THURSDAY, Feb. 19 (HealthDay News) -- In middle age, people are significantly more likely to have a silent cerebral infarction than a clinical stroke, according to research presented at the American Stroke Association's International Stroke Conference held Feb. 17 to 20 in San Diego.
Jose Rafael Romero, M.D., of Boston University School of Medicine, and colleagues studied 1,059 subjects (mean age 64) who initially had no history of stroke or transient ischemic attacks and who underwent MRI brain scans at least one year apart during 1999-2003 and 2004-2006. They also studied a subset of 925 subjects (mean age 63) who were free of silent stroke at the first MRI and followed-up for a mean of 5.4 years.
Overall, the researchers identified incident initial silent cerebral infarction in 10.2 percent of subjects and clinical stroke in 1.5 percent. Compared to the incidence of clinical stroke, they found that the incidence of silent cerebral infarction was significantly higher in subjects under age 65 (4.5 percent versus 0.8 percent), but that the difference was significantly more narrow in subjects over age 75 (17.4 percent for silent cerebral infarction versus 9.1 percent for clinical stroke). The investigators also found that 2.4 percent of subjects under age 50 had silent cerebral infarctions but that none of them had clinical strokes.
"Silent cerebral infarction adds substantially to the overall burden of cerebrovascular disease," the authors conclude. "In middle-aged subjects, silent cerebral infarction is five times as frequent as symptomatic stroke. Among persons with an initial silent cerebral infarction, almost one in five will suffer a recurrent silent cerebral infarction over the next five years. Estimates of ischemic vascular burden that are based on clinical stroke underestimate the true impact."
Abstract #P129
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