The diagnostic utility of 3D electroencephalography source imaging in pediatric epilepsy surgery

Abstract

SUMMARYObjective: The aim of this study was to investigate the utility of three-dimensional electroencephalography source imaging (3D-ESI) with low-resolution electroencephalographic data in the pediatric noninvasive presurgical evaluation, and to compare the findings with positron emission tomography (PET) and ictal single-photon emission computed tomography (iSPECT). Methods: We retrospectively selected 60 patients from a database of 594 patients who underwent excisional surgery for drug-resistant epilepsy. Patients were <18 years at time of surgery, had at least one presurgical volumetric brain magnetic resonance imaging (MRI), and at least 1 year of outcome data. 3D-ESI was performed with NeuroScan software CURRY V.7.0. For each patient the surgical resection was planned utilizing 3D-ESI as an adjunctive tool to supplement MRI and electrocorticographic data. Our analyses addressed three critical variables: pathology (focal cortical dysplasia vs. other pathologies), imaging (MRI negative vs. positive cases), and surgery (temporal resection vs. extratemporal and multilobar resections). We also compared the localizing utility and surgical outcome of 3D-ESI findings with PET, iSPECT, and the colocalized surgical resection. Statistical analyses were performed using the Statistical Package for the Social Sciences, Version 20. Results: Mean age at surgery was 11.18 years (range 1-18 years). 3D-ESI showed a strong correlation with the surgical resection cavity (65.0%), particularly within the temporal lobe. 3D-ESI demonstrated better localization in MRI-negative cases (78.6%), which was not statistically significant. 3D-ESI also correlated with a superior surgical outcome profile compared to PET and iSPECT. Significance: Our findings demonstrate that 3D-ESI data obtained with low-resolution electroencephalography achieves reasonably accurate noninvasive localization of epileptic spikes in pediatric focal epilepsy, especially in temporal lobe and MRI-negative cases, and is comparable to iSPECT and PET. Given its lesser expense and lack of radiation exposure, 3D-ESI is a useful and efficient tool for evaluating surgical candidacy in pediatric epilepsy surgery centers, particularly if PET and iSPECT are unavailable.

Interictal epileptogenic zone localization in patients with focal epilepsy using electric source imaging and directed functional connectivity from low‐densityEEG

“…A previous study using ESI based on both high‐density and low‐density EEG obtained a sensitivity of 84% when using individual MRI studies and high‐density EEG, and a sensitivity of 66% when using low‐density EEG and individual MRI studies . In another study based on low‐density EEG (19 channels), ESI reached a 65% concordance . Another study using also low‐density EEG obtained a localization accuracy of 51% and 62% using two different inverse solution methods, which was similar to other conventional neuroimaging methods (structural MRI, PET, and SPECT) .…”

“…3 In another study based on lowdensity EEG (19 channels), ESI reached a 65% concordance. 7 Another study using also low-density EEG obtained a localization accuracy of 51% and 62% using two different inverse solution methods, which was similar to other conventional neuroimaging methods (structural MRI, PET, and SPECT). 31 In our study, the percentage of concordance with the presumed EZ using ESI reached 90% in TLE and 57% in ETLE.…”

“…State‐of‐the‐art ESI for epilepsy presurgical evaluation is performed using high‐density EEG recordings (96‐256 channels), which are not yet widely available. ESI applied to standard clinical recordings (long‐term or short duration) is less accurate compared to high density but can nevertheless yield clinically useful information …”

“…ESI applied to standard clinical recordings (long-term or short duration) is less accurate compared to high density but can nevertheless yield clinically useful information. 3,6,7 There is an increasing consensus that epilepsy involves large-scale brain networks rather than single sources. 8,9 A better understanding about the interactions between brain regions is crucial for understanding this disorder and could provide important diagnostic and prognostic information.…”

Combined electroencephalography–functional magnetic resonance imaging and electrical source imaging improves localization of pediatric focal epilepsy

“…ESI has been shown to localize the EZ with high sensitivity and specificity in a mixed group of adults and children using high-density (>32 channel) EEG 16 and has shown promise in a pediatric cohort. 17 ESI has a limited spatial accuracy and can have limitations in cases with deep sources 18 , previous surgery, 19 or where IEDs are not typical discrete events. Studies have investigated the spatial consistency of EEG-fMRI and ESI maps 20,21 and their localization performance, 22 but they have not been combined to improve their potential predictive value.…”