Epileptogenic zones can be localized by F-18 fluorodeoxyglucose positron emission tomography (FDG PET) and ictal single-photon emission computed tomography(SPECT). In medial temporal lobe epilepsy, the diagnostic sensitivity of FDG PET or ictal SPECT is excellent, however, the sensitivity of MRI is so high that the incremental sensitivity by FDG PET or ictal SPECT has yet to be proven. When MRI findings are ambiguous or normal, or discordant with those of ictal EEG, FDG PET and ictal SPECT are helpful for localization without the need for invasive ictal EEG. In neocortical epilepsy, the sensitivities of FDG PET or ictal SPECT are fair. However, because almost a half of the patients are normal on MRI, FDG PET and ictal SPECT are helpful for localization or at least for lateralization in these non-lesional epilepsies in order to guide the subdural insertion of electrodes. Interpretation of FDG PET has been recently advanced by voxel-based analysis and automatic volume of interest analysis based on a population template. Both analytical methods confirmed the performance of previous visual interpretation results. Ictal SPECT was analyzed using subtraction methods(coregistered to MRI) and voxel-based analysis. Rapidity of injection of tracers, HMPAO versus ECD, and repeated ictal SPECT, which remain the technical issues of ictal SPECT, are detailed.
Epilepsy/*radionuclide imaging ; Fludeoxyglucose F 18/diagnostic use ; Human ; Radiopharmaceuticals/diagnostic use ; *Tomography, Emission-Computed ; *Tomography, Emission-Computed, Single-Photon

Both interictal Tc-99m hexamethyl-propyleneamine oxime single photon emission computed tomography (HM-PAO SPECT) brain scintigraphy was done in a patient with the syndrome of chronic encephalitis and epilepsy. The low density area in the temporo-occipital lobe on brain CT scan revealed decreased radioactivity during interictal state and it was reversed to increased radioactivity during ictal state on HM-PAO SPECT brain imaging. In authors' opinion, ictal and interictal Tc-99m HM-PAO SPECT brain scintigraphy could be a safe and convincing study for Searching epileptogenic foci.
Brain* ; Encephalitis* ; Epilepsy* ; Humans ; Neuroimaging ; Radioactivity ; Radionuclide Imaging* ; Tomography, Emission-Computed, Single-Photon* ; Tomography, X-Ray Computed

Few studies have included magnetoencephalography (MEG) when assessing the diagnostic value of presurgical modalities in a nonlesional epilepsy population. Here, we compare single photon emission computed tomography (SPECT), positron emission tomography (PET), video-EEG (VEEG), and MEG, with intracranial EEG (iEEG) to determine the value of individual modalities to surgical decisions. We analyzed 23 adult epilepsy patients with no abnormal MRI findings who had undergone surgical resection. Localization of individual presurgical tests was determined for hemispheric and lobar locations based on visual analysis. Each localization result was compared with the ictal onset zone (IOZ) defined by using iEEG. The highest to the lowest hemispheric concordance rates were MEG (83%) > ictal VEEG (78%) > PET (70%) > ictal SPECT (57%). The highest to lowest lobar concordance rates were ictal VEEG = MEG (65%) > PET (57%) > ictal SPECT (52%). Statistical analysis showed MEG to have a higher hemispheric concordance than that of ictal SPECT (P = 0.031). We analyzed the effects of MEG clustered-area resection on surgical outcome. Patients who had resection of MEG clusters showed a better surgical outcome than those without such resection (P = 0.038). It is suggested that MEG-based localization had the highest concordance with the iEEG-defined IOZ. Furthermore, MEG cluster resection has prognostic significance in predicting surgical outcome.
Adolescent ; Adult ; Brain/*pathology/surgery ; *Brain Mapping ; Electroencephalography ; Epilepsy/*radionuclide imaging/surgery ; Female ; Humans ; Magnetic Resonance Imaging ; *Magnetoencephalography ; Male ; Middle Aged ; Positron-Emission Tomography ; Preoperative Care ; Tomography, Emission-Computed, Single-Photon ; Video Recording

Few studies have included magnetoencephalography (MEG) when assessing the diagnostic value of presurgical modalities in a nonlesional epilepsy population. Here, we compare single photon emission computed tomography (SPECT), positron emission tomography (PET), video-EEG (VEEG), and MEG, with intracranial EEG (iEEG) to determine the value of individual modalities to surgical decisions. We analyzed 23 adult epilepsy patients with no abnormal MRI findings who had undergone surgical resection. Localization of individual presurgical tests was determined for hemispheric and lobar locations based on visual analysis. Each localization result was compared with the ictal onset zone (IOZ) defined by using iEEG. The highest to the lowest hemispheric concordance rates were MEG (83%) > ictal VEEG (78%) > PET (70%) > ictal SPECT (57%). The highest to lowest lobar concordance rates were ictal VEEG = MEG (65%) > PET (57%) > ictal SPECT (52%). Statistical analysis showed MEG to have a higher hemispheric concordance than that of ictal SPECT (P = 0.031). We analyzed the effects of MEG clustered-area resection on surgical outcome. Patients who had resection of MEG clusters showed a better surgical outcome than those without such resection (P = 0.038). It is suggested that MEG-based localization had the highest concordance with the iEEG-defined IOZ. Furthermore, MEG cluster resection has prognostic significance in predicting surgical outcome.
Adolescent ; Adult ; Brain/*pathology/surgery ; *Brain Mapping ; Electroencephalography ; Epilepsy/*radionuclide imaging/surgery ; Female ; Humans ; Magnetic Resonance Imaging ; *Magnetoencephalography ; Male ; Middle Aged ; Positron-Emission Tomography ; Preoperative Care ; Tomography, Emission-Computed, Single-Photon ; Video Recording