Department of Psychology, Programs in Cognitive and Brain Sciences, and Integrative Neuroscience, University of Nevada, 1664 N. Virginia St., MS 296, Reno, NV, 89557, USA.
Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02215, USA.
Sci Rep. 2021 Feb 2;11(1):2789. doi: 10.1038/s41598-021-80995-1.
Mild traumatic brain injury (mTBI), or concussion, accounts for 85% of all TBIs. Yet survivors anticipate full cognitive recovery within several months of injury, if not sooner, dependent upon the specific outcome/measure. Recovery is variable and deficits in executive function, e.g., working memory (WM) can persist years post-mTBI. We tested whether cognitive deficits persist in otherwise healthy undergraduates, as a conservative indicator for mTBI survivors at large. We collected WM performance (change detection, n-back tasks) using various stimuli (shapes, locations, letters; aurally presented numbers and letters), and wide-ranging cognitive assessments (e.g., RBANS). We replicated the observation of a general visual WM deficit, with preserved auditory WM. Surprisingly, visual WM deficits were equivalent in participants with a history of mTBI (mean 4.3 years post-injury) and in undergraduates with recent sports-related mTBI (mean 17 days post-injury). In seeking the underlying mechanism of these behavioral deficits, we collected resting state fMRI (rsfMRI) and EEG (rsEEG). RsfMRI revealed significantly reduced connectivity within WM-relevant networks (default mode, central executive, dorsal attention, salience), whereas rsEEG identified no differences (modularity, global efficiency, local efficiency). In summary, otherwise healthy current undergraduates with a history of mTBI present behavioral deficits with evidence of persistent disconnection long after full recovery is expected.
轻度创伤性脑损伤（mTBI）或脑震荡占所有 TBI 的 85%。然而，幸存者预计在受伤后几个月内（如果不是更早的话），根据特定的结果/措施，就能完全恢复认知能力。恢复情况因人而异，执行功能（例如工作记忆（WM））缺陷可能会在 mTBI 后持续多年。我们测试了在其他方面健康的本科生中是否存在认知缺陷，作为广义 mTBI 幸存者的保守指标。我们使用各种刺激（形状、位置、字母；听觉呈现的数字和字母）收集 WM 表现（变化检测、n 回任务），并进行广泛的认知评估（例如 RBANS）。我们复制了普遍存在的视觉 WM 缺陷的观察结果，听觉 WM 保留完好。令人惊讶的是，有 mTBI 病史的参与者（受伤后平均 4.3 年）和最近因运动相关 mTBI 的本科生（受伤后平均 17 天）的视觉 WM 缺陷相当。在寻求这些行为缺陷的潜在机制时，我们收集了静息状态 fMRI（rsfMRI）和 EEG（rsEEG）。rsfMRI 显示与 WM 相关的网络（默认模式、中央执行、背侧注意、突显）内的连接显著减少，而 rsEEG 没有发现差异（模块性、全局效率、局部效率）。总之，有 mTBI 病史的其他方面健康的当前本科生表现出行为缺陷，并且在完全恢复后很长一段时间内都存在持续的连接中断的证据。
