Stroke or Cerebrovascular accident (CVA)

Benjawan Nunthachai

brain has three main components

the cerebrum (which consists of the left and right cerebral hemispheres), the cerebellum, and the brain stem.

The cerebral hemispheres of the brain make up the largest part of your brain.

The cerebellum is the structure located behind the brain stem, and the brain stem is the lowest section of the brain and is connected to the spinal cord.

• A stroke occurs if the flow of oxygen-rich blood to a portion of the brain is blocked. Without oxygen, brain cells start to die after a few minutes. Sudden bleeding in the brain also can cause a stroke if it damages brain cells.

• If brain cells die or are damaged because of a stroke, symptoms occur in the parts of the body that these brain cells control. Examples of stroke symptoms include sudden weakness; paralysis or numbness of the face, arms, or legs (paralysis is an inability to move); trouble speaking or understanding speech; and trouble seeing.

What Is a Stroke?

Other Names for a Stroke•Brain attack•Cerebrovascular accident (CVA)•Hemorrhagic stroke (includes intracerebral hemorrhage and subarachnoid hemorrhage)•Ischemic stroke (includes thrombotic stroke and embolic stroke)

Overview

• The two main types of stroke are ischemic (is-KE-mik) and hemorrhagic (hem-ah-RAJ-ik). Ischemic is the more common type of stroke.

• An ischemic stroke occurs if an artery that supplies oxygen-rich blood to the brain becomes blocked. Blood clots often cause the blockages that lead to ischemic strokes.

• A hemorrhagic stroke occurs if an artery in the brain leaks blood or ruptures (breaks open). The pressure from the leaked blood damages brain cells. High blood pressure and aneurysms (AN-u-risms) are examples of conditions that can cause hemorrhagic strokes. (Aneurysms are balloon-like bulges in an artery that can stretch and burst.)

Region of the Cerebrum Damaged by Stroke

Signs and Symptoms

Wernicke's area (central language area) Difficulty speaking understandably and comprehending speech; confusion

between left and right; difficulty reading, writing, naming objects, and calculating

Broca's area (speech) Difficulty speaking and, sometimes, writing

Parietal lobe on the left side of the brain Loss of coordination of the right arm and leg

Facial and limb areas of the motor cortex on the left side of the brain

Paralysis of the right arm and leg and the right side of the face

Facial and arm areas of the sensory cortex Absence of sensation in the right arm and the right side of the face Optic radiation Loss of the right half of the visual field of

both eyes

Classification• Stroke is divided into two types of ischemic

stroke and Hemorrhagic strokes. • A prognosis of the results of a study in Korea

stated that, 75.2% of ischemic strokes suffered by men with a prevalence of hypertension, smoking and alcohol consumption.

http://topworldofhealth.blogspot.com/2011/10/stroke-types-treatments-preventions.html

Types of Stroke• Ischemic Stroke• An ischemic stroke occurs if an artery that supplies oxygen-rich blood to the brain

becomes blocked. Blood clots often cause the blockages that lead to ischemic strokes.

• The two types of ischemic stroke are thrombotic (throm-BOT-ik) and embolic (em-BOL-ik). In a thrombotic stroke, a blood clot (thrombus) forms in an artery that supplies blood to the brain.

• In an embolic stroke, a blood clot or other substance (such as plaque, a fatty material) travels through the bloodstream to an artery in the brain. (A blood clot or piece of plaque that travels through the bloodstream is called an embolus.)

• With both types of ischemic stroke, the blood clot or plaque blocks the flow of oxygen-rich blood to a portion of the brain.

http://www.nhlbi.nih.gov/health/health-topics/topics/stroke/printall-index.html

Ischemic Stroke

The illustration shows how an ischemic stroke can occur in the brain. If a blood clot breaks away from plaque buildup in a carotid (neck) artery, it can travel to and lodge in an artery in the brain. The clot can block blood flow to part of the brain, causing brain tissue death.

Hemorrhagic Stroke• A hemorrhagic stroke occurs if an artery in the brain leaks blood or

ruptures (breaks open). The pressure from the leaked blood damages brain cells.

• The two types of hemorrhagic stroke are intracerebral (in-trah-SER-e-bral) and subarachnoid (sub-ah-RAK-noyd). In an intracerebral hemorrhage, a blood vessel inside the brain leaks blood or ruptures.

• In a subarachnoid hemorrhage, a blood vessel on the surface of the brain leaks blood or ruptures. When this happens, bleeding occurs between the inner and middle layers of the membranes that cover the brain.

• In both types of hemorrhagic stroke, the leaked blood causes swelling of the brain and increased pressure in the skull. The swelling and pressure damage cells and tissues in the brain.

Hemorrhagic Stroke

The illustration shows how a hemorrhagic stroke can occur in the brain. An aneurysm in a cerebral artery breaks open, which causes bleeding in the brain. The pressure of the blood causes brain tissue death.

Hemorrhagic Stroke

Ischemic Stroke

Who Is at Risk for a Stroke?The major risk factors for stroke include:

• High blood pressure is the main risk factor for stroke. Blood pressure is considered high if it stays at or above 140/90 mmHg over time. If you have diabetes or chronic kidney disease, high blood pressure is defined as 130/80 mmHg or higher. (The mmHg is millimeters of mercury—the units used to measure blood pressure.)

Who Is at Risk for a Stroke?The major risk factors for stroke

include:• Smoking can damage blood vessels

and raise blood pressure. Smoking also may reduce the amount of oxygen that reaches your body's tissues. Exposure to secondhand smoke also can damage the blood vessels.

Who Is at Risk for a Stroke?The major risk factors for stroke include•Brain aneurysms or arteriovenous malformations (AVMs). Aneurysms are balloon-like bulges in an artery that can stretch and burst. AVMs are tangles of faulty arteries and veins that can rupture (break open) within the brain. AVMs may be present at birth, but often aren’t diagnosed until they rupture.

Who Is at Risk for a Stroke?The major risk factors for stroke include

• Diabetes is a disease in which the blood sugar level is high because the body doesn't make enough insulin or doesn't use its insulin properly. Insulin is a hormone that helps move blood sugar into cells where it’s used for energy.

•Heart diseases. Coronary heart disease (also called coronary artery disease), cardiomyopathy (KAR-de-o-mi-OP-a-the), heart failure, and atrial fibrillation can cause blood clots that can lead to a stroke.

Who Is at Risk for a Stroke?The major risk factors for stroke

include• Age and gender. Your risk of stroke

increases as you get older. At younger ages, men are more likely than women to have strokes. However, women are more likely to die from strokes. Women who take birth control pills also are at slightly higher risk of stroke.

Who Is at Risk for a Stroke?The major risk factors for stroke

include•Personal or family history of stroke or TIA. If you’ve had a stroke, you’re at higher risk for another one. Your risk of having a repeat stroke is the highest right after a stroke. A TIA also increases your risk of having a stroke, as does having a family history of stroke.

Other risk factors for stroke, many of which of you can control, include:

•Alcohol and illegal drug use, including cocaine, amphetamines, and other drugs•Unhealthy cholesterol levels•Lack of physical activity•Unhealthy diet•Obesity•Stress and depression•Certain medical conditions, such as sickle cell anemia, vasculitis ( inflammation of the blood vessels), and bleeding disorders

An ischemic stroke occurs when a blood vessel supplying the brain

becomes blocked, as by a clot.

A hemorrhagic stroke occurs when a blood vessel bursts, leaking blood into the brain.