Neurofilament light chain (NfL) is an emerging biomarker of neural degeneration. NfL is an integral component of axons and is released into the bloodstream and cerebrospinal fluid during neurodegeneration; hence it can be used to monitor disease progression. Given that several neurological disorders are accompanied by cognitive decline, recent literature has investigated the relationship between NfL levels and cognition. The objective of this scoping review was to determine whether a consistent relationship between NfL and cognition exists in the context of variable degrees of neurodegeneration present across several neurological disorders. Four electronic databases were searched for relevant articles and 160 articles were initially identified. After article screening, 37 studies met the final inclusion criteria. Studies were then qualitatively synthesized to determine the relationship between NfL and cognition across a variety of neurological disorders. The large majority of studies found that NfL levels are inversely correlated with cognition, such that higher NfL levels are associated with poorer cognition. This relationship was not universal, however, and this discrepancy was speculated to be due to the nature of the neurological disorder, individual differences between participants, or methodological inconsistencies. Further study is required, and associated recommendations were proposed for the design of future investigations.

中文翻译：

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神经丝轻链与神经系统疾病认知的关系：范围综述

神经丝轻链 (NfL) 是一种新兴的神经退行性生物标志物。NfL 是轴突的一个组成部分，在神经变性过程中被释放到血流和脑脊液中；因此它可用于监测疾病进展。鉴于几种神经系统疾病伴随着认知能力下降，最近的文献研究了 NfL 水平与认知能力之间的关系。本次范围界定审查的目的是确定 NfL 和认知之间是否存在一致的关系，在几种神经系统疾病存在不同程度的神经退行性变的情况下。在四个电子数据库中搜索相关文章，初步确定了160篇文章。文章筛选后，37 项研究符合最终纳入标准。然后定性地综合研究以确定 NfL 与各种神经系统疾病的认知之间的关系。大多数研究发现 NfL 水平与认知呈负相关，因此较高的 NfL 水平与较差的认知相关。然而，这种关系并不普遍，这种差异被推测是由于神经系统疾病的性质、参与者之间的个体差异或方法论的不一致造成的。需要进一步研究，并为未来调查的设计提出了相关建议。因此，较高的 NfL 水平与较差的认知有关。然而，这种关系并不普遍，这种差异被推测是由于神经系统疾病的性质、参与者之间的个体差异或方法论的不一致造成的。需要进一步研究，并为未来调查的设计提出了相关建议。因此，较高的 NfL 水平与较差的认知有关。然而，这种关系并不普遍，这种差异被推测是由于神经系统疾病的性质、参与者之间的个体差异或方法论的不一致造成的。需要进一步研究，并为未来调查的设计提出了相关建议。