MRI white matter hyperintensities: three-year follow-up of the Austrian Stroke Prevention Study.

OBJECTIVE: To determine the rate, clinical predictors, and cognitive consequences of MRI white matter hyperintensity evolution over 3 years.
METHODS: In the setting of the Austrian Stroke Prevention Study, 1.5-T MRI was performed at baseline and at a 3-year follow-up in 273 community-dwelling elderly (mean age, 60+/-6.1 years) without neuropsychiatric disease. At each visit individuals underwent a structured clinical interview and examination, EKG, echocardiography, extensive laboratory workup, and demanding neuropsychological testing. MR images were read by three independent raters, and the change of white matter hyperintensities from baseline was assessed by direct image comparison. The change was graded as absent, minor, or marked. Minor change was defined as a difference of no more than one to four punctate lesions between both scans. A change was considered to be marked if there was a difference of more than four abnormalities or a transition to early-confluent and confluent lesions.
RESULTS: Combined ratings indicated lesion progression in 49 individuals (17.9%). Lesion progression was minor in 27 participants (9.9%) and was marked in 22 (8.1%). Regression of white matter hyperintensities did not occur. Diastolic blood pressure (odds ratio, 1.07/mm Hg) and early-confluent or confluent white matter hyperintensities at baseline (odds ratio, 2.62) were the only significant predictors of white matter hyperintensity progression. Lesion progression had no influence on the course of neuropsychological test performance over the observational period.
CONCLUSIONS: White matter hyperintensities progress in elderly normal subjects. Our data may be used as a reference for future observational and interventional studies on white matter hyperintensity progression in various CNS diseases. The lack of an association between lesion progression and cognitive functioning needs to be explored further.