Grant: Travel Awards - Institute Community Support

Vascular cognitive impairment (VCI) is associated with vascular risk factors (such as high blood pressure) and is the second most common cause of dementia. It is characterized by damage to the white matter of the brain called white matter lesions (WML). The relationship between WMLs and thinking ability is still not clear - some studies report an association between WMLs and decreased thinking ability while others have found no associations. Recently, it was reported that greater WML is associated with thinning of the brain cortex. We hypothesized that cortical thinning might be a potential pathway for WML to cause decreased thinking ability. Thus, the purpose of this study was two-fold: 1) To investigate whether WML progression was associated with changes in cortical thickness; and 2) To assess the individual contribution of WML progression and changes in cortical thickness on thinking ability. To do this, we conducted a sub-analysis of a 2-arm randomized controlled trial assessing the effect of aerobic exercise on cognitive function in VCI. All measures were collected twice - once at the start and again six months later. Twenty-nine participants completed a brain scan to measure WMLs and cortical thickness and they also completed multiple tests that measured thinking ability. In our statistical analysis we found that increased WML was associated with cortical thinning over time. Additionally, increased cortical thinning was associated with slower thinking as measured by the Digit Symbol Substitution Test. The results of our study points to the importance of secondary prevention to reduce WML progression as this could benefit thinking ability and delay the onset of dementia. From a public health standpoint, it is critical that we target people with VCI as vascular risk factors can be controlled and modified. Strategies to preserve the health of people with VCI will help these people avoid early institutional care and reduce heath care costs.