What is a Transient Ischemic Attack (TIA)?
TIA stands for transient ischemic attack and is a type of stroke that occurs when there is a sudden stoppage in blood flow to part of the brain. Symptoms are usually not life-threatening but can lead to other complications if not treated properly. TIA can be caused by a number of different factors and luckily for you, there are several treatments available that can help.
Symptoms
Symptoms of transient ischemic attack vary, depending on the part of the brain involved. These include speech difficulty, arm weakness, and facial drooping. If you think you may have had a TIA, call your doctor right away. Getting prompt medical attention can prevent permanent disability.
People who have diabetes and high blood pressure are at higher risk for TIA. The condition may be caused by blood clots in the carotid artery, which is an artery that carries blood from the heart to the brain. These blood clots are often formed by cholesterol buildup. In some cases, they are able to detach from the artery and move to other parts of the body. A blocked artery can require surgery to fix.
Other factors that can affect your chances of developing a TIA include gender, age, and genetics. You should also get regular blood tests to find out if you have any illnesses. You should also treat any high cholesterol levels. You should also avoid smoking and alcohol.
The risks for developing a TIA include high cholesterol, high blood pressure, and diabetes. Fortunately, there are many treatments for the disease. A combination of lifestyle changes and medicines can help lower your risks. You should also be aware of the symptoms of a transient ischemic attack and seek medical help if you have them.
Symptoms of a transient ischemic attack are similar to those of a stroke. These symptoms can be hard to distinguish between. However, they are very important to recognize. If you have a TIA, call your doctor immediately and start treatment as soon as possible.
If you think you have a TIA, you should have a complete physical examination. Your doctor will look for signs of a blood clot in your brain. He or she will also check your blood for electrolytes and glucose levels. He or she will also check your heart for pulse and blood pressure. If there are any abnormalities, imaging will be performed.
Causes
During a transient ischemic attack (TIA), the blood supply to a part of the brain or spinal cord is temporarily interrupted. Usually, the symptoms of a TIA resolve after about an hour. However, if the symptoms return or get worse, it can be a warning sign of a full-blown stroke.
The goal of treatment for a TIA is to stop the episode from getting worse and prevent the risk of a second episode. This is done by targeting the underlying disease that is causing the attack.
A thorough history is taken to identify risk factors. A patient’s physical exam includes neurological tests. A complete blood count (CBC) is also typically performed. Other medical tests are ordered to determine the causes of the TIA.
If the attack is caused by a blockage in a blood vessel, the procedure to treat the blockage involves inserting a stent. This small metal wire mesh is inserted into the blocked artery to help maintain its patency.
Other treatments may include thrombolytic agents that dissolve clots blocking blood flow to the brain. Anticoagulants are also typically prescribed for patients with cardiac comorbidities.
Patients with a previous TIA are at higher risk of a full-blown stroke. If they experience another episode, their heads should be elevated. This will reduce arterial pressure and enable efficient venous return blood flow.
ED evaluation of a patient with a TIA should include a coagulation profile and a non-contrast CT of the head. Other recommended tests include a urinalysis and a fingerstick glucose level.
In addition, a patient should be evaluated for comorbidities and changes in lifestyle. If these are present, a supplemental treatment plan can be implemented to help them adhere to a healthier lifestyle.
Antiplatelet therapy
Using antiplatelet therapy to prevent a transient ischemic attack (TIA) can be a life-saving treatment. Antiplatelets reduce the risk of vascular events such as stroke and also decrease the overall mortality rate in patients with known cerebrovascular disease.
There are four antiplatelets that have been extensively studied in clinical trials. These include aspirin, clopidogrel, dipyridamole, and ticagrelor. Each drug has been shown to have different advantages and disadvantages. The choice of medication is based on the patient’s characteristics, the physio-pathological mechanisms of ischemic injury, and the risks and benefits of a particular drug.
Recent data have indicated that dual antiplatelet therapy can reduce recurrent ischemic events by up to four times. The benefits of this treatment are greater if the drugs are used during the early risk period, which is typically the first 24 hours after a TIA.
However, the use of this type of therapy has been associated with a higher risk of hemorrhagic complications. Therefore, dual antiplatelet therapy should be avoided in patients who are at high risk for major bleeding.
The most commonly used antiplatelet therapy is aspirin. For patients who are not at risk for bleeding, low-dose aspirin and clopidogrel (Plavix) have been shown to reduce recurrent stroke. This drug combination is considered the standard of care in noncardioembolic ischemic stroke.
