伴有和不伴有抑郁的阿尔茨海默病患者在静音Stroop任务下脑功能激活的差异

Different patterns of brain activation between Alzheimer's disease with and without depression:a fMRI study during attention task

目的研究 Alzheimer 病(AD)与 AD 伴抑郁患者(depression in Alzheimer’s disease,dAD)在注意任务下脑功能激活区的差异。方法收集临床诊断轻度 AD 患者20例,符合《精神疾病诊断与统计手册第Ⅳ版》标准(DSM-Ⅳ),其临床痴呆评定量表(CDR)评分1.0,其中9例 dAD 患者符合国立精神疾病研究院制定的痴呆伴抑郁的诊断标准(NIMH-dAD 标准),其康奈尔痴呆中抑郁量表评分(CSDD)>12。另有10名健康老龄者为对照组。在静音 Stroop 任务下,计算完成任务的反应时间、错误率和漏报率等行为学指标,同时采集 fMRI 脑部功能图像,使用 SPM2软件分析。结果 dAD、AD 与对照组的反应时间(ms)分别为2214.4±107.1、2020.6±558.3、840.0±254.5,dAD 与 AD 组均明显慢于对照组(P<0.01),且 dAD 组比 AD 组更慢(P=0.04)。dAD、AD、对照组的错误率分别为:8.3%、6.9%、0.7%;其漏报率分别为:3.6%、2.9%、0,虽然 dAD 与 AD 组在错误率(P=0.13)和漏报率(P=0.10)间并无差异,但均明显高于对照组(P<0.01)。对照组在双侧前额背外侧皮质、双侧前扣带回、右侧顶叶和左额下回有明显的激活。AD 组仅在左侧顶叶、左前扣带回和右额叶背外侧皮质等有少量激活。dAD 组仅在前额皮质和部分右侧前额背外侧皮质处有少量激活。结论与对照组相比,AD 伴有和不伴抑郁的患者均存在异常的脑功能成像,但二者间有着明显的差别,抑郁加重 AD的注意功能损害。

Objective To examine whether Alzheimer＇ s disease（AD） with and without depression has different patterns of brain activation during an fMRI attention task, and to investigate whether depression exacerbates attention disorder in AD. Methods Twenty mild AD patients were enrolled, who fulfilled DSM- Ⅳ criteria and had CDR = 1.0, among whom 9 with depression fulfilled NIMH-dAD criteria and had CSDD 〉 12. Meanwhile 10 healthy elderly subjects of similar age and gender ratio were matched as controls. There was no significant difference of age, gender, education, onset duration and MMSE. Attention task was carried out with silent color-word task： all participants pressed the left or right button to select the answer of congruence or ineongruenee when color nouns in red, green, blue or yellow ink appearing on the left part of screen and a target color appearing on the right part of the screen by. During the tasks, reaction time, false ratio, missing ratio and fMRI image acquisition was respectively recorded, which were later analyzed on SPSS 11.0 statistieal parametric mapping software 2 （SPM2） respectively. Results The reaction time in dAD, AD and control group were （ 2214. 4±1071 ）, （ 2020. 6±558. 3 ） and （ 840. 0±254. 5 ） ms respectively. The false ratio were 8.3%, 6. 9% and 0. 7% respectively, and the omit ratio were 3. 6%, 2. 9% and 0 respectively. Either AD with or without depression was slower than the controls in reaction time （P 〈 0. 01 ）. Furthermore, AD with depression was far slower than that without depression （P = 0. 04 ）. However, AD with and without depression had no significant differences of false or missing ratio in colorword task （P = 0. 13, P = 0. 10）. In Stroop fMRI task, both sides of the dorsal lateral frontal cortex and anterior eingulate cortex, left inferior frontal gyre, right parietal lobe were significantly activated in control group ; only a few area in left parietal lobe, left anterior eingulate cortex and right dorsal lateral frontal cortex were activated in AD group; and a few activated in bilateral prefrontal cortex, as well as right dorsal lateral frontal cortex were activated in dAD group. Conclusions AD and dAD patients have more seriously attention dysfunction. Furthermore, patterns of brain activation between AD with and without depression were quite different. These findings suggest impaired limbic dysfunction may play an important role in dAD.