Executive Function Deficits in Mild Alzheimer's Disease

Twenty mildly impaired patients with Alzheimer's disease (AD; Mini-Mental State Examination; [MMSE] = 25.1) and 20 controls (MMSE = 29.4) were administered 7 tests to assess executive function. Tests of memory, naming, and copying were included. The executive function tests were the Self-Ordering Test, Controlled Oral Word Association Test (FAS), Trail Making Test, Hukok Logical Matrices, the Proverb Interpretation Test, the Similarities subtest of the Wechsler Adult Intelligence Scale-Revised, and the Cued Reaction Time Test. AD patients differed significantly from controls on 4 executive function tests (the Self-Ordering, Hukok, Trail Making, and FAS) and on the memory test. The executive function tasks on which the AD patients were impaired in comparison with controls primarily required concurrent manipulation of information. Tests of simple concept formation, cue-directed behavior, attention, naming, or figure copying did not differentiate the groups.