  Purpose: Research into epileptic networks has recently allowed deeper
insights into the epileptic process. Here we investigated the importance of
individual network nodes for seizure dynamics.
  Methods: We analysed intracranial electroencephalographic recordings of 86
focal seizures with different anatomical onset locations. With time-resolved
correlation analyses, we derived a sequence of weighted epileptic networks
spanning the pre-ictal, ictal, and post-ictal period, and each recording site
represents a network node. We assessed node importance with commonly used
centrality indices that take into account different network properties.
  Results: A high variability of temporal evolution of node importance was
observed, both intra- and interindividually. Nevertheless, nodes near and far
off the seizure onset zone (SOZ) were rated as most important for seizure
dynamics more often (65% of cases) than nodes from within the SOZ (35% of
cases).
  Conclusion: Our findings underline the high relevance of brain outside of the
SOZ but within the large-scale epileptic network for seizure dynamics.
Knowledge about these network constituents may elucidate targets for
individualised therapeutic interventions that aim at preventing seizure
generation and spread.
