PRESURGICAL LOCALIZATION OF FRONTAL LOBE EPILEPSY USING INTERICTAL EEG AND MEG, WITH ELECTROCORTICAL VALIDATION
Abstract number :
1.302
Submission category :
Year :
2002
Submission ID :
74
Source :
www.aesnet.org
Presentation date :
12/7/2002 12:00:00 AM
Published date :
Dec 1, 2002, 06:00 AM
Authors :
Pauly P. Ossenblok, Frans S. Leijten, Ellen H. Veltman, Irma Van Velzen, Geertjan Huiskamp, Albert Colon, Paul A. Boon. Clinical Neurophysiology, Epilepsy Center Kempenhaeghe, Heeze, Netherlands; Clinical Neurophysiology, University Medical Center, Utrech
RATIONALE: The localization of frontal lobe epilepsy (FLE) is complex and surgical management, therefore, remains less successful in comparison with temporal lobe epilepsy. This study aims at demonstrating that advanced source analysis of simultaneously recorded interictal EEG and MEG is a useful additional tool for the presurgical localization of FLE.
METHODS: Sixteen patients with FLE were participating in this study. Six of these patients were candidates for epilepsy surgery and underwent preoperative subdural recordings (ECoG). Prior to these recordings, the onset and dynamics of the interictal EEG and MEG discharges of each of these patients were studied, using equivalent and dipole source distribution models. On a cortical rendering, the analysis results of the interictal transients were plotted relative to the anatomy obtained from 3D-MRI, thus enabling the systematic assessment of the onset and propagation path underlying the interictal EEG and MEG compared to the interictal ECoG.
RESULTS: Advanced source analysis of the interictal EEG and MEG transients enabled us to delineate the irritative zone and to differentiate this area from the secondary propagation areas. The localization of the irritative zone was in good agreement with the interictal onset area determined on the basis of the subdural recordings for each of the 6 patients, while 4 of these patients who underwent resective surgery were seizure free after their operation. However, independent source analysis of the interictal EEG and MEG discharges revealed distinct propagation patterns underlying these discharges. This probably explains the differences in shape and spatial distribution that occurred in the simultaneously recorded interictal EEG and MEG discharges of most of the patients studied.
CONCLUSIONS: The results of this study indicate that advanced source analysis of both interictal EEG and MEG is successful in guiding the intracranial recordings.
[Supported by: The Epilepsy Foundation of the Netherlands (grant 20-10).]