Health  Vol.5 No.6 A , June 2013
New network and synchronization approaches in focal epilepsy research and treatment

Traditional approaches to focal epileptic surgery rely in the identification and resection of the epileptic zone. However, a significant minority of epileptic patients continue to experience seizures after surgery, a fact that shows how difficult it is to define this concept. In this work we will review some of the recent advances in the use of complex network theory and synchronization analysis in the study of neurophysiological epileptic records which shed new light on fragmented understanding of the epilepsy dynamic we have today. More important would be the potential treatments which could be implemented from the new information and change of perspective gathered by using this methodology, particularly the substitution of the traditional resective surgery in temporal lobe epilepsy patients.

Cite this paper: Pastor, J. , Sola, R. , Zelaya, L. , Garnés, O. and Ortega, G. (2013) New network and synchronization approaches in focal epilepsy research and treatment. Health, 5, 1-8. doi: 10.4236/health.2013.56A1001.

[1]   Chou Dichter, M.A. (1997) Basic mechanisms of epilepsy: Targets for therapeutic intervention. Epilepsia, 389, S2- S6. doi:10.1111/j.1528-1157.1997.tb05200.x

[2]   Rosenow, F. and Luders, H. (2001) Presurgical evaluation of epilepsy. Brain, 124, 1683-1700. doi:10.1093/brain/124.9.1683

[3]   Pastor, J., Menéndez de la Prida, L., Hernando, V. and Sola, R.G. (2006) Voltage sources in mesial temporal lobe epilepsy recorded with foramen ovale electrodes. Clinical Neurophysiology, 117, 2604-2614. doi:10.1016/j.clinph.2006.07.311

[4]   Spencer, S.S. (2002) Neural networks in human epilepsy: Evidence of and implications for treatment. Epilepsia, 43, 219-27. doi:10.1046/j.1528-1157.2002.26901.x

[5]   Albert, R. and Barabási, A.-L. (2002) Statistical mechanics of complex networks. Reviews of Modern Physics, 74, 47-97. doi:10.1103/RevModPhys.74.47

[6]   Boccaletti, S., Latora, V., Moreno, Y., Chavez, M. and Hwang, D.-H. (2006) Complex networks: Structure and dynamics. Physics Reports, 424, 175-308. doi:10.1016/j.physrep.2005.10.009

[7]   Sporns, O., Chialvo, D.R., Kaiser, M. and Hilgetag, C.C. (2004) Organization, development and function of complex brain networks. Trends in Cognitive Sciences, 8, 418-425. doi:10.1016/j.tics.2004.07.008

[8]   Barrat, A., Barthelemy, M. and Vespignani, A. (2008) Dynamical processes on complex networks. Cambridge University Press, Cambridge.

[9]   Wilke, C., Worrell, G. and He, B. (2011) Graph analysis of epileptogenic networks in human partial epilepsy. Epilepsia, 52, 84-93. doi:10.1111/j.1528-1167.2010.02785.x

[10]   Ponten, S.C., Douw, L., Bartolomei, F., Reijneveld, J.C. and Stam, C.J. (2009) Indications for network regularization during absence seizures: Weighted and unweighted graph theoretical analyses. Experimental Neurology, 217, 197-204. doi:10.1016/j.expneurol.2009.02.001

[11]   Van Dellen, E., Douw, L., Baayen, J.C., Heimans, J.J., Ponten, S.C., Vandertop, W.P., Velis, D.N., Stam, C.J. and Reijneveld, J.C. (2009). Long-term effects of temporal lobe epilepsy on local neural networks: A graph theoreticcal analysis of corticography recordings. PLoS ONE, 4, e8081. doi:10.1371/journal.pone.0008081

[12]   Zhang, Z., Lu, G., Zhong, Y., Tan, Q., Liao, W., Chen, Z., Shi, J. and Liu, Y. (2009) Impaired perceptual networks in temporal lobe epilepsy revealed by resting fMRI. Journal of Neurology, 256, 1705-1713. doi:10.1007/s00415-009-5187-2

[13]   King, D., Spencer, S., McCarthy, G. and Spencer, D. (1997) Surface and depth EEG findings in patients with hippocampal atrophy. Neurology, 48, 1363-1367. doi:10.1212/WNL.48.5.1363

