Background

Reaction time (RT) deficits are reported following concussion, but it is unknown when these deficits normalize to pre-injury status. It is also unclear how factors such as RT measurement technique and participant characteristics influence post-concussion RT.

Objective

The purpose of this systematic review and meta-analysis was to (1) characterize acute post-concussion (0–3 days) RT impairments, (2) examine RT recovery over time, and (3) explore moderating factors related to acute RT impairment following concussion.

Methods

Database searches (PubMed, CINAHL, EBSCOhost) were conducted according to PRISMA guidelines for articles published in English from January 2002 to March 2019. Studies compared baseline-to-post-injury RT within individuals (within-subject) and/or RT in concussed individuals to non-concussed controls (between-subject). Sixty studies met inclusion criteria, reporting on a total of 9688 participants with 214 discrete RT effects (Hedges’ d; between-subject: N = 29, k = 129; within-subject: N = 42, k = 85). Of the 214 effects, 93 occurred in the acute (0–3 days) post-injury timeframe (k = 47 between-subject). Numerous demographic [sex, age, concussion history, population type (athlete, military, and general population), athlete level (high school, college), and sport], and method-based (RT test and measure type, computerized neurocognitive testing platform, concussion definition, and time post-injury) moderators were examined for mean effect influence. Mixed-effects multi-level modeling with restricted-maximum-likelihood estimation was used to account for nested effects and high heterogeneity for the pooled effect size (D+).

Results

Significant medium-magnitude RT deficits were observed acutely for between- (D+ = − 0.7279, 95% CI − 0.9919, − 0.4639, I² = 88.66, p < 0.0001) and within-subject (D+ = − 0.7472, 95% CI − 0.9089, − 0.5855, I² = 89.21, p < 0.0001) effect models. RT deficits were present at the sub-acute and intermediate-term timeframes for between-subject effects (sub-acute: D+ = − 0.5655, 95% CI − 0.6958, − 0.4352, p < 0.0001; intermediate-term: D+ = − 0.3219, 95% CI − 0.5988, − 0.0450, p = 0.0245). No significant RT mean effect was observed for the between-subject model at the long-term timeframe, indicating RT recovery among concussed participants relative to controls (D+ = 0.3505, 95% CI − 0.4787, 1.1797, p = 0.3639). Sex was a significant moderator for between-subject effects, with every 1% male sample size increase demonstrating − 0.0171 (95% CI − 0.0312, − 0.0029, p = 0.0193) larger RT deficits. Within-subject effect models resulted in RT measure type (simple: [D+ = − 0.9826] vs. mixed: [D+ = − 0.6557], p = 0.0438) and computerized neurocognitive testing platforms (ANAM: [D+ = − 0.3735] vs. HeadMinder CRI: [D+ = − 1.4799] vs. ImPACT: [D+ = − 0.6749], p = 0.0004) having significantly different RT-deficit magnitudes. No other moderators produced significantly different RT-deficit magnitudes (between-subject: [p ≥ 0.0763], within-subject: [p ≥ 0.1723]).

Conclusions

Robust RT deficits were observed acutely following concussion. Minimal magnitude differences were noted when comparing between- and within-subject effects, suggesting that pre-injury baselines may not add clinical value in determining post-injury RT impairment. RT deficits persisted up till the intermediate-term (21–59 days post-injury) timeframe and indicate lingering deficits exist. Mean effect size differences were observed between RT measure types and computerized neurocognitive testing platforms; however, all categories displayed negative effects consistent with impaired RT following concussion. Clinical interpretation suggests that measuring RT post-concussion is more important than considering the RT method employed so long as reliable and valid tools are used. PROSPERO Registration #CRD42019119323.

中文翻译：

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脑震荡后反应时间不足的检查：系统评价和荟萃分析。

背景

脑震荡后有反应时间（RT）不足的报道，但尚不清楚这些不足何时恢复为损伤前状态。还不清楚诸如RT测量技术和参与者特征之类的因素如何影响脑震荡后的RT。

目的

该系统评价和荟萃分析的目的是（1）描述急性脑震荡（0–3天）后RT损伤的特征，（2）检查一段时间内的RT恢复，以及（3）探索与急性RT损伤相关的调节因素脑震荡之后。

方法

数据库检索（PubMed，CINAHL，EBSCOhost）是根据PRISMA指南从2002年1月至2019年3月以英文发表的文章进行的。研究比较了个体（受试者）内基线至损伤后RT和/或脑震荡患者的RT个体与非脑震荡对照者（受试者之间）。六十研究符合纳入标准，在一个总的9688名参与者214个离散RT效果报告（树篱d受试者之间-：Ñ  = 29，ķ  = 129;受试者内：Ñ  = 42，ķ  = 85）。在214种影响中，有93种发生在损伤后的急性（0–3天）期间（k = 47个主题间）。众多的人口统计信息[性别，年龄，脑震荡历史，人口类型（运动员，军事和一般人口），运动员水平（高中，大学）和运动]，以及基于方法的（RT测试和测量类型，计算机化的神经认知测试平台） ，脑震荡定义和受伤后的时间）主持人检查了平均影响。具有受限最大似然估计的混合效应多层次建模用于说明嵌套效应和合并效应大小（D +）的高度异质性。

结果

敏锐地观察between-显著中等大小RT缺陷（d + = - 0.7279，95％CI - 0.9919， - 0.4639，我²  = 88.66，p  <0.0001）和个体内（d + = - 0.7472，95％ CI − 0.9089，− 0.5855，I ²  = 89.21，p  <0.0001）效应模型。在受试者之间的亚急性和中期时间范围内存在RT缺陷（亚急性：D + = − 0.5655，95％CI − 0.6958，− 0.4352，p  <0.0001;中期：D + = − 0.3219，95％CI − 0.5988，− 0.0450，p = 0.0245）。在长期时间框架内，受试者间模型未观察到显着的RT均值效应，表明脑震荡参与者相对于对照者的RT恢复（D + = 0.3505，95％CI-0.4787，1.1797，p  = 0.3639）。性别是受试者之间影响的重要调节剂，男性样本量每增加1％，表明-RT缺陷增加-0.0171（95％CI-0.0312，-0.0029，p  = 0.0193）。受试者内部效应模型产生了RT测量类型（简单：[ D + = − 0.9826]，而混合测量：[ D + = − 0.6557]，p  = 0.0438）和计算机化的神经认知测试平台（ANAM：[ D + = − 0.3735] ]与HeadMinder CRI：[ D+ = − 1.4799]与ImPACT：[ D + = − 0.6749]，p  = 0.0004）具有显着不同的RT缺陷幅度。没有其他管理员产生显著不同RT-赤字大小（对象之间-：[ p  ≥0.0763]，受试者内：[ p  ≥0.1723]）。

结论

脑震荡后急性观察到健壮的逆转录缺乏症。比较受试者之间和受试者内部的影响时，观察到最小的幅度差异，表明损伤前基线可能不会增加确定损伤后RT损伤的临床价值。RT缺陷持续到中期（损伤后21-59天），表明存在持续存在的缺陷。在RT测量类型和计算机化的神经认知测试平台之间观察到平均效应大小差异；但是，所有类别均显示出与脑震荡后RT受损相一致的负面影响。临床解释表明，只要使用可靠且有效的工具，在脑震荡后测量RT比考虑使用RT方法更为重要。PROSPERO注册号CRD42019119323。