EEG source imaging in pediatric epilepsy surgery: a new perspective in presurgical workup.
OBJECTIVE
Epilepsy is a relatively frequent disease in children, with considerable impact on cognitive and social life. Successful epilepsy surgery depends on unambiguous focus identification and requires a comprehensive presurgical workup, including several neuroimaging techniques [magnetic resonance imaging, positron emission tomography (PET), and single-photon emission computed tomography (SPECT)]. These may be difficult to apply in younger or developmentally delayed children or both, requiring sedation, and hence, a significant workforce. Modern electric source imaging (ESI) provides accurate epileptic source-localization information in most patients, with minimal patient discomfort or need for cooperation. The purpose of the present study was to determine the usefulness of ESI in pediatric EEG recordings performed with routine electrode arrays.


METHODS
Preoperative EEGs recorded from 19 to 29 scalp electrodes were reviewed, and interictal epileptiform activity was analyzed by using a linear source-imaging procedure (depth-weighted minimum norm) in combination with statistical parametric mapping.


RESULTS
In 27 (90%) of 30 patients, the ESI correctly localized the epileptogenic region. These numbers compare favorably with the results from other imaging techniques in the same patients (PET, 82%; ictal SPECT, 70%). In extratemporal epilepsy, ESI was correct in all cases, and in temporal lobe epilepsy, in 10 of 13 cases. In two temporal lobe patients showing less-accurate ESI results, 128-electrode data could be analyzed, and in both cases, the 128-electrode ESI was correct.


CONCLUSIONS
ESI with standard clinical EEG recordings provides excellent localizing information in pediatric patients, in particular in extratemporal lobe epilepsy. The lower yield in temporal lobe epilepsy seems to be due to undersampling of basal temporal areas with routine scalp recordings.
Sperli
Francesca
F
University of Rome Tor Vergata, Rome, Italy, and Functional Brain Mapping Laboratory, Neurology Clinic, University Hospital, Geneva, Switzerland.
Spinelli
Laurent
L
Seeck
Margitta
M
Kurian
Mary
M
Michel
Christoph M
CM
Lantz
Göran
G
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000465:Algorithms; D001931:Brain Mapping / Q000379:methods*; D002540:Cerebral Cortex / Q000503:physiopathology / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D004566:Electrodes / Q000706:statistics & numerical data; D004569:Electroencephalography / Q000379:methods / Q000706:statistics & numerical data*; D004827:Epilepsy / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery*; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery; D005260:Female; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data; D008297:Male; D049268:Positron-Emission Tomography / Q000706:statistics & numerical data; D011300:Preoperative Care / Q000379:methods* / Q000706:statistics & numerical data; D013702:Temporal Lobe / Q000503:physiopathology; D015899:Tomography, Emission-Computed, Single-Photon / Q000706:statistics & numerical data; D016896:Treatment Outcome