Xu G, Antuono P G, Jones J, Xu Y, Wu G, Ward D, Li S-J
Department of Biophysics, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
Neurology. 2007 Oct 23;69(17):1650-6. doi: 10.1212/01.wnl.0000296941.06685.22.
To determine how memory-encoding tasks elicit functional perfusion change in subjects with amnestic mild cognitive impairment (aMCI).
Twelve subjects with aMCI and 14 age-matched cognitively normal (CN) subjects were recruited for this study. Arterial spin-labeling perfusion MRI (ASL-MRI) was employed to measure regional cerebral blood flow (CBF) during both control and encoding task conditions.
Experimental results demonstrated that hypoperfusion occurred in the right precuneus and cuneus in the aMCI group, and not the CN group, during the control state. During the memory-task performance, the difference in these regional hypoperfusion areas extended to the posterior cingulate. These regional perfusion rates correlated with the Mini-Mental State Examination and the Rey Auditory Verbal Learning Test scores. In addition, a CBF percentage increase (22.7%) occurred in the right parahippocampus region during the memory-encoding task performance in the CN group, with approximately no change in the aMCI group.
Subjects with amnestic mild cognitive impairment had significant regional cerebral hypoperfusion and lacked the dynamic capability to modulate their regional cerebral blood flow responses to the challenge of the functional tasks.
确定记忆编码任务如何引发遗忘型轻度认知障碍（aMCI）受试者的功能性灌注变化。
本研究招募了12名aMCI受试者和14名年龄匹配的认知正常（CN）受试者。采用动脉自旋标记灌注磁共振成像（ASL-MRI）在对照和编码任务条件下测量局部脑血流量（CBF）。
实验结果表明，在对照状态下，aMCI组右侧楔前叶和楔叶出现灌注不足，而CN组未出现。在记忆任务执行期间，这些局部灌注不足区域的差异扩展到后扣带回。这些局部灌注率与简易精神状态检查表和雷伊听觉词语学习测试分数相关。此外，在CN组记忆编码任务执行期间，右侧海马旁回区域的CBF百分比增加（22.7%），而aMCI组几乎没有变化。
遗忘型轻度认知障碍受试者存在明显的局部脑灌注不足，并且缺乏对功能性任务挑战调节其局部脑血流反应的动态能力。
