Reducing false positives in MCI. The role of neuropsychological assessment

Longitudinal studies of MCI report that a significant proportion of diagnosed cases of MCI display a recovery to normal levels of functioning over time, suggesting an unacceptably high rate of false positive diagnosis for existing MCI diagnostic criteria. A sample of 118 community dwelling adults diagnosed as MCI or healthy control according to current criteria were recruited into the present study. Each participant underwent two subsequent comprehensive assessments over 20-months. Participants were reclassified as either MCI (n= 60) or unimpaired (n= 58) according to temporal stability of cognitive performances. Discriminant function analysis of initial test performances identified a combination of baseline measures of complex sustained attention, semantic memory, working memory, episodic memory, and selective attention resulted in the correct classification of 80.0% of longitudinally confirmed MCI cases and 87.9% of unimpaired cases. Further, using the discriminant function the rate of false positive diagnosis (5.93%) was considerably lower than those reported in previously published MCI studies. The results indicate that episodic memory dysfunction is predictive of temporally stable MCI but only in combination with subclinical deficits to other domains such as attentional processing and semantic memory. Further, comprehensive neuropsychological assessment may enhance the sensitivity and specificity of a MCI diagnosis