White Matter Hyperintensity (WMH) lesions are commonly seen on magnetic resonance images of elderly people, and used as marker for cerebrovascular diseases [1]. Their significance has been extensively investigated in studies of ageing and dementia [2, 3]. However, there is few cross-sectional MRI studies have examined WMH volume in relation to cognitive function in normal elderly subjects [4]. In the present investigation, we examine the influence of WMH volume on cognitive performance in normal ageing women.

We used data from the Women’s Healthy Ageing Project (WHAP), a longitudinal study of Australian women. In 2012, 116 women underwent 3T brain MRI and cognitive assessments, their mean age was 69.1 ± 2.6 years. We implemented a manual technique using ITK-snap to measure total WMH volume from FLAIR images, visually checked by qualified neuroradiologist. To account for differences in head size, the total WMH volume was normalized by intracranial volume (ICV). Given the skewed distribution of the normalized total WMH volume, the values were logarithmically transformed. Cognitive assessments included measures of four different cognitive domains (verbal episodic memory, executive function, semantic memory and visuospatial ability). Linear regressions analysis was used to examine the relationship of logarithmically-transformed total WMH volume with each cognitive domains, adjusted for age, education, apolipoprotein E-E4 status and Framingham cardiovascular risk scores.

Age is significantly associated with cognitive performance on a time-dependent tasks specifically involving assessment of executive function and working memory (p < 0.05). After adjusting for age, education, APOE e4 status and Framingham cardiovascular risk scores, increased total WMH volume was associated with lower performance in executive function (p = 0.003) and visuospatial abilities (p = 0.01), but not with verbal episodic memory, or semantic memory (all p > 0.05) Table 1.

In cognitively normal women, larger WMH volumes influence cognitive performance on tasks involving executive function and visuospatial abilities. This provides further evidence to support the role for small vessels-cerebrovascular pathology in cognitive impairments among elderly subjects. As vascular risk factors for the development of WMH are modifiable, these findings suggest intervention strategies to delay or prevent progression of WMH; this could be useful in preventing cognitive decline.