Stroke and Transient Ischemic Attack

Restriction of blood flow to the brain results in a stroke. When the brain cells are deprived of oxygen and do not get enough glucose, it may result in cell death resulting in permanent brain damage or death.

What are the symptoms of Stroke?

The most common symptoms of a stroke are:

• Weakness or numbness of the face, arm, or leg on one side of the body
• Loss of vision or dimming (like a curtain falling) in one or both eyes
• Loss of speech, difficulty talking, or understanding others
• Sudden, severe headache with no known cause
• Loss of balance or unstable walking, usually combined with another symptom

What should a person do in case they suffer from Stroke?

Stroke is a medical emergency and requires immediate treatment. This increases the chances of a full recovery or even prevents death.

Think “FAST” and do the following:

Face: Ask the person to smile. Does one side of the face droop?

Arms: Ask the person to raise both arms. Does one arm drift downward? Or is one arm unable to rise?

Speech: Ask the person to repeat a few words. Is the person’s speech slurred or different from usual?

Time. If you see any of these signs, call emergency medical help right away.

Every minute counts. The longer a stroke goes untreated, the greater the potential for brain damage and disability.

What are the causes and risk factors of Stroke?

There are 2 types of stroke:

1. Ischemic stroke – similar to a heart attack but occurring in the blood vessels of the brain.

• • most common type of stroke occurring when a blood clot blocks the flow of blood and oxygen to the brain.
  • These blood clots are typically formed in areas with atherosclerosis. (see atherosclerosis)
  • Factors increasing the risk of atherosclerosis development are as follows:
    
    • smoking
    • high blood pressure (hypertension)
    • obesity
    • high cholesterol levels
    • diabetes
    • excessive alcohol intake

1. Hemorrhagic stroke – Rupturing of a blood vessel in the brain.

1. • • The main cause of haemorrhagic stroke is high blood pressure, weakening the arteries in the brain and make them more likely to split or rupture.
     • Things that increase the risk of high blood pressure include:
       
       • being overweight
       • drinking excessive amounts of alcohol
       • smoking
       • a lack of exercise
       • stress

What is Transient Ischemic Attack (TIA)?

• A transient ischemic attack (TIA) is a temporary period of symptoms like those of a stroke, but not causing permanent damage.
• In TIA, symptoms may come for some time and disappear and may also be known as a ministroke.
• A TIA is caused by a temporary decrease in blood supply to part of the brain, lasting for as little as five minutes.
• The causes are similar to those of ischemic stroke (atherosclerosis).

Emergency medical care is needed even with TIA. The presence of a TIA could mean a partially blocked or narrowed artery leading to the brain.

How are Stroke and Transient Ischemic Attack diagnosed?

The doctor conducts a physical exam including listening to the heart by the stethoscope and assessing the blood pressure. The doctor might also advise a neurological exam to look at a potential stroke the affects the nervous system.

Blood tests: To check for blood clotting time and whether the blood sugar is too high or low or also if there are chances of an infection.

Computerized tomography (CT) scan: A CT scan for detailed image of the brain to show the bleeding in the brain, an ischemic stroke, a tumor, or other conditions. A dye is injected into the bloodstream to view the blood vessels in the neck and brain in greater detail (computerized tomography angiography).

Magnetic resonance imaging (MRI): An MRI uses powerful radio waves and a magnetic field to create a detailed view of the brain to detect brain tissue damaged by an ischemic stroke and brain hemorrhages. Sometimes, magnetic resonance angiography or magnetic resonance venography is conducted in which a dye is injected into a blood vessel to view the arteries and veins and highlight blood flow.

Other tests that are conducted are:

• Carotid ultrasound.
• Cerebral angiogram
• Echocardiogram: An echocardiogram uses sound waves to create detailed images of the heart. An echocardiogram can find a source of clots in the heart that may have traveled to the brain and caused a stroke.

What are the treatment options for Stroke?

Fast action and effective treatment stroke can prevent long-term disability and save lives.

The specific treatments depend on the type of stroke.

Ischemic stroke

Treating an ischemic stroke requires blood flow to be quickly restored to the brain. This may be done with:

Emergency IV medicine: This medicine breaks up a clot and has to be given within 4.5 hours of symptom occurrence. Faster administration of medicine reduces complications. Recombinant tissue plasminogen activator (TPA) is most commonly used in ischemic stroke. Also known as ‘clot buster’, this medicine restores blood flow by dissolving the blood clot caused the stroke.

Emergency endovascular procedures: Sometimes ischemic strokes are directly treated inside the blocked blood vessel.

Direct ingestion of medicines to the brain: A long, thin tube called a catheter is moved through the arteries to the brain to deliver TPA directly where the stroke is happening.

Removing the clot with a stent retriever: A device attached to a catheter can directly remove the clot from the blocked blood vessel in the brain.

Hemorrhagic stroke

Treatment focuses on controlling the bleeding and reducing pressure in the brain caused by excess fluid.

Possible treatment options are:

• Emergency measures:

If a person is on blood-thinning medications, then counteractive medications for the blood thinners’ effects is prescribed. These treatments include medicines or a transfusion of blood products. Medicines also can lower the pressure in the brain, lower blood pressure, prevent spasms of the blood vessels and prevent seizures.

• Surgery

If the bleeding area is large, surgery may be required for removal of the blood and relieve pressure on the brain.

Following procedures may be advised by the doctor if aneurysm, arteriovenous malformation (AVM) or other blood vessel condition caused the stroke –

• Surgical clipping.
• Coiling, also known as endovascular embolization.
• Surgical removal of a tangle of thin-walled blood vessels, known as an AVM.
• Stereotactic radiosurgery.

Is it possible to prevent Stroke?

Up to 50% of all strokes are preventable and many risk factors can be controlled before they cause problems. These controllable Risk Factors for Stroke are:

• High blood pressure
• Atrial fibrillation
• Uncontrolled diabetes
• High cholesterol
• Smoking
• Excessive alcohol intake
• Obesity
• Carotid or coronary artery disease

Uncontrollable Risk Factors for Stroke:

• Age (>65)
• Gender (Men have more strokes, but women have deadlier strokes)
• Race (African-Americans are at increased risk)
• Family history of stroke