A recent randomized controlled trial showed that dual antiplatelet therapy is beneficial for patients with mild ischemic stroke. A 10- to 21-day course of treatment improves the quality of life and reduces recurrent ischemic events. A longer course of treatment has not been proven to reduce recurrent ischemic events.
The most important factor to consider when choosing an antiplatelet is the type of ischemic lesion. The best choice for secondary prevention is dipyridamole plus aspirin.
Clopidogrel
Among the drugs used to treat a transient Ischemic Attack (TIA), clopidogrel is a common choice. It is a thienopyridine derivative and inhibits platelet aggregation. It also prevents thromboxane A2 synthesis, thereby reducing the risk of hemorrhage. In addition, it can be used for secondary prevention of ischemic stroke.
In the POINT trial, clopidogrel was added to daily aspirin for 21 days in patients with a high-risk transient ischemic attack. The results were analyzed in a secondary analysis, which showed that the combination of clopidogrel and aspirin reduced the risk of major ischemic events.
The CHANCE trial was another study of the short-term benefits of dual antiplatelet therapy (DAPT) in patients with a minor ischemic stroke. It was stopped early due to early safety concerns.
In the primary analyses, the clopidogrel-aspirin group showed no difference in major ischemic events. However, there was a slight increase in major hemorrhage. This is likely related to the age and gender of the participants, as well as the coagulopathy. The benefit of the combination outweighs the risk of major hemorrhage.
Although the results are favorable, a longer course of treatment may be necessary to achieve a reduction in the risk of recurrent ischemic stroke. A 10- to 21-day course of dual antiplatelet therapy with clopidogrel and aspirin is recommended.
The CHANCE trial was conducted at Chinese centers, which have a higher incidence of large-artery intracranial atherosclerosis than the Western population. This may reflect a genetic polymorphism that affects clopidogrel resistance. A clopidogrel-aspirin regimen should be started after imaging rules out hematoma.
There are several factors that increase the risk of bleeding during clopidogrel therapy, including aging, hypertension, coagulopathy, and the use of other antiplatelet agents. These risks may outweigh the benefits of clopidogrel-aspirin in patients with a transient ischemic attack.
Ticagrelor
Compared to aspirin, ticagrelor has been studied for the prevention of transient ischemic attacks. A transient ischemic attack (TIA) is a brief episode of neurological symptoms that lasts a few minutes. It is caused by a temporary lack of blood in the brain. It occurs in about 240,000 people in the United States every year.
The primary goal of preventive treatment for a TIA is to reduce the risk of a disabling stroke. The secondary goals include reducing the risk of cardiovascular death and reducing the risk of a subsequent ischemic stroke. Using dual antiplatelet therapy is an effective approach for reducing ischemic events in patients with TIA. In the THALES trial, the combination of ticagrelor plus aspirin was superior to aspirin alone in preventing disabling stroke at 30 days.
The secondary analysis of the THALES trial was presented at the European Stroke Organization Conference. The study was conducted in 674 hospitals in 33 countries. The results were based on 11,016 patients with mild-to-moderate ischemic stroke. The trial was double-blind and randomized. The study was international and included patients 40 years of age or older.
Ticagrelor and aspirin were given in a combination of 90 mg twice daily for days 2 to 30. The addition of ticagrelor was associated with a significant reduction in major hemorrhage in the first week. The hazard ratios with 95% confidence intervals were reported for periods with at least one event in each treatment group. The ticagrelor-aspirin combination was also more effective at preventing myocardial infarction and disabling stroke in the short term. However, the benefits of the drug were attenuated in the following three weeks.
Among the most important findings from the SOCRATES trial was the relative risk of major hemorrhage. The absolute risk of hemorrhage was small and meaningful in the first three days and remained low thereafter. The study lacked clinical follow-up beyond 90 days. It also had a high rate of premature discontinuation due to dyspnea.
Health Sources:
Health A to Z. (n.d.). HSE.ie. https://www2.hse.ie/az/
U.S. National Library of Medicine. (n.d.). https://www.ncbi.nlm.nih.gov/
Directory Health Topics. (n.d.). https://www.healthline.com/directory/topics
Health A-Z. (2022, April 26). Verywell Health. https://www.verywellhealth.com/health-a-z-4014770
Harvard Health. (2015, November 17). Health A to Z. https://www.health.harvard.edu/health-a-to-z
Health Conditions A-Z Sitemap. (n.d.). EverydayHealth.com. https://www.everydayhealth.com/conditions/
