Executive function and working memory of patients with mild cognitive impairment

Objective To investigate the characteristics of the executive function and working memory in patients with mild cognitive impairment (MCI), and the relations between working memory and executive function and the effects of working memory on patient' s daily functioning.Methods Thirty patients with MCI and 30 healthy elderly subjects were tested with a wide neuropsychoingical battery of tests including those of executive function, working memory and other cognition domain tests.Executive function was evaluated by using the verbal fluency test (VFT), color trail test (CTT), digital span (DS).Results The results showed the presence of significant executive function and working memory impairment in MCI patients as compared with the healthy controls.The scores of executive function test in MCI patients were decreased significantly in CTT (130.8±58.2 vs 52.0±13.5), CTT-B (210.2±81.8 vs 121.0±33.4),DS (3.4±0.9 vs 4.2±1.1), VFT (8.9±5.4 vs 16.4±5.4) and visuo-objective working memory (0.73±0.12 vs 0.85±9.18) respectively (t = 7.108, 5.159,-2.544,-4.879, and-4.351, all P <0.01 or P < 0.05) .In the stepwise liner regression analysis objective working memory test made a significant independent contribution to ADL (β =-0.720, t =-3.571, P < 0.01).Conclusion The patients with MCI have the deficit in executive function and working memory.Visuo-objective working memory is closely correlated with general cognitive function such as daily function, resulting in daily function decline. Key words: Cognition disorders;  Activities of daily living;  Memory;  Neuropsychological tests