In a study of two U.S. states, researchers found the rate of strokes among adults younger than 55 nearly doubled between 1993 and 2005.

Among whites ages 20 to 54, the rate rose from 26 strokes for every 100,000 people, to 48 per 100,000. And among African Americans, it climbed from 83 to 128 per 100,000.

The researchers said they could only speculate on possible explanations. One might be that doctors are detecting strokes in young people more often - both as a result of better brain-imaging technology and of being more vigilant for stroke in the young.

"But I really don't think that's the major reason," said lead researcher Dr. Brett M. Kissela, of the University of Cincinnati College of Medicine.

"We're definitely seeing a higher incidence of risk factors for stroke now," he said in an interview.

Those risk factors include obesity, diabetes and high blood pressure. "And if you're developing them at the age of 20," Kissela said, "then you may have a stroke at a younger age, too."

A researcher not involved in the study agreed that better diagnosis and a real increase in young people's risk of stroke are both probably at work.

"Now MRI allows us to detect smaller strokes," said Dr. Mitchell S.V. Elkind, of Columbia University in New York, who co-wrote an editorial published with the study.

"Strokes come in all shapes and sizes," Elkind said. That includes subtle symptoms like mild degrees of blurry vision, weakness or numbness.

In the past, doctors might not have thought "stroke" when a relatively young person had symptoms like that. And MRI scans, which can detect subtle brain damage from stroke, were not used often back in the 1990s.

Kissela's team found that in 1993-1994, only 18 percent of all stroke patients in their study had an MRI. By 2005, that figure had risen to 58 percent.

"But that probably doesn't explain it all," Elkind said, referring to the rising incidence in young people.

"We know there's been an increase in obesity and diabetes," Elkind said. He added that drug abuse can also cause strokes, and this study did find an increasing rate of drug abuse among young stroke patients over time.

The results, which appear in the journal Neurology, are based on nearly 5,900 Ohio and Kentucky adults who suffered a first-time stroke between 1993 and 2005.

Over that time, 20- to 54-year-olds accounted for a growing proportion of strokes: from 13 percent in 1993, to almost 19 percent by 2005.

The study group came from only two U.S. states, but both Kissela and Elkind said the findings likely reflect what's happening nationally.

Indeed, a government study last year found a similar pattern nationwide: Between 1995 and 2008, the number of Americans ages 15 to 44 hospitalized for a stroke rose by more than one-third.

Kissela said the findings underscore the importance of a healthy lifestyle to stave off stroke risk factors in young people. He also said younger adults shouldn't see themselves as "invincible," and instead get to the doctor to see if they do, in fact, have health problems like high blood pressure or cholesterol.

"It's a small percentage of young people who have strokes," Kissela said, "but it can happen."

And, Elkind pointed out, since more-severe strokes may cause permanent disability, they could be particularly devastating to a younger person.

He advised that everyone, regardless of age, be aware of the potential symptoms of a stroke. Those include severe headache, a sudden loss of coordination or balance, sudden numbness or weakness (especially on one side of the body), and trouble seeing, speaking or understanding speech.

Most strokes happen when a blood clot blocks the flow of blood, and therefore oxygen, to the brain. If people get to the hospital quickly, doctors can treat them with clot-dissolving drugs that may be able to stop the stroke in progress.

SOURCE: bit.ly/lUcacJ Neurology, online October 10, 2012.

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