轻度认知功能障碍患者的执行功能和工作记忆研究

Executive function and working memory of patients with mild cognitive impairment

目的了解轻度认知功能障碍（MCI）患者的执行功能和工作记忆是否损害及工作记忆损害特点，探讨执行功能对MCI患者的日常生活活动能力（ADL）的影响。方法运用神经心理学测试的方法对30例MCI患者进行执行功能、工作记忆及其他认知功能检查，同时进行ADL评定，另外选择30名健康老人作为对照组。结果MCI组的执行功能和工作记忆成绩（分）显著低于对照组，其中数字颜色连线干扰（130．8±58．2）、数字颜色连线B（210．2±81．8）、词汇流畅性测试（8．9±5．4）、视觉客体工作记忆（0．73±0．12）和数字广度（3．4±0．9），除视觉空间工作记忆外，与对照组比较（52．0±13．5、121．0±33．4、16．4±5．4、0．85±9．18、4．2±1．1）差异均有统计学意义（t=7．108、5．159、-4．879、-4．351、-2．544，均P〈0．01或P〈0．05）。用多元逐步回归方法分析执行功能对ADL的影响，结果客体工作记忆、空间工作记忆和词汇流畅性与ADL的影响相关，而客体工作记忆与ADL的影响有显著相关性（β=-0．720，t=-3．571，P=0．001）。结论MCI患者具有明显的执行功能障碍和工作记忆损害，工作记忆与MCI患者的ADL有良好相关性，而且视觉客体工作记忆与MCI患者的ADL测查具有显著相关性，因此MCI患者的执行功能障碍可能是导致其ADL下降和客体工作记忆损害的主要因素。

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 neuropsychological 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±8.2 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.