Ischemic Stroke

Definition

A stroke happens when blood supply to an area of the brain is stopped. Medical care is needed right away. Cells in the brain die if they are without oxygen for more than a few minutes.

There are two main types of stroke:

• Ischemic—blood flow is blocked; most common type of stroke
• Hemorrhagic—bleeding in the brain

Hemorrhagic vs. Ischemic Stroke

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Causes

An ischemic stroke is caused by a blockage in blood vessels of the brain. This may be caused by:

• A clot from another part of the body breaks free, travels to the brain, and becomes trapped in a blood vessel.
• A clot that forms in an artery of the brain.
• An inner wall of an artery of the brain tears.

Risk Factors

This problem is more common in older adults and people with a family history of stroke. Health issues that can increase the risk of stroke are:

• History of transient ischemic attacks (TIA or mini-strokes)
• Obesity or metabolic syndrome
• Type 2 diabetes or prediabetes
• High blood pressure
• High cholesterol
• Heart diseases or injury such as previous heart attack, atrial fibrillation or enlarged heart
• Diseases of blood vessels such as carotid artery stenosis or atherosclerosis

Habits that can increase the risk of stroke are:

• Smoking
• A diet that is high in saturated fat, trans fat, cholesterol, and sodium
• Low levels of physical activity
• High alcohol use
• Drug abuse from cocaine , amphetamines, or heroin use

Symptoms

Symptoms occur suddenly. Some problems may be:

• Muscle weakness
• Hearing and vision problems
• Sensory changes
• Problems with balance
• A feeling of spinning when a person is still
• Problems breathing
• Problems chewing, swallowing, and speaking

Note: These are signs of an emergency. Call for medical help if you are having signs of a stroke.

Diagnosis

A stroke needs to be diagnosed quickly. The doctor will look for signs of nerve or brain problems. Blood tests may be done to look for clotting problems.

Images of the brain and blood flow can be taken with:

• CT scan
• Angiogram —to look at the heart and its blood supply
• CT angiogram
• MRI scan
• Magnetic resonance angiography (MRA)
• Doppler ultrasound

The heart will also be checked with:

• Electrocardiogram (ECG) to look at the heart's electrical activity
• Echocardiogram to look at the heart's muscle movements

Treatment

Emergency care will be needed. The goal is to break up the clot and restore blood flow as quickly as possible. Restoring blood flow will halt more damage to the brain. The clot may be broken up or removed with medicine or procedure.

Medications

A medicine called tPA can quickly dissolve blood clots. It will restore blood flow and increase the chance of a full recovery. The treatment needs to be given within 3 to 4 hours of the start of stroke symptoms. This is why it is important to get medical care as soon as symptoms start.

Medicine called blood thinners may also be given. It can stop new clots and slow or stop the growth of clots that are already there.

Procedures

Endovascular procedures can deliver treatment straight to the area. It may be needed for clots that are large, block a large area, or don't respond to medicine. A catheter (tube) is passed through blood vessels until it reaches the blocked artery. Once there the doctor may:

• Insert medicine like tPA directly into clot
• Remove the clot through tubes, called mechanical thrombectomy
• Place a mesh tube called a stent to prop open the blood vessel—may also release medicine to stop clots from forming

Recovery

Early treatment can prevent long term problems. A treatment plan will be made to prevent future strokes.

Damage caused by the stroke cannot be reversed. Long term effects will depend where the brain injury happened and how much was damaged. Therapy may be needed to regain skills or adapt to changes. Rehabilitation may include:

• Physical therapy—to improve movement
• Occupational therapy—to help with daily tasks and self care
• Speech therapy—to improve swallowing and speech
• Psychological therapy—to address behavioral changes and provide support

Prevention

The risk of stroke can be lowered by:

• Managing chronic health problems, such as high blood pressure and diabetes
• Maintaining a healthy weight through diet and exercise
• Eating a diet that is low in fat and cholesterol and rich in whole grains, fruits, and vegetables
• Not smoking
• Limiting alcohol