White matter disease as a biomarker for long-term cerebrovascular disease and dementia

Abstract

White matter disease is commonly detected on brain MRI of aging individuals as white matter hyperintensities (WMH), or 'leukoaraiosis." Over the years, it has become increasingly clear that the presence and extent of WMH is a radiographic marker of small cerebral vessel disease and an important predictor of the lifelong risk of stroke, cognitive impairment, and functional disability. A number of large population-based studies have outlined the significance of WMH as a biomarker for long-term cerebrovascular disease and dementia. In this review, we describe the conceptual framework and methodology that support this association and link the existing knowledge to future lines of investigation in the field.

Figure 1

Severity of MRI-detected white matter hyperintensity. Total burden of white matter disease varies significantly among asymptomatic adults and patients with known cerebrovascular disease. In age-matched individuals, white matter hyperintensity (WMH) volume may vary from mild to very severe (upper panel). Using validated, semi-automated volumetric protocol, WMH volume can be quantified (lower panel, in red, WMH maps are derived from contiguous, supratentorial axial T2-FLAIR MRI slices using previously published method [10]) with a high degree of accuracy and precision.