Association of White Matter Hyperintensity Volume With Decreased Cognitive Functioning

OBJECTIVE: To examine the relationship between white matter hyperintensity (WMH) volume on magnetic resonance images and cognitive tests in a large, population-based sample. METHODS: Quantitative magnetic resonance imaging and neuropsychological evaluations were performed in 1820 dementia- and stroke-free participants from the Framingham Offspring Cohort. The WMH volume relative to total cranial volume was computed; WMH volumes more than 1 SD above the age-predicted mean were defined as large. Adjusting for age, sex, education, height, and Framingham Stroke Risk Profile, we examined the relationship between WMH and 3 cognitive factors derived from a neuropsychological test battery (verbal memory, visuospatial memory and organization, and visual scanning and motor speed) and 3 individual measures of new learning, abstract reasoning, and naming. RESULTS: Compared with those with no or little WMH volume, participants with large WMH volume performed worse on the cognitive factors of visuospatial memory and organization (P = .04) and visual scanning and motor speed (P = .01), as well as on new learning (P = .04), but not on verbal memory (P = .52). CONCLUSIONS: In this younger community-based population of nondemented individuals, those with large WMH volume, as compared with those with less or no WMH volumes, performed significantly worse in cognitive domains generally associated with frontal lobe systems and, to a lesser extent, the medial temporal area. Further study will clarify whether large WMH volume and associated cognitive impairment lead to future risk of stroke or dementia.