Abstract
ObjectiveEpileptic seizures with insular genesis are often difficult to distinguish from those originating in the temporal lobe due to their complex and variable semiology. Here, we analyzed differentiating characteristics in the clinical spectrum of insulo-opercular seizures.MethodsIctal semiology in patients with a diagnosis of insulo-opercular epilepsy (IOE) based on imaging of epileptogenic lesions or electrophysiological evidence of an insulo-opercular seizure origin was retrospectively analyzed and compared to age-matched controls with mesial temporal lobe epilepsy (MTE).ResultsForty-six IOE and 46 matched MTE patients were included. The most prominent ictal features in IOE were focal motor phenomena in 80.4% of these patients. Somatosensory sensations, version, tonic and clonic features, when present, were more frequent contralateral to the SOZ in MTE patients, while they occurred about equally often ipsilateral and contralateral to the SOZ in IOE patients. Ipsilateral manual automatisms were significantly more frequent in MTE patients than in IOE (p = 0.010). Multivariate analysis correctly identified IOE in 78.3% and MTE in 84.8% using five semiologic features (Chi-square = 53.79 with 5 degrees of freedom, p < 0.0001). A subanalysis comparing patients with purely insular lesions with MTE patients using only the earliest ictal signs showed that somatosensory sensations are significantly more frequent in insular epilepsy (p = 0.010), while automatisms were significantly more frequent in MTE patients (p = 0.06).SignificanceOur study represents the first in-depth analysis of ictal semiology in IOE compared to MTE. Use of these differentiating characteristics can serve for a correct syndrome classification and to steer appropriate diagnostic and local therapeutic procedures.
Highlights
Among focal epilepsies, insulo-opercular epilepsy (IOE) poses particular problems in its identification and treatment
This IOE cohort was compared to 46 age-matched patients with previous successful selective amygdalohippocampectomy for drug-refractory mesial temporal lobe epilepsy (MTE) (Engel I outcome at a minimum of 12 months after surgery)
The study was approved by the Ethics Review Board of the University Medical Center Freiburg and the patients gave their written consent that the data collected for presurgical epilepsy diagnosis may be used for scientific evaluation. This series consists of 46 patients with IOE (27 women, mean age at evaluation 28 years; mean age at onset 16 years, mean duration of epilepsy 12 years) and 46 MTE patients with a lesion in the same hemisphere and approximately the same age at presurgical workup
Summary
Insulo-opercular epilepsy (IOE) poses particular problems in its identification and treatment. An improved understanding of semiological features of insulo-opercular epilepsy remains essential to raise suspicion for this syndrome. The patient numbers included in previous reports on insulo-opercular seizure semiology have frequently been low [13,14,15]. Ictal semiology of insulo-opercular seizures comprises various non-specific patterns including somatosensory/viscerosensory, autonomic, speech-related abnormalities, fear and a variety of motor signs including automatisms [16, 17]. These semiological features are not exclusive to IOE but are found in frontal and temporal lobe epilepsy
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
