Stroke Glossary

Aneurysm

Blood-filled pouch that balloons out from weak spot in artery wall. If one bursts in the brain, it causes a hemorrhagic stroke.

Angiogram

Imaging test used to view blood vessels. Contrast solution is injected while X-rays are simultaneously taken.

Angiography

see angiogram.

Anoxia

Absence of oxygen.

Anticoagulant

Drug that helps prevent the clotting (coagulation) of blood. See Heparin, Coumadin, Warfarin.

Antiplatelet therapy

Medicines like aspirin that reduce blood's tendency to clot but are not true anticoagulants, like Warfarin.

Aspirin

See Antiplatelet therapy.

Aphasia

Total or partial loss of the ability to use words, frequently caused by a stroke that injures the brain's language center.

Atrial fibrillation

Abnormal heart rhythm that typically leads to diminished delivery of blood and nutrients to the brain and other organs. This condition can also lead to the formation of blood clots in the heart that can travel to the brain and cause a stroke.

Blood brain barrier

Elaborate network of supportive brain cells, called glia, surrounding blood vessels and protecting neurons from toxic effects of direct exposure to blood.

Blood pressure

Pressure of the blood against the walls of the arteries resulting from two forces: the heart pumping blood through the circulatory system and arteries resisting the blood flow.

Brain attack

See stroke.

Carotid artery

Artery located on either side of the neck; supplies the anterior portion of the brain with blood.

CAT scan

Series of cross-sectional X-rays of the brain and head; also called computerized axial tomography.

Central stroke pain

(Also known as central pain syndrome): pain caused by damage to an area in the central brain. Mixture of sensations including heat and cold, burning, tingling, numbness, sharp stabbing and underlying aching.

Cerebral blood flow (CBF)

The flow of blood through the arteries that lead to the brain, called the cerebrovascular system.

Cerebral embolism

See embolic stroke.

Cerebral hemorrhage

Bleeding that occurs within the brain tissue.

Cerebrovascular disease

Reduction in brain's blood supply from narrowing of arteries through stenosis (plaque buildup), or blockage from a blood clot.

Cholesterol

Waxy substance produced by the liver, also found in foods. Circulates in the Blood, helps maintain tissues and cell membranes. Excess cholesterol can contribute to narrowing of arteries and high blood pressure.

Circulatory system

The heart and blood vessels.

Clipping

Surgical treatment of brain aneurysm by clamping the distorted vessel, surgically removing the bulging section, and closing the opening in the artery wall.

Clot

Coagulated blood that can block blood flow in arteries in the brain causing strokes. See also thrombus.

Coil

Small, flexible coiled wire that is endovascularly placed in an aneurysm to stabilize it. The body then produces a blood clot inside the aneurysm, strengthening the artery walls and reducing the risk of rupture.

Concentric Medical, Inc.

A medical device company located in Mountain View, CA, focused on the design, development and commercialization of products for restoring blood flow in patients who have experienced an ischemic stroke. www.concentric-medical.com

Coumadin

Anticoagulant, also known as Warfarin.

Duplex Doppler ultrasound

Diagnostic imaging technique using sound waves to visualize blood movement and vascular components.

Dysarthria

Language disorder afflicting some stroke patients, characterized by difficulty with speaking or forming words.

Dysphagia

Trouble eating and swallowing, afflicting some patients after strokes.

Edema

Swelling of a cell that results from the influx of excess water or fluid.

Embolic stroke

Stroke caused by an embolus, or free-roaming clot. (Also called ischemic stroke.)

Emboli

Plural of embolus.(i.e. multiple clots.)

Embolism

Wandering clot that usually forms in the heart, may cause an ischemic stroke if it blocks a cerebral artery. The most common cause of these emboli is blood clots that form during atrial fibrillation.

Embolus

Free-roaming clot that typically starts in the heart. Can cause embolic or ischemic stroke by blocking blood flow to brain.

Endothelial wall

Flat layer of cells comprising a blood vessel's innermost lining.

Extracranial and intracranial bypass

Surgery that restores blood flow to a blood-deprived area of the brain by rerouting a healthy artery in the scalp to the area of brain affected by a blocked artery.

Functional magnetic resonance imaging

(fMRI) - a specialized type of MR imaging that uses slight changes in blood flow to monitor brain activity.

Glia

Also called neuroglia, these cells comprise the blood-brain barrier protecting nerve cells from infection, toxins and trauma while providing them nutrients and oxygen.

