Cerebrovascular Accident Vs TIA

Overview 

Both cerebrovascular accidents (CVAs) and transient ischaemic attacks (TIAs) occur from a disruption to blood flow in the brain. CVAs are also commonly known as strokes, with TIAs being called mini-strokes. The reason for this is that whilst the pathophysiology may be similar for both CVAs and TIAs, the length of duration differs. This results in two different clinical pictures, allowing us to differentiate between them. 

CVAs last longer and cause longer-lasting side effects. These can include problems with speech, swallowing and mobility. TIAs are shorter (hence ‘mini strokes’) and symptoms resolve much quicker. 

Cerebrovascular accident (CVA)

Types of a cerebrovascular accident

There are two main types of CVAs:

• Haemorrhagic CVAs - A haemorrhagic event is one in which there is intracranial bleeding. Haemorrhagic CVAs are a result of a bleed in one or more of the blood vessels in the brain
• Ischaemic CVAs - An ischaemic event is one in which the blood flow to a part of the body is restricted (or stopped), leading to tissue damage. CVAs that are ischaemic are a result of decreased blood flow to parts of the brain tissue. There are two possible causes of this blockage: thrombotic processes and embolic processes

The thrombotic process is characterized by the formation of blot clots (or thrombus) in the vessels, leading to occlusion of the vessel. An embolic process occurs when a foreign body blocks a vessel. This can be by a piece of another thrombus from elsewhere, a bubble of gas, or fat.  

Causes

Strokes are caused by various risk factors, including

• High blood pressure
• Abnormal heart rhythm (atrial fibrillation)
• Diabetes
• Cardiovascular diseases e.g. coronary heart disease and carotid stenosis
• Prior TIA or stroke
• High cholesterol levels 
• High fat percentage 
• Smoking
• Excessive alcohol intake
• Family history 

Symptoms

Symptoms of a stroke include:

• Sudden weakness/inability to use your limbs. This is usually one-sided and can affect your face, arms, torso and legs
• Sudden inability to speak or understand what is being said
• Sudden dizziness that doesn’t resolve
• Sudden visual loss 
• Sudden difficulty swallowing

Tips to prevent cerebrovascular accident 

• Diet - ensure that you have a low fat and low salt diet, and include plenty of healthy forms of fatty acids, various vitamin supplements, and other antioxidants, fibre and wholegrains⁴
• Exercise - the recommended guidance is 150 minutes of moderately intense exercise a week, or 75 minutes of high intensity exercises in a week¹
• Stop smoking
• Reduce alcohol intake
• Ensure any medical conditions are well treated - speak to your doctor about this but here are some examples
  • High blood pressure - make sure your blood pressure is not higher than 140/90 
  • Atrial fibrillation - usually treated with heart rate control medication and blood thinners to reduce the risk of stroke
  • Prior TIA or stroke - blood thinners 

When to contact a medical specialist?

If you experience any of the symptoms mentioned above then you should seek urgent medical attention. Remember the acronym act FAST: face, arms, speech, and time to call for help.  

TIA

TIA (known as a mini-stroke) is a shorter-lasting stroke episode. The main clinical symptoms are the same, but the length of time is vastly different.

Types of TIA

TIAs are caused by a temporary blockage in the blood supply to the brain tissue. The blockage is removed by the body, and therefore the symptoms don’t last as long. Once the blockage is gone so are the symptoms! 

A common cause for this blockage is atherosclerosis. This is a process in which there is damage to a blood vessel, leading to the formation of a clot in that area. This clot can be comprised of blood, fat, cholesterol or any other substance within the blood that tends to stick. This formation is called an atherosclerotic plaque. As blood flows around this plaque it can cause part of it to break off. This piece (called an embolus) can then travel through the blood vessels and become lodged elsewhere. 

Causes

The causes of TIA are similar to that of stroke. This is because ischaemic strokes are caused by blockages to the blood supply as well. 

Symptoms

Symptoms of a TIA include³

• Sudden weakness/inability to use your limbs. This is usually one-sided and can affect your face, arms, torso and legs
• Sudden inability to speak or understand what is being said
• Sudden loss of balance or coordination dizziness that doesn’t resolve
• Sudden visual loss 
• Sudden difficulty swallowing
• Sudden, severe headache

The symptoms of a TIA and a CVA can be the same. The main difference is the length of time that these symptoms last. A TIA can last for a few minutes to 24 hours. If the symptoms persist longer than 24 hours it is classified as stroke.²  

Tips to prevent TIA

Due to the risk factors for CVAs and TIAs being similar, the preventive measures are also similar. It is best to optimise lifestyle factors that you can modify, including medical conditions that need treatment. 

When to contact a medical specialist?

It is impossible to tell whether it is a CVA or TIA at the onset of symptoms. TIAs can be a warning sign of strokes, so even if the symptoms resolve, you should seek urgent medical attention. As such, it is imperative to call for help if there is any suspicion of a stroke. The same acronym works for both strokes and TIAs: act FAST! 

The other important point to note is that stroke and TIA patients may have to adhere to certain restrictions to their lifestyle. For example, you will need to inform the DVLA about this incident. If you drive a car or motorcycle, it is recommended that you stop driving for a month after a TIA. If you drive a bus, lorry, or coach, you must stop for at least a year after having a TIA. Medical specialists will assess you at these points to see if you can resume driving.

Which is more common between the two? 

TIAs are more common than strokes, as reported by the National Institute for Health Care and Excellence. 

Summary

Strokes and TIAs have similar pathology and risk factors. If you have any suspicion that you may be suffering a stroke or TIA, then you should seek urgent medical help. TIAs can be a warning sign that something is awry in the body and therefore you need to address the risk factors underlying it. 

If you do suffer from a stroke or TIA, there are various treatments out there to help, as well as stroke rehabilitation. The important thing is to seek help early to get access to these treatments. Think and act FAST!