Article Figures & Data
Figures
- Figure 1.
Summary of our computational method. We used interictal scalp EEG to infer functional networks. Then, to interrogate the networks, we considered a computational model of ictogenicity to simulate seizure-like activity on the functional networks. This allowed us to assess the propensity of a functional network to generate seizures in silico, the BNI. It further enabled us to measure the NI (i.e., the effect of removing a node on the BNI), which represents the local ictogenic propensity.
- Figure 2.
Violin plot of BNI comparing the PPR and non-PPR groups. The white dot represents the median, the black box represents the interquartile range, and the other dots within the shaded region correspond to the BNI of each individual. The BNI values are not statistically higher in the PPR group than in the non-PPR group (p = 0.89, one-sided Mann–Whitney U test).
- Figure 3.
NI of the occipital lobe nodes in the PPR and non-PPR groups. The NI values in the O2 region are statistically significantly higher in the PPR group than in the non-PPR group. The p-values correspond to one-sided Mann–Whitney U tests corrected with the Bonferroni–Holm procedure.
- Figure 4.
NI of all the network nodes in the PPR and non-PPR groups. This figure excludes the nodes corresponding to the occipital lobe nodes (presented in Fig. 3). p-Values, effect sizes, and confidence intervals are presented in Table 3. All these differences in NI are not statistically significant.
Tables
- Table 1
Demographics and clinical information of the group of individuals that presented PPR on EEG
ID Age (years) Gender Syndrome Medication PPR1 24 M JME Lamotrigine PPR2 16 M GTCSO None PPR3 15 M GTSO Valproate PPR4 13 F JAE None PPR5 15 F JAE Levetiracetam,
lamotriginePPR6 13 F JME None PPR7 16 F JME Lamotrigine PPR8 17 F JME Lamotrigine PPR9 19 F JAE Clobazam PPR10 18 M GTCSO None PPR11 16 F GTCSO Levetiracetam PPR12 17 F JME Levetiracetam PPR13 13 F JME None PPR14 24 F JME Valproate PPR15 19 F GTCSO None PPR16 22 F GTCSO None PPR17 14 F JME None PPR18 31 F JME None PPR19 18 M JME None PPR20 23 F GTCSO Levetiracetam PPR21 19 M GTCSO Valproate PPR22 23 F GTCSO Sertraline PPR23 26 M JME Valproate, zonisamide PPR24 13 F JME None PPR25 14 F GTCSO None PPR26 13 F JAE None M, Male; F, female; GTCSO, generalized tonic-clonic seizures only.
- Table 2
Demographics and clinical information of the group of individuals that did not show a PPR on EEG
ID Age (years) Gender Syndrome Medication Non-PPR1 16 M JME None Non-PPR2 28 F JME Valproate Non-PPR3 30 M JME Valproate Non-PPR4 19 M JME None Non-PPR5 24 F JME Levetiracetam Non-PPR6 18 M JME Epilim Non-PPR7 19 M JME None Non-PPR8 27 F JME Valproate Non-PPR9 20 F JME Lamotrigine Non-PPR10 18 M JME None Non-PPR11 18 F JME None Non-PPR12 22 F JME Duloxetine Non-PPR13 22 F JME Lamotrigine, carbamazepine Non-PPR14 23 M JME None Non-PPR15 21 F JME Topiramate, levetiracetam, clobazam Non-PPR16 30 M GTCSO Carbamazepine Non-PPR17 20 F JME Epilim Non-PPR18 20 F JME None Non-PPR19 20 M JME Valproate Non-PPR20 31 F JME Lamotrigine, Sumatriptan M, Male; F, female; GTCSO, generalized tonic-clonic seizures only.
- Table 3
Assessment of NI differences between the two groups in each node (as presented in Fig. 4)
Node Uncorrected p-value Corrected p-value U statistic z Effect size CI lower limit CI upper limit C3 0.54 1 583 −0.6 −0.016 −0.048 0.025 C4 0.35 1 568 −0.94 −0.026 −0.060 0.011 CZ 0.59 1 586 −0.54 −0.002 −0.057 0.046 F3 0.65 1 590 −0.45 −0.019 −0.068 0.029 F4 0.73 1 595 −0.34 −0.020 −0.072 0.031 F7 0.63 1 633 0.48 0.068 −0.024 0.124 F8 0.56 1 638 0.59 0.038 −0.014 0.073 FP1 0.47 1 578 −0.72 −0.014 −0.064 0.050 FP2 0.94 1 607 −0.08 0.015 −0.027 0.058 FPZ 0.75 1 626 0.32 0.045 −0.072 0.179 FZ 0.79 1 599 −0.25 −0.006 −0.056 0.050 P3 0.29 1 659 1.05 0.067 −0.001 0.121 P4 0.35 1 653 0.92 0.022 −0.045 0.106 PZ 0.29 1 659 1.05 0.024 −0.032 0.096 T3 0.60 1 635 0.52 0.010 −0.046 0.051 T4 0.08 1 689 1.72 0.042 −0.002 0.079 T5 0.85 1 602 −0.19 −0.004 −0.057 0.057 T6 0.26 1 560 −1.12 −0.015 −0.051 0.031 The p-values, U statistics, and z-scores correspond to two-sided Mann–Whitney U tests assessing whether NI is different between the two groups at a given node. The p-values were corrected using the Bonferroni–Holm procedure, and none is significant. The effect size (median difference of NI) and confidence intervals further show that there are no statistical differences between the groups in any of these nodes.
- Table 4
Assessment of relative power and connectivity differences on occipital electrodes between the PPR and non-PPR groups
Measure Node Uncorrected p-value U statistic z-score Effect size CI lower limit CI upper limit Relative low alpha power O1 0.79 575 −0.81 −0.028 −0.095 0.047 O2 0.74 582 −0.65 −0.013 −0.089 0.049 Relative alpha power O1 0.86 562 −1.10 −0.078 −0.13 0.049 O2 0.80 573 −0.85 −0.039 −0.14 0.041 Occipital connectivity O1 0.94 543 −1.52 −0.76 −2.18 0.48 O2 0.76 580 −0.70 −0.34 −2.18 1.17 The relative power was computed following the methods of Vaudano et al. (2017). We considered the following two frequency bands: low alpha power (6–9 Hz) as in the main analysis; and alpha power (7.5–12.5 Hz) as in the study by Vaudano et al. (2017). The occipital connectivity corresponds to the connection strength of the electrodes (i.e., sum of in-strength and out-strength; Rubinov and Sporns, 2010). The p-values, U statistics, and z-scores correspond to one-sided Mann–Whitney U tests assessing whether the relative power (or connectivity strength) is higher in the PPR group relative to the non-PPR group at a given occipital electrode. All p-values are not significant. The effect size (median difference) and confidence intervals further show that there are no statistical differences between the groups when using these measures.
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