Background: Voxel-wise lesion-symptom mapping (VLSM) is a statistical technique to infer the structure-function relationship in patients with cerebral strokes. Previous VLSM research suggests that it is important to adjust for various confounders such as lesion size to minimize the inflation of true effects. The aim of this work is to investigate the regional impact of covariates on true effects in VLSM. Methods: A total of 222 follow-up datasets of acute ischemic stroke patients with known NIH Stroke Scale (NIHSS) score at 48-h post-stroke were available for this study. Patient age, lesion volume, and follow-up imaging time were tested for multicollinearity using variance inflation factor analysis and used as covariates in VLSM analyses. Covariate importance maps were computed from the VLSM results by standardizing the beta coefficients of general linear models. Results: Covariates were found to have distinct regional importance with respect to lesion eloquence in the brain. Age has a relatively higher importance in the superior temporal gyrus, inferior parietal lobule, and in the pre- and post-central gyri. Volume explains more variability in the opercular area of the insula, inferior frontal gyrus, and caudate. Follow-up imaging time accounts for most of the variance in the globus pallidus, ventromedial- and dorsolateral putamen, dorsal caudate, pre-motor thalamus, and the dorsal insula. Conclusions: This is the first study investigating and revealing distinctive regional patterns of importance for covariates typically used in VLSM. These covariate importance maps can improve our understanding of the lesion-deficit relationships in patients and could prove valuable for patient-specific treatment and rehabilitation planning.

中文翻译：

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协变量在体素明智病变症状映射中的影响。

背景：体素化病变症状图谱（VLSM）是一种统计技术，可推断脑卒中患者的结构与功能的关系。VLSM的先前研究表明，重要的是要调整各种混杂因素，例如病变大小，以最大程度地减少真实效果的影响。这项工作的目的是调查VLSM中协变量对真实效果的区域影响。方法：本研究共有222例在卒中后48小时具有NIH卒中量表（NIHSS）评分的急性缺血性卒中患者的随访数据。使用方差膨胀因子分析测试了患者年龄，病变体积和随访成像时间的多重共线性，并将其用作VLSM分析的协变量。通过标准化通用线性模型的β系数，从VLSM结果中计算出协变量重要性图。结果：发现协变量在脑部病变口才方面具有明显的区域重要性。年龄在颞上回，顶下小叶以及中央前和中央后回中具有相对较高的重要性。体积解释了岛状，下额回和尾状的手术区域的更多变异性。随访成像时间占苍白球，腹侧和背外侧壳，背尾状核，运动前丘脑和背岛的大部分差异。结论：这是第一项研究，揭示并揭示了对于VLSM通常使用的协变量具有重要意义的独特区域模式。