School of Psychology, University of Adelaide, Adelaide, Australia.
School of Psychology, University of Adelaide, Adelaide, Australia.
Neurosci Biobehav Rev. 2018 Sep;92:93-103. doi: 10.1016/j.neubiorev.2018.05.023. Epub 2018 May 24.
Cognitive impairments are common following a traumatic brain injury (TBI) and frequently result from white matter (WM) damage. This damage can be quantified using diffusion tensor imaging (DTI), which measures the directionality (fractional anisotropy: FA) and amount (mean diffusivity/apparent diffusion coefficient: MD/ADC) of water diffusion in WM, with high FA and low MD/ADC thought to indicate greater WM integrity. However, the relationship between DTI and cognitive outcomes is currently unclear. The data from 20 studies that examined the relationship between WM integrity (measured using DTI) and cognition (categorised into seven domains) following mild-severe adult TBI were meta-analysed. Overall, high FA and low MD/ADC in most brain regions was associated with better cognitive performance, with memory and attention most strongly related to DTI findings. Specifically, memory and/or attention were very strongly related to DTI findings in the corpus callosum, fornix, internal capsule, arcuate and uncinate fasciculi. However, most findings were based on single studies and therefore await replication. Larger-scale, longitudinal studies are now needed to determine the predictive utility of DTI.
认知障碍在脑外伤（TBI）后很常见，通常是由于白质（WM）损伤引起的。这种损伤可以使用弥散张量成像（DTI）进行量化，它测量 WM 中水分子扩散的方向（各向异性分数：FA）和数量（平均扩散系数/表观扩散系数：MD/ADC），高 FA 和低 MD/ADC 被认为表明 WM 完整性更高。然而，DTI 与认知结果之间的关系目前尚不清楚。对 20 项研究的数据进行了荟萃分析，这些研究检查了轻度至重度成人 TBI 后 WM 完整性（通过 DTI 测量）与认知（分为七个领域）之间的关系。总的来说，大多数脑区的高 FA 和低 MD/ADC 与更好的认知表现相关，记忆和注意力与 DTI 发现的相关性最强。具体来说，记忆和/或注意力与胼胝体、穹窿、内囊、弓状束和钩束的 DTI 发现密切相关。然而，大多数发现都基于单个研究，因此需要进行复制。现在需要更大规模的纵向研究来确定 DTI 的预测效用。
