Figures
Figure 1
Implantation scheme and example of ictal “pure occipital” discharge during invasive EEG monitoring. Note the rapid rhythms of discharge in the occipital lobe, predominant in the lingual gyrus and cuneus. Seizure onset zone is depicted in red. Visual subjective symptoms began two seconds after the onset of the discharge. Low filter: 0.530 Hz; high filter: 120 Hz, 35 sec; amplitude: 600 μV/cm. LP and LA mesial plots correspond to within the MRI lesion in the cuneus, OI mesial plots correspond to within the lingual gyrus, and PO mesial plots correspond to within the cuneus gyrus outside the MRI lesion.
Figure 1
Figure 2
Number of different seizure semiology patterns according to dorsal or ventral propagation pathways (n =20), in the global population (n =20), DD group (n =12), and VD group (n =8).
Figure 2
Figure 3
Objective seizure semiology in the global population (blue), DD group (red) and VD group (green), expressed as number of patients. The subjective symptoms (aura) are not listed.
Figure 3
Figure 4
Earliest ictal symptom according to age. One child aged 13 years old had two types of seizures: infantile spams and isolated loss of consciousness.
Figure 4
Figure 5
MRI (sagittal view) of five patients from the series. Left: during SEEG with depth electrodes; the SOZ is delineated in grey and arrows symbolize the seizure propagation pathway. Right: after surgery.
Figure 5
Figure 6
Implantation scheme and example of “occipital +” ictal discharge during invasive EEG monitoring. Note the rapid rhythms of discharge on internal plots for TB, PA, OI, OS and PA electrodes, maximal on the internal plots for OI, OS and TB. The discharge is wider than for the “pure occipital” SOZ (see Figure 1 ). On the implantation scheme, electrodes included in the SOZ are circled in grey. Objective visual symptoms (head and left eye deviation) began three seconds after the onset of the discharge, as indicated by the second arrow. The first arrow indicates the beginning of the ictal discharge. Low filter: 0.530 Hz; high filter: 120 Hz, 15 seconds; amplitude: 600 μV/cm.
Figure 6
Tables
Authors
1 Colentina Clinical Hospital, Neurology Department, Bucharest, Romania
2 Pediatric Neurosurgery, Rothschild Foundation Hospital, Paris
3 Neurosurgery Department, CHU Rennes, Rennes
4 Neurology Department, CHU Rennes, Rennes, France
* Correspondence: Mathilde Chipaux
Pediatric Neurosurgery,
Rothschild Foundation Hospital,
Paris, France
Aims
Occipital epilepsy is the least common among surgical series because: (1) the location makes it hard to asses by EEG; (2) the seizure semiology often reflects propagation; and (3) surgery entails a high risk of neurological deficits. In children, subjective symptoms are harder to assess, adding to the difficulty of a proper diagnosis.