Age-related changes of lateral ventricular width and periventricular white matter in the human brain: a diffusion tensor imaging study.

Abstract

Aging is the accumulation of multidimensional deterioration of processing of biological, psychological, and social changes with expansion over time (Bowen and Atwood, 2004; Grady, 2012). Aging-related changes are typically accompanied by decline in cognitive function, urinary control, sensory-motor function, and gait ability (Bradley et al., 1991; Bowen and Atwood, 2004; Hedden and Gabrieli, 2004; Grady, 2012; Moran et al., 2012). In addition, a number of studies have suggested changes in brain structure with normal aging, such as decrease in cortical thickness or increase in ventricular width (Blatter et al., 1995; Tang et al., 1997; Uylings and de Brabander, 2002; Preul et al., 2006; Apostolova et al., 2012). In particular, ventricular enlargement has been suggested as a structural biomarker for normal aging and progression of some illnesses, such as Alzheimer's disease (Blatter et al., 1995; Tang et al., 1997; Uylings and de Brabander, 2002; Preul et al., 2006; Apostolova et al., 2012). However, the question of how this structural change in the brain in normal elderly affects change of white matters remains a topic of interest and concern. Diffusion tensor imaging allows for evaluation of white matter due to its ability to capture and quantify water diffusion characteristics (Mori et al., 1999; Assaf and Pasternak, 2008; Neil, 2008). In normal white matter, water molecules move relatively freely in a direction parallel to nerve fiber tracts, however, their movements are restricted across tracts, which cause diffusion anisotropy in white matter. This selective restriction of water molecule movement allows for exploration of physical changes in white matter caused by normal aging using diffusion anisotropy. Some studies using DTI have reported on changes in periventricular white matter in patients with stroke or other brain injuries (Yeo et al., 2011; Hattori et al., 2012; Jang et al., 2013). In the current study, using DTI, we investigated ventricular enlargement with normal aging, and its effect on periventricular white matter.