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Spinal Cord Strokes

Spinal cord strokes are a rare but important differential consideration in central nervous system vascular disease. As in the brain, spinal cord strokes can be divided into two large groups—ischemic and hemorrhagic. They account for about 1% of all strokes and about 5–8% of acute myelopathies . Spinal Cord Vascular Supply The arterial supply of the spinal cord is unique. A large single anterior spinal artery…

Stroke and Eye Findings

Introduction Stroke patients often have visual symptoms and signs, the characteristics of which vary mostly depending on the type of vessel involved (arteries versus veins), the type of stroke (ischemic or hemorrhagic), and the size of the arteries involved (large versus small artery disease). Because the blood supply to the eye is mostly provided by branches of the ophthalmic artery, the first intracranial branch of the…

Brain Injury From Cerebral Hypoperfusion

Introduction There is a spectrum of brain injury from cerebral hypoperfusion ranging from transient loss of consciousness to devastating anoxic neuronal damage. At the root of this injury is the fact that with limited stores of high-energy phosphate compounds and a high metabolic demand, the brain is critically dependent on cerebral blood flow (CBF) to continuously supply oxygen and glucose. CBF in turn is governed by…

Aortic Arch Artherosclerotic Disease

Introduction Ischemic stroke etiologies can be classified into thrombotic, embolic, or cerebral infarcts secondary to systemic hypoperfusion. Aortic arch disease has been a subject of study for many years as a potential source of embolic stroke and is common in individuals over 60 years of age. Complex, ulcerated plaques are common, and mural thrombi can superimpose upon ulcers. Mural thrombi can occasionally be loosely adherent and…

The Heart and Stroke

Overview Globally, stroke is the fifth leading cause of death in Western countries after cancer and heart disease. There are several ways in which stroke and heart disease interrelate . Cardiogenic stroke occurs when (1) clots embolize from the heart and reach the brain via the arterial circulation, or (2) as a result of severe heart failure and cerebral hypoperfusion. Medications as well as certain cardiac…

Basilar Artery Disease

Anatomy The two vertebral arteries merge at the pontomedullary junction to form the basilar artery (BA). This artery lies within the prepontine cistern and is the main stem of the posterior circulation. It directly supplies a large territory of vital brain tissue including the brainstem and cerebellum and provides the main conduit for blood flow to the thalami and medial temporal and parietal lobes. The BA…

Vertebral Artery Disease

Vascular Anatomy The vertebral arteries (VAs) originate from the most proximal portion of the subclavian arteries (SAs) and constitute the birthplace of the so-called posterior circulation. An important feature of the SA system is that the right artery originates from the innominate artery, whereas the left arises as the last brachiocephalic branch of the aortic arch, providing different sources of blood supply to the vertebrobasilar system.…

Primer in Cerebrovascular Disease: Innominate and Subclavian Disease

Introduction Diseases of the subclavian and innominate artery are rare entities that impact less than 5% of the population. Limited data are available to describe their prevalence and natural history, and current knowledge is derived predominantly from case reports and small case series. Evaluation and Workup Diseases involving the subclavian and innominate arteries are largely asymptomatic and discovered incidentally on radiographic imaging performed for other reasons.…

Posterior Circulation: Large Artery Occlusive Disease and Embolism

Introduction In many respects, strokes involving the posterior circulation parallel those of the anterior circulation. Ischemic infarcts may be due to atherothrombosis of large arteries, lacunes from occlusion of small penetrating arteries, or embolism from either the heart or proximal vascular sites. Unlike those of the anterior circulation, however, the vessels of the posterior circulation are more difficult to study by noninvasive means. Carotid stenosis in…

Carotid Artery Disease

Introduction Numerous pathological processes affect the cervical and intracranial carotid artery. The most common and widely studied is atherosclerosis of the cervical carotid artery. Atherosclerosis of the intracranial carotid arteries has the same pathophysiological basis and can present with similar symptoms. It has a higher prevalence among African-American and Asian populations. Some other diseases affecting the carotid artery that are occasionally encountered in practice include carotid…

