Understanding Stroke

Stroke, also referred to as a cerebral vascular accident (CVA) or a brain attack, is an interruption in the flow of blood to cells in the brain. When the cells in the brain are deprived of oxygen, they die. A stroke occurs when a blockage in an artery prevents blood from reaching cells in the brain, or an artery ruptures inside or outside the brain and causes a hemorrhage.

Stroke needs the same urgent treatment as a heart attack and every second is critical to the victim’s care, survival and subsequent quality of life. The more you know about stroke and its warning signs, the more prepared you can become to find treatment.

Types of Stroke

There are two types of stroke:

Ischemic Stroke

Ischemic strokes are caused by the build up of fatty deposits on the inside of an artery wall which then becomes completely clogged. Ischemic strokes account for eighty percent of all strokes suffered. Some ischemic strokes are preceded by stroke-like symptoms called transient ischemic attacks (TIA). These may occur months before the stroke. The loss of vision in a TIA may be described as a feeling that a shade is being pulled down over your eyes. The symptoms are usually temporary and improve within 10 to 20 minutes.

Hemorrhagic Stroke

Hemorrhagic stroke occurs when an artery inside the brain ruptures or when an aneurysm at the base of the brain bursts. Twenty percent of all strokes suffered are hemorrhagic strokes. Symptoms more specific to this type of stroke include headache, nausea and vomiting, neck stiffness, seizures, sudden changes in mental state and lethargy. Hemorrhagic strokes usually occur in the daytime and during physical activity. The symptoms typically begin very suddenly and evolve over several hours.

Stroke Symptoms

Warning signs of possible stroke may include a combination of the following symptoms:

• Sudden numbness or weakness of the face, arm or leg, particularly when it happens on one side of the body
• Confusion, trouble speaking or understanding others
• Vision problems in one or both eyes, such as dimness, blurring or loss of vision
• Loss of balance or coordination, dizziness and trouble walking
• Severe headache with no known cause

Detection and Diagnosis

Palmdale Regional Medical Center uses advanced medical technology to help diagnose and treat stroke, including:

Cerebral Computed Tomography (CT) Scan

The first and most important test after a stroke is a CT scan, which is a series of X-rays of your brain that can help identify whether there is bleeding. This test will help your doctor determine whether the stroke is ischemic or hemorrhagic.

Magnetic Resonance Imaging (MRI) Scan

An MRI is a test that uses a magnetic field and pulses of radio wave energy to make pictures of organs and structures inside the body. In many cases, MRI gives information that cannot be seen on an X-ray, ultrasound, or computed tomography (CT) scan. An MRI can determine the amount of damage to the brain and help predict recovery.

Magnetic Resonance Angiography

A test used to visualize the blood vessels that supply the brain. An angiogram is considered minimally invasive and is performed through the artery in the leg. A small tube (catheter) is navigated to the blood vessels in the neck. Magnetic resonance imaging is used to obtain pictures of the blood vessels in the neck and brain. An angiogram helps to identify blockages that cause ischemic stroke.

This test also identifies aneurysms and arteriovenous malformations, which cause hemorrhaghic stroke. An angiogram can help to lay the groundwork for treatment.

Carotid Doppler and Transcranial Doppler

A carotid doppler test uses high-frequency sound waves to identify narrowing in the arteries that supply blood to the brain. A transcranial doppler test uses high-frequency sound waves to measure the rate and direction of blood flow in blood vessels.

Treatment Options

Treatment options depend on the type of stroke:

For an Ischemic Stroke

If your stroke is diagnosed within three hours of the start of symptoms, you may be given a clot-dissolving medication called tissue plasminogen activator (tPA), which can increase your chances of survival and recovery.

However, if you had a hemorrhagic stroke, use of tPA would be life-threatening. If IV tPA doesn’t work, tPA and other clot-dissolving agents can be delivered directly to the area of blockage with the angiogram technique and very small catheters. If these medications don’t work, the clot can potentially be removed with fine-grasping instruments or the blocked vessel can be re-opened with stents.

For a Hemorrhagic Stroke

Initial treatment of a hemorrhagic stroke is difficult. Efforts are made to control bleeding, reduce pressure in the brain and stabilize vital signs, especially blood pressure. There are few medications available to treat hemorrhagic stroke. Surgery generally is not used to control mild to moderate bleeding resulting from a hemorrhagic stroke.

However, if a large amount of bleeding has occurred and the person is rapidly getting worse, surgery may be needed to remove the blood that has built up inside the brain and to lower pressure inside the head. If bleeding is due to a ruptured aneurysm, whether surgery can be done depends on the location of the aneurysm and the person’s condition following the stroke. Surgery can involve clipping the aneurysm in an open-brain procedure. Another option is sealing the aneurysm with coils delivered through the angiogram technique. This is the less invasive option, but is not suitable for all aneurysms.

Prevention

Taking the following steps can help you control risk factors and other medical conditions that could lead to a stroke:

• Have regular medical checkups. Work with your doctor to control your high blood pressure. This is especially important if you also have diabetes.
• Become more active. The more physically active you are, the greater the reduction in risk. Exercise can also help raise HDL (“good”) cholesterol levels in your body, which also reduces the risk of stroke.
• Get tested for high cholesterol, heart disease (especially atrial fibrillation), diabetes or disorders that affect your blood vessels.
• Don’t smoke. If you do smoke, quit. Daily cigarette smoking increases the risk of stroke by two times.
• Take cholesterol-lowering medications called statins if you have high cholesterol or have had a heart attack, TIA or stroke.