Interictal EEG during sleep displaying right frontal polyspikes with a phase reversal at F4, also visible over the midline and homologous contralateral territories. Bipolar longitudinal followed by bipolar transversal montages, followed by EKG and EMG electrodes for the left and right deltoids. HPF: 1.6 Hz; LPF: 120 Hz; notch: 50 Hz.
Ictal EEG during wakefulness displaying a startle-reflex seizure elicited by a sensory stimulus (sudden touch of the left leg: black vertical bar). Note the right ictal activity starting with a fast-rhythmic discharge, most prominent in the fronto-central channels, followed by a polymorphic diffuse slowing. The green vertical bar marks the clinical onset. Note the associated myogenic potential in the contralateral deltoid. Bipolar longitudinal, followed by bipolar transversal montages, followed by EKG and EMG electrodes for the left and right deltoids. HPF: 1.6 Hz; LPF: 15 Hz; notch: 50 Hz.
MRI co-registered with 18 FDG-PET, demonstrating right frontal premotor ventral hypometabolism (cross sign). The corresponding T1-weighted MRI image does not show any obvious abnormality.
Personalized volumetric reconstruction of the patient's right hemisphere displaying the stereotactic localization of the 11 intracerebral electrodes (first SEEG study). The reconstruction was performed with FreeSurfer software and the colours mark the precentral gyrus (blue) and the postcentral gyrus (red).
Interictal SEEG activity showing continuous spiking over the lateral contacts of electrodes H (premotor accessory inferior frontal gyrus [IFG]) and N (premotor MFG gyrus). Intracranial bipolar channels between adjunct electrodes exploring key cortical structures followed by EKG and EMG channels for left and right deltoid and quadriceps. HPF: 0.001 Hz; LPF: 300 Hz; notch: 50 Hz. ACC: anterior cingulate cortex; Ant-Sup INS: anterior-superior insular cortex; DMPFC: dorsomedial prefrontal cortex; IFG PFC: lateral prefrontal cortex, frontal inferior gyrus; IFG PMC: lateral premotor cortex, frontal inferior gyrus; M1C: primary motor cortex (precentral gyrus); MCC: middle cingulate cortex; MFG PFC: lateral prefrontal cortex, frontal middle gyrus; MFG PMC: lateral premotor cortex, frontal middle gyrus; MOFC: medial orbitofrontal cortex; OFC: orbitofrontal cortex; OpF: frontal operculum; OpR: Rolandic operculum; SFG: superior frontal gyrus; SFG PFC: lateral prefrontal cortex, frontal superior gyrus; SFG PMC: lateral premotor cortex, frontal superior gyrus Sup INS: superior insular cortex.
Ictal SEEG activity showing LVFA (green vertical line marks the debut), superimposed on a slow wave at the middle and lateral contacts of electrodes M (primary motor hand area) and internal and middle contacts of the electrode R (insula and Rolandic operculum). The pathological interictal H and N electrodes display a propagation pattern composed of small polyspikes that precede the LVFA on M and R, followed by a large spike and a flattening. Montage and filters as for
. figure 5
Personalized volumetric reconstruction of the patient's right hemisphere, displaying the intracerebral stereotactic location of the second SEEG implantation. Note the new electrodes in comparison to
. A: posterior IFG; C: posterior IFS; L: motor face area; P: sensory hand area; S: posterior Rolandic operculum; L: temporal operculum and the disappearance of electrodes K, J, Y in the prefrontal cortex and O in the orbitofrontal cortex. Reconstruction and colours are the same as for figure 3 . figure 3
Ictal SEEG activity showing a short startle-reflex seizure elicited by a sudden noise (hand clap: green vertical line). LVFA superimposed on a slow wave on the middle and lateral contacts of electrode C (IFS in the premotor cortex). A phase reversal was observed between C3-C4 and C5-C6. The discharge propagated over the M electrode (primary hand motor area), L electrode (primary face motor area) and A (IFG gyrus in the premotor cortex). Note the associated short myogenic potential in the contralateral deltoid. Montage and filters as for
. ACC: anterior cingulate cortex; IFG PFC: lateral prefrontal cortex, frontal inferior gyrus; IFG PMC: lateral premotor cortex, frontal inferior gyrus; M1C: primary motor cortex (precentral gyrus); MCC: middle cingulate cortex; MFG PFC: lateral prefrontal cortex, frontal middle gyrus; MFG PMC: lateral premotor cortex, frontal middle gyrus; OpF: frontal operculum; OpR: Rolandic operculum; OpP: parietal operculum; OpT: temporal operculum; Post INS: posterior insular cortex; S1C: primary sensory cortex (postcentral gyrus); SFG PFC: lateral prefrontal cortex, frontal superior gyrus; SFG PMC: lateral premotor cortex, frontal superior gyrus; Sup INS: superior insular cortex. figure 5
Right: preoperative drawing of the resective surgery. Left: postoperative surgical cavity, with the position of the electrodes R and H marked with paper labels.
Van Gogh Epilepsy Surgery Unit, Neurology Department, CIC 1414, University Hospital, Rennes, France
Physics Department, University of Bucharest, Bucharest, Romania
Neurology Department, Grenoble University Hospital, Grenoble, France
Grenoble Neuroscience Institute, Grenoble Alpes University, Grenoble, France
Laboratory of Signal and Image Analysis, INSERM U1099, University Rennes 1, France
Neurology Department, University Emergency Hospital, Bucharest, Romania
Neurology Department, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
Claudio Munari Epilepsy Surgery Centre, Neurosciences Department, GOM Niguarda Hospital, Milano, Italy
Correspondence: Mihai Dragos Maliia
Van Gogh Epilepsy Surgery Unit,
CIC 1414, University Hospital,
The SEEG International Course, organised in 2017, focused on the investigation and surgery of insulo-perisylvian epilepsies. We present one representative complex case that was discussed. The patient had seizures displaying startle/reflex components. He was MRI negative, while other non-invasive investigations offered only partially concordant data. Initial SEEG exploration resulted in an incomplete definition of the epileptogenic zone. A second SEEG followed, which led to a thorough assessment of the seizure onset zone and the epileptic network, localised to the lateral inferior premotor cortex, explaining the incongruent data obtained beforehand. This was the basis of a tailored resection with a favourable outcome. The patient has been seizure-free for five years without any motor nor cognitive deficits, but with pharmacodependence to one AED. The electroclinical reasoning is presented, accompanied by relevant commentaries and recommendations from the tutors [
Published with video sequences].