A Transient ischemic attack (short TIA) arises as a result of a circulatory disorder in the brain. The attack leads to reversible neurological deficits.
What is a transient ischemic attack?
Ischemias are caused by microcirculation disorders in the brain vessels. Microembolisms of cerebral blood vessels are mainly responsible for the circulatory disorders.© GraphicsRF - stock.adobe.com
At a transient ischemic attack (TIA) the blood flow to the brain is disturbed. The symptoms are similar to those of a stroke. This is why the TIA is also known as a minor stroke. The neurological disorders that result from a microembolism in the brain subside within 24 hours. On average, the attacks last one to two hours.
Any neurological failure that lasts longer than 24 hours suggests an ischemic stroke. The attacks occur most frequently between the ages of 60 and 70. The transitory ischemic attack can be seen as 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. Every third patient with a transient ischemic attack will have a stroke in their lifetime. Half of all strokes occur in the year after the TIA.
causes
A TIA occurs when certain areas of the brain are insufficiently supplied with oxygen. This undersupply is also known as ischemia. Ischemias are caused by microcirculation disorders in the brain vessels. Microembolisms of cerebral blood vessels are mainly responsible for the circulatory disorders. Many TIAs have been found to be caused by minor strokes.
The causes are therefore similar to the causes of the stroke. Arterial embolisms of the blood vessels often occur. Thrombosis of the venous drainage vessels can also result in ischemia. If, for example, vascular ruptures occur as a result of high blood pressure, the brain is not supplied with enough oxygen.
The hemorrhage also results in neurological failure symptoms. A TIA can also develop with spontaneous bleeding with impaired blood clotting, with subarachnoid hemorrhage, and with subdural or epidural hematomas. The attacks are rarely triggered by vascular spasms, such as a migraine attack.
Symptoms, ailments & signs
The symptoms of a TIA are similar to the symptoms of a complete stroke. But they are usually not quite as pronounced. One-sided arm and leg paralysis are characteristic. In medical terminology, these are also known as hemiplegia or hemiparesis. Those affected can have speech disorders. Language comprehension and word finding are impaired.
In spontaneous speech there are confusion problems and word creations. In some cases, the patients have an obsessive urge to express themselves verbally (logorrhea), so that an uninterrupted and rapid flow of speech develops. In addition to speech disorders, there may also be speech disorders. With a speech disorder, those affected can no longer articulate speech sounds correctly. The flow of speech can be disturbed by stuttering or rumbling.
Microembolisms in the retinal vessels or in the area of the optic nerves can lead to amaurosis fugax, a temporary blindness. Hearing disorders and balance disorders with dizziness and so-called drop seizures can also occur. Drop attacks are sudden falls in a normal state of consciousness. They are caused by a loss of tone in the leg muscles.
The patient's consciousness may be clouded. If it is really a TIA, the symptoms resolve completely within 24 hours. Ischemias are tolerable for the brain within a time window of five to eight minutes. If the ischemia persists, the symptoms do not resolve. In this case, there is a stroke.
Diagnosis & course of disease
Since symptoms don't usually last very long, TIA is difficult to diagnose. The focus of diagnostics is therefore placed on the anamnesis and clinical examination. If the patient is known to have arrhythmias or coronary artery disease, this supports the suspicion of a TIA in the presence of reversible neurological symptoms.
Magnetic resonance tomography with diffusion weighting can be used as an imaging method. Brain tissue with insufficient blood supply can be diagnosed. However, the sensitivity is only 50 percent, so that not every undersupply is recognized. Other imaging methods that are used to diagnose TIA are Doppler sonography of the extracranial brain vessels, transcranial Doppler ultrasound examination, computed tomography, magnetic resonance angiography and digital subtraction angiography.
Complications
This disease can lead to various complaints and complications. These depend very much on the exact severity of the disease. In general, patients suffer from severe circulatory disorders in the brain. Speech disorders and general thought disorders occur. The everyday life of those affected is therefore significantly more difficult and restricted.
In many cases, the patients also suffer from stuttering and continue to suffer from hearing or visual problems. In serious cases, they depend on the help of other people in their lives. There is a clouding of consciousness and a continued loss of consciousness.
The muscle tone also decreases significantly due to the disease, so that those affected can no longer carry out simple everyday activities. Furthermore, a stroke can occur, which in the worst case can lead to the death of the patient. The treatment of this condition is done with the help of drugs. There are no further complications.
