There is increasing evidence that mildly impaired patients with Alzheimer's disease (AD) may be distinguished from mildly impaired patients with multi-infarct cognitive disorder (MICD) by their degree of semantic memory impairment. However, despite these observed group differences, it is unknown whether AD and MICD patients differ in their ability to perform a broad array of functional activities required for daily living and the degree to which severity of cognitive impairment is associated with functional deficits. Using a measure assessing numerous functional domains within the clinical setting, we were able to directly compare the functional capacity of mildly impaired AD and MICD patients, as well as a more cognitively impaired AD group.

Although mildly impaired AD patients scored significantly lower on tests of semantic memory relative to their mildly impaired MICD counterparts, deficits in functional capacity were relatively equivalent. The AD group with more severe cognitive impairment scored lower on both memory and functional measures. A relatively high proportion of mildly impaired AD and MICD subjects evidenced impairment across a number of functional domains, suggesting that functional impairment may occur with relatively high frequency in these patient groups.