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Spatiotemporal mapping of interictal epileptiform discharges in human absence epilepsy: A MEG study.
Epilepsy Res. 2016 Jan; 119:67-76.ER

Abstract

PURPOSE

Although absence epilepsy is considered to be a prototypic type of generalized epilepsy, it is still under debate whether generalized 3 Hz spike-and-wave discharges (SWDs) might have a cortical focal origin. Here it is investigated whether focal interictal epileptiform discharges (IEDs), which typically occur in the electro- (EEG) and magnetoencephalogram (MEG) in case of focal epilepsy, are present in the MEG of children with absence epilepsy. Next, the location of the sources of the IEDs is established, and it is investigated whether the location is concordant to the earlier established focal cortical regions involved in the generalized SWDs of these children.

METHODS

Whole head MEG recordings of seven children with absence epilepsy were reviewed with respect to the presence of IEDs (spikes and sharp waves). These IEDs were grouped into distinct clusters, in which each contribution to a cluster yields a comparable magnetic field distribution. Source localization was then performed onto the average signal of each cluster using an equivalent current dipole model and a realistic head model of the cortical surface.

RESULTS

IEDs were detected in 6 out of 7 patients. Source reconstruction indicated most often frontal, central or parietal origins of the IED in either the left and or right hemisphere. Spatiotemporal assessment of the IEDs indicated a stable location of the averages of these discharges, indicating a single underlying cortical source.

DISCUSSION

The outcome of this pilot study shows that MEG is well suited for the detection of IEDs and suggests that their estimated sources coincide rather well with the cortical regions involved during the spikes of the SWDs. It is discussed whether the presence of IEDs, classically seen as a marker of focal epilepsies, indicate that absence epilepsy should be considered as a focal type of epilepsy, in which changes in the network are evolving rapidly.

Authors+Show Affiliations

Department Function and Medical Technology, Academic Center of Epileptology, Kempenhaeghe & Maastricht UMC+, PO Box 61, 5590AB Heeze, The Netherlands; Department of Biomedical Engineering, Eindhoven University of Technology, PO Box 513, 5600MB Eindhoven, The Netherlands. Electronic address: y.j.w.rozendaal@tue.nl.Donders Centre of Cognition, Radboud University, PO Box 9104, 6500HE Nijmegen, The Netherlands. Electronic address: g.vanluijtelaar@donders.ru.nl.Department Function and Medical Technology, Academic Center of Epileptology, Kempenhaeghe & Maastricht UMC+, PO Box 61, 5590AB Heeze, The Netherlands. Electronic address: ossenblokP@kempenhaeghe.nl.

Pub Type(s)

Journal Article

Language

eng

PubMed ID

26681490

Citation

Rozendaal, Yvonne J W., et al. "Spatiotemporal Mapping of Interictal Epileptiform Discharges in Human Absence Epilepsy: a MEG Study." Epilepsy Research, vol. 119, 2016, pp. 67-76.
Rozendaal YJ, van Luijtelaar G, Ossenblok PP. Spatiotemporal mapping of interictal epileptiform discharges in human absence epilepsy: A MEG study. Epilepsy Res. 2016;119:67-76.
Rozendaal, Y. J., van Luijtelaar, G., & Ossenblok, P. P. (2016). Spatiotemporal mapping of interictal epileptiform discharges in human absence epilepsy: A MEG study. Epilepsy Research, 119, 67-76. https://doi.org/10.1016/j.eplepsyres.2015.11.013
Rozendaal YJ, van Luijtelaar G, Ossenblok PP. Spatiotemporal Mapping of Interictal Epileptiform Discharges in Human Absence Epilepsy: a MEG Study. Epilepsy Res. 2016;119:67-76. PubMed PMID: 26681490.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Spatiotemporal mapping of interictal epileptiform discharges in human absence epilepsy: A MEG study. AU - Rozendaal,Yvonne J W, AU - van Luijtelaar,Gilles, AU - Ossenblok,Pauly P W, Y1 - 2015/12/01/ PY - 2015/06/05/received PY - 2015/10/03/revised PY - 2015/11/13/accepted PY - 2015/12/19/entrez PY - 2015/12/19/pubmed PY - 2016/10/1/medline KW - Childhood absence epilepsy KW - Current dipole source localization KW - Interictal epileptiform discharges KW - Involvement of focal cortical regions KW - Magnetoencephalography SP - 67 EP - 76 JF - Epilepsy research JO - Epilepsy Res. VL - 119 N2 - PURPOSE: Although absence epilepsy is considered to be a prototypic type of generalized epilepsy, it is still under debate whether generalized 3 Hz spike-and-wave discharges (SWDs) might have a cortical focal origin. Here it is investigated whether focal interictal epileptiform discharges (IEDs), which typically occur in the electro- (EEG) and magnetoencephalogram (MEG) in case of focal epilepsy, are present in the MEG of children with absence epilepsy. Next, the location of the sources of the IEDs is established, and it is investigated whether the location is concordant to the earlier established focal cortical regions involved in the generalized SWDs of these children. METHODS: Whole head MEG recordings of seven children with absence epilepsy were reviewed with respect to the presence of IEDs (spikes and sharp waves). These IEDs were grouped into distinct clusters, in which each contribution to a cluster yields a comparable magnetic field distribution. Source localization was then performed onto the average signal of each cluster using an equivalent current dipole model and a realistic head model of the cortical surface. RESULTS: IEDs were detected in 6 out of 7 patients. Source reconstruction indicated most often frontal, central or parietal origins of the IED in either the left and or right hemisphere. Spatiotemporal assessment of the IEDs indicated a stable location of the averages of these discharges, indicating a single underlying cortical source. DISCUSSION: The outcome of this pilot study shows that MEG is well suited for the detection of IEDs and suggests that their estimated sources coincide rather well with the cortical regions involved during the spikes of the SWDs. It is discussed whether the presence of IEDs, classically seen as a marker of focal epilepsies, indicate that absence epilepsy should be considered as a focal type of epilepsy, in which changes in the network are evolving rapidly. SN - 1872-6844 UR - https://www.unboundmedicine.com/medline/citation/26681490/Spatiotemporal_mapping_of_interictal_epileptiform_discharges_in_human_absence_epilepsy:_A_MEG_study_ DB - PRIME DP - Unbound Medicine ER -