ABSTRACT

Background: Repeat sports-related concussive/subconcussive injury (RC/SCI) is related to memory impairment.

Objective & Methods: We sought to determine memory differences between persons with RC/SCI, moderate-to-severe single-impact traumatic brain injury (SI-TBI), and healthy controls. MRI scans from a subsample of participants with SI-TBI were used to identify the neuroanatomical correlates of observed memory process differences between the brain injury groups.

Results: Both brain injury groups evidenced worse learning and recall in contrast to controls, although SI-TBI group had poorer memory than the RC/SCI group. Regarding memory process differences, in contrast to controls, the SI-TBI group evidenced difficulties with encoding, consolidation, and retrieval, while the RC/SCI group showed deficits in consolidation and retrieval. Delayed recall was predicted by encoding, with consolidation as a secondary predictor in the SI-TBI group. In the RC/SCI group, delayed recall was only predicted by consolidation. MRI data showed that the consolidation index we used mapped onto hippocampal atrophy.

Conclusions: RC/SCI is primarily associated with consolidation deficits, which differs from SI-TBI. Given the role of the hippocampus in memory consolidation and the fact that hyperphosphorylated tau tends to accumulate in the medial temporal lobe in RC/SCI, consolidation deficits may be a cognitive marker of chronic traumatic encephalopathy in athletes.

摘要

背景：重复运动相关的脑震荡/亚脑震荡损伤（RC/SCI）与记忆障碍有关。

目的和方法：我们试图确定 RC/SCI 患者、中度至重度单次冲击性脑外伤 (SI-TBI) 患者和健康对照组之间的记忆差异。来自 SI-TBI 参与者子样本的 MRI 扫描用于识别脑损伤组之间观察到的记忆过程差异的神经解剖学相关性。

结果：与对照组相比，两个脑损伤组的学习和回忆能力都较差，尽管 SI-TBI 组的记忆力比 RC/SCI 组差。关于记忆过程的差异，与对照组相比，SI-TBI 组在编码、巩固和检索方面存在困难，而 RC/SCI 组在巩固和检索方面存在缺陷。延迟回忆通过编码预测，合并作为 SI-TBI 组的次要预测因子。在 RC/SCI 组中，延迟回忆只能通过巩固来预测。MRI 数据显示，我们使用的巩固指数映射到海马萎缩。

结论：RC/SCI 主要与整合缺陷有关，这与 SI-TBI 不同。鉴于海马在记忆巩固中的作用以及过度磷酸化的 tau 倾向于在 RC/SCI 中颞叶内侧积聚这一事实，巩固缺陷可能是运动员慢性创伤性脑病的认知标志物。