Cerebral infarct five times as common as stroke.
"Silent cerebral infarcts have been referred to as 'silent' because patients and/or clinicians may not recognize them when they occur, but silent infarcts are associated with a higher risk of cognitive impairment and clinical stroke," Dr. Jose Rafael Romero said in an interview after his poster presentation at the International Stroke Conference.
"Given that hypertension is the main risk factor associated with higher risk of silent cerebral infarcts, and is a modifiable risk factor, early surveillance and treatment should be emphasized. Although our study is not a clinical trial to answer that question [if treatment of hypertension decreases the incidence of silent cerebral infarcts], it supports the recommendation by several guidelines for early treatment of hypertension and surveillance."
Dr. Romero of the department of neurology at Boston University and his colleagues studied 1,485 participants in the original Framingham cohort and their offspring. They were free of stroke or transient ischemic attacks and had undergone two brain MRI scans at least 1 year apart, in 1999-2003 and 2004-2006. The researchers defined silent cerebral infarction (SCI) as a lesion greater than 3 mm with a hyperintense signal on [T.sub.2]-weighted images and cerebrospinal fluid signal intensity on subtraction images, separate from the circle of Willis vessels and perivascular spaces.
The mean age of the patients at baseline was 63 years, 46% were women, and 40% had hypertension. Over a mean follow-up period of 5 years, silent cerebral infarct was observed in 8.7% of study participants while clinical stroke occurred in 1.7% of study participants. The majority of SCIs (83%) were single incident in nature.
An age-stratified analysis revealed that the incidence of SCI was more than five times that of clinical stroke among those younger than 65 years of age (4.8% vs. 0.9%). The incidence of both SCI and stroke increased among those aged 65-74 years (13% vs. 2.8%) and those aged 75 years and older (16.9% vs. 3.2%).
The participants were primarily of European descent. "Therefore we cannot generalize our findings to other ethnic/racial groups," Dr. Romero said at the conference, sponsored by the American Heart Association. The study was supported by grants from the National Institute of Neurological Disorders and Stroke, the National Institute on Aging, and the National Heart, Lung, and Blood Institute's Framingham Heart Study.
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|Title Annotation:||CLINICAL ROUNDS|
|Publication:||OB GYN News|
|Date:||May 1, 2009|
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