Yamaguchi S, Tsuchiya H, Yamagata S, Toyoda G, Kobayashi S
Department of Internal Medicine III, Shimane Medical University, Izumo, Japan.
Clin Neurophysiol. 2000 Feb;111(2):195-203. doi: 10.1016/s1388-2457(99)00228-x.
Non-target, deviant stimuli generate an earlier latency, front-central novelty P3, whereas correctly detected task-relevant stimuli generate a parietal maximal target P3. We examined whether the P3 component to novel stimuli is affected by dementing processes, and is therefore useful for distinguishing Alzheimer's type dementia (AD) from vascular dementia (VD).
We recorded ERPs to task-relevant stimuli (target P3) and novel task-irrelevant stimuli (novelty P3) in an auditory oddball task in AD (n = 16), VD (n = 16), and age-matched controls (n = 18). The amplitude, latency, and scalp topography of target and novelty P3 were compared among 3 groups using ANOVA. The relationship between P3 measures and intelligence scores were evaluated by correlation analysis.
The amplitude, latency and scalp topography of the target P3 were comparably affected by both AD and VD. However, the amplitude of the novelty P3 was markedly reduced in VD, but not in AD, and the scalp topographics were different in the 3 groups. The amplitude was maximal at frontal sites in controls, at central sites in AD, and at parietal sites in VD. The target P3 latency was prolonged in both AD and VD, whereas the novelty P3 latency was only prolonged in VD. AD was discriminated satisfactorily from VD by using the novelty amplitude at Cz and the ratio of the amplitudes at Fz and Pz as independent variables.
These results suggest that the response to novel stimuli is differentially affected by dementia with degenerative and vascular etiology.
非目标性、异常刺激会产生潜伏期更早的额中央区新奇性P3，而正确检测到的与任务相关的刺激会产生顶叶最大的目标P3。我们研究了对新奇刺激的P3成分是否受痴呆进程影响，因此是否有助于区分阿尔茨海默病型痴呆（AD）和血管性痴呆（VD）。
我们在听觉oddball任务中记录了AD组（n = 16）、VD组（n = 16）和年龄匹配的对照组（n = 18）对与任务相关的刺激（目标P3）和新的与任务无关的刺激（新奇性P3）的事件相关电位。使用方差分析比较三组中目标P3和新奇性P3的振幅、潜伏期和头皮地形图。通过相关分析评估P3测量值与智力分数之间的关系。
AD和VD对目标P3的振幅、潜伏期和头皮地形图的影响相当。然而，VD组中新奇性P3的振幅明显降低，而AD组中未降低，且三组的头皮地形图不同。对照组中振幅在额部位点最大，AD组在中央位点最大，VD组在顶叶位点最大。AD和VD组的目标P3潜伏期均延长，而新奇性P3潜伏期仅在VD组延长。以Cz处的新奇性振幅以及Fz和Pz处的振幅之比作为自变量，可令人满意地区分AD和VD。
这些结果表明，对新奇刺激的反应受退行性和血管性病因痴呆的影响不同。
