Table 1.
Clinical profile: age, gender, MRI abnormalities, EEG activity, and location of noninvasive techniques (ESI and ASL) and invasive techniques (sEEG).
Table 2.
Quantification results from ESI and ASL in the six patients (patients nos. 7–12) with focal epilepsy.
Fig 1.
Spike average (epochs of 1 s) of interictal activities visualized according to the projected location of the scalp electrodes in the six patients.
Fig 2.
Imaging analysis results in the six patients (patients nos. 7–12) with focal epilepsy.
ESI and ASL images of the same anatomical space were acquired for each patient and two axial sections are shown (z coordinates in native space). (A) Spike average: 256-channel EEG traces with a duration of 1 s (spike average). The global field power is used for the onset (red line). (B) ESI results: EEG source imaging at 50% rising phase of the peak (up) and at the peak (down). The scale indicates the current density (CD) [μA/mm3]. (C) ASL results. The scale indicates the cerebral blood flow (CBF) values [ml/100g/min].
Fig 3.
ASL imaging results in the new group of six patients (patients nos. 7–12) with focal epilepsy.
A) Regions of interest (ROIs) for the quantification of current density (CD) and cerebral blood flow (CBF) values at the same anatomical level in each subject. ROIs are superimposed over axial T1-weighted slices in MNI space. B) Statistical analysis results from the template-based comparison. CBF maps (normalized values) for the same axial slices reported in part A) are shown here for the control group (template) and patients, together with the statistical map. In all patients, only areas with a statistically significant decrease in perfusion as compared to the healthy subjects were detected (blue scale, FDR corrected, q < 0.05).
Fig 4.
ASL imaging results in the six focal epilepsy patients described in the previous study (patients nos. 1–6).
A) Regions of interest for quantification of current density (CD) and cerebral blood flow (CBF) values at the same anatomical level in each subject. ROIs are superimposed over axial T1-weighted slices in MNI space. B) Statistical analysis results from the template-based comparison. CBF maps (normalized values) for the same axial slices reported in part A) are shown here for the control group (template) and patients, together with the statistical map. Areas with a statistically significant decrease in perfusion (hypoperfusion), as compared to the healthy subjects, were detected in four patients (blue scale, FDR corrected, q < 0.05). Conversely, areas with a statistically significant increase in perfusion (hyperperfusion), as compared to the healthy subjects, were detected in two patients (yellow scale, FDR corrected, q < 0.05).
Fig 5.
Parameter estimates for the normal perfusion template, computed from the control group.
A) Mean CBF estimates expressed in normalized units. B) Within-subject variance, estimated from the temporal information given by the multiple repetitions, for a representative subject. C) Average within-subject variance in the control group. D) Between-subject variance estimated from the heteroscedastic model. Axial slices of interest are displayed in radiological convention.
Fig 6.
Postoperative imaging in three patients from the previously described patient group (patients nos. 2, 4 and 6).
The presurgical ESI and ASL results are overlaid on the coregistered postoperative MRI scans of each patient. Two different sections are shown for each plane (sagittal, coronal and axial). The rising phase of activity and the statistical results from the one-versus-many analysis are presented for ESI and ASL, respectively.
Fig 7.
Postoperative imaging in two patients of the new group (patients. nos. 7 and 10).
The presurgical ESI and ASL results are overlaid on the coregistered postoperative MRI scans for each patient. Two different sections are shown for each plane (sagittal, coronal and axial). The rising phase of activity and the statistical results from the one-versus-many analysis are presented for ESI and ASL, respectively.