on March 13, 2008
Published online before print March 13, 2008, doi: 10.1161/STROKEAHA.107.501932
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Submitted on August 14, 2007
From the Stroke Service, Department of Neurology (H.A., J.R., K.L.F., A.B.S.), A.A. Martinos Center for Biomedical Imaging, Department of Radiology (H.A., E.M.A., P.W.S., O.W., R.G.G., A.G.S.), and the Center for Human Genetic Research (J.R.), Massachusetts General Hospital, Harvard Medical School, Boston, Mass; the Program in Medical and Population Genetics (J.R.), Broad Institute of MIT and Harvard, Cambridge, Mass; and the National Institute of Neurological Disorders and Stroke (W.J.K.), National Institutes of Health, Bethesda, Md. * To whom correspondence should be addressed. E-mail: hay{at}partners.org.
Background and Purpose—Leukoaraiosis (LA) is associated with structural and functional vascular changes that may compromise tissue perfusion at the microvascular level. We hypothesized that the volume of LA correlated with the proportion of initially ischemic but eventually infarcted tissue in acute human stroke. Methods—We studied 61 consecutive patients with diffusion-weighted imaging–mean transit time mismatch. All patients were scanned twice within 12 hours of symptom onset and between days 4 and 30. We explored the relationship between the volume of white matter regions with LA on acute images and the proportion of diffusion-weighted imaging–mean transit time mismatch tissue that progressed to infarction (percentage mismatch lost). Results—Bivariate analyses showed a statistically significant correlation between percentage mismatch lost and LA volume (r=0.33, P<0.01). A linear regression model with percentage mismatch lost as response and LA volume, acute diffusion-weighted imaging and mean transit time volumes, age, admission blood glucose level, admission mean arterial blood pressure, etiologic stroke subtype, time to acute MRI, and time between acute and follow-up imaging as covariates revealed that LA volume was an independent predictor of infarct growth (P=0.04). The adjusted percentage mismatch lost in the highest quartile of LA volume was 1.9-fold (95% CI: 1.2 to 3.1) greater than the percentage mismatch lost in the lowest quartile. Conclusion—LA volume at the time of acute ischemic stroke is a predictor infarct growth. Because LA is associated with factors that modulate tissue perfusion as well as tissue capacity for handling of ischemia, LA volume appears to be a composite predictive marker for the fate of acutely ischemic tissue.
Revised on September 13, 2007
Accepted on September 24, 2007
Severity of Leukoaraiosis and Susceptibility to Infarct Growth in Acute Stroke
Hakan Ay MD*;
Key words: acute stroke • cerebral infarct • diffusion-weighted imaging • leukoaraiosis • MRI
Related Article:
Stroke 2008 39: 1401-1403.