Hemiparesis

Weakness on one side of the body.

Hemiplegia

Paralysis on one side of the body.

Hemorrhagic stroke

Bleeding in the brain.

Heparin

Type of anticoagulant.

High blood pressure

Defined in an adult as a systolic pressure of 140 mm Hg or higher and/or a diastolic pressure of 90 mm Hg or higher. Can occur in children or adults; particularly prevalent in African Americans, middle-aged and elderly people, obese people and heavy drinkers.

Hypertension

See high blood pressure.

Hypoxia

Decreased oxygen delivery to a cell.

Infarct

Dead area in the brain caused by a loss of blood supply.

Intracerebral hemorrhage

Occurs when a vessel in the brain leaks blood into the brain.

Ischemia

Loss of blood flow to tissue caused by blood vessel obstruction.

Ischemic cascade

Series of events lasting for several hours to several days following initial ischemia. Causes extensive cell death and tissue damage.

Ischemic penumbra

Areas of damaged, living brain cells arranged in a patchwork pattern around areas of dead brain cells.

Ischemic stroke

Most common type of stroke, accounting for about 87% of all strokes and caused by a blockage of the arteries supplying blood flow to the brain.

Lacunar infarction

Small area of dead brain tissue cause by occlusion of a small artery in the brain. Occurs when a blood clot blocks a cerebral artery.

Magnetic resonance angiography

(MRA) - imaging technique using contrast and magnetic resonance to create an image of the flowing blood through the vessel; often used to detect narrowing or obstruction of the brain arteries.

Magnetic resonance imaging

(MRI)- imaging technology using magnetic fields to detect subtle changes in the water content of tissues. The brain images are more detailed than CAT scans but are not as good at detecting an early hemorrhage.

Merci Retrieval System

Medical devices manufactured by Concentric Medical, Inc. for removing clot in patients experiencing ischemic stroke. The system includes three components, the Merci Retriever®, the Merci® Microcatheter and the Merci® Balloon Guide Catheter.

Necrosis

Cell death resulting from anoxia, trauma or any other form of irreversible damage.

Neuroglia

See Glia.

Neuron

Main functional cell of the brain and nervous system.

Neuroprotective agents

Medications that protect the brain from secondary injury caused by stroke.

Recombinant tissue plasminogen activator

(rt-PA). Genetically engineered form of t-PA, an anti-clotting substance made by the body.

Risk factors

Traits and lifestyle habits that increase the risk of disease. For stroke, these include smoking, obesity, diet, gender, race/ethnicity, physical fitness and age.

Stenosis

Narrowing of an artery due to the buildup of plaque on the inside wall of the artery.

Stroke

Sudden neurological affliction caused by interrupted blood flow to the brain.

Subarachnoid hemorrhage

Bleeding within the outer membranes of the brain into the clear fluid that surrounds the brain.

Thrombolysis

Breaking up of a blood clot using a clot-busting drug that dissolves the clot.

Thrombolytics

Drugs used to treat an ongoing, acute ischemic stroke by dissolving the blood clot to restore arterial blood flow.

Thrombosis

Formation or presence of a blood clot inside a blood vessel or cavity of the heart. If it lodges in an artery wall, a stroke can result.

Thrombotic stroke

Stroke caused by thrombosis. See also ischemic stroke.

Thrombus

Blood clot.

TIA

See transient ischemic attack.

Tissue necrosis factors

Chemicals released by dying cells that cause secondary cell death during the inflammatory immune response associated with the ischemic cascade.

tPA

A clot dissolving drug that can improve long-term stroke patient outcomes if given within the first three hours of symptoms. (Also see recombinant tissue plasminogen activator.)

Transient ischemic attack

(TIA). A short-lived stroke that lasts from a few minutes up to 24 hours; also called a mini-stroke or warning stroke, often preceding an ischemic stroke.

Vasodilators

Medications that increase blood flow to the brain by expanding or dilating blood vessels.

Vasospasm

Dangerous side effect of subarachnoid hemorrhage in which the blood vessels in the subarachnoid space constrict erratically, cutting off blood flow.

Vertebral artery

An artery on either side of the neck; supplying the posterior portion of the brain. See carotid artery.

Warfarin

A commonly used anticoagulant, also known as Coumadin®.

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APM0302_B_3632, 2009-04