Chen Jiu, Zhang Zhijun, Li Shijiang
Department of Neurology, Affiliated ZhongDa Hospital, Neuropsychiatric Institute and Medical School of Southeast University, Nanjing, 210009, China.
Neurosci Bull. 2015 Feb;31(1):128-40. doi: 10.1007/s12264-014-1490-8. Epub 2015 Jan 16.
Impaired structure and function of the hippocampus is a valuable predictor of progression from amnestic mild cognitive impairment (aMCI) to Alzheimer's disease (AD). As a part of the medial temporal lobe memory system, the hippocampus is one of the brain regions affected earliest by AD neuropathology, and shows progressive degeneration as aMCI progresses to AD. Currently, no validated biomarkers can precisely predict the conversion from aMCI to AD. Therefore, there is a great need of sensitive tools for the early detection of AD progression. In this review, we summarize the specific structural and functional changes in the hippocampus from recent aMCI studies using neurophysiological and neuroimaging data. We suggest that a combination of advanced multi-modal neuroimaging measures in discovering biomarkers will provide more precise and sensitive measures of hippocampal changes than using only one of them. These will potentially affect early diagnosis and disease-modifying treatments. We propose a new sequential and progressive framework in which the impairment spreads from the integrity of fibers to volume and then to function in hippocampal subregions. Meanwhile, this is likely to be accompanied by progressive impairment of behavioral and neuropsychological performance in the progression of aMCI to AD.
海马体结构和功能受损是遗忘型轻度认知障碍（aMCI）进展为阿尔茨海默病（AD）的一个重要预测指标。作为内侧颞叶记忆系统的一部分，海马体是最早受到AD神经病理学影响的脑区之一，并且随着aMCI进展为AD而呈现进行性退变。目前，尚无经过验证的生物标志物能够精确预测从aMCI到AD的转化。因此，迫切需要用于早期检测AD进展的敏感工具。在本综述中，我们利用神经生理学和神经影像学数据，总结了近期aMCI研究中海马体的特定结构和功能变化。我们认为，与仅使用其中一种方法相比，先进的多模态神经影像学测量方法相结合来发现生物标志物，将能提供更精确、更敏感的海马体变化测量方法。这些方法可能会影响早期诊断和疾病修饰治疗。我们提出了一个新的顺序性和渐进性框架，其中损伤从纤维完整性扩展到体积，然后扩展到海马体亚区域的功能。同时，在aMCI进展为AD的过程中，这可能伴随着行为和神经心理表现的进行性损伤。
