Université Paris Saclay-APHP, Neurophysiologie et Epileptologie, Le Kremlin Bicêtre, France
Univ. Grenoble Alpes, Inserm, GIN, Grenoble Institut des Neurosciences, 38000, Grenoble, France
Aix Marseille Univ, Inserm, INS, Institut de Neurosciences des Systèmes, Marseille, France
Service de Neurologie, CHU de Rennes, France
Service de Neurochirurgie, CHU de Grenoble, France
Hôpital Fondation Rothschild, Neurochirurgie pédiatrique, Paris, France
Université Paris Saclay-APHP, Neurochirurgie, Le Kremlin Bicêtre, France
Université Paris-Saclay, CEA, CNRS, Inserm, BioMaps, Orsay, France
Objective. The semiology of temporo-basal epilepsy has rarely been analysed in the literature. In this paper, we report three patients with proven basal temporal epilepsy with somatomotor or somatosensory facial ictal semiology, highly suggestive of insulo-opercular onset.
Methods. The three patients had a temporobasal lesion and their drugresistant epilepsy was cured with resection of the lesion (follow-up duration: 7-17 years). We reviewed the medical charts, non-invasive EEG data as well as the stereoelectroencephalography (SEEG) performed in two patients. Quantitative analysis of ictal fast gamma activity was performed for one patient.
Results. Early ictal features were orofacial, either somatomotor in two patients or ipsilateral somatosensory in one. The three patients had prior sensations compatible with a temporal lobe onset. Interictal and ictal EEG pointed to the temporal lobe. The propagation of the discharge to the insula and operculum before the occurrence of facial features was seen on SEEG. Facial features occurred 7-20 seconds after electrical onset. Quantitative analysis of six seizures in one patient confirmed the visual analysis, showing statistically significant fast gamma activity originating from basal areas and then propagating to insuloopercular regions after a few seconds.
Significance. We report three cases of lesional temporo-basal epilepsy responsible for orofacial semiology related to propagation of insulo-opercular ictal discharge. In MRI-negative patients with facial manifestations, this origin should be suspected when EEG is suggestive. These observations may contribute to our understanding of brain networks.