Institute of Medical Science, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada.
J Neurol Neurosurg Psychiatry. 2021 Dec;92(12):1259-1270. doi: 10.1136/jnnp-2021-326604. Epub 2021 Oct 11.
Postconcussion syndrome (PCS) is a term attributed to the constellation of symptoms that fail to recover after a concussion. PCS is associated with a variety of symptoms such as headaches, concentration deficits, fatigue, depression and anxiety that have an enormous impact on patients' lives. There is currently no diagnostic biomarker for PCS. There have been attempts at identifying structural and functional brain changes in patients with PCS, using diffusion tensor imaging (DTI) and functional MRI (fMRI), respectively, and relate them to specific PCS symptoms. In this scoping review, we appraised, synthesised and summarised all empirical studies that (1) investigated structural or functional brain changes in PCS using DTI or fMRI, respectively, and (2) assessed behavioural alterations in patients with PCS. We performed a literature search in MEDLINE (Ovid), Embase (Ovid) and PsycINFO (Ovid) for primary research articles published up to February 2020. We identified 8306 articles and included 45 articles that investigated the relationship between DTI and fMRI parameters and behavioural changes in patients with PCS: 20 diffusion, 20 fMRI studies and 5 papers with both modalities. Most frequently studied structures were the corpus callosum, superior longitudinal fasciculus in diffusion and the dorsolateral prefrontal cortex and default mode network in the fMRI literature. Although some white matter and fMRI changes were correlated with cognitive or neuropsychiatric symptoms, there were no consistent, converging findings on the relationship between neuroimaging abnormalities and behavioural changes which could be largely due to the complex and heterogeneous presentation of PCS. Furthermore, the heterogeneity of symptoms in PCS may preclude discovery of one biomarker for all patients. Further research should take advantage of multimodal neuroimaging to better understand the brain-behaviour relationship, with a focus on individual differences rather than on group comparisons.
脑震荡后综合征（PCS）是指脑震荡后未能恢复的一系列症状。PCS 与各种症状相关，如头痛、注意力缺陷、疲劳、抑郁和焦虑，这些症状对患者的生活有巨大影响。目前尚无 PCS 的诊断生物标志物。已经有人尝试使用弥散张量成像（DTI）和功能磁共振成像（fMRI）分别识别 PCS 患者的结构和功能脑变化，并将其与特定的 PCS 症状相关联。在这项范围综述中，我们评估、综合和总结了所有使用 DTI 或 fMRI 分别研究 PCS 结构或功能脑变化，以及评估 PCS 患者行为改变的实证研究。我们在 MEDLINE（Ovid）、Embase（Ovid）和 PsycINFO（Ovid）中进行了文献检索，检索了截至 2020 年 2 月发表的关于使用 DTI 和 fMRI 研究 PCS 患者之间关系的主要研究文章。我们共确定了 8306 篇文章，纳入了 45 篇研究 DTI 和 fMRI 参数与 PCS 患者行为变化之间关系的文章：20 篇弥散研究、20 篇 fMRI 研究和 5 篇同时具有两种模态的研究。最常研究的结构是胼胝体、弥散中的上纵束和 fMRI 文献中的背外侧前额叶皮质和默认模式网络。虽然一些白质和 fMRI 变化与认知或神经精神症状相关，但神经影像学异常与行为变化之间的关系没有一致、一致的发现，这主要是由于 PCS 的复杂和异质性表现。此外，PCS 中的症状异质性可能排除了为所有患者发现一种生物标志物的可能性。进一步的研究应该利用多模态神经影像学来更好地理解大脑-行为关系，重点关注个体差异，而不是组间比较。
