ABSTRACT

Introduction: The neurocognitive outcomes of sustaining a mild traumatic brain injury (mTBI) during late adulthood are vastly understudied. In young, asymptomatic adults, mTBI-related synaptic plasticity alterations have been associated with persistent implicit motor sequence learning impairments outlasting the usual cognitive recovery period. The current study examined whether uncomplicated mTBI sustained during late adulthood could exert persistent deleterious consequences on implicit motor sequence learning.

Method: Thirty participants (aged 50–70 years) who experienced an uncomplicated mTBI within 3 to 24 months of testing, and 40 age-, sex- and education-equivalent healthy controls performed an implicit serial reaction time task (SRT task). The SRT task consisted of 10 blocks of a repeating sequence embedded among 4 random blocks. Participants also completed a battery of standardized neuropsychological tests of attention, memory and executive functioning.

Results: While both mTBI participants and controls showed significant implicit motor sequence learning effects, the mTBI group achieved a lower level of competence at performing the SRT task as evidenced by smaller gains in reaction times across the 10 training blocks of the repeating sequence. The time elapsed since the injury was unrelated to implicit motor learning effects. There was no evidence of a persistent effect of mTBI on any neuropsychological domain compared to controls.

Conclusions: Findings from this study suggest that a single mTBI sustained during older age may have persistent repercussions on training-dependent motor sequence learning capacity outlasting the recovery of mTBI symptoms and gold-standard neuropsychological tests performance.

摘要

简介：在成年后期持续轻度脑外伤（mTBI）的神经认知结果被大大研究。在年轻，无症状的成年人中，mTBI相关的突触可塑性改变与持续的认知恢复期持续存在的隐式运动序列学习障碍有关。目前的研究检查了成年后期持续的单纯性mTBI是否会对隐式运动序列学习产生持续的有害影响。

方法：30名参与者（年龄在50-70岁之间）在3到24个月的测试中经历了简单的mTBI，并且有40名年龄，性别和受教育程度相当的健康对照者执行了隐式的连续反应时间任务（SRT任务）。SRT任务由嵌入4个随机块中的10个重复序列块组成。参与者还完成了一系列有关注意力，记忆力和执行功能的标准化神经心理学测试。

结果：尽管mTBI参与者和对照组均表现出显着的内隐运动序列学习效果，但mTBI组在执行SRT任务时却表现出较低的能力水平，这是由重复序列的10个训练块中的反应时间增加所证明的。自受伤以来经过的时间与内隐的运动学习效果无关。与对照相比，没有证据显示mTBI对任何神经心理学领域都具有持续作用。

结论：这项研究的结果表明，在老年人中持续存在的单个mTBI可能会对训练相关的运动序列学习能力产生持续影响，从而使mTBI症状的恢复和金标准的神经心理测试表现持久。