Assaf Berger1,2, Noa Cohen3,2, Firas Fahoum4,2, Mordekhay Medvedovsky5,6, Aaron Meller3,2, Dana Ekstein5,6, Mony Benifla7,8, Orna Aizenstein9,2, Itzhak Fried1,2, Tomer Gazit3,2, Ido Strauss1,2. 1. 1Department of Neurosurgery. 2. 7Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv. 3. 2Sagol Brain Institute. 4. 3Department of Neurology, and. 5. 4Department of Neurology, Hadassah Medical Center, Jerusalem. 6. 8Hebrew University Hadassah Medical School, Jerusalem; and. 7. 5Department of Neurosurgery, Rambam Health Care Campus, Haifa. 8. 9Rappaport Faculty of Medicine-Technion, Haifa, Israel. 9. 6Department of Radiology, Tel Aviv Medical Center, Tel Aviv.
Abstract
OBJECTIVE: Preoperative localization of seizure onset zones (SOZs) is an evolving field in the treatment of refractory epilepsy. Both magnetic source imaging (MSI), and the more recent EEG-correlated functional MRI (EEG-fMRI), have shown applicability in assisting surgical planning. The purpose of this study was to evaluate the capability of each method and their combination in localizing the seizure onset lobe (SL). METHODS: The study included 14 patients who underwent both MSI and EEG-fMRI before undergoing implantation of intracranial EEG (icEEG) as part of the presurgical planning of the resection of an epileptogenic zone (EZ) during the years 2012-2018. The estimated location of the SL by each method was compared with the location determined by icEEG. Identification rates of the SL were compared between the different methods. RESULTS: MSI and EEG-fMRI showed similar identification rates of SL locations in relation to icEEG results (88% ± 31% and 73% ± 42%, respectively; p = 0.281). The additive use of the coverage lobes of both methods correctly identified 100% of the SL, significantly higher than EEG-fMRI alone (p = 0.039) and nonsignificantly higher than MSI (p = 0.180). False-identification rates of the additive coverage lobes were significantly higher than MSI (p = 0.026) and EEG-fMRI (p = 0.027). The intersecting lobes of both methods showed the lowest false identification rate (13% ± 6%, p = 0.01). CONCLUSIONS: Both MSI and EEG-fMRI can assist in the presurgical evaluation of patients with refractory epilepsy. The additive use of both tests confers a high identification rate in finding the SL. This combination can help in focusing implantation of icEEG electrodes targeting the SOZ.
OBJECTIVE: Preoperative localization of seizure onset zones (SOZs) is an evolving field in the treatment of refractory epilepsy. Both magnetic source imaging (MSI), and the more recent EEG-correlated functional MRI (EEG-fMRI), have shown applicability in assisting surgical planning. The purpose of this study was to evaluate the capability of each method and their combination in localizing the seizure onset lobe (SL). METHODS: The study included 14 patients who underwent both MSI and EEG-fMRI before undergoing implantation of intracranial EEG (icEEG) as part of the presurgical planning of the resection of an epileptogenic zone (EZ) during the years 2012-2018. The estimated location of the SL by each method was compared with the location determined by icEEG. Identification rates of the SL were compared between the different methods. RESULTS: MSI and EEG-fMRI showed similar identification rates of SL locations in relation to icEEG results (88% ± 31% and 73% ± 42%, respectively; p = 0.281). The additive use of the coverage lobes of both methods correctly identified 100% of the SL, significantly higher than EEG-fMRI alone (p = 0.039) and nonsignificantly higher than MSI (p = 0.180). False-identification rates of the additive coverage lobes were significantly higher than MSI (p = 0.026) and EEG-fMRI (p = 0.027). The intersecting lobes of both methods showed the lowest false identification rate (13% ± 6%, p = 0.01). CONCLUSIONS: Both MSI and EEG-fMRI can assist in the presurgical evaluation of patients with refractory epilepsy. The additive use of both tests confers a high identification rate in finding the SL. This combination can help in focusing implantation of icEEG electrodes targeting the SOZ.
Entities:
Keywords:
EEG-fMRI; MSI; icEEG; magnetic source imaging; refractory epilepsy; seizure onset zone