Impairment in Proverb Interpretation as an Executive Function Deficit in Patients with Amnestic Mild Cognitive Impairment and Early Alzheimer's Disease

BACKGROUND/AIMS Proverb interpretation is assumed to reflect executive functions. We hypothesized that proverb interpretation is impaired in patients with amnestic mild cognitive impairment (aMCI) diagnosed as single-domain impairment by common neuropsychological testing. METHODS We compared performance in a proverb interpretation test in single-domain aMCI patients and patients with early Alzheimer's disease (EAD). RESULTS The groups with aMCI and EAD performed significantly worse than healthy controls. Both patient groups gave concrete answers with a similar frequency. However, patients with EAD tended to give senseless answers more frequently. CONCLUSIONS Our data suggest that in patients diagnosed as single-domain aMCI, deterioration of executive functions is detectable with subtle and appropriate neuropsychological testing. Implementation of these procedures may improve the early prediction of AD.