Morphological Description of Frontal EEG Interictal and Ictal Discharges in an Adult Cohort of 175 Patients

Sep 10, 2026

Clinical and electroencephalogram (EEG) features in frontal lobe epilepsy vary substantially, making diagnosis difficult. This prospective cross-sectional study enrolled adults with frontal interictal epileptiform discharges (IED) after clinical events compatible with epileptic seizures, then analyzed interictal and ictal EEG using statistical methods to characterize morphology. The ictal onset morphological seizure pattern stayed globally stable over time, isolated sharp waves were most frequent IED waveforms, and frontal seizures were often short and sometimes clustered, with subtle ictal electrical expression. Findings support differentiation of frontal lobe epilepsy cases and reduce false negatives in EEG interpretation.

LanguageEnglish

CategoryResearch & Report

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Pages13

Reading Time33 min

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Abstract

Introduction

Frontal lobe epilepsy classification and diagnostic challenges

Interictal epileptiform discharges and ictal EEG features

Article Morphological Description of Frontal EEG Interictal and Ictal Discharges in an Adult Cohort of 175 Patients Beatriz Garc½a-Lâpez 1, Mar½a Sueiras-Gil 2, Ana Isabel Gâmez-Men²ndez 1, Fernando V¡zquez-S¡nchez 3, *, Mar½a Carmen Lloria-Gil 1, Jerânimo J. Gonz¡lez-Bernal 4, Josefa Gonz¡lez-Santos 4,*, Mirian Santamar½a-Pela²z 4, Raól Soto-C¡mara 4, * and Troels Wesenberg Kjaer 5 􀀁􀀂􀀃􀀁􀀄 􀀆􀀇􀀈 􀀁􀀂􀀃􀀄􀀅􀀆􀀇 Citation: García-López, B.; Sueiras-Gil, M.; Gómez-Menéndez, A.I.; Vázquez-Sánchez, F.; Lloria-Gil, M.C.; González-Bernal, J.J.; González-Santos, J.; Santamaría-Pelaéz, M.; Soto-Cámara, R.; Wesenberg Kjaer, T. Morphological Description of Frontal EEG Interictal and Ictal Discharges in an Adult Cohort of 175 Patients. J. Clin. Med. 2021, 10, 1219 . [https://doi.org/10.3390/jcm10061219](https://doi.org/10.3390/jcm10061219) Academic Editors: Lindsay A. Farrer, Umberto Aguglia and Sang Ryong Kim Received: 10 January 2021 Accepted: 11 March 2021 Published: 15 March 2021 Publisher's Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional afﬁliations. Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ([https://](https://)[ ](https://)[creativecommons.org/licenses/by/](creativecommons.org/licenses/by/)[ ](creativecommons.org/licenses/by/)[4.0/](4.0/)) . 1 Neurophysiology Department, Burgos University Hospital, 09006 Burgos, Spain; [bgarcialo@saludcastillayleon.es](bgarcialo@saludcastillayleon.es) (B.G.-L.); [agomm@saludcastillayleon.es](agomm@saludcastillayleon.es) (A.I.G.-M.); [mclloriag@saludcastillayleon.es](mclloriag@saludcastillayleon.es) (M.C.L.-G.) 2 Neurophysiology Department, Valld'Hebron University Hospital, 08035 Barcelona, Spain; [msueiras@vhebron.net](msueiras@vhebron.net) 3 Neurology Department, Burgos University Hospital, 09006 Burgos, Spain 4 Department of Health Sciences, University of Burgos, 09001 Burgos, Spain; jejavier@ubu.es (J.J.G.-B.); [mspelaez@ubu.es](mspelaez@ubu.es) (M.S.-P.) 5 Sjællands Universitets Hospital, 4000 Roskilde, Denmark; [twk@regionsjaelland.dk](twk@regionsjaelland.dk) * Correspondence: fvazsan@saludcastillayleon.es (F.V.-S.); mjgonzalez@ubu.es (J.G.-S.); [rscamara@ubu.es](rscamara@ubu.es) (R.S.-C.) Abstract: Clinical and electroencephalogram (EEG) features in frontal lobe epilepsy (FLE) vary considerably among patients, making the diagnosis a challenge. The objective of this study was to describe interictal and ictal EEG activity, identifying variables that could help to differentiate and diagnose frontal lobe epilepsy cases. A prospective cross-sectional study from patients with frontal interictal epileptiform discharges (IED) referred to the Vall d'Hebron University Hospital (Barcelona, Spain) after a clinical event compatible with epileptic seizures was designed. The interictal and ictal activity were analyzed to provide a detailed EEG description of the cases, using different statistical