Figure 4.

CBF changes ipsi- and contralateral to side of seizure onset (lateralized analysis) overlaid on a structural MRI in the coronal plane. Same patients and data are shown as in Fig. 3. Changes ipsilateral to seizure onset are shown on the left side of the brain sections, and contralateral changes on the right side (combining patients with left- and right-onset seizures). CBF increases (warm colours) and decreases (cool colours) were analysed compared with baseline interictal images. (A) Pre-generalization period (n = 9). Significant increases occur in the ipsilateral temporal lobes (the most common region of seizure onset), while decreases occur in the bilateral cingulate gyrus and anterior medial frontal association cortex. (B) Generalization period (n = 10). Significant increases occur in the bilateral superior medial cerebellum. Increases seen in thalamus, basal ganglia and contralateral Rolandic cortex did not reach significance at the cluster level. Significant decreases occur in the bilateral frontal association cortex (slightly more pronounced contralateral). (C) Post-ictal period (n = 24). Significant increases occur in the bilateral cerebellum, midbrain, ipsilateral basal ganglia and adjacent white matter, while decreases occur in the bilateral frontal association cortex (more pronounced contralateral), bilateral cingulate and precuneus, and in the contralateral lateral parietal cortex. For A–C, extent threshold, k = 125 voxels (voxel size = 2 × 2 × 2 mm³). Height threshold, P = 0.01. Equivalently, only voxel clusters >1 cm³ in volume and with Z-scores greater than 2.33 are displayed. Only regions with corrected P < 0.05 are considered significant at the cluster level (Table 2).