Transient ischaemic attack (TIA)
Transient ischaemic attack (TIA)
Most people who have had a TIA will need to take 1 or more medicines every day, long-term, to help reduce their chances of having a stroke or another TIA.
Aspirin and other antiplatelet medicines
You’ll probably be given aspirin straightaway after a suspected TIA.
Aspirin works as an antiplatelet medicine.
Platelets are blood cells that help blood to clot.
Antiplatelet medicines work by reducing the ability of the platelets to stick together and form clots.
You may also be given other antiplatelets such as clopidogrel or dipyridamole.
The main side effects of antiplatelet medications include indigestion and an increased risk of bleeding – for example, you may bleed for longer if you cut yourself, and you may bruise easily.
Anticoagulant medicines can help to prevent blood clots by changing the chemical composition of the blood in a way that stops clots from forming.
They’re usually offered to people who had a TIA that was caused by a blood clot in their heart. This is often due to a condition called atrial fibrillation, which causes your heart to beat irregularly.
Warfarin, apixaban, dabigatran, edoxaban and rivaroxaban are examples of anticoagulants that may be offered to some people who have had a TIA.
A side effect of all anticoagulants is the risk of bleeding because these medicines reduce the blood’s ability to clot. You may need regular blood tests while taking warfarin, so doctors can check your dose is not too high or too low.
Find out more about anticoagulants.
Blood pressure medicines
If you have high blood pressure, you’ll be offered a type of medicine called an antihypertensive to control it. This is because high blood pressure increases your risk of having a TIA or stroke.
There are lots of different types of medicine that can help control your blood pressure, including:
- thiazide diuretics
- angiotensin-converting enzyme (ACE) inhibitors
- calcium channel blockers
Your doctor will advise you about which antihypertensive is the most suitable for you. Some people may be offered a combination of 2 or more different medicines.
Find out more about treating high blood pressure.
If you have high cholesterol, you’ll be advised to take a medicine known as a statin. Statins reduce the level of cholesterol in your blood by blocking an enzyme in the liver that produces cholesterol.
Statins may also help to reduce your risk of a stroke whatever your cholesterol level is. You may be offered a statin even if your cholesterol level is not particularly high.
Examples of statins often given to people who have had a TIA include atorvastatin, simvastatin and rosuvastatin.
Find out more about statins.
Small Strokes Can Cause Big Damage
WEDNESDAY, Dec. 12, 2012 — Chances are if you’re a senior managing your health, you’ve already had a conversation with your doctor about stroke risk. While many patients know the warning signs of stroke — slurred speech, weakness on one side of the body, coordination problems, double vision, and headaches — health care providers often fail to educate patients about their risk for silent or “mini-strokes,” which can cause progressive, permanent damage and lead to dementia.
A new study published in the Journal of Neuroscience, examined the effects of these so-called mini-strokes. They frequently are not diagnosed or detected by a doctor because a patient does not immediately present with stroke signs. Mini-strokes may lead to permanent neurological damage and increase risk for full blown stroke.
Maiken Nedergaard, MD, lead author of the study and professor of neurosurgery at the University of Rochester Medical Center, says at least half of individuals over the age of 60 will experience one mini-stroke in their lifetime. She calls the prevalence of mini-strokes “an epidemic.”
“Often you don’t have symptoms. That’s the scary thing about them, you don’t know they’re occurring,” says Dr. Nedergaard. “If you are elderly and something doesn’t work quite right, you think, I should take a nap. You don’t go to the hospital unless you have big stroke.”
Mini-strokes often are detected well after the damage has been done, she says, and quite possibly by the time a patient has had several of them. A typical scenario, says Nedergaard, may be a patient who visits her doctor for chronic migraines. The doctor may order an MRI to rule out brain tumors, only to discover the patient has had several mini-strokes, which appear on a scan as “little dots where the tissue has grown,” she says.
“When you have a stroke, there’s an area of the brain that dies rapidly almost at the epicenter of the injury, but there are neurons around it that die slowly,” says Larry Goldstein, MD, professor of medicine, director of the Stroke Center at Duke University and a spokesperson for the American Heart Association.
The study authors say mini-strokes are similar in nature to ischemic strokes, which are full blown episodes provoked by a loss of blood supply, depriving an area of the brain from oxygen. Ischemic stroke effects, including blurry vision, numbness, and slurred speech, are usually present immediately after the event. “A big stroke is caused by a clot in the artery. We assume that’s the same that happens in the mini-stroke, but it’s not clear,” says Nedergaard. “What we do know is they cause this very delayed loss of cells in the brain.”
Nedergaard and her colleagues used rodents to examine the impact of small strokes. Strokes were provoked by injecting mice with cholesterol crystals, she says. The researchers put the mice who had mini-stroke through a series of tasks, such as recalling objects and responding to audio cues. They found the mice who suffered strokes were more likely to fail these tasks.
