Fukuyama Hidenao
Human Brain Research Center, Kyoto University Graduate School of Medicine.
Rinsho Shinkeigaku. 2006 Nov;46(11):791-4.
I summarized the present status of Neuroimaging studies in mild cognitive impairment (MCI). Nation wide multi-center study with regard to single photon emission study had been started 3 year before and it is now going on in a good cooperation of many institute, covering 319 cases. This study was name as J-COSMIC (Japan Cooperative SPECT Study on Assessment of Mild Impairment of Cognitive Function). After one-year follow-up, 30 out of 120 cases were converted to Alzheimer's disease from MCI. Since last year, ADNI (Alzheimer' disease Neuroimaging Initiative) had started in US, very similar to J-COSMIC, but they adopted PET and MRI as the examination tool. The findings based on J-COSMIC is still unclear, but, we can say that the general cognitive evaluation methods such as MMSE is better than WMS-R, which measures the memory function itself with wide variation in each case. Similar to small size previous works, converter from MCI to Alzheimer's disease tended to show hypoperfusion in the parietal and frontal regions. Recent advance in the molecular imaging enabled us to visualize the deposition of amyloid protein in the brain parenchyma. It is still controversial as to application of the early diagnosis of Alzheimer's disease or MCI. S. Minoshima reported the hypometabolism in the early stage of Alzheimer's disease in the posterior cingulate gyrus or precuneus, but it has been still unknown why these areas showed hypoperfusion or hypometabolism in early phase of Alzheimer's disease. We examined the fiber connection of posterior cingulate region with other brain structures using diffusion weighted images. It was very surprising that such kind of small structures had a lot of connections, not only contralateral side, but also, parietal and temporal lobes, as well as anterior cigulate cortex. The function has been still been unclear, but we will be able to disclose their functions in the human brain in the future, which will be helpful for understanding the pathophysiological changes in MCI.
我总结了轻度认知障碍（MCI）的神经影像学研究现状。关于单光子发射研究的全国多中心研究已于3年前启动，目前正在许多机构的良好合作下进行，涵盖319例病例。这项研究名为J - COSMIC（日本认知功能轻度损害评估合作SPECT研究）。经过一年的随访，120例病例中有30例从MCI转变为阿尔茨海默病。自去年以来，美国启动了阿尔茨海默病神经影像学计划（ADNI），与J - COSMIC非常相似，但他们采用PET和MRI作为检查工具。基于J - COSMIC的研究结果仍不明确，但我们可以说，像MMSE这样的一般认知评估方法比WMS - R更好，WMS - R是测量记忆功能本身的方法，每个病例的差异很大。与之前的小规模研究相似，从MCI转变为阿尔茨海默病的患者往往在顶叶和额叶区域出现灌注不足。分子成像的最新进展使我们能够可视化淀粉样蛋白在脑实质中的沉积。关于阿尔茨海默病或MCI早期诊断的应用仍存在争议。S. Minoshima报告了阿尔茨海默病早期后扣带回或楔前叶的代谢减低，但仍不清楚为什么这些区域在阿尔茨海默病早期会出现灌注不足或代谢减低。我们使用扩散加权图像检查了后扣带回区域与其他脑结构的纤维连接。非常令人惊讶的是，这样小的结构有很多连接，不仅与对侧，而且与顶叶和颞叶以及前扣带回皮质都有连接。其功能仍不清楚，但我们将来能够揭示它们在人脑中的功能，这将有助于理解MCI的病理生理变化。
