Wake Forest Research Group Find Brain Infarcts Common In General Public

May 08, 1998

WINSTON-SALEM, NC--A surprise may be lurking in the brains of many people -- evidence of silent cerebral infarcts, or dead spots within their brains. Cigarette smoking and uncontrolled high blood pressure may be to blame.

New results from one of the first studies of the brains of members of the general public uncovered scores of participants who have the silent cerebral infarcts and have had no symptoms.

For years, silent cerebral infarcts have been found in patients who already have symptoms, such as those with transient ischemic attacks, or ministrokes, said George Howard, Dr. P.H., professor of public health sciences and neurology at the Wake Forest University Baptist Medical Center, writing in the May 7 issue of Stroke, Journal of the American Heart Association.

However, until this study, "Little was known about the prevalence and risk factors for silent cerebral infarcts in the general population."

Magnetic Resonance Imaging (MRI) exams of 1,737 participants in the Atherosclerosis Risk in Communities (ARIC) study found that 11 percent of the group had had a silent cerebral infarction. The percentage is so high that the investigators concluded that silent cerebral infarctions "represents a relatively common abnormality."

What causes it?

"Among the major cardiovascular risk factors considered, current cigarette smoking and hypertension (high blood pressure) were significantly associated with silent cerebral infarctions," said Howard. He said both smoking and high blood pressure had long been known as risk factors for stroke, so he was not surprised that both also increase the risk of silent cerebral infarctions.

In fact, the researchers found a stepwise relationship between smoking and silent cerebral ischemia "that parallels the relationship between smoking and carotid atherosclerosis."

Howard added, "The data showed a trend for a slight increase in the prevalence of silent cerebral infarcts among those exposed to second-hand smoke, a further increase for those who had smoked cigarettes in the past and the highest prevalence among those who are currently smoking cigarettes."

Furthermore, as the number of pack-years of smoking increased, so did the prevalence of silent cerebral infarction.

"Both are additional arguments for smoking avoidance and cessation," Howard said.

None of the other risk factors characteristically associated with stroke -- except high blood pressure ? were significantly associated with silent cerebral infarctions, he said. Those other factors include diabetes, partial blockage of the carotid artery, cholesterol levels, and advancing age.

Despite the study results, Howard said "The clinical implications of silent cerebral infarctions remain unclear."

In patients who have symptoms, he said the presence of silent cerebral infarctions is related both to subsequent strokes and to higher mortality rates.

"One could speculate that these lesions may be associated with a poor prognosis in the general population as well," he said. "However, there have been no prospective studies of the impact of silent cerebral infarction on the long term mortality and morbidity of the general population."

The 1,737 participants represented about 10 percent of the participants in the massive Atherosclerosis Risk in Communities study. ARIC, an National Institutes of Health-sponsored study conceived as a successor to the famed Framingham Heart Study, involves randomly selected participants in Forsyth County, N.C., Jackson, Miss., Hagerstown, Md. and suburban Minneapolis, Minn. All participants were between 45 and 65 when the trial began in 1986.

ARIC is an observational study. The health of the participants is monitored regularly, and physical condition, lifestyle, diet and other parameters are recorded, but diagnosis and treatment is left in the hands of personal physicians.

The participants in the current analysis were all from Forsyth County or Jackson. Experienced readers of the MRI results at an MRI Reading Center looked for infarcts that were at least 3 millimeters in diameter and that changed the MRI signal in characteristic ways.

Both the ARIC study, and the companion Cardiovascular Health Study among the elderly will provide such long term analysis, as they record illnesses and death over the years..

The research team also included investigators from the University of North Carolina at Chapel Hill, the National Heart, Lung and Blood Institute, and the Johns Hopkins University School of Medicine.
Contact: Robert Conn, Karen Richardson, Jim Steele or Mark Wright at 336-716-4587

Wake Forest Baptist Medical Center

Related Smoking Articles from Brightsurf:

Smoking rates falling in adults, but stroke survivors' smoking rates remain steady
While the rate of Americans who smoke tobacco has fallen steadily over the last two decades, the rate of stroke survivors who smoke has not changed significantly.

What is your risk from smoking? Your network knows!
A new study from researchers at Penn's Annenberg School for Communication found that most people, smokers and non-smokers alike, were nowhere near accurate in their answers to questions about smoking's health effects.

Want to quit smoking? Partner up
Kicking the habit works best in pairs. That's the main message of a study presented today at EuroPrevent 2019, a scientific congress of the European Society of Cardiology (ESC).

Smoking and mortality in Asia
In this analysis of data from 20 studies conducted in China, Japan, South Korea, Singapore, Taiwan and India with more than 1 million participants, deaths associated with smoking continued to increase among men in Asia grouped by the years in which they were born.

Predictors of successfully quitting smoking among smokers registered at the quit smoking clinic at a public hospital in northeastern Malaysia
In the current issue of Family Medicine and Community Health, Nur Izzati Mohammad et al. consider how cigarette smoking is one of the risk factors leading to noncommunicable diseases such as cardiovascular and respiratory system diseases and cancer.

Restaurant and bar smoking bans do reduce smoking, especially among the highly educated
Smoking risk drops significantly in college graduates when they live near areas that have completely banned smoking in bars and restaurants, according to a new study in the American Journal of Epidemiology.

How the UK smoking ban increased wellbeing
Married women with children reported the largest increase in well-being following the smoking bans in the UK in 2006 and 2007 but there was no comparable increase for married men with children.

Smoking study personalizes treatment
A simple blood test is allowing Vanderbilt University Medical Center (VUMC) researchers to determine which patients should be prescribed varenicline (Chantix) to stop smoking and which patients could do just as well, and avoid side effects, by using a nicotine patch.

A biophysical smoking gun
While much about Alzheimer's disease remains a mystery, scientists do know that part of the disease's progression involves a normal protein called tau, aggregating to form ropelike inclusions within brain cells that eventually strangle the neurons.

A case where smoking helped
A mutation in the hemoglobin of a young woman in Germany was found to cause her mild anemia.

Read More: Smoking News and Smoking Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.