F. Moeller, M. Muthuraman, J. Raethjen, and M. Siniatchkin contributed equally to this work
Representation and propagation of epileptic activity in absences and generalized photoparoxysmal responses
Article first published online: 19 MAR 2012
Copyright © 2012 Wiley Periodicals, Inc.
Human Brain Mapping
Volume 34, Issue 8, pages 1896–1909, August 2013
How to Cite
Moeller, F., Muthuraman, M., Stephani, U., Deuschl, G., Raethjen, J. and Siniatchkin, M. (2013), Representation and propagation of epileptic activity in absences and generalized photoparoxysmal responses. Hum. Brain Mapp., 34: 1896–1909. doi: 10.1002/hbm.22026
- Issue published online: 8 JUL 2013
- Article first published online: 19 MAR 2012
- Manuscript Accepted: 13 DEC 2011
- Manuscript Received: 12 SEP 2011
- German Research Foundation (DFG). Grant Number: SI 1419/2-1, SFB 855 (Project D2 and D3)
Although functional imaging studies described networks associated with generalized epileptic activity, propagation patterns within these networks are not clear. In this study, electroencephalogram (EEG)-based coherent source imaging dynamic imaging of coherent sources (DICS) was applied to different types of generalized epileptiform discharges, namely absence seizures (10 patients) and photoparoxysmal responses (PPR) (eight patients) to describe the representation and propagation of these discharges in the brain. The results of electrical source imaging were compared to EEG-functional magnetic resonance imaging (fMRI) which had been obtained from the same data sets of simultaneous EEG and fMRI recordings. Similar networks were described by DICS and fMRI: (1) absence seizures were associated with thalamic involvement in all patients. Concordant results were also found for brain areas of the default mode network and the occipital cortex. (2) Both DICS and fMRI identified the occipital, parietal, and the frontal cortex in a network associated with PPR. (3) However, only when PPR preceded a generalized tonic-clonic seizure, the thalamus was involved in the generation of PPR as shown by both imaging techniques. Partial directed coherence suggested that during absences, the thalamus acts as a pacemaker while PPR could be explained by a cortical propagation from the occipital cortex via the parietal cortex to the frontal cortex. In conclusion, the electrical source imaging is not only able to describe similar neuronal networks as revealed by fMRI, including deep sources of neuronal activity such as the thalamus, but also demonstrates interactions interactions within these networks and sheds light on pathogenetic mechanisms of absence seizures and PPR. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.