Hypertension may lead to ‘silent’ strokes

"Silent" strokes, which are strokes that don't result in any noticeable symptoms but cause brain damage, are common in people over 60, and especially in those with high blood pressure, according to a study published in the July 28, 2009, print issue of Neurology, the medical journal of the American Academy of Neurology.

"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," said 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."

The study involved 477 people age 60 to 64 who were followed for four years. At the beginning of the study 7.8 percent of the participants had the silent strokes, which are also called lacunar infarcts. They occur when blood flow is blocked in one of the arteries leading to areas deep within the brain, such as the putamen or the thalamus. By the end of the study, an additional 1.6 percent of the participants had developed silent strokes.

People with high blood pressure were 60 percent more likely to have silent strokes than those with normal blood pressure. Also, people with another type of small brain damage called white matter hyperintensities were nearly five times as likely to have silent strokes as those without the condition.

The study was supported by the National Health and Medical Research Council of Australia.

The American Academy of Neurology, an association of more than 21,000 neurologists and neuroscience professionals, is dedicated to promoting the highest quality patient-centered neurologic care through education and research. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as stroke, Alzheimer's disease, epilepsy, Parkinson's disease, and multiple sclerosis.

For more information about the American Academy of Neurology, visit http://www.aan.com or www.TheBrainMatters.org.