Maria E Peltola1, Agnès Trébuchon2, Stanislas Lagarde2, Didier Scavarda3, Romain Carron4, Liisa Metsähonkala5, Leena Lauronen6, Anne Lépine7, Nathalie Villeneuve7, Fabrice Bartolomei2. 1. Epilepsia Helsinki, HUS Medical Imaging Center, Clinical Neurophysiology, Helsinki University Hospital, University of Helsinki, Helsinki, Finland. Electronic address: maria.peltola@hus.fi. 2. Aix Marseille Univ, APHM, INSERM, INS, Inst Neurosci Syst, Timone Hospital, Epileptology Department, Marseille, France. 3. Aix Marseille Univ, APHM, INSERM, INS, Inst Neurosci Syst, Timone Hospital, Pediatric Neurosurgery Department, Marseille, France. 4. Aix Marseille Univ, APHM, INSERM, INS, Inst Neurosci Syst, Timone Hospital, Functional and Stereotactic Neurosurgery Department, Marseille, France. 5. Epilepsia Helsinki, Department of Pediatric Neurology, Helsinki University Hospital, Helsinki, Finland. 6. Epilepsia Helsinki, HUS Medical Imaging Center, Clinical Neurophysiology, Helsinki University Hospital, University of Helsinki, Helsinki, Finland. 7. APHM, Timone Hospital, Pediatric Neurology Department, Marseille, France.
Abstract
PURPOSE: In this study, we aimed to improve our knowledge of insular epilepsy by studying anatomoelectroclinical correlations in pure insular-onset epilepsy and characterizing differences between anterior and posterior insular-onset seizures. METHODS: Patients in whom seizure-onset zone was confined to the insula and peri-insular sulcus were selected from 301 consecutive presurgical stereo-electroencephalography (EEG) recordings performed between years 2010 and 2017 in two epilepsy centers. Ictal-onset zone in stereo-EEG was delineated visually and quantitatively using epileptogenic index method. Seizure characteristics were reanalyzed, and anatomoelectroclinical correlations were assessed. Characteristics of posterior and anterior insular-onset seizures were compared. RESULTS: Eleven insular cases were identified, five of them with an anterior insular seizure onset and six with a posterior one. Nonpainful somatosensory symptoms and autonomic symptoms were the most common symptoms (73% of patients) followed by speech-related symptoms (55%) and ipsilateral eye blinking (45%). Six patients had seizures restricted to somatosensory or viscerosensory symptoms. In all patients, seizures progressed to motor symptoms. Somatosensory symptoms did not differentiate anterior from posterior insular seizures. However, hyperkinetic signs, speech modifications, and viscerosensory symptoms were related to an anterior insular seizure-onset zone. Pain, asymmetric tonic, focal clonic, and tonic symptoms were more frequent in patients with a posterior insular seizure onset. CONCLUSIONS: Seizure semiology is heterogeneous in pure insular-onset epilepsy. Differences between the anterior and posterior insular seizures reflect the functional organization of the insula. Particularly, the different types of motor symptoms may help to distinguish anterior from posterior insular seizure onset.
PURPOSE: In this study, we aimed to improve our knowledge of insular epilepsy by studying anatomoelectroclinical correlations in pure insular-onset epilepsy and characterizing differences between anterior and posterior insular-onset seizures. METHODS:Patients in whom seizure-onset zone was confined to the insula and peri-insular sulcus were selected from 301 consecutive presurgical stereo-electroencephalography (EEG) recordings performed between years 2010 and 2017 in two epilepsy centers. Ictal-onset zone in stereo-EEG was delineated visually and quantitatively using epileptogenic index method. Seizure characteristics were reanalyzed, and anatomoelectroclinical correlations were assessed. Characteristics of posterior and anterior insular-onset seizures were compared. RESULTS: Eleven insular cases were identified, five of them with an anterior insular seizure onset and six with a posterior one. Nonpainful somatosensory symptoms and autonomic symptoms were the most common symptoms (73% of patients) followed by speech-related symptoms (55%) and ipsilateral eye blinking (45%). Six patients had seizures restricted to somatosensory or viscerosensory symptoms. In all patients, seizures progressed to motor symptoms. Somatosensory symptoms did not differentiate anterior from posterior insular seizures. However, hyperkinetic signs, speech modifications, and viscerosensory symptoms were related to an anterior insular seizure-onset zone. Pain, asymmetric tonic, focal clonic, and tonic symptoms were more frequent in patients with a posterior insular seizure onset. CONCLUSIONS:Seizure semiology is heterogeneous in pure insular-onset epilepsy. Differences between the anterior and posterior insular seizures reflect the functional organization of the insula. Particularly, the different types of motor symptoms may help to distinguish anterior from posterior insular seizure onset.