Reproducibility of interictal spike propagation in children with refractory epilepsy

Samuel B. Tomlinson, Jeremy N. Wong, Erin C. Conrad, Benjamin C. Kennedy, Eric D. Marsh*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

9 Scopus citations


Objective: Interictal spikes are a characteristic feature of invasive electroencephalography (EEG) recordings in children with refractory epilepsy. Spikes frequently co-occur across multiple brain regions with discernable latencies, suggesting that spikes can propagate through distributed neural networks. The purpose of this study was to examine the long-term reproducibility of spike propagation patterns over hours to days of interictal recording. Methods: Twelve children (mean age 13.1 years) were retrospectively studied. A mean ± standard deviation (SD) of 47.2 ± 40.1 hours of interictal EEG recordings were examined per patient (range 17.5-166.5 hours). Interictal recordings were divided into 30-minute segments. Networks were extracted based on the frequency of spike coactivation between pairs of electrodes. For each 30-minute segment, electrodes were assigned a “Degree Preference (DP)” based on the tendency to appear upstream or downstream within propagation sequences. The consistency of DPs across segments (“DP-Stability”) was quantified using the Spearman rank correlation. Results: Regions exhibited highly stable preferences to appear upstream, intermediate, or downstream in spike propagation sequences. Across networks, the mean ± SD DP-Stability was 0.88 ± 0.07, indicating that propagation patterns observed in 30-minute segments were representative of the patterns observed in the full interictal window. At the group level, regions involved in seizure generation appeared more upstream in spike propagation sequences. Significance: Interictal spike propagation is a highly reproducible output of epileptic networks. These findings shed new light on the spatiotemporal dynamics that may constrain the network mechanisms of refractory epilepsy.

Original languageEnglish (US)
Pages (from-to)898-910
Number of pages13
Issue number5
StatePublished - May 2019


  • epilepsy surgery
  • interictal spike
  • invasive EEG
  • network
  • propagation

ASJC Scopus subject areas

  • Clinical Neurology
  • Neurology


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