A transient ischemic attack (TIA for short) occurs as a result of a circulatory disturbance in the brain. Reversible neurologic deficits occur as part of the attack.
What is a transient ischemic attack?
In a transient ischemic attack (TIA), blood flow to the brain is disrupted. The symptoms are similar to those of a stroke. For this reason, TIA is also called a small stroke. The neurological disturbances due to microembolism in the brain resolve within 24 hours. On average, attacks last one to two hours. Any neurological deficits lasting longer than 24 hours indicate an ischemic stroke. The attacks occur most frequently between the ages of 60 and 70. The transient ischemic attack can be considered a harbinger of a real stroke and should therefore be urgently clarified by a doctor. In the first two hours after a TIA, the risk of stroke is increased by ten percent. In the first two weeks, the risk increases by an additional five percent. One in three patients with a transient ischemic attack will suffer a stroke in their lifetime. Half of all strokes occur in the year after the TIA.
Causes
A TIA results from a deficiency in the supply of oxygen to certain areas of the brain. This undersupply is also known as ischemia. Ischemias are caused by microcirculatory disturbances in the cerebral vessels. Mainly, microemboli of cerebral blood vessels are responsible for the circulatory disturbances. It has been found that many TIAs are caused by minor strokes. Therefore, the causes are similar to the causes of stroke. Arterial emboli of the blood vessels are common. Thrombosis of the venous outflow vessels can also result in ischemia. For example, if vascular ruptures occur as a result of high blood pressure, the brain is not supplied with enough oxygen. The hemorrhages also result in neurological deficiency symptoms. A TIA can also develop in spontaneous hemorrhages due to impaired blood clotting, subarachnoid hemorrhages, and subdural or epidural hematomas. Rarely, attacks are triggered by vasospasm, such as in a migraine attack.
Symptoms, complaints, and signs
The symptoms of a TIA are similar to the symptoms of complete stroke. However, they are usually not quite as pronounced. Hemiplegic arm and leg paralysis are characteristic. In medical terminology, these are also called hemiplegia or hemiparesis. Affected persons may have speech disorders. In this case, speech comprehension and word finding are impaired. In spontaneous speech, word confusion disorders and word neologisms are found. In some cases, patients have a compulsive urge to express themselves verbally (logorrhea), resulting in an uninterrupted and rapid flow of speech. In addition to speech disorders, speech disorders may also be present. In the case of a speech disorder, the affected person can no longer correctly articulate speech sounds. The flow of speech may be disturbed by stuttering or poluttering. Microemboli in the retinal vessels or in the area of the optic nerves can cause amaurosis fugax, a temporary blindness. Hearing and balance disorders with dizziness and so-called drop attacks may also occur. Drop attacks are sudden falls while the patient is normally conscious. They result from a loss of tone in the leg muscles. The patient’s consciousness may be clouded. If it is truly a TIA, the symptoms resolve completely within 24 hours. For the brain, ischemia is tolerable in a window of five to eight minutes. If the ischemia lasts longer, the symptoms do not regress. In this case, a stroke is present.
Diagnosis and course of disease
Because symptoms usually do not last very long, a TIA is difficult to diagnose. Therefore, the focus of diagnosis is on history and clinical examination. If the patient is known to have cardiac arrhythmias or coronary artery disease, this corroborates the suspicion of TIA in the presence of reversible neurologic symptoms. Magnetic resonance imaging with diffusion weighting may be used as an imaging modality.This can be used to diagnose brain tissue with insufficient blood supply. However, the sensitivity is only 50 percent, so not every insufficiency is detected. Other imaging modalities used to diagnose TIA include Doppler ultrasonography of the extracranial cerebral vessels, transcranial Doppler ultrasonography, computed tomography, magnetic resonance angiography, and digital subtraction angiography.
Complications
This condition can lead to various complaints and complications. These depend very much on the exact manifestation of the disease. In general, patients suffer from a severe circulatory disorder in the brain. This leads to speech disorders and general impaired thinking. The everyday life of those affected is therefore significantly more difficult and restricted. In many cases, patients also suffer from stuttering and hearing or vision problems. In severe cases, they are dependent on the help of other people in their lives. There is a clouding of consciousness and further loss of consciousness. Muscle tone also decreases sharply as a result of the disease, so that those affected are no longer able to perform simple activities in everyday life. Furthermore, a stroke can occur, which in the worst case can lead to the death of the patient. The treatment of this disease is carried out with the help of medication. This does not lead to further complications. However, this does not completely reduce the symptoms, so that a stroke can still occur. The life expectancy of the affected person is significantly reduced as a result. The patient’s relatives or parents may also be affected by these symptoms.