However, this does not completely limit the symptoms, so a stroke can continue to occur. The life expectancy of the person affected is significantly reduced as a result. The relatives or parents of the patient can also be affected by these symptoms.
When should you go to the doctor?
Behavioral abnormalities, balance disorders, dizziness or general dysfunction must be brought to a doctor immediately. If there are changes in the ability to speak, impaired vision or irregularities in memory, there is an acute need for action. In the event of sudden peculiarities or abnormalities, medical care is required as quickly as possible.
A word finding disorder and a decrease in speech comprehension are warning signals of the organism. They indicate a memory disorder. If there is a clouding of consciousness or a loss of consciousness, an emergency service must be alerted. The person concerned is in a life-threatening situation.
Although the attack resolves completely in most patients, a stroke can occur if the disease progresses poorly. Therefore, you should always consult a doctor and initiate an extensive examination. If there are movement disorders, coordination difficulties or a loss of muscle strength, a doctor is required.
A feeling of illness, a decrease in mental performance or a general malaise should also be examined and treated. Paralysis or compulsive acts are cause for concern. Talking without ceasing and a very fast 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 in health.
Treatment & Therapy
As long as the symptoms of TIA persist, the same treatment is given as for a stroke. An attempt is made to dissolve the embolus with medication. Special drugs, the fibrinolytics, are used for this. If drug treatment is unsuccessful, surgery, a thrombendarterectomy, may be indicated.
When the symptoms of TIA are gone, the focus is on preventing further attacks. The transitory ischemic attacks are often harbingers of a “major” stroke. The ABCD2 score is used to assess the risk. The five risk factors age, blood pressure, symptoms, duration of symptoms and the disease diabetes mellitus are included in this score.
Depending on the criterion, different points are awarded, so that in total a score between zero and seven can be achieved. The ABCD2 score provides information about how high the risk is of suffering a stroke within two days of a transitory attack. Zero to three points indicate a low risk.
Four to five points stand for a moderate and six to seven points for a high two-day risk. With six to seven points, the probability that patients will develop a stroke within the two days is eight percent.
prevention
Anticoagulants are given to prevent another TIA. An operation on the blood vessels supplying the brain can possibly improve the blood circulation and thus prevent further attacks.
Aftercare
After treating a transitory ischemic attack, especially in the case of causative ateriosclerosis, it may be essential to take blood-thinning medication (Macumar) to prevent possible strokes and heart attacks. It is important to check the Quick and INR values in the blood regularly to prevent the blood from becoming too thin. If the blood pressure is high, antihypertensive drugs should also be taken.
In addition, regular follow-up examinations of the brain (MRT, CT) but also of the heart (EKG) by the appropriate specialists are extremely important in order to detect vascular constrictions and possible reduced blood flow at an early stage and thus to prevent another transitory 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 the tobacco smoke also sticks the blood platelets together. Alcohol consumption should be avoided, as alcohol also constricts blood vessels and increases blood pressure. In addition, physical activity promotes blood circulation and lowers blood pressure sustainably.
The extensive avoidance of salt, which can be found in finished products, but also in snacks (chips, pretzel sticks, crackers) and a diet low in vitamin K (avoidance of green vegetables such as kale and broccoli) also help to improve blood circulation in blood vessels and cause serious secondary diseases avoid.
You can do that yourself
Even if the symptoms completely disappear within 24 hours, the TIA should always be seen as a harbinger of apoplexy. To avoid this, those affected should minimize the risk factors and develop positive compliance.
Since, following a transient ischemic attack, the causes are usually remedied with the help of drugs, drug training is important. Those affected have to learn which preparations to take and when and whom to inform about the application. In addition, aftercare is an important part of curation and prevention. Doctors should make it clear to the sick the importance of the appointments.
The risk factors that lead to a TIA can be diverse. People with diabetes should aim for an HbA1c below 8% in order to delay the long-term effects of the disease. People with high blood pressure minimize the risk of apoplexy many times over if the average systolic value does not exceed 140 mm Hg and the diastolic value does not exceed 90 mm Hg.
Atherosclerotic deposits, which are due to an increased consumption of LDL, can be reduced enormously by those affected by changing their eating habits. Because a diet that is low in fat and cholesterol as well as high in fiber and vitamins prevents new deposits on the one hand and loosens existing deposits on the other. If the cause of the ischemia is excessive alcohol consumption, withdrawal can reduce the risk of complications.