128-channel EEG source imaging in epilepsy: clinical yield and localization precision.
The authors evaluated the feasibility, clinical yield, and localization precision of high-resolution EEG source imaging of interictal epileptic activity. A consecutive series of 44 patients with intractable epilepsy of various causes, who underwent a comprehensive presurgical epilepsy evaluation, were subjected to a 128-channel EEG recording. A standardized source imaging procedure constrained to the individual gray matter was applied to the averaged spikes of each patient. In 32 patients, the presurgical workup identified a focal epileptogenic area. The 128-channel EEG source imaging correctly localized this area in 30 of these patients (93.7%). Imprecise localization was explained by simplifications of the recordings and analysis procedure, which was accepted for the benefit of speed and standardization. In a subgroup of 24 patients who underwent operations, the sublobar precision of the 128-channel EEG source imaging was evaluated by calculating the distance of the source maximum to the resected area. This analysis revealed zero distance in 19 cases (79%). The authors conclude that high-resolution interictal EEG source imaging is a valuable noninvasive functional neuroimaging technique. The speed, ease, flexibility, and low cost of this technique warrant its use in clinical practice.
Michel
Christoph M
CM
Functional Brain Mapping Laboratory, Neurology Clinic, University Hospital, Geneva, Switzerland. christoph.michel@hcuge.ch
Lantz
Göran
G
Spinelli
Laurent
L
De Peralta
Rolando Grave
RG
Landis
Theodor
T
Seeck
Margitta
M
D000293:Adolescent; D000328:Adult; D000465:Algorithms; D001931:Brain Mapping / Q000295:instrumentation / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D004569:Electroencephalography / Q000295:instrumentation / Q000379:methods*; D004827:Epilepsy / Q000175:diagnosis* / Q000601:surgery; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome