Generality
Transient ischemic attack, more simply called TIA, is a temporary and reversible neurological deficit, caused by a transient reduction in blood flow to the brain.
The TIA is very similar, due to causes, symptoms and signs, to ischemic stroke, with the only difference that the neurological deficit is not permanent (as in stroke) but transient and reversible.
A transient ischemic attack, while not causing permanent brain damage, should never be overlooked; in fact, it could be the first indication of a stroke predisposition, whose outcome can be lethal.
Through a careful diagnosis, one can go back to the vascular anomaly that caused the TIA and, based on this, set the therapy; therapy, which can be both pharmacological and surgical.
The prevention of risk factors and careful lifestyle care are essential to avoid worsening the situation and the onset of a stroke.
Figure: Transient ischemic attack is a particular form of ischemic stroke. The obstruction, due to a blood clot, can occur in a cerebral artery, but also in the carotid arteries. From the site: fibrillazioneatriale.it
What is the transient ischemic attack
The transient ischemic attack, also known by the acronym TIA, is a particular form of ischemic stroke, whose manifestations, at the cerebral level, are temporary; in fact, signs and symptoms resolve spontaneously in a short time (within a few minutes or in any case within the following 24 hours).
Despite this transitory nature, the TIA is an episode not to be overlooked; in fact, not only can it recur, but it often constitutes the first indication of something wrong with our brain, as well as a warning of the actual stroke.
ICTUS AND ICTUS ISCHEMICO
When we talk about stroke we are referring to a serious pathological condition, caused by a missed or insufficient blood supply to the brain. This determines, more or less slowly (depending on the severity of the stroke), the death of the brain tissue, due to lack of oxygen and nutrients, and the loss of motor skills (and not only) connected to the area of the encephalon involved.
Stroke is defined as ischemic if at the origin of the disorder there is an obstacle within the cerebral arterial vessels, which prevents normal blood supply to the brain tissues. This obstacle can be represented by a mobile blood clot ( embolus ) or anchored to the vessel wall ( thrombus ).
The embolus very often originates in the heart ; the thrombus, on the other hand, can form in an arterial vessel of the brain, in a carotid artery or in a vertebral artery, after the rupture of an atherosclerotic plaque .
Epidemiology
It is difficult to provide a precise datum concerning the real incidence of TIA, since, being a transitory event, the patient, in some cases, does not care and the disorder goes unnoticed.
The annual incidence is therefore vague and the calculated value, for Italy, is around one case per 1, 000 inhabitants (about 60, 000 episodes, considering the entire population).
Since TIA is a particular form of stroke, it shares with it various epidemiological aspects. As a stroke, in fact, TIA affects the most:
- Elderly people (75% of those affected are over 65)
- More men than women, especially before reaching old age
- Individuals of African, Asian and Caribbean race, due to a predisposition of these ethnic groups to diabetes and heart diseases
People with TIA are more likely to develop similar episodes in the future, or even a real stroke. It appears, in fact, that about one in five cases of stroke is preceded by an episode of TIA.
Causes
We have already seen how at the origin of TIA there is an insufficient flow of blood to a more or less extended area of the brain; this deficit, called ischemia, is linked to the presence of a blood clot (thrombus or embolus) that occludes one of the cerebral arterial vessels. In these conditions, the brain cells, no longer properly sprayed, find themselves without oxygen and nourishment and, for this reason, they enter a state of suffering that can be lethal.
Deepening: Why are thrombi and emboli formed?
A thrombus is an occlusive solid mass that is generated inside a blood vessel after the lesion of an atherosclerotic plaque . The latter is a collection of fat cells and cholesterol, which is formed spontaneously on the inner wall of a vessel or due to certain pathological conditions (see risk factors).
The presence of a plaque hardens the vessel wall and this predisposes it to breaks and injuries. After an injury, the repairing cells, the platelets, are recalled which, together with cholesterol, give rise to the actual thrombus.
An embolus, on the other hand, is a mobile blood clot, which was originally part of a thrombus from which it came off. Often, emboli that cause a TIA come from a heart that is not in perfect health.
THE RISK FACTORS
The risk factors of the transient ischemic attack are numerous and deserve special attention. In fact, knowing the conditions that favor the onset of a TIA is fundamental both for prevention and treatment.
In general, two categories of risk factors can be recognized: those that are potentially treatable and those that cannot be treated .