When should you go to the doctor?
Abnormalities of behavior, disturbances of balance, dizziness, or general dysfunction should be presented to a physician immediately. If there are changes in the ability to speak, a restriction of vision, and irregularities in memory activity, there is an acute need for action. In case of sudden peculiarities or abnormalities, medical care is needed as soon as possible. A word-finding disorder as well as a decrease in speech comprehension are warning signals of the organism. They indicate a memory disorder. If clouding of consciousness or loss of consciousness occurs, an emergency medical service must be alerted. There is a life-threatening situation for the affected person. Although the attack recedes completely in most patients, an unfavorable course of the disease can lead to a stroke. Therefore, consultation with a physician should always be sought and a comprehensive examination initiated. If disturbances of the movement sequences, difficulties of the coordination as well as a loss of the muscle strength show up, a physician is needed. A feeling of illness, a decrease in mental capacity or a general feeling of malaise should also be examined and treated. If there is paralysis or compulsive behavior, there is cause for concern. Talking without stopping and a very rapid flow of speech are characteristic. Those affected often do not allow themselves to be interrupted in their torrent of speech. Medical help must be sought to prevent further deterioration of health.
Treatment and therapy
As long as the symptoms of TIA persist, the same treatment is given as for stroke. An attempt is made to dissolve the embolus with medication. Special drugs called fibrinolytics are used for this purpose. If treatment with medication is unsuccessful, surgery, a thromboendarterectomy, may be indicated. Once the symptoms of TIA have resolved, the focus is on preventing further attacks. Transient ischemic attacks are often precursors to a “major” stroke. The ABCD2 score is used to assess risk. This score incorporates the five risk factors age, blood pressure, symptoms, duration of symptoms and the disease diabetes mellitus. Different points are assigned depending on the criterion, so that in total a score between zero and seven can be achieved. The ABCD2 score provides information on how high the risk is of suffering a stroke within two days of a transient attack. A score of zero to three indicates a low risk.Four to five points represent a moderate two-day risk and six to seven points represent a high two-day risk. At six to seven points, patients are eight percent more likely to develop a stroke within the two days.
Prevention
Anticoagulants are given to prevent another TIA. Surgery on the vessels supplying the brain may improve blood flow to prevent further attacks.
Follow-up care
After treatment of a transient ischemic attack, it may be essential to take blood-thinning medications (Macumar) to prevent possible strokes and myocardial infarctions, especially if atherosclerosis is the cause. It is important to check the Quick and INR values in the blood regularly to prevent the blood from becoming too thin. In addition, if blood pressure is elevated, antihypertensive medications should be taken. In addition, regular follow-up examinations of the brain (MRI, CT) but also of the heart (ECG) by appropriate specialists are extremely important in order to detect vascular constrictions and possible reduced blood flow at an early stage and thus prevent a recurrence of a transient ischemic attack, but also heart attacks and strokes. Patients should also refrain from smoking. The nicotine contained in tobacco constricts the blood vessels, and the carbon monoxide inhaled through tobacco smoke also clogs the blood platelets. Alcohol consumption should be avoided, since alcohol also has a vasoconstrictor effect and also increases blood pressure. Besides sporty activity promotes the blood circulation and lowers the blood pressure lastingly. Avoiding salt as far as possible, which is found in particular in convenience foods, but also snack foods (chips, salt sticks, crackers), and a diet low in vitamin K (avoid green vegetables such as kale and broccoli) also help to improve vascular circulation and prevent serious secondary diseases.
Here’s what you can do yourself
Even if the symptoms disappear completely within 24 hours, TIA should always be seen as a harbinger of apoplexy. To avoid it, affected individuals should minimize risk factors and develop positive compliance. Since the causes of a transient ischemic attack are usually treated with medication, medication training is important. Patients need to learn which medications to take and when, and who to inform about the application. Furthermore, follow-up care forms an important part of curation and prevention. Doctors should make the importance of appointments clear to sufferers. The risk factors that led to a TIA can be many. People with diabetes should aim for an HbA1c of less than 8% to delay late effects of the disease. People with hypertension minimize the risk of apoplexy many times over if, on average, the systolic value does not exceed 140 mm Hg and the diastolic value does not exceed 90 mm Hg. Arteriosclerotic deposits, which can be traced back to increased LDL consumption, can be reduced enormously by those affected by changing their dietary habits. This is because a diet low in fat and cholesterol and rich in fiber and vitamins will on the one hand prevent new deposits and on the other hand dissolve existing deposits. If the cause of ischemia is excessive alcohol consumption, sufferers can reduce the risks of secondary diseases with the help of withdrawal.