Advanced Search

Browse by Discipline

Scientific Societies

E-print Alerts

Add E-prints

E-print Network

  Advanced Search  

Epilepsy Research 69 (2006) 3044 Improved spatial characterization of the epileptic

Summary: Epilepsy Research 69 (2006) 30­44
Improved spatial characterization of the epileptic
brain by focusing on nonlinearity
Ralph G. Andrzejaka,b,, Florian Mormannb, Guido Widmanb,
Thomas Kreuza,b,1, Christian E. Elgerb, Klaus Lehnertzb,c
a John von Neumann Institute for Computing, Forschungszentrum Jšulich GmbH, Jšulich, Germany
b Department of Epileptology, University of Bonn, Sigmund Freud Str. 25, D-53105 Bonn, Germany
c Helmholtz Institute for Radiation and Nuclear Physics, University of Bonn, Germany
Received 13 August 2005; received in revised form 16 November 2005; accepted 8 December 2005
Available online 28 February 2006
An advanced characterization of the complicated dynamical system brain is one of science's biggest challenges. Nonlinear
time series analysis allows characterizing nonlinear dynamical systems in which low-dimensional nonlinearity gives rise to
complex and irregular behavior. While several studies indicate that nonlinear methods can extract valuable information from
neuronal dynamics, others doubt their necessity and conjecture that the same information can be obtained using classical
linear techniques. To address this issue, we compared these two concepts, but included furthermore a combination of nonlinear
measures with surrogates, an approach that has been designed to specifically focus on nonlinearity. As a benchmark we used
the discriminative power to detect the seizure-generating hemisphere in medically intractable mesial temporal lobe epilepsy. We
analyzed intracranial electroencephalographic recordings from the seizure-free interval of 29 patients. While the performance
of both linear and nonlinear measures was weak, if not insignificant, a very high performance was obtained by the use of


Source: Andrzejak, Ralph Gregor - Departament de Tecnologia, Universitat Pompeu Fabra


Collections: Computer Technologies and Information Sciences