Department of Neurorehabilitation, Hospital of Vipiteno (SABES-ASDAA) - Lehrkrankenhaus der Paracelsus Medizinischen Privatuniversität, Margarethenstr. 24, 39049, Vipiteno-Sterzing, BZ, Italy.
Laboratory of Observational, Diagnosis and Education (ODFLab), Department of Psychology and Cognitive Science, University of Trento, 38068, Rovereto, Italy.
Sci Rep. 2022 Jul 30;12(1):13123. doi: 10.1038/s41598-022-17463-x.
Fatigue, attentional deficits and cognitive fluctuations are the most characterizing symptoms of neurological involvement in Post COVID-19 syndrome (PCS). As the intraindividual variability (IIV) in cognitive performances has been recognized as a hallmark of brain-related disorders associated with cognitive deficits, it could be an interesting measure to elucidate the mechanisms subtending both the attentive impairment and the cognitive fluctuations in these patients. By referring to IIV analysis of Reaction Times (RTs), the present study aims to define the attentive impairment and its relation to fluctuations and fatigue, in patients suffering from Post COVID-19 neurological symptoms. 74 patients were enrolled. They underwent an extensive clinical and neuropsychological assessments, as well as computerized Sustained Attention and Stroop tasks. For studying IIV, RTs distributions of performances in computerized tasks were fitted with ex-Gaussian distribution, for obtaining the τ values. Finally, the Resting Motor Threshold (RMT) was also collected to estimate cortical excitability. 29 healthy volunteers served as controls. Patients showed poorer scores in Montreal Cognitive Assessment and higher RMT, in comparison with controls. In Sustained Attention Task, Mean, µ, σ and τ values were significantly higher in PCS patients (p value = < 0.0001; 0.001; 0.018 and < 0.0001, respectively). Repeated measures ANOVA comparing the RTs mean in Stroop task within-subject and between-subjects revealed significant condition and group effect (p < 0.0001 both) and significant interaction (p = 0.005), indicating worst performances in patients. The mean of the derived interference value was significantly higher in PCS patients than in controls (p = 0.036). Patients suffering from PCS show deficits in attention, both in the sustained and executive components. Both high RTs means and high IIV subtend these deficits and could explain the often-complained cognitive fluctuations in this population.
疲劳、注意力缺陷和认知波动是新冠后综合征（PCS）神经受累的最具特征性症状。由于认知表现的个体内变异性（IIV）已被认为是与认知缺陷相关的脑相关疾病的标志，因此它可能是一种有趣的测量方法，可以阐明这些患者注意力损伤和认知波动的机制。通过参考反应时（RT）的 IIV 分析，本研究旨在定义患有新冠后神经症状的患者的注意力损伤及其与波动和疲劳的关系。共纳入 74 名患者。他们接受了广泛的临床和神经心理学评估，以及计算机持续注意力和斯特鲁普任务。为了研究 IIV，对计算机任务中的 RTs 分布进行了拟合，以获得τ值。最后，还收集了静息运动阈值（RMT）以估计皮质兴奋性。29 名健康志愿者作为对照组。与对照组相比，患者在蒙特利尔认知评估中得分较低，RMT 较高。在持续注意力任务中，PCS 患者的 Mean、µ、σ和τ值均显著升高（p 值 < 0.0001；0.001；0.018 和 < 0.0001，分别）。重复测量方差分析比较了 Stroop 任务中 RTs 均值的个体内和个体间差异，结果显示条件和组间均有显著差异（p < 0.0001），且交互作用显著（p = 0.005），表明患者的表现更差。PCS 患者的干扰值平均值明显高于对照组（p = 0.036）。患有 PCS 的患者在注意力方面存在缺陷，包括持续性和执行性成分。高 RTs 均值和高 IIV 都构成了这些缺陷，并可以解释该人群中经常出现的认知波动。
