Transient ischemic attack.

Transient ischemic attack (TIA) is focal cerebral ischemia that causes sudden neurological symptoms lasting less than 1 hour. Diagnosis is based on clinical symptoms. Carotid endarterectomy, antiplatelet drugs, and warfarin reduce the risk of stroke in certain types of TIA.

A transient ischemic attack is similar to an ischemic stroke except that symptoms last less than 1 hour; most transient ischemic attacks last less than 5 minutes. Although the definition of "transient ischemic attack" is clinical and is currently under revision, infarction is unlikely if the symptoms resolve within 1 hour. Transient ischemic attacks occur more frequently in older and middle-aged individuals and carry a markedly increased risk of stroke in the 24 hours following the attack.

Causes transient ischemic attack

Transient ischemic attacks are predominantly caused by cerebral embolism originating from atherosclerotic plaques and ulcerated plaques in the carotid or vertebral arteries, although most causes of ischemic stroke can also result in transient ischemic attacks. Sometimes transient ischemic attacks develop against the background of hypoperfusion due to severe hypoxemia and hypooxygenation of the blood (e.g., in severe anemia, carbon monoxide poisoning) or due to increased blood viscosity (in polycythemia), especially if the cerebral arteries were initially stenotic. Ischemia does not develop with systemic hypotension, except in cases of its combination with severe arterial stenosis, since autoregulation always maintains cerebral blood flow at the desired level within a wide range of systemic arterial pressure values.

In subclavian steal syndrome, stenosis of the subclavian artery proximal to the origin of the vertebral artery leads to the fact that in situations of increased blood supply to the arm (physical work), blood actively flows into the subclavian artery, stealing the vertebrobasilar basin with the development of ischemic symptoms.

Sometimes transient ischemic attacks are observed in children with severe cardiovascular diseases, which are accompanied by high hematocrit levels and frequent embolism.

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Symptoms transient ischemic attack

Symptoms of a TIA may include:

1. Paralysis or weakness: Usually one-sided, paralysis or weakness occurs in an arm, leg, or half of the face.
2. Speech disorders: Difficulty expressing yourself or understanding speech. This may include dysphasia (speech problems) or aphasia (complete loss of the ability to speak or understand speech).
3. Vision problems: Blurred vision, double vision, partial vision loss, or blindness in one eye.
4. Dizziness or loss of balance: Feeling dizzy or off-balance, which may lead to a fall.
5. Loss of consciousness: In some cases, a TIA may be accompanied by loss of consciousness or fainting.
6. Difficulty with coordination: Inappropriate movement, loss of coordination, or ataxia.
7. Severe headache: A severe headache can be a symptom of a TIA.

Symptoms of a TIA may be similar to those of a stroke, but they usually resolve within a short time, often less than 24 hours. Although TIA symptoms may be temporary, they are a warning sign of a future stroke.

Neurological impairment is similar to that seen in stroke. Transient monocular blindness ( transient blindness ) may develop when the ophthalmic artery is affected, usually lasting less than 5 minutes. Symptoms occur suddenly, last from 2 to 30 minutes, and end with complete regression of neurological symptoms. The frequency of transient ischemic attacks may vary from 2-3 episodes in one day to 2-3 episodes over several years. Symptoms are stereotypical for repeated transient ischemic attacks in the carotid artery basin and may vary with the development of successive transient ischemic attacks in the vertebrobasilar artery basin.

Complications and consequences

Transient ischemic attacks (TIAs) can precede strokes and often serve as a warning sign of the possibility of a future stroke. Although TIAs themselves usually do not leave residual neurological deficits, they can have serious complications and consequences:

1. Risk of stroke: One of the main consequences of TIA is an increased risk of developing a stroke in the future. After a TIA, the risk of stroke increases several times, and the longer the TIA lasts, the higher the likelihood of stroke.
2. Post-traumatic stress disorder: Some patients may experience psychological effects after a TIA, such as anxiety, depression, and fear of further attacks.
3. Loss of quality of life: TIA and the anticipation of a possible stroke can affect quality of life, cause anxiety, and reduce the ability to perform everyday tasks.
4. Complications with treatment: After a TIA, medications and lifestyle changes (eg, diet, physical activity, smoking cessation) may be required, which may cause complications or require effort on the part of the patient.
5. Forgoing medical care: Some people who have had a TIA may underestimate its severity and not seek medical attention, which can lead to missing important treatment.
6. Decreased quality of life: Constant worry about the possibility of another TIA or stroke can greatly impact a patient's psychological and emotional well-being.

After a TIA, it is important to see a doctor to assess your risk of stroke and develop a prevention plan. Your doctor may recommend medications, lifestyle changes, and other measures to reduce your risk of stroke. Prompt and comprehensive treatment can help minimize the complications and consequences of a TIA.

Diagnostics transient ischemic attack

The diagnosis is made retrospectively based on complete regression of sudden neurological symptoms within 1 hour. Isolated peripheral facial palsy, loss of consciousness, or impaired consciousness do not fit the clinical picture of transient ischemic attacks. Transient ischemic attacks should be differentiated from diseases that cause similar symptoms (eg, hypoglycemia, migraine aura, Todd's paralysis). Since ischemic infarction, small hemorrhage, and mass effect lesions cannot be excluded based on clinical symptoms, neuroimaging studies should be performed. CT is the method of choice to exclude hemorrhage. MRI can detect developing infarction in the first few hours; CT may not detect infarction within the first 24 hours. Diffusion-weighted MRI can reliably exclude infarction in patients with suspected transient ischemic attack, the only drawback of this method is its limited availability.

