Title
An optimal strategy for epilepsy surgery: Disruption of the rich-club?
Abstract
Surgery is a therapeutic option for people with epilepsy whose seizures are not controlled by anti-epilepsy drugs. In pre-surgical planning, an array of data modalities, often including intra-cranial EEG, is used in an attempt to map regions of the brain thought to be crucial for the generation of seizures. These regions are then resected with the hope that the individual is rendered seizure free as a consequence. However, post-operative seizure freedom is currently sub-optimal, suggesting that the pre-surgical assessment may be improved by taking advantage of a mechanistic understanding of seizure generation in large brain networks. Herein we use mathematical models to uncover the relative contribution of regions of the brain to seizure generation and consequently which brain regions should be considered for resection. A critical advantage of this modeling approach is that the effect of different surgical strategies can be predicted and quantitatively compared in advance of surgery. Herein we seek to understand seizure generation in networks with different topologies and study how the removal of different nodes in these networks reduces the occurrence of seizures. Since this a computationally demanding problem, a first step for this aim is to facilitate tractability of this approach for large networks. To do this, we demonstrate that predictions arising from a neural mass model are preserved in a lower dimensional, canonical model that is quicker to simulate. We then use this simpler model to study the emergence of seizures in artificial networks with different topologies, and calculate which nodes should be removed to render the network seizure free. We find that for scale-free and rich-club networks there exist specific nodes that are critical for seizure generation and should therefore be removed, whereas for small-world networks the strategy should instead focus on removing sufficient brain tissue. We demonstrate the validity of our approach by analysing intra-cranial EEG recordings from a database comprising 16 patients who have undergone epilepsy surgery, revealing rich-club structures within the obtained functional networks. We show that the postsurgical outcome for these patients was better when a greater proportion of the rich club was removed, in agreement with our theoretical predictions.
Year
DOI
Venue
2017
10.1371/journal.pcbi.1005637
PLOS COMPUTATIONAL BIOLOGY
Field
DocType
Volume
Epilepsy surgery,Neuroscience,Biology,Scale-free network,Epilepsy,Network topology,Canonical model,Artificial intelligence,Bioinformatics,Network analysis,Artificial neural network,Electroencephalography
Journal
13
Issue
ISSN
Citations 
8
1553-7358
0
PageRank 
References 
Authors
0.34
20
7
Name
Order
Citations
PageRank
Marinho A Lopes100.68
Mark P Richardson21047.85
Eugenio Abela300.34
Christian Rummel401.01
Kaspar Schindler5556.57
Marc Goodfellow6566.87
John R Terry76311.50