VA San Diego Healthcare System, San Diego, CA, USA.
The Pennsylvania State University, University Park, PA, USA.
J Int Neuropsychol Soc. 2021 Feb;27(2):197-203. doi: 10.1017/S1355617720000727. Epub 2020 Aug 10.
The purpose of this study was to evaluate whether loss of consciousness (LOC), retrograde amnesia (RA), and anterograde amnesia (AA) independently influence a particular aspect of post-concussion cognitive functioning-across-test intra-individual variability (IIV), or cognitive dispersion.
Concussed athletes (N = 111) were evaluated, on average, 6.04 days post-injury (SD = 5.90; Mdn = 4 days; Range = 1-26 days) via clinical interview and neuropsychological assessment. Primary outcomes of interest included two measures of IIV-an intra-individual standard deviation (ISD) score and a maximum discrepancy (MD) score-computed from 18 norm-referenced variables.
Analyses of covariance (ANCOVAs) adjusting for time since injury and sex revealed a significant effect of LOC on the ISD (p = .018, ηp2 = .051) and MD (p = .034, ηp2 = .041) scores, such that athletes with LOC displayed significantly greater IIV than athletes without LOC. In contrast, measures of IIV did not significantly differ between athletes who did and did not experience RA or AA (all p > .05).
LOC, but not RA or AA, was associated with greater variability, or inconsistencies, in cognitive performance acutely following concussion. Though future studies are needed to verify the clinical significance of these findings, our results suggest that LOC may contribute to post-concussion cognitive dysfunction and may be a risk factor for less efficient cognitive functioning.
本研究旨在评估意识丧失（LOC）、逆行性遗忘（RA）和顺行性遗忘（AA）是否独立影响脑震荡后认知功能的特定方面——跨测试个体内变异性（IIV）或认知分散。
平均在损伤后 6.04 天（SD=5.90；Mdn=4 天；范围=1-26 天）对脑震荡运动员（N=111）进行评估，通过临床访谈和神经心理学评估进行评估。主要观察指标包括两个 IIV 指标的个体内标准差（ISD）评分和最大差异（MD）评分，均由 18 个参照标准变量计算得出。
对损伤后时间和性别进行协方差分析（ANCOVAs），结果显示 LOC 对 ISD（p=0.018，ηp2=0.051）和 MD（p=0.034，ηp2=0.041）评分有显著影响，即有 LOC 的运动员的 IIV 明显大于没有 LOC 的运动员。相比之下，经历 RA 或 AA 的运动员之间的 IIV 测量值没有显著差异（均 p>0.05）。
LOC 与脑震荡后认知表现的变异性或不一致性显著相关，但 RA 或 AA 则没有。虽然需要进一步的研究来验证这些发现的临床意义，但我们的结果表明，LOC 可能导致脑震荡后认知功能障碍，并可能是认知功能效率较低的危险因素。