The diagnostic algorithm for transient ischemic attacks is the same as for ischemic stroke. The search for probable causes of cerebrovascular accident is aimed at identifying stenosis of the carotid arteries, atrial fibrillation or sources of cardiogenic emboli, blood diseases. Additionally, all possible risk factors for stroke are assessed. Bearing in mind the increased risk of developing ischemic stroke in a patient with a transient ischemic attack, the examination is carried out quickly, usually during inpatient treatment.

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Differential diagnosis

Differential diagnosis of transient ischemic attacks (TIAs) involves identifying and ruling out other conditions that can mimic the symptoms of a TIA. It is important to differentiate TIAs from other medical conditions because proper diagnosis helps determine the best treatment and stroke prevention. Some conditions that can mimic TIAs and require differential diagnosis include:

1. Stroke: A stroke is a disruption in the blood supply to the brain that can cause symptoms similar to a TIA, but is usually long-lasting and leaves residual neurological deficits. A computed tomography (CT) scan or magnetic resonance imaging (MRI) can help differentiate a stroke from a TIA.
2. Migraine: Migraine auras can mimic TIA symptoms, such as visual disturbances, paralysis, or dizziness. However, they are usually accompanied by headache and often have different characteristics.
3. Epileptic seizures: Epileptic seizures can cause brief disturbances in consciousness, movement, or sensation that may resemble a TIA.
4. Transient panic attacks: Panic attacks may cause physical symptoms similar to TIAs, such as palpitations, dizziness, and hyperventilation, but there are no neurological deficits.
5. Medication side effects: Some medications can cause temporary disturbances in consciousness or neurological symptoms that may be mistaken for a TIA.
6. Hypoglycemia: Low blood sugar (hypoglycemia) can mimic TIA symptoms, including weakness, dizziness, and loss of consciousness.
7. Medical conditions: Some medical conditions, such as carotid body syndrome, can cause TIA-like symptoms due to uncontrolled constriction of blood vessels.

Differential diagnosis of TIA may require various diagnostic methods, such as CT, MRI, EEG, blood tests, and others.

Treatment transient ischemic attack

Treatment for transient ischemic attacks (TIAs) aims to prevent further stroke and manage risk factors for cardiovascular disease. TIAs are warning signs that a person is at increased risk for stroke. Here are some key aspects of TIA treatment:

1. Pharmacological treatment:
   • Antiplatelet drugs: Antiplatelet drugs such as aspirin or other antiplatelet medications are often prescribed to reduce blood clotting and prevent blood clots. Warfarin is prescribed if a source of cardiogenic embolism is present.
   • Statins: If you have high cholesterol, your doctor may prescribe statins to control and lower cholesterol and improve blood vessel health.
2. Blood pressure control: Treating hypertension (high blood pressure) is an important part of managing the risk of TIA and stroke. Your doctor may prescribe antihypertensive medications and recommend lifestyle changes, such as reducing salt in your diet and increasing physical activity.
3. Managing Diabetes: If you have diabetes, it is important to closely control your blood glucose levels. This may require medication and maintaining a healthy lifestyle.
4. Managing risk factors: Smoking, being overweight, poor diet, and physical inactivity can increase your risk of TIA and stroke. Stopping smoking, eating a healthy diet, and engaging in regular physical activity can significantly reduce your risk.
5. Anticoagulants (in some cases): In rare cases where TIAs are associated with atrial fibrillation (an abnormal heart rhythm), your doctor may consider prescribing anticoagulants (such as warfarin) to prevent blood clots from forming in the heart.
6. Surgery (rare): In some situations where there is a high risk of recurrent TIA or stroke, surgery may be needed to remove atherosclerotic plaque or relax the vessel wall. Carotid endarterectomy, arterial angioplasty, and stenting are effective primarily in patients without neurological deficits after a transient ischemic attack but who remain at high risk of stroke.

Treatment for TIA should be individualized and prescribed by a doctor based on the patient’s risk assessment and medical history. It is important to follow doctor’s orders and have regular checkups to prevent stroke and other cardiovascular problems.

Forecast

The prognosis of transient ischemic attacks (TIAs) depends on several factors, including their cause, duration, frequency, and the effectiveness of treatment and prevention measures. Here are the key factors that influence the prognosis of TIAs:

1. Cause of TIA: The prognosis depends on what caused the TIA. For example, if the TIA was caused by a temporary reduction in blood flow in veins (venous TIA), the prognosis may be better than if the cause was a reduction in blood flow in arteries (arterial TIA), since arterial TIAs can be precursors to stroke.
2. Duration and frequency: TIAs that last longer or recur are usually associated with a higher risk of stroke.
3. Effectiveness of treatment: Seeking medical attention early and starting treatment reduces the risk of a subsequent stroke. Medications and preventive measures may be prescribed to reduce the risk.
4. Associated conditions: Prognosis may also depend on the presence of other medical conditions, such as diabetes, hypertension, and cardiovascular disease, which can increase the risk of recurrent TIAs and strokes.

It is important to note that TIAs should not be ignored, even if symptoms resolve quickly. They often serve as a warning sign of a possible stroke, and prompt treatment and preventive measures can significantly improve the prognosis.