Kikuchi Mitsuru, Wada Yuji, Takeda Tsutomu, Oe Hiroyasu, Hashimoto Takuma, Koshino Yoshifumi
Department of Psychiatry and Neurobiology, Graduate School of Medical Science, Kanazawa University, 13-1 Takara-machi, Japan.
Clin Neurophysiol. 2002 Jul;113(7):1045-51. doi: 10.1016/s1388-2457(02)00129-3.
The distinction between electroencephalogram (EEG) driving responses in normal aging and Alzheimer's disease (AD) is unclear. This study was conducted to explore the structure of harmonic responses of EEG coherence during photic stimulation (PS) in AD.
EEG interhemispheric coherence was analyzed for each harmonic responses during PS (white flickers at 5, 10 and 15 flashes/sec) in younger subjects (20-25 years), non-demented elderly subjects (50-67 years) and AD patients (43-66 years).
The elderly subjects had higher interhemispheric coherence during PS than the younger subjects, with significant differences found in the 6th (30Hz) and 8th (40Hz) harmonic responses to 5Hz PS. The AD patients had significantly smaller coherence than the elderly subjects in the 2nd (10Hz) and 4th (20Hz) harmonic responses to 5Hz PS, and in the fundamental (10Hz) and 2nd (20Hz) harmonic responses to 10Hz PS. These coherence values did not correlate with duration of the disease or with cognitive functioning as evaluated by MMSE score.
A failure of stimulation-related brain activation in AD patients was observed in alpha-related frequencies, suggesting that AD is not the end result of normal aging of the brain, at least in terms of the mechanisms which are involved in PS-related functional organization.
正常衰老与阿尔茨海默病（AD）患者脑电图（EEG）驱动反应之间的区别尚不清楚。本研究旨在探讨AD患者在光刺激（PS）期间EEG相干性谐波反应的结构。
分析了年轻受试者（20 - 25岁）、非痴呆老年受试者（50 - 67岁）和AD患者（43 - 66岁）在PS（5、10和15次闪烁/秒的白色闪烁）期间各谐波反应的EEG半球间相干性。
老年受试者在PS期间的半球间相干性高于年轻受试者，在对5Hz PS的第6谐波（30Hz）和第8谐波（40Hz）反应中发现有显著差异。AD患者在对5Hz PS的第2谐波（10Hz）和第4谐波（20Hz）反应中，以及在对10Hz PS的基波（10Hz）和第2谐波（20Hz）反应中，相干性显著小于老年受试者。这些相干值与疾病持续时间或MMSE评分评估的认知功能无关。
在与α相关的频率中观察到AD患者存在刺激相关的脑激活障碍，这表明AD至少在与PS相关功能组织的机制方面并非大脑正常衰老的最终结果。
