'Hidden' Brain Abnormalities Common

Oct. 31, 2007 — -- Could you have a brain tumor -- and not even know it?

New research suggests that benign brain tumors, hidden brain aneurysms and "silent" strokes are all more common than we think. And some of us are walking around with them without even knowing it.

Incidental brain findings -- brain abnormalities that show few if any outward signs -- are common in the general population, researchers say in a study published Wednesday in the New England Journal of Medicine.

Dutch researchers used magnetic resonance imaging, or MRI, to take a peek at the brains of 2,000 healthy individuals with an average age of 63.

What they found was that as many as 7 percent of the subjects had signs of stroke. Nearly 2 percent had a benign brain tumor, and nearly another 2 percent had a brain aneurysm.

The researchers also noted that older subjects seemed to be more likely to show the signs of hidden strokes and benign brain tumors including meningiomas -- a finding consistent with previous research. Brain aneurysms, on the other hand, showed no such age-related increase.

Is Ignorance Bliss?

The findings raise an interesting question: Is it better to know about a brain abnormality, even if you have no symptoms?

Some experts believe that knowing that one has a brain tumor may result in faster treatment rather than discovering it later, when it produces symptoms such as headache or vision changes.

Dr. Henry Brem, chairman of the department of neurosurgery at the Johns Hopkins University School of Medicine in Baltimore, believes that this knowledge may be beneficial because less risk is involved when small tumors are managed before they create symptoms.

"More knowledge is always beneficial," he said. "With additional discoveries of earlier stage brain diseases, the patient and physician have the opportunity to individualize the treatment and make the best decision for that individual patient.

"Overall this will lead to better outcomes with less complication."

Dr. Patrick Kelly, chairman of the department of neurosurgery at NYU School of Medicine in New York, agrees. He adds that he hopes low-cost screening will one day become routine.

"I firmly believe that when brain tumors finally become symptomatic, many are incurable," said Kelly, who has operated on 7,000 brain tumors, many of which were the deadliest type: glioblastoma multiforme.

He said it is particularly important to detect such tumors early.

"It is easier and safer to deal with a small low-grade tumor than a big one that has evolved into a malignant and incurable lesion," he said.

But Dr. Clifford Saper, chairman of the department of neurology at Harvard Medical School in Boston, believes that the brain abnormalities of most of the individuals in the study could have initially been selected by a much less expensive screening method -- a 10-minute questionnaire about neurological symptoms -- instead of a $1,000 one-hour test.

"Most of the things that were picked up are things that probably would not require treatment until they became symptomatic," he added.

Knowledge May Be Dangerous

Other neurologists and neurosurgeons say they are concerned that this information may be dangerous, as it could lead to unnecessary high-risk treatments or instill undue fear.

"Detecting these lesions could lead to more invasive diagnostic procedures, such as brain biopsies, which do also carry a significant risk of morbidity and mortality," said Dr. Roger Härtl, assistant professor of neurological surgery at Weill Cornell Medical College in New York.

Saper agrees. "Every anxious patient in the United States will want a useless MRI scan next week.

"This can contribute more to medical cost, and little to medical care or patient health, but it will scare the heck out of a lot of people and cause a lot of needless worry and testing."

Brain experts also question whether the findings in a white middle class suburb in the Netherlands can be applied to the diverse ethnic population of the United States.

"Obviously different ethnic groups may have different incidence of certain diseases," said Härtl.

"Multiethnic cohorts with a greater representation of blacks and Hispanics may have a greater burden of these findings," added Dr. Ralph Sacco, chair of neurology at the University of Miami.

"The 'healthy' study population in this study may [actually] underestimate the true number of these conditions," Sacco added.

Hints for Stroke Prevention

Still, the findings may offer valuable insight into disease processes -- as well as allow those at risk of certain brain problems to make healthy lifestyle changes before it's too late.

Although little can be done to prevent brain tumors or aneurysms, "these studies might force much greater energy and care into primary prevention of stroke," said Dr. Dennis Landis, chairman of the department of neurology at Baylor College of Medicine in Houston.

Other doctors agree.

"This study is a wake-up call to employ lifestyle changes," Kelly said.

The findings "might stimulate treating physicians to opt for a more aggressive stroke prevention strategy than if the brain was normal," said Dr. Louis Caplan, professor of neurology at Harvard Medical School.

"All in all this paper does not present any surprises, but offers support for the use of screening techniques to enable us to prevent events once we are forewarned, said Dr. Eugene Flamm, chairman of the department of neurosurgery at Albert Einstein College of Medicine in Bronx, N.Y.