Anterior Circulation: Large Artery Occlusive Disease and Embolism

Introduction Ischemic brain infarctions involving the anterior circulation are by far the most common type of ischemic stroke due to the relative amount of blood that flows to this area as opposed to the posterior circulation. Mechanisms causing anterior circulation cerebral infarction can be separated into three broad categories: cardiogenic embolism, artery-to-artery embolism, and hemodynamic insufficiency due to low perfusion. Cardiogenic embolism accounts for about 25%…

Small Artery Occlusive Diseases

Introduction Two Different Subtypes of Small Artery Occlusive Diseases Small artery occlusive diseases, known as lacunar stroke, constitute approximately 25% of ischemic strokes and are particularly frequent among Hispanics and Asians. C. Miller Fisher performed detailed clinicopathological examinations and described two different subtypes of lacunar strokes: those caused by an intrinsic disease of the small arteries (40–200 μm diameter) categorized as small artery disease such as…

Types of Stroke and Their Differential Diagnosis

Acknowledgment Thanks to Li-An Ho for the illustrations. Introduction Stroke is typically defined as the sudden onset of a neurologic deficit caused by vascular abnormalities. There are two main categories: (1) ischemia (infarction)—restricted blood flow due to vascular stenosis/occlusion and the consequent insufficient oxygen and glucose supply to an area of the central nervous system (CNS) and (2) hemorrhage—bleeding in or around the brain. Ischemic stroke…

Transient Focal Neurological Events

The most common temporary focal neurological events are transient ischemic attacks (TIAs), migrainous accompaniments, seizures, and functional psychogenic episodes . Transient Ischemic Attacks A TIA is defined as a transient episode of neurological dysfunction caused by focal brain, spinal cord, or retinal ischemia, without acute infarction . In past years TIAs were arbitrarily characterized as lasting less than 24 h. Modern brain and vascular imaging showed…

Rodent Behavioral Tests Sensitive to Functional Recovery and Compensation

Introduction Research scientists rely upon rodent models to help us better understand and test potential treatments for stroke survivors. Although there are limitations in the use of rodents to study human neurological disorders, it is possible to identify and focus on the functional overlaps and similarities between species’ brains and behaviors when designing studies investigating stroke prevention, acute neuroprotection, and chronic poststroke interventions. There is overwhelming…

Blood Biomarkers in Acute Stroke

Introduction Blood biomarkers may improve the diagnostic workup and may facilitate therapeutic decision making in acute stroke patients. This includes the differentiation of “true” stroke patients from stroke mimics, the discrimination between intracerebral hemorrhage (ICH) and ischemic stroke, the prediction of complications of thrombolysis, the etiologic classification of ischemic stroke, and the prediction of recurrent events in patients having a first transitory ischemic attack (TIA). Since…

Proteomes and Biomarkers of the Neurovascular Unit

Introduction Brain endothelial cells (BECs) that form the blood–brain barrier (BBB) exhibit a unique polarized phenotype characterized by firmly sealed tight junctions, thick and elaborate luminal glycocalyx, and a multitude of transporters and ion pumps responsible for controlled exchange of water and nutrients between blood and brain compartments. Adjoining pericytes embedded in the vascular basement membrane, astrocytes projecting end feet that envelope capillaries and microvessels, and…

Genomic Tools

Introduction Although an enormous amount of work has been performed trying to understand the molecular events associated with stroke in animal models, much less has been done assessing the molecular biology of stroke in humans. A number of human studies have examined clotting pathways and some inflammatory pathways; most of the studies have focused on candidate molecules or pathways that are thought to be important in…

Experimental Methods for Measuring Blood Flow in Brain Capillaries

Blood reaches the cortex through larger arterioles, then disperses through the bulk of the tissue through capillaries, and then coalesces back into venules to exit the brain tissue. Much of the gas and nutrient exchange occurs at the capillary level, so that understanding blood flow at this scale is important for both normal and disease physiology. Advancements in optical microscopy now enable researchers to assess flow…

Principles and Methods of Molecular Imaging in Stroke

Molecular imaging is defined as the in vivo measurement of biological processes at the cellular and molecular levels . The technique visualizes pathophysiologic processes noninvasively in real time, with the potential for serial monitoring, and provides information regarding specific molecular alterations underlying the disease status of individual subjects. By complementing conventional “anatomical or physiological” imaging, molecular imaging enables early detection of disease, staging of disease, and quantitative…