Subcortical white matter (WM) alternations are ubiquitous findings on MR scans of demented patients. Both their clinical and diagnostic significance remain controversial. The reasons for this controversy revolve around the limitations caused by the restriction of range found in most scales used to measure MR periventricular and deep WM alterations, and a lack of census regarding diagnostic criteria for vascular dementia (e.g., Carey et al., 1998). The leukoaraiosis scale (LA) is an ordinal measure described by Junque and colleagues (1990) to measure subcortical WM alterations. Libon et al., (1998) has shown that the LA scale enjoys strong interrater reliability (r=.98) and ease of scoring. Using the LA scale, we obtained measures of total subcortical WM alteration in a group of individuals with AD (n=49) and individuals with IVD (n=47) matched for age, education, and level of dementia (M LA=9.6, SD=6.7, Range=0-26). The purpose of the present research is to assess if the LA scale can be associated with a unique pattern of cognitive strengths and weaknesses on neuropsychological tests. Using a series of linear regression analyses, we found that as participants accumulate greater subcortical WM alteration (i.e., a higher LA score) there is a disassociation with respect to performance on tests of memory and executive function. Specifically, high LA scores are associated with high delayed recognition test performance (r=.35, p<.001) but low scores on executive control (r=.33, p<.01). Similarly, as patients accumulate greater WM alterations, scores on tests of semantic knowledge (r=.47, p<.001; r=.30, p<.01) increase, whereas scores on tests of visuoconstruction and graphomotor function (r=.60, p<.001) decline. In sum, this quantitative measure of subcortical WM alterations is associated with a specific pattern of cognitive strengths and weaknesses independent of clinical diagnosis.