Semiologic subgroups of insulo‐opercular seizures based on connectional architecture atlas

Abstract

Objective: Insulo-opercular seizures are characterized by diverse semiology, related to the insula's multiple functional roles and extensive connectivity. We aimed to identify semiologic subgroups and correlate these with insulo-opercular subregions based on connectional architecture. Methods: We retrospectively collected a large series of 37 patients with insuloopercular seizures explored by stereoelectroencephalography (SEEG) from three epilepsy centers. A new human brain atlas (Brainnetome Atlas, BNA) based on both anatomic and functional connections was employed to segment insulo-opercular cortex. Semiology and SEEG changes were carefully reviewed and quantified. Principal component analysis and cluster analysis were used to correlate semiologic characteristics with insulo-opercular subregions. Results: Four main semiologic subgroups were identified, organized along an anteroventral to posterodorsal axis based on BNA. Group 1 was characterized by epigastric sensation and/or integrated gestural motor behaviors with or without feelings of fear or rage, involving the anteroventral insular regions and mesial temporal lobes. Group 2 was characterized by auditory sensations and symmetric proximal/axial tonic signs involving the posteroventral temporal operculum. The characteristics of group 3 were orofacial and laryngeal signs, involving the intermediate insulo-opercular regions.The features of group 4 were somatosensory signs followed by nonintegrated gestural motor behaviors and/or asymmetric tonic signs involving the posterodorsal insuloopercular regions with propagation to the mesial frontal lobes. Thus anteroventral seizure organizations predominantly showed limbic system semiology, whereas more posterodorsal regions were associated with semiology involving mainly the sensorimotor system. Subjective symptoms proved to be particularly discriminating factors. Significance: Insulo-opercular seizures can be categorized in terms of clinical semiology and correlate with connectional architecture subregions along an anteroventral-posterodorsal axis in line with the cytoarchitectonic gradient rather than the gyral anatomy [Corrections added on May 13, 2020, after first online publication: Affiliations of authors "Xiu Wang" and "Xiao Wang" were changed from 5 and 6 to 4 and 5.] | 985 WANG et Al.

Ictal blinking in focal seizures: Insights from SEEG recordings

“…Benbadis et al showed that unilateral blinking could be a reliable lateralizing sign after he described 38 seizures in 14 patients, with unilateral blinking ipsilateral to the lesion in 10, which led to a positive predictive value for ipsilateral ictal EEG localization of 83% [5]. Ipsilateral blinking has been found to be a frequent sign in insular seizures [11,12]. Cases reports have reported similar features using scalp EEG [8,9].…”

“…Ictal blinking has been reported to be a frequent early sign in occipital lobe seizures [7], but has been also observed in other forms of epilepsies as temporal, frontal lobe or insular seizures [8][9][10][11][12].…”

“…Others authors suggested also a frontal origin mostly based on scalp EEG recordings [5,8,9]. Recent papers have also emphasize its frequency in insular epilepsies [11,12].…”

Sleep-Related Hypermotor Epilepsy: Etiology, Electro-Clinical Features, and Therapeutic Strategies

“…64 Each patient also expressed fear because the ventral anterior insula is involved in emotional processing. 100,101 According to the anatomic-electro-clinical data of insular lobe epilepsy by Wang et al, 102 based on the Brainnetome Atlas, the semiology followed the anteroposterior "anteroventral to posterodorsal axis" distribution pattern. The semiology pattern in a group of patients with an epileptic network involving the anteroventral insular regions showed integrated gestural motor behaviors or feelings of rage or fear, whereas that in a group of patients with an epileptic network involving the posterodorsal insular regions showed non-integrated gestural motor behaviors or asymmetric tonic posture (Figure 2).…”

Unilateral Blinking: Insights from Stereo-EEG and Tractography

“…Ictal blinking has been described in epilepsy patients, most frequently with parieto-occipital and insulo-opercular seizure onsets and typically manifested bilaterally (Marchi et al 2016 ; Lagarde et al 2020 ; Peltola et al 2020 ; Wang et al 2020 ). Unilateral blinking only occurred in association with an activation of the mesial temporal lobe in a large-scaled SEEG study (Lagarde et al 2020 ).…”