What is a transient ischaemic attack?

A transient ischemic attack (TIA) is a temporary neurological episode. It is also known as a 'mini-stroke'. It is caused by a temporary blockage or narrowing in a blood vessel leading to the brain. A person experiencing TIA will have signs and symptoms like those of a stroke, but will recover completely within minutes or a few hours.

TIA's main significance is as a warning sign: TIAs occur when the blood vessels feeding the brain are not in good condition. A person who has had a TIA is at serious risk of stroke, often within days of the TIA.

Neurological

Of the nervous system, including the brain.

Signs and symptoms

The signs and symptoms of a TIA are like those of a stroke. The difference between TIA and stroke is that in a TIA signs and symptoms are completely resolved, usually within a few minutes, while a stroke's effects are permanent. Thus, it is impossible - and inadvisable - to try and tell a TIA from a stroke while it is occurring.

Early warning signs - FAST

The FAST test is a set of early warning signs for stroke that anyone can use to recognize stroke. FAST is an acronym used to remember these points:

  • Face - is the person's face droopy, flaccid, especially just on one side? Can they smile?
  • Arms - can the person lift both their arms above their head?
  • Speech - is the person having problems speaking and/or understanding speech? Is speech slurred?
  • Time - the quicker you act, the better the chance of survival and recovery. Call 911, even if the symptoms go away.

The FAST signs - Face, Arms, Speech, and Time - are indicators of a stroke occurring.The FAST test is used to diagnose early warning signs of a stroke.  

Additional TIA signs and symptoms

Symptoms of a TIA include:

  • Sudden paralysis of one side of the body (hemiplegia);
  • Sudden weakness on one side of the body (hemiparesis), inability to move or lift the arm;
  • Movement and coordination problems, especially if on one side only;
  • Confusion, difficulty with speech or understanding speech, formulating thoughts, memory loss;
  • Sudden, severe headache;
  • Dizziness, vertigo;
  • Nausea, vomiting, and;
  • Blurred vision, loss of vision, or seeing only half the regular vision field (hemianopia), or a sudden blindness in one eye (amaurosis fugax). [1]

TIA and migraine

The early signs of a stroke can sometimes be similar to those of migraine. An authoritative diagnosis can only be made with a brain scan. For people who suffer from migraines, it is important to notice irregularities in their migraine symptoms and be alert to the possibility of stroke. An attack that is much more sudden than usual, and/or has different visual symptoms, might not be a migraine attack, but an early sign of stroke.

Nausea

A sensation of sickness and unease, typically felt in the stomach, often accompanied by the urge to vomit. Nausea is a common symptom with many possible causes.

Paralysis

An inability to move or feel; a loss of muscle function or sensation.

1. Murtagh, J. (2008). John Murtagh’s Patient Education (Australian edition.). North Ryde, N.S.W.: McGraw-Hill Book Company Australia.

Causes and types

A TIA is caused by a temporary blockage or narrowing in a blood vessel leading to the brain. Loss of blood supply to an area of the brain will cause a temporary problem within that area. In a TIA, the blood clot normally dissolves after a few minutes, and normal blood flow to the brain area is resumed.

A TIA can be the result of:

  • A blood clot that forms in one of the brain's arteries;
  • A blood clot that arrives at the artery from elsewhere in the body;
  • A narrowing in a brain artery that reduces the blood flow within it, or;
  • Minor damage to an artery that causes some bleeding before the blood vessel self-repairs.

A transient ischaemic attack is normally caused by a temporary blockage of a brain artery. 

Arteries

A blood vessel carrying blood saturated with oxygen from the heart to the body's tissues.

Clot

The thickened or solid mass formed from a liquid, such as blood. Blood clots normally form at an injury site to prevent further blood loss.

1. Murtagh, J. (2008). John Murtagh’s Patient Education (Australian edition.). North Ryde, N.S.W.: McGraw-Hill Book Company Australia.

Risk factors

Risk factors for TIA are similar to those of stroke, and include:

Blood pressure

The pressure the blood places on the walls of the arteries, largely mirroring the contraction of the heart, and consisting of two readings. The higher reading is systolic blood pressure, when the heart contracts, and the lower is diastolic blood pressure, when the heart is relaxed.

Heart disease

A class of diseases that involves the dysfunction of the heart and/or the blood vessels.

Cholesterol

A type of fat produced by the body that is necessary for metabolism.

Diabetes

A metabolic disorder that is caused by problems with insulin secretion and regulation and which is characterized by high blood sugar levels. Also known as diabetes mellitus.

Stress

The word ‘stress’ can have a variety of meanings, but generally describes the physical and mental responses of the body to a demand placed upon it. Often used to describe conditions where the demand is high or unable to be resolved and creates anxiety and tension.

1. Murtagh, J. (2008). John Murtagh’s Patient Education (Australian edition.). North Ryde, N.S.W.: McGraw-Hill Book Company Australia.

Methods for diagnosis

Since a TIA is sudden and is over quickly, diagnosis of a TIA typically happens after it has passed. Your doctor will ask you about your medical history and status, and about the symptoms you have experienced. Your doctor may then have you undergo a brain scan (a CT scan or an MRI) to understand why the TIA occurred and check for the risk of a future stroke. Blood tests can also help with diagnosis.

Your heart activity may also be examined and monitored, as stroke events can be closely related to heartbeat abnormalities.

Blood tests

During a blood test, blood can be drawn using a needle or by a finger prick. Your blood can then be analyzed to help diagnose and monitor a wide range of health conditions.

MRI

A type of imaging that uses a magnetic field and low-energy radio waves, instead of X-rays, to obtain images of organs.

1. Murtagh, J. (2008). John Murtagh’s Patient Education (Australian edition.). North Ryde, N.S.W.: McGraw-Hill Book Company Australia.

Types of treatment

TIA in itself is not treated, as it is a temporary event and leaves no lasting damage. After a TIA, the focus will be on monitoring you for signs of a stroke and preventing a stroke from occurring. This may include medication (for example, drugs to lower blood pressure) and lifestyle change (such as quitting smoking). Surgery is also an option in some cases.

The specific treatment after a TIA depends on underlying risk factors.

Blood pressure

The pressure the blood places on the walls of the arteries, largely mirroring the contraction of the heart, and consisting of two readings. The higher reading is systolic blood pressure, when the heart contracts, and the lower is diastolic blood pressure, when the heart is relaxed.

1. Murtagh, J. (2008). John Murtagh’s Patient Education (Australian edition.). North Ryde, N.S.W.: McGraw-Hill Book Company Australia.

Prognosis

A TIA in itself is thought to leave no lasting damage, and its main significance is as a warning sign. However, some recent research suggests that TIAs can cause minor brain injury. [2] These may not affect the person in a noticeable way, but if TIAs recur, they may have a cumulative effect on brain health.

2. Edwards, J.D., Meehan, S.K., Levy, A.R., et al. (2011). Changes in Intracortical Excitability After Transient Ischemic Attack Are Associated With ABCD2 Score. Stroke 42: 728–733.

Prevention

You can lower your chances of a TIA (or the chances of further TIAs and a stroke) by adopting a healthier lifestyle; by limiting your alcohol consumption, quitting smoking, exercising and eating healthier food.

2. Edwards, J.D., Meehan, S.K., Levy, A.R., et al. (2011). Changes in Intracortical Excitability After Transient Ischemic Attack Are Associated With ABCD2 Score. Stroke 42: 728–733.