · August 1981 Although calculation of the cerebrospinal fluid to serum glucose ratio is widely recommended as a way to identify pathologic hypoglycorrhachia, few data are available to document its accuracy. In order to provide a better basis for interpretation of this q ... Full text Link to item Cite

Sarcoidosis mimicking glioma: case report and review of intracranial sarcoid mass lesions.

Journal Article Neurology · July 1981 Sarcoidosis may rarely cause a discrete intracranial mass lesion. We report a case originally diagnosed as a malignant glioma because of the uneven enhancement and marked white matter edema seen on computerized tomography. Twenty-two reported cases are ana ... Full text Link to item Cite

Scintigraphy with indium-111 platelets in cerebrovascular disease

Journal Article Neurology · January 1, 1981 Cite