Silent Stroke Caused by High Blood Pressure

Silent Stroke Caused by High Blood Pressure

The work of Australian researchers, published in the July 28, 2009 issue of the journal Neurology, offers a somber warning. That those over 60 who have high blood pressure are likely to experience what’s known as a “silent stroke” caused potentially by high blood pressure and not even know it.

Despite the name, these types of strokes are of concern because they do unseen damage to the brain, have been suspected of affecting memory and thinking, as well as being potentially linked to a type of dementia.

The study involved 477 healthy subjects from 60 to 64 years old who underwent brain scans by the team.

At the beginning of the research 7.8% of the subjects had evidence of “silent strokes” (known to medicine as silent lacunar infarctions) that hadn’t brought any noticeable symptoms yet still had affected blood flow to arteries deep in the brain.

The damage could be seen on MRI scans, even though the subjects had no outward symptoms. By the end of the study another 1.6% of the participants had experienced these so-called “silent strokes”.

“These strokes are not truly silent, because they have been linked to memory and thinking problems and are a possible cause of a type of dementia,” cautions study author Perminder Sachdev, MD, PhD, of the University of New South Wales in Sydney, Australia. “High blood pressure is very treatable, so this may be a strong target for preventing vascular disease.”

Subjects with high blood pressure had a 60% higher chance of a silent stroke as compared to subjects with a normal blood pressure reading.

Participants with another brain condition known as white matter hyperintensities were just about five times more likely to suffer a silent stroke than those who had no evidence of this condition.

Often the stroke victim was not aware of any cognitive decline.

Yet “silent strokes” might be the real reason behind some of the changes we all mistakenly think of as part of normal aging like increasing forgetfulness, being easily confused or experiencing a noticeable slowdown of reasoning or decision making.

Researchers speculate that the effect of these “silent strokes” might be cumulative and account for slowing of motor functions, a reduction in information processing speed and less memory for detail.

This work supports earlier studies linking high blood pressure and stroke risk.

Some of the other risk factors for “silent stroke”, besides high blood pressure, include diabetes, heart disease, smoking and old age.

If you’re worried about your risk, start by talking with your doctor to see what kind of changes you might make to reduce your risk.

The encouraging news, according to the National Stroke Association, is that nearly 80% of all strokes are preventable.

Don’t put off a regular checkup so that you know your blood pressure and cholesterol numbers. Smoking and heavy drinking are no-no’s, while other risks like high cholesterol, diabetes or lack of exercise can be modified just by making changes in your diet and activity levels.