Evolution of Acute Lacunar Infarcts: Factors Predicting Progression to White Matter Hyperintensity (P01.011)

Abstract

Objective: To study the neuroimaging evolution of acute lacunar infarcts and to determine the predictors for conversion of acute lacunar infarcts to WMH. Background White matter hyperintensity (WMH) is associated with increased incidence of dementia, ischemic strokes and mortality. The role of ischemia as a mechanism for WMH needs to be clarified. Design/Methods: Retrospective study of patients with MRI-confirmed acute lacunar infarcts who presented to a tertiary hospital between 2008-2009. Only subjects who had a repeat MRI at least 6 months after the initial acute infarct were evaluated. Data on demographics, vascular risk factors and MRI imaging were collected. A neurologist blinded to the clinical details evaluated all MRIs. Diameter and location of the acute infarct on DWI was determined. The status of the infarct on the follow-up T2 MRI was determined after ensuring anatomical correlation. On the follow-up scan, the infarct was classified as “lacune” if the lesion was homogenous with a well defined boundary and as “WMH” when the lesion appeared heterogenous with ill defined boundaries. The burden of the periventricular and deep sub cortical WMH was scored on both the initial and follow-up MRI using the modified Fazekas scale. Results: 44 patients with a mean age of 66.8 years were identified. The mean interval between the initial and follow-up MRI was 23.9 months. In 77% of patients, the acute lacunar infarct evolved to become non-homogenous and ill-defined, resembling chronic WMH. On univariate logistic regression, the factors associated with progression to WMH included hypertension (OR 10.3, p=0.017) and the interval from acute infarct (OR 1.2, p=0.01). Presence of diabetes mellitus demonstrated a trend towards significance (OR 4.25, p=0.09). Conclusions: This study demonstrates that a large majority of acute infarcts progress to WMH. Presence of hypertension and diabetes mellitus are important predictors for conversion of acute infarcts to WMH. Disclosure: Dr. Fong has nothing to disclose. Dr. Chew has nothing to disclose. Dr. Kandiah has received personal compensation for activities with Lundbeck, Novartis, and Essai as a speaker.