Long-term effects of temporal lobe epilepsy on local neural networks: a graph theoretical analysis of corticography recordings.

PURPOSE: Pharmaco-resistant temporal lobe epilepsy (TLE) is often treated with surgical intervention at some point. As epilepsy surgery is considered a last resort by most physicians, a long history of epileptic seizures prior to surgery is not uncommon. Little is known about the effects of ongoing...

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Main Authors: Edwin van Dellen, Linda Douw, Johannes C Baayen, Jan J Heimans, Sophie C Ponten, W Peter Vandertop, Demetrios N Velis, Cornelis J Stam, Jaap C Reijneveld
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2009-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC2778557?pdf=render
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author Edwin van Dellen
Linda Douw
Johannes C Baayen
Jan J Heimans
Sophie C Ponten
W Peter Vandertop
Demetrios N Velis
Cornelis J Stam
Jaap C Reijneveld
author_facet Edwin van Dellen
Linda Douw
Johannes C Baayen
Jan J Heimans
Sophie C Ponten
W Peter Vandertop
Demetrios N Velis
Cornelis J Stam
Jaap C Reijneveld
author_sort Edwin van Dellen
collection DOAJ
description PURPOSE: Pharmaco-resistant temporal lobe epilepsy (TLE) is often treated with surgical intervention at some point. As epilepsy surgery is considered a last resort by most physicians, a long history of epileptic seizures prior to surgery is not uncommon. Little is known about the effects of ongoing TLE on neural functioning. A better understanding of these effects might influence the moment of surgical intervention. Functional connectivity (interaction between spatially distributed brain areas) and network structure (integration and segregation of information processing) are thought to be essential for optimal brain functioning. We report on the impact of TLE duration on temporal lobe functional connectivity and network characteristics. METHODS: Functional connectivity of the temporal lobe at the time of surgery was assessed by means of interictal electrocorticography (ECoG) recordings of 27 TLE patients by using the phase lag index (PLI). Graphs (abstract network representations) were reconstructed from the PLI matrix and characterized by the clustering coefficient C (local clustering), the path length L (overall network interconnectedness), and the "small world index" S (network configuration). RESULTS: Functional connectivity (average PLI), clustering coefficients, and the small world index were negatively correlated with TLE duration in the broad frequency band (0.5-48 Hz). DISCUSSION: Temporal lobe functional connectivity is lower in patients with longer TLE history, and longer TLE duration is correlated with more random network configuration. Our findings suggest that the neural networks of TLE patients become more pathological over time, possibly due to temporal lobe changes associated with long-standing lesional epilepsy.
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spelling doaj.art-b1af47fa3f4c4fa7b3d70b79b3d221502022-12-22T00:43:34ZengPublic Library of Science (PLoS)PLoS ONE1932-62032009-01-01411e808110.1371/journal.pone.0008081Long-term effects of temporal lobe epilepsy on local neural networks: a graph theoretical analysis of corticography recordings.Edwin van DellenLinda DouwJohannes C BaayenJan J HeimansSophie C PontenW Peter VandertopDemetrios N VelisCornelis J StamJaap C ReijneveldPURPOSE: Pharmaco-resistant temporal lobe epilepsy (TLE) is often treated with surgical intervention at some point. As epilepsy surgery is considered a last resort by most physicians, a long history of epileptic seizures prior to surgery is not uncommon. Little is known about the effects of ongoing TLE on neural functioning. A better understanding of these effects might influence the moment of surgical intervention. Functional connectivity (interaction between spatially distributed brain areas) and network structure (integration and segregation of information processing) are thought to be essential for optimal brain functioning. We report on the impact of TLE duration on temporal lobe functional connectivity and network characteristics. METHODS: Functional connectivity of the temporal lobe at the time of surgery was assessed by means of interictal electrocorticography (ECoG) recordings of 27 TLE patients by using the phase lag index (PLI). Graphs (abstract network representations) were reconstructed from the PLI matrix and characterized by the clustering coefficient C (local clustering), the path length L (overall network interconnectedness), and the "small world index" S (network configuration). RESULTS: Functional connectivity (average PLI), clustering coefficients, and the small world index were negatively correlated with TLE duration in the broad frequency band (0.5-48 Hz). DISCUSSION: Temporal lobe functional connectivity is lower in patients with longer TLE history, and longer TLE duration is correlated with more random network configuration. Our findings suggest that the neural networks of TLE patients become more pathological over time, possibly due to temporal lobe changes associated with long-standing lesional epilepsy.http://europepmc.org/articles/PMC2778557?pdf=render
spellingShingle Edwin van Dellen
Linda Douw
Johannes C Baayen
Jan J Heimans
Sophie C Ponten
W Peter Vandertop
Demetrios N Velis
Cornelis J Stam
Jaap C Reijneveld
Long-term effects of temporal lobe epilepsy on local neural networks: a graph theoretical analysis of corticography recordings.
PLoS ONE
title Long-term effects of temporal lobe epilepsy on local neural networks: a graph theoretical analysis of corticography recordings.
title_full Long-term effects of temporal lobe epilepsy on local neural networks: a graph theoretical analysis of corticography recordings.
title_fullStr Long-term effects of temporal lobe epilepsy on local neural networks: a graph theoretical analysis of corticography recordings.
title_full_unstemmed Long-term effects of temporal lobe epilepsy on local neural networks: a graph theoretical analysis of corticography recordings.
title_short Long-term effects of temporal lobe epilepsy on local neural networks: a graph theoretical analysis of corticography recordings.
title_sort long term effects of temporal lobe epilepsy on local neural networks a graph theoretical analysis of corticography recordings
url http://europepmc.org/articles/PMC2778557?pdf=render
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