Risk factors previously associated with clinical stroke were also found to be associated with midlife silent cerebral infarction (SCI), according to a study published in the June issue of Stroke: Journal of the American Heart Association.
The researchers said that previous estimates of the prevalence of SCI on MRI in community-based samples have varied between 5.8 and 17.7 percent depending on age, ethnicity, presence of comorbidities and imaging techniques. They documented the prevalence and risk factors associated with SCI at midlife in the community-based Framingham sample.
Rohit R. Das MD, MPH, from department of neurology at Boston University, and colleagues examined a study sample comprised of 2,040 Framingham Offspring (53 percent female; mean age, 62 years) who attended the sixth examination (1996–1998), underwent volumetric brain MRI (1999–2005,) and were free of clinical stroke at MRI. The investigators examined the age- and sex-specific prevalences and the clinical correlates of SCI using multivariable logistic regression models.
The researchers found that at least one SCI was present in 10.7 percent of participants; 84 percent had a single lesion. SCI was largely located in the basal ganglia (52 percent), other subcortical (35 percent) areas, and cortical areas (11 percent), the authors wrote.
The investigators found that prevalent SCI was associated with the Framingham Stroke Risk Profile score (OR, 1.27); stage I hypertension was determined by JNC-7 criteria (OR, 1.56), an elevated plasma homocysteine in the highest quartile (OR, 2.23), atrial fibrillation (OR, 2.16), carotid stenosis >25 percent (OR, 1.62) and increased carotid intimal-medial thickness above the lowest quintile (OR, 1.65).
Das and colleagues concluded that the results support current guidelines emphasizing early detection and treatment of stroke risk factors.
The researchers said the findings demonstrate a significant relationship between atrial fibrillation and silent cerebral infarction, although it is unclear from the data whether screening for and treating the heart condition would be useful.
The researchers acknowledged that the findings may not be general to patients who are not of European descent.
The study was also limited, they wrote, because the participants underwent only one MRI.