“Silent strokes are really common but their effects are not silent,” says Philip B. Gorelick, MD, MPH, medical director of the Hauenstein Neuroscience Center of Saint Mary’s Health Care in Grand Rapids, Mich. He says one in three patients who have a mini-stroke will sustain permanent damage.
According to the Centers for Disease Control, stroke is the third leading cause of death in the United States. They typically occur in people over the age of 65, and cause more than 140,000 deaths each year. Around 795,000 people suffer a stroke annually. About 600,000 of these are first attacks and 185,000 are recurrent attacks. Strokes are common among people with atrial fibrillation, high blood pressure, and smokers.
Nedergaard says currently there’s no treatment available to reverse brain damage caused by a stroke or to lower a patient’s chances for having recurring episodes or developing dementia. This is why preventative medicine is crucial.
To lower one’s risk for having a stroke, doctors advocate for preventive medicine and a healthy lifestyle, which includes a low sodium and low cholesterol diet, a regular exercise program, only moderate amounts of alcohol, and not smoking cigarettes. Some doctors may recommend cholesterol-busting medications such as Plavix and anticoagulants such as aspirin.
Long-Term Impact of TIA
Don’t let the name fool you. Despite their short-term duration, transient ischemic attacks (TIAs; “mini strokes”) may not be “transient” after all. According to a new study, TIAs may have long-term consequencesthey can shorten life expectancy by up to 20 percent.
The study, published online in the journal Stroke, analyzed the hospital and death records of more than 22,000 adults up to nine years after hospitalization for a TIA and found that the life expectancy of these patients was lower than that of the general population.
In addition, the study found that among patients who had experienced a TIA, mortality was greater in older people. Compared with people diagnosed with TIA under age 50, those ages 65 to 74 had a relative risk of early death that was almost five times higher, those ages 75 to 84 had a relative risk almost eight times higher and those 85 and older had a relative risk that was 11 times higher.
Several factors may explain this finding. However, the take-home point is that individuals already treated for TIA have more to gain from controlling their risk factors than those who have not yet experienced a TIA.
What is a TIA?
Sometimes referred to as “mini” strokes, TIAs originate in the same manner as a stroke but don’t cause permanent brain damage. Both stroke and TIA occur when a clot blocks blood flow to the brain.
Sometimes the blocked artery reopens in time to avoid permanent damage. This is a TIA, and it explains why symptoms of brain dysfunction are of such short duration, disappearing within 24 hours or much sooner.
If the artery doesn’t reopen or reopens too late, brain tissue is permanently damaged and can lead to long-term disability and even death. This is a stroke.
Symptoms of TIA
Symptoms of TIA include:
- Numbness or weakness of the face, arms or legs, especially on one side of the body
- Confusion, trouble speaking or difficulty understanding speech
- Abrupt loss of vision in one or both eyes
- Trouble walking, dizziness or loss of balance or coordination
- A sudden headache without known cause
TIA Risk factors
Although your risk of TIA increases with age, there are other risk factors you can control. These include:
- High blood pressure
- High cholesterol
The stroke research team, led by Dr. Lara Boyd, physical therapist and neuroscientist with the Brain Research Centre at Vancouver Coastal Health and the University of British Columbia, studied 13 patients from the Stroke Prevention Clinic at Vancouver General Hospital and compared them against 13 healthy study participants. The TIA subjects had all experienced an acute episode affecting motor systems, but had symptoms resolved within 24 hours. The patients were studied within 14-30 days of their episode, and showed no impairment through clinical evaluation or standard imaging (CT or MRI). Participants then underwent a unique brain mapping procedure using transcranial magnetic stimulation (TMS) with profound results.
“What we found has never been seen before,” says Dr. Boyd, who also holds the Canada Research Chair in Neurobiology of Motor Learning at UBC. “The brain mapping capabilities of the TMS showed us that TIA is actually causing damage to the brain that lasts much longer than we previously thought it did. In fact, we are not sure if the brain ever recovers.”
In the TIA group, brain cells on the affected side of the brain showed changes in their excitability — making it harder for both excitatory and inhibitory neurons to respond as compared to the undamaged side and to a group of people with healthy brains. These changes are very concerning to the researchers as they show that TIA is likely not a transient event.
A transient ischemic attack is characterized as a brief episode of blood loss to the brain, creating symptoms such as numbness or tingling, temporary loss of vision, difficulty speaking, or weakness on one side of the body. Symptoms usually resolve quickly and many people do not take such an episode seriously. However, TIAs are often warning signs of a future stroke. The risk of a stroke increases dramatically in the days after an attack, and the TIA may offer an opportunity to find a cause or minimize the risk to prevent the permanent neurologic damage that results because of a stroke.
“These findings are very important,” says Dr. Philip Teal, head of the Stroke Prevention Clinic at VGH and co-author of the study. “We know that TIA is a warning sign of future stroke. We treat every TIA as though it will result in a stroke, but not every person goes on to have a stroke. By refining this brain mapping technique, our hope is to identify who is most at risk, and direct treatment more appropriately.”