Preoperative Heart Rate Variability as Predictors of Vagus Nerve Stimulation Outcome in Patients with Drug-resistant Epilepsy

Figures

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  Figure 1. The illustration of the coarse graining procedure for scales 1 to τ.

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  Figure 2. CI derived from MSE profile. The linear-fitted slope (Slope 5) and the area under MSE profile between scale 1 and 5 (Area 1–5) represent the complexity behavior in short scales. Long time scale complexities were quantified by the area under MSE profile between scale 6 and 15 (Area 6–15), and between scale 6 to 20 (Area 6–20).

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  Figure 3. The sample entropy over different time scales. (A) The red square open symbols represented the entropy of patients with DRE before VNS, and the light blue open circles the entropy of healthy control subjects. (B) The dark blue solid squares represented the entropy of Responders0 before VNS, and the green open squares the entropy of Non-responders0 before VNS treatment. Symbols represent the mean values of entropy for each group and bars represent the standard error (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\rm{SE}}=\mathrm{SD}/\sqrt{n}$$\end{document}SE=SD/n, where n is the number of subjects). *p < 0.05, **p < 0.01, and ***p < 0.001 for comparison between the responders0 and non-responders0.

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  Figure 4. Analysis of the discrimination power of the responders0 and non-responders0 by receiver operating characteristic (ROC) curve analysis. The areas under the curve of Area 1–5, Area 6–15 and Area 6–20 were 0.770, 0.875 and 0.891, respectively.

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  Figure 5. Analysis of the discrimination power of the responders50 and non-responders50 by receiver operating characteristic (ROC) curve analysis. The areas under the curve of RMSSD, pNN50, VLF, LF, HF, TP and LF/HF were 0.774, 0.766, 0.675, 0.682, 0.762, 0.729 and 0.662, respectively.