DECLINE OF FRONTAL-LOBE FUNCTIONS IN SUBJECTS WITH AGE-ASSOCIATED MEMORY IMPAIRMENT

Objective: To assess frontal lobe functions of subjects with age-assoc iated memory impairment (AAMI) and to examine whether performance on n europsychological tests is correlated with the volume of the frontal l obes in magnetic resonance imaging. Design: Cross-sectional two-group comparison. Setting: The Memory Research Clinic of Kuopio University a nd the Magnetic Resonance Imaging Center of Kuopio University Hospital . Participants: Ninety subjects (mean age, 70.5 years), 43 with AAMI d iagnosed according to National Institute of Mental Health criteria and 47 age-matched healthy controls. Measurements: Four neuropsychologica l tests were used to assess frontal lobe function: Verbal Fluency Test (VFT), Modified Wisconsin Card Sorting Test (WCST), Trail Making Test (TMT), and Stroop Test (ST). A 1.5-T magnetic resonance imager was us ed for volume measurements. Results: The AAMI subjects scored signific antly worse on the WCST, ST, and TMT compared with controls (ANCOVA, a djusted for age and education, p < 0.05). The frontal lobe volumes did not differ between AAMI subjects and controls. Conclusions: AAMI subj ects appear to be impaired not only in tests assessing memory but also in tests of executive functions. This finding agrees with previous re ports suggesting a central role for frontal dysfunction in memory loss of elderly people.