Stroke Archive

Some studies suggest a possible link. But don't switch to regular sugary sodas — try infused water instead.

For diet soda fans, recent news reports linking these popular drinks to a higher risk of stroke may have been alarming. A closer look at the study behind the headlines suggests there's no need to panic. But beverages naturally low in calories are probably a healthier option than artificially sweetened drinks.

For starters, observational studies like this one (see "Diet soda and the brain: The latest findings") cannot prove cause and effect. Also, only 97 people had strokes during the 10-year follow-up, which means only two or three of those strokes could possibly be attributed to drinking diet soda, says Dr. Kathryn Rexrode, an associate professor of medicine at Harvard-affiliated Brigham and Women's Hospital who co-authored an earlier, larger study looking at soda consumption and stroke risk.

News briefs

A ministroke, or transient ischemic attack (TIA), occurs when blood flow to part of the brain is blocked temporarily. It often causes one or two symptoms of a full-blown stroke — such as sudden face drooping, arm or leg weakness, confusion, slurred speech, or terrible headache — and typically lasts just a few minutes. If you've had a TIA, you are at much higher risk for subsequently suffering a full-blown stroke. So when you have symptoms that might indicate a TIA — or a full-blown stroke — call 911. You may need brain imaging to tell whether a stroke has occurred and what type of stroke it is, so you can get immediate treatment for a stroke. If it's a TIA, you may need additional treatments to prevent a future stroke. Unfortunately, most people who experience symptoms of ministrokes don't call 911 for help, according to results of a survey from the American Heart Association/American Stroke Association (AHA/ASA), published online May 1, 2017. Of the 2,000 people who took the AHA/ASA survey, about 35% said they'd experienced a TIA symptom. But only 3% of that group called 911. As a result, some likely suffered preventable permanent brain damage.

Recent findings raise concerns about lowering diastolic blood pressure — the second number in your blood pressure reading — too far.

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More of us than ever before are taking medications to lower our blood pressure. Longstanding guidelines suggest that most people should aim for a systolic blood pressure (the first number in a reading) no higher than 140 millimeters of mercury (mm Hg). But in 2015, the results of the Systolic Blood Pressure Intervention Trial (SPRINT) suggested that reaching a target of 120 mm Hg could further reduce the risks associated with high blood pressure, including heart attack, stroke, heart failure, and death.

Yet reaching that lower target often requires three blood pressure medications, which can increase the likelihood of side effects. Two observational studies and one clinical trial have raised concerns about lowering blood pressure — particularly diastolic pressure — too far. Diastolic blood pressure (the second number in a reading) represents the pressure between beats when the heart relaxes. "When your systolic blood pressure gets too low, it can manifest as lightheadedness, fainting, and weakness. But low diastolic pressure by itself doesn't have any symptoms," says Dr. Paul Conlin, professor of medicine at Harvard Medical School and chief of medicine at the VA Boston Healthcare System.

Three telltale symptoms occur in 75% of all strokes, often in combination. Don't ignore them — even if they're short-lived.

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Every 40 seconds, someone in the United States has a stroke. Also known as "brain attacks," strokes result from an injury to a blood vessel that limits blood flow to part of the brain. Rapid diagnosis and treatment can prevent potentially devastating disability or death — which is why everyone should know the common warning signs of a stroke.

In 2013, the American Stroke Association unveiled a stroke awareness campaign based on the mnemonic FAST. Around that the time, a national survey suggested that 28% of Americans didn't know any stroke symptoms, and nearly half weren't sure what to do if they experienced or witnessed the symptoms of a stroke. But four years later, things seem to be improving.

Research we're watching

Aging brains often show signs of microscopic strokes, which result from damage to tiny blood vessels within the brain. Those that occur in the brain's outermost layer — called cortical cerebral microinfarcts (CMIs) — usually don't cause any symptoms. But they are more common in autopsies of people diagnosed with dementia. Now, new research suggests a link between blood markers for early heart disease and CMIs.

The study, published online Feb. 6, 2017, by JAMA Neurology, included 243 people who attended a memory clinic. All had brain scans to check for CMIs and blood tests that measured two substances associated with early signs of heart damage. People who had CMIs (nearly 29% of the participants) were much more likely to have heart disease than those who didn't have CMIs. Higher levels of both substances associated with heart damage were also linked to CMIs — even when the researchers left out people who already had obvious symptoms of heart disease.

In the journals

Low-dose aspirin therapy is standard treatment for people who have suffered a heart attack or stroke to protect them from a second one. But what about people who don't have cardiovascular disease, but do have specific risk factors, such as type 2 diabetes? A study published in the Feb. 14, 2017, Circulation found that low-dose aspirin therapy in fact did not lower this group's risk for heart attack or stroke.

The researchers recruited more than 2,500 people, ages 30 to 85, with type 2 diabetes and randomly assigned them to take either 81 mg or 100 mg of aspirin daily, or no aspirin, for three years. At the 10-year follow-up, they found that the aspirin therapy did not lower risk of either heart attack or stroke compared with taking no aspirin at all. The reason is not clear, but the researchers speculated that people with diabetes might not experience the expected anti-clotting action of aspirin.

Ask the doctor

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Q. I've been taking the blood thinner warfarin (Coumadin) for a few years. I know there are new kinds of blood thinners, but I've heard they have downsides. Should I stick with warfarin?

A. Here's what you need to know. Some medical conditions lead to blood clots. The most common one is the irregular heart rhythm called atrial fibrillation. About 20% of all strokes are caused by clots that result from atrial fibrillation — usually because of inadequate treatment with blood thinners.

Research we're watching

Following a Nordic diet — which features fish, whole grains, plus fruits and vegetables popular in Scandinavian countries — may help lower the risk of stroke, a new study suggests.

The study, published in the February 2017 issue of Stroke, included more than 55,000 Danish people from a national health registry, all of whom filled out questionnaires about their diets and other lifestyle habits. Researchers looked at how closely the participants followed the Healthy Nordic Food Index, which includes six food categories: fish, apples and pears, root vegetables (such as carrots and celery root), cabbages (which also include broccoli, cauliflower, kale, and Brussels sprouts), rye bread, and oatmeal.

In the journals

People who suffer from migraines have increased risks of stroke and hospital readmission within 30 days after having surgery, according to research published online Jan. 10, 2017, by BMJ.

The study included 124,558 patients (45% of whom were men), who had a history of migraines, either with or without aura (a period of symptoms, such as flashes of light or facial tingling, that precedes the migraine). The researchers monitored the condition of all the patients after either inpatient or outpatient surgery. They then looked at how many had strokes and how many were readmitted to the hospital over the following 30 days.

Early treatment of the most common type of stroke, ischemic stroke, can limit brain damage and vastly improve outcomes. Ischemic stroke is the kind caused by atherosclerosis, which causes blood clots that block the blood supply to a part of the brain. Yet too few ischemic stroke patients receive important clot-busting drugs, which are most effective when given within three hours after symptoms start. Patients often arrive at the hospital after that window of opportunity has closed. They delay getting treatment because stroke symptoms may not be that pronounced or they are mistaken as coming from other, less serious problems.

As a result, doctors are looking for ways to make it easier for the layperson to identify a stroke. The Cincinnati Prehospital Stroke Scale is one such attempt. Some experts say it leaves out too many symptoms. Others say it will cause false alarms because it's not specific enough..