Progression of white matter hyperintensities in elderly individuals over 3 years.

OBJECTIVE The aims of this study were to examine white matter hyperintensities (WMHs) in the brains of elderly individuals, the rate of progression, the anatomic regions most vulnerable, and the predictors of change. METHODS We examined 51 healthy volunteers (mean age 71 years) with T2-weighted brain MRI on the same scanner 3 years apart. WMH volumes were determined by an automated method, and the anatomic location of change was determined for both deep WMHs (DWMHs) and periventricular WMHs (PVWMHs). RESULTS The total brain WMH volume increased by 39.6%, i.e., 13.2% per year, with the change in DWMH being 43.8% and 29.7% in PVWMH. The increase was significant in all regions except the occipital lobe and cerebellum. Age, sex, and cerebrovascular risk factors were not significant predictors of WMH progression. The main predictor of progression was baseline level of WMH. The number of WMH lesions increased by a mean of 1.78, and the progression was mainly accounted for by an increase in very large (>16 mm) lesions. Eight subjects showed a slight decrease in WMH. CONCLUSIONS White matter hyperintensities are progressive in most elderly individuals with an increasing rate of progression as the burden of lesions increases. The rate of progression is greater in deep white matter and in the anterior brain regions. Risk factors for progression are not well understood, and genetic and other environmental factors must be examined. Quantitation of white matter hyperintensities may serve as a surrogate marker of the progression of small vessel disease.