Abstract：
This systematic review aimed to evaluate previous studies which used near-infrared spectroscopy (NIRS) in dementia given its suitability as a diagnostic and investigative tool in this population. From 800 identified records which used NIRS in dementia and prodromal stages, 88 studies were evaluated which employed a range of tasks testing memory (29), word retrieval (24), motor (8) and visuo-spatial function (4), and which explored the resting state (32). Across these domains, dementia exhibited blunted haemodynamic responses, often localised to frontal regions of interest, and a lack of task-appropriate frontal lateralisation. Prodromal stages, such as mild cognitive impairment, revealed mixed results. Reduced cognitive performance accompanied by either diminished functional responses or hyperactivity was identified, the latter suggesting a compensatory response not present at the dementia stage. Despite clear evidence of alterations in brain oxygenation in dementia and prodromal stages, a consensus as to the nature of these changes is difficult to reach. This is likely partially due to the lack of standardisation in optical techniques and processing methods for the application of NIRS to dementia. Further studies are required exploring more naturalistic settings and a wider range of dementia subtypes.
摘要：
本系统综述旨在评估以前在痴呆症中使用近红外光谱（NIRS）的研究，因为它适合作为该人群的诊断和调查工具。从800份在痴呆和前驱阶段使用NIRS的鉴定记录中，对88项研究进行了评估，这些研究采用了一系列测试记忆的任务(29)，单词检索(24)，运动(8)和视觉空间功能(4)，并探索了静止状态(32)。在这些领域，痴呆表现出迟钝的血液动力学反应，通常位于感兴趣的额叶区域，缺乏适合任务的正面偏侧化。前驱阶段，如轻度认知障碍，结果喜忧参半。认知能力下降伴随着功能反应减弱或过度活跃被发现，后者提示在痴呆阶段不存在代偿反应。尽管有明确的证据表明痴呆和前驱阶段的脑氧合改变，很难就这些变化的性质达成共识。这可能部分是由于在将NIRS应用于痴呆症的光学技术和处理方法方面缺乏标准化。需要进一步的研究探索更自然的环境和更广泛的痴呆亚型。
