Department of Psychology, University of Houston, Houston, TX, USA.
Department of Internal Medicine, University of Texas Health Science Center in Houston, School of Medicine, Houston, TX, USA.
J Neurovirol. 2018 Aug;24(4):506-513. doi: 10.1007/s13365-018-0641-5. Epub 2018 Apr 25.
West Nile Virus (WNV) can be a neuroinvasive pathogen that may produce persistent mild-to-moderate neurocognitive impairments in some infected persons. Intra-individual variability (IIV) is an index of a person's performance across a neuropsychological test or battery, which is an indicator of neurocognitive control and integrity of prefrontal systems. The present study examined possible associations of IIV to neurological health and well-being in WNV infection. Participants included 84 adults with a range of clinical WNV disease (31 West Nile Encephalitis, 16 West Nile Meningitis, 37 West Nile Fever) who completed the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). IIV was operationalized as covariance of variation (CoV), or the intra-individual standard deviation across 5 age-adjusted RBANS standard scores divided by the mean of standard scores. Participants were assessed for health-related quality of life (QoL) using the RAND 36-item short form health survey (SF-36). Analyses revealed that the West Nile Encephalitis group had higher neurocognitive CoV compared to the West Nile Fever group, and this difference was associated with a medium effect size (Cohen's d = .52). Mixed linear models controlling for estimated IQ, activities of daily living, depression, neuroinvasive disease groups, and fatigue showed that higher RBANS CoV was associated with lower physical, but not mental health QoL. In persons with WNV infection, there is a modest association between elevations in IIV and encephalitis, and even subtle disruptions in neuropsychological functioning show relationships with important self-reported functioning as measured by physical health quality of life. Future studies should examine whether IIV predicts long-term health outcomes (e.g., mortality) in individuals infected with WNV.
西尼罗河病毒（WNV）是一种神经侵袭性病原体，可能导致一些感染者持续出现轻度至中度的神经认知障碍。个体内变异性（IIV）是一个人在神经心理学测试或成套测试中表现的指标，它是神经认知控制和前额叶系统完整性的指标。本研究探讨了 IIV 与 WNV 感染的神经健康和幸福感之间的可能关联。参与者包括 84 名成年人，他们患有不同程度的临床 WNV 疾病（31 例西尼罗河脑炎、16 例西尼罗河脑膜炎、37 例西尼罗河发热），完成了重复评估神经心理状态测试（RBANS）。IIV 被操作化为协方差变异（CoV），即 5 个年龄调整后的 RBANS 标准分数的个体内标准差除以标准分数的平均值。参与者使用 RAND 36 项简短健康调查问卷（SF-36）评估健康相关生活质量（QoL）。分析显示，西尼罗河脑炎组的神经认知 CoV 高于西尼罗河发热组，差异具有中等效应大小（Cohen's d=0.52）。控制估计智商、日常生活活动、抑郁、神经侵袭性疾病组和疲劳的混合线性模型显示，较高的 RBANS CoV 与较低的身体健康，但不是心理健康 QoL 相关。在 WNV 感染的人中，IIV 的升高与脑炎之间存在适度关联，甚至神经心理学功能的细微障碍也与身体健康质量所测量的重要自我报告功能相关。未来的研究应探讨 IIV 是否可以预测感染 WNV 的个体的长期健康结果（例如死亡率）。