By potentially treatable risk factors we mean all those circumstances for which there is a pharmacological or behavioral remedy. For example, diabetes (one of the main risk factors for stroke) can be treated either by hypoglycemic drugs or by adopting a healthy lifestyle (a diet low in fat and simple sugars and movement).
By untreatable risk factors, on the other hand, we mean some characteristics of the patient that cannot be changed, such as age, race, etc.
The risk factors that can be treated:
- Hypertension
- Cardiovascular diseases (or heart disease)
- Carotid artery diseases
- Smoking and passive smoking
- Physical inactivity
- Diabetes
- Obesity and overweight
- High cholesterol
- Contraceptive pill and hormone therapy (based on estrogen)
- Excess alcohol
- Use of drugs (cocaine and methamphetamine)
- High levels of homocysteine in the blood
Untreatable risk factors:
- Family history of TIA, stroke and heart attack
- Age over 55-60 years
- Sex. TIA is more common in males than in females
- Race. The most affected populations are Asian, African and Caribbean.
- Sickle cell anemia. Red blood cells, due to their particular shape, tend to form agglomerates that obstruct blood vessels
Symptoms, signs and complications
To learn more: Symptoms Transient ischemic attack
Knowing what the classic symptoms and signs of a TIA are is essential to recognize the disorder, if it occurs.
In fact, in some cases, the TIA can go unnoticed or in any case be taken lightly by the patient, since it is a transient and reversible situation. However, as we have seen, it must always be borne in mind that at least one in five people affected by a stroke has had a TIA before. The transient ischemic attack, therefore, can be considered a real alarm bell.
SYMPTOMS
The symptoms of TIA resemble those of a stroke and, as such, are not always the same; much depends on the area of the brain involved in the disorder, as different regions of the brain govern different districts of our body. This means, therefore, that every patient, suffering from a transient ischemic attack, represents a case in itself. The classic signs and symptoms are:
If you experience similar symptoms call 118 immediately. From the Irish heart condition awareness campaign. Paralysis and numbness in the face and limbs
Characteristics: these disorders, also associated with tingling and weakness, occur only on one side of the body (for example, they concern only the limbs of the left side or only those of the right side).
To recognize the sign: raise your arms above your head or in front of you, and see which one tends to fall without our will; or smile (in front of a mirror) and observe which corner of the mouth slowly returns to a normal position.
- Difficulty speaking and understanding
Characteristics: the patient speaks with a jubilation and unclear; fails to understand what others are saying.
- Difficulty walking and balancing
Characteristics: the patient suddenly begins to stumble, to suffer from vertigo and to lose balance and motor coordination.
- Visual difficulties
Characteristics: the patient, all of a sudden, begins to lose his visual abilities. The view, in fact, becomes fogged or blurred. The disorder can affect one or both eyes.
WHY IS THE TIA TEMPORARY? HOW LONG DOES IT LAST?
The transient ischemic attack differs from stroke only because of the temporary and reversible nature of its symptoms. For the rest, there are no other differences.
But how can this temporariness be explained? The blood clot, embolus or thrombus that is, creates a transient obstruction. In contrast, in ischemic stroke, the blood clot permanently blocks the affected vessel.
An episode of TIA usually lasts from a few minutes to an hour; the cases in which the disorder lasts longer are rare. If it exceeds 24 hours, it is not classified as a TIA but as a stroke.
To understand that the TIA has run out, we are obviously relying on the symptoms, which disappear.
WHEN TO REFER TO THE DOCTOR?
Since stroke and TIA share the same symptomatology, they are not able to distinguish them from one another, except because the transient ischemic attack, at some point, spontaneously ends. However, waiting to see the evolution of the situation is not a smart choice! It would mean running a big risk, as it could have dramatic implications. When the typical symptoms occur, immediate medical assistance should be sought.
At this point, only the opinion of the doctor and diagnostic tests will be more clear.
COMPLICATIONS
The TIA is exhausted by itself, without leaving any complications or permanent signs on the affected individual. Therefore, to speak of complications of transient ischemic attack is not appropriate. However, reaffirming the concept that often a TIA anticipates a stroke, one can define precisely the latter, that is the stroke, the only real complication.
Stroke requires immediate relief (the risk of death is high), the administration of adequate drugs, surgery, a long rehabilitation (physical and psychological) and the correction of an incorrect lifestyle (if this is one of the causes of the disorder).
CONTINUE: Diagnosis, Treatment, Prevention »
