Despite indications that TBI may be a precursor of cognitive decline and subsequent development of Alzheimer’s disease, little is known about the time course of this relationship and the factors involved. This systematic review summarizes the evidence pertinent to this subject matter.

All English language studies of longitudinal design, and works cited within them, found in six literature databases, were considered, and their quality assessed.

Of 65 articles appraised, 44 studies were selected. Results were organized by timing of assessments, injury severity, and cognitive domains assessed. Differences in the course of cognitive performance were observed across injury severity groups and cognitive domains, with differential proportions of reports of improvement, decline, or no change over time. The evidence for genetic, sex-, age-, and injury-related factors as determinants of cognitive outcome was inconsistent.

The non-uniform trajectory of cognitive performance post-TBI supports the notion that this construct is non-homogeneous, and that different factors influence its course. Agreement on a core set of predictors and consideration of psychometric properties of outcome measures is needed.

尽管有迹象表明TBI可能是认知能力下降和阿尔茨海默氏病随后发展的先兆，但对这种关系的时程以及所涉及的因素知之甚少。这篇系统的综述总结了与该主题有关的证据。

我们考虑了在六个文献数据库中发现的所有关于纵向设计的英语研究及其中引用的作品，并对其质量进行了评估。

在评估的65篇文章中，选择了44项研究。通过评估的时间安排，损伤的严重程度和评估的认知范围来组织结果。在损伤严重程度组和认知域之间观察到认知表现过程的差异，随着时间的推移，改善，下降或无变化的报告比例不同。遗传，性别，年龄和伤害相关因素作为认知结果决定因素的证据不一致。

TBI后认知表现的不均匀轨迹支持以下观点：这种结构是不均匀的，并且不同的因素会影响其过程。需要就一套核心的预测指标达成共识，并考虑结果测量的心理计量学特性。