Figure 4
Patient 35. Male, born 1/2001, with no family or personal antecedents. Neurological examination revealed no focal deficits, mild psychomotor impairment, slight divergent strabismus of the right eye, and probable right hemianopic deficit. Epilepsy onset on the eighth day of life occurred with highly frequent seizures, characterised by horizontal nystagmus beating rapidly towards both sides, apparently without loss of contact. After several months, the ictal episodes constituted a sustained eye deviation to the right, followed by blinking and pendular horizontal nystagmus; sometimes the seizure continued with a postural hypertonia of the right limbs, while the child also presented with daily dialeptic seizures.
MRI revealed the presence of a vast TPO dysplastic lesion (A).
Interictal EEG showed the presence of left OT subcontinuous delta activity, intermixed with spikes and a short burst of fast activity, localised over the left OT region and diffused to the posterior temporal and, to a lesser degree, to the OP region (B), while ictal EEG showed a left O ictal onset (C). A partial lesionectomy consisting of a tailored OT resection (D) led to complete seizure freedom for nearly four years, associated with developmental gain. Afterwards, the seizures reappeared and were characterised by amaurosis, horizontal monocular nystagmus, head deviation to the right, blinking, lip corner deviation (“smile”), and hypertonia of the right limbs.
EEG showed rare spike-waves, localised over the left temporo-parietal region and a left parieto-occipital ictal onset with early temporal spread (E).
An SEEG investigation was performed in the left parieto-temporal region and showed: subcontinuous interictal parietal spikes (F; electrode Q7-8), an independent frequent infraclinical paroxysmal activity in the mesial temporal region (F; electrode C4-5), and an ictal onset over the intermediate mesial inferior parietal region (F; electrode Q2-3). The resection was extended to the inferior parietal region, but a complete disconnection of the temporal lobe was also performed in order to achieve complete posterior quadrant surgery (G). Histopathological examination revealed FCD IIA. The child was classified as Engel class Ia since 2007 and AEDs were definitively stopped in 2012. The neuropsychological evaluation at five years follow-up demonstrated a normal psycho-cognitive level.
Scheme SEEG:
Electrode N: parietal cingulate gyrus, inferior postcentral gyrus; Electrode B: anterior parahippocampic gyrus, hippocampus, anterior fusiform gyrus, intermediate part of inferior temporal gyrus; Electrode Q: posterior precuneus, posterior part of superior parietal lobule, posterior part of inferior parietal lobule; Electrode A: uncus, amygdala, middle temporal gyrus.
Electrode P: anterior precuneus, anterior part of inferior parietal lobule; Electrode X: cingulate gyrus (splenium), posterior precuneus, supramarginalis gyrus; Electrode M: posterior paracentral lobule, intermediate postcentral gyrus; Electrode C: parahippocampic gyrus, posterior hippocampus, posterior part of middle temporal gyrus; Electrode Z: posterior paracentral lobule, anterior part of superior parietal lobule; Electrode K: anterior precuneus, posterior part of superior parietal lobule; Electrode D: intermediate fusiform gyrus, posterior part of inferior and of middle temporal gyrus; Electrode U: intermediate part of superior temporal gyrus; Electrode W: transverse temporal gyrus, posterior part of superior temporal gyrus; Electrode S: lateral insula, central operculum.