[14]   Bernasconi, N., Bernasconi, A., Andermann, F., Dubeau, F., Feindel, W. and Reutens, D.C. (1999) Entorhinal cortex in temporal lobe epilepsy: A quantitative MRI study. Neurology, 52, 1870-1876. doi:10.1212/WNL.52.9.1870

[15]   Katz, A., Marks, D.A., McCarthy, G. and Spencer, S.S. (1991) Does interictal spiking change prior to seizures? Electroencephalography and Clinical Neurophysiology, 79, 153-156. doi:10.1016/0013-4694(91)90054-8

[16]   Alarcon, G., Garcia Seoane, J.J., Binnie, C.D., Martin Miguel, M.C., Juler, J., Polkey, C.E., Elwes, R.D.C. and Ortiz Blasco, J.M. (1997) Origin and propagation of interictal discharges in the acute electrocorticogram. Implications for pathophysiology and surgical treatment of temporal lobe epilepsy. Brain, 120, 2259-2282. doi:10.1093/brain/120.12.2259

[17]   Bourien, J., Bartolomei, F., Bellanger, J.J., Gavaret, M., Chauvel, P. and Wendling, F. (2005) A method to identify reproducible subsets of co-activated structures during interictal spikes. Application to intracerebral EEG in temporal lobe epilepsy. Clinical Neurophysiology, 116, 443- 455. doi:10.1016/j.clinph.2004.08.010

[18]   Spencer, S.S. and Spencer, D.D. (1994) Entorhinal-hippocampal interactions in medial temporal lobe epilepsy. Epilepsia, 35, 721-727. doi:10.1111/j.1528-1157.1994.tb02502.x

[19]   Stam, C.J. and Reijneveld, J.C. (2007) Graph theoretical analysis of complex networks in the brain. Nonlinear Biomedical Physics, 1, 3. doi:10.1186/1753-4631-1-3

[20]   Bullmore, E. and Sporns, O. (2009) Complex brain networks: Graph theoretical analysis of structural and functional systems. Nature Reviews Neuroscience, 10, 186- 198. doi:10.1038/nrn2575

[21]   Friston, K.J., Frith, C.D. and Frackowiak, R.S.J. (1993) Time-dependent changes in effective connectivity measured with PET. Human Brain Mapping, 1, 69-79. doi:10.1002/hbm.460010108

[22]   Ortega, G.J., Menendez de la Prida, L., Sola, R.G. and Pastor, J. (2008) Synchronization clusters of interictal activity in the lateral temporal cortex of epileptic patients: Intraoperative electrocorticographic analysis. Epilepsia 49, 269-280. doi:10.1111/j.1528-1167.2007.01266.x

[23]   Palmigiano, A., Pastor, J., Garcia de Sola, R. and Ortega, G.J. (2012) Stability of synchronization clusters and seizurability in temporal lobe epilepsy. PLoS ONE, 7, e41799. doi:10.1371/journal.pone.0041799

[24]   Ortega, G.J., Sola, R.G. and Pastor, J. (2008) Complex network analysis of human ECoG data. Neuroscience Letters, 447, 129-133. doi:10.1016/j.neulet.2008.09.080

[25]   Ortega, G.J., Peco, I.H., Sola, R.G. and Pastor, J. (2011) Impaired mesial synchronization in temporal lobe epilepsy. Clinical Neurophysiology, 122, 1106-1116. doi:10.1016/j.clinph.2010.11.001

[26]   Pastor, J., Garcia de Sola, R. and Ortega, G.J. (2012) Hyper-synchronization, de-synchronization, synchronization and seizures. In: D. Stevanovic, Ed., Epilepsy—Histological, Electroencephalographic and Psychological Aspects, InTech, ISBN: 978-953-51-0082-9. doi:10.5772/31004

[27]   Milton, G.J., Chkhenkeli, S.A. and Towle, V.L. (2007) Brain connectivity and the spread of epileptic seizures. Handbook of Brain Connectivity Understanding Complex Systems, 477-503. doi:10.1007/978-3-540-71512-2_17

[28]   Kandel, E.R., Schwartz, J.H. and Jessell, T.M. (2000) Principles of Neural Science. 4th Edition, McGraw-Hill, New York.