Open Access

N. Japaridze, Muthuraman Muthuraman, A. R. Anwar, Kidist Gebremariam Mideksa, Günther Deuschl, Ulrich Stephani, Michael Siniatchkin

• The aim of this study was to investigate the dynamics of neuronal networks during focal seizures using dynamic imaging of coherent sources (DICS) (Gross et al. 2001) and renormalized partial directed coherence (RPDC) (Schelter et al. 2009). Ictal EEG recordings from a patient with drug resistant focal epilepsy, due to a focal cortical dysplasia (FCD) in the left parieto-occipital region, (shown by a high resolution 3-T MRI) were analyzed. DICS revealed the neuronal networks concomitant with the location of the FCD, shown by a high resolution 3-T MRI and areas of decreased metabolism shown by functional neuroimaging methods. The sources identified during the seizure onset and propagation phases were similar. Only the causality was different, showing that the strongest source, located in the occipito-temporal region, is most probably a pacemaker/seizure onset zone of the ictal neuronal networks in this case. The DICS analyses of pre-seizure phase showed the sources in the DMN areas ofThe aim of this study was to investigate the dynamics of neuronal networks during focal seizures using dynamic imaging of coherent sources (DICS) (Gross et al. 2001) and renormalized partial directed coherence (RPDC) (Schelter et al. 2009). Ictal EEG recordings from a patient with drug resistant focal epilepsy, due to a focal cortical dysplasia (FCD) in the left parieto-occipital region, (shown by a high resolution 3-T MRI) were analyzed. DICS revealed the neuronal networks concomitant with the location of the FCD, shown by a high resolution 3-T MRI and areas of decreased metabolism shown by functional neuroimaging methods. The sources identified during the seizure onset and propagation phases were similar. Only the causality was different, showing that the strongest source, located in the occipito-temporal region, is most probably a pacemaker/seizure onset zone of the ictal neuronal networks in this case. The DICS analyses of pre-seizure phase showed the sources in the DMN areas of the brain. We can conclude that analyses of multiple habitual seizures of the same patients by the methods of DICS and RPDC gives us valuable information regarding the seizure onset zone and ictal networks. It can be a useful additive tool during the pre-epilepsy surgical investigations of the patients with drug resistant focal epilepsies.…