Thanks to the embedding of the laboratory in the Department of neurology and the existence of a very active presurgical epilepsy evaluation unit in the Department, we performed many studies on EEG source localization in epilepsy.

 

We showed that the spatial EEG analysis methods allow us to precisely and reliably identify the epileptogenic zone in patients with partial epilepsy. The localization precision drastically enhanced with the introduction of a fast, comfortable, and easy to use high resolution EEG system. The application of the 256-channel electrode cap (Electrical Geodesics Inc., Eugene, OR, USA) lasts not much longer than 10 minutes. Thanks to this system, clinical applications of high-resolution EEG have become feasible.

 

We have in the meanwhile recorded more than 100 epileptic patients with 128-256 electrodes, and we have developed a standardized protocol for the analysis and localization of interictal discharges. We have shown that our EEG source localization results are as precise as other functional imaging procedures, which is of particular importance for the application in children.

 

Finally we have pioneered the EEG-triggered fMRI in epilepsy and have shown the importance of combining the two imaging techniques to capture the spatio-temporal dynamics of the epileptic activity.

 

 

 

 

 

Dynamic source imaging of interictal epileptic discharges (see Michel et al., 2004)

 

 

 

 

Key papers:

 

Sperli F, Spinelli L, Seeck M, Kurian M, Michel CM, Lantz G. EEG source imaging in paediatric epilepsy surgery: a new perspective in presurgical workup. Epilepsia, 2006, 47:981–990.

Michel CM, Lantz G, Spinelli L, Grave de Peralta R, Landis T, Seeck M. 128-channel EEG source imaging in epilepsy: clinical yield and localization precision. Journal of Clinical Neurophysiology, 2004; 21:71-83.

Lantz G, Spinelli L, Seeck M, Grave de Peralta R, Sottas OC, Michel CM. Propagation of interictal epileptiform activity can lead to erroneous source localizations: A 128 channel EEG mapping study. Journal of Clinical Neurophysiology, 2003,20:311-319.

Lantz G, Grave de Peralta R, Spinelli L, Seeck M, Michel CM. Epileptic source localization with high density EEG: how many electrodes are needed? Clinical Neurophysiology 2003;114:63-99.

Seeck M, Lazeyras F, Michel CM, Blanke O, Gericke G, Ives J, Delavelle J, Golay X, Haenggeli CA, de Tribolet N, Landis T. Non-invasive epileptic focus localization using EEG-triggered functional MRI and electromagnetic tomography. Electroencephalography and Clinical Neurophysiology, 1998, 106: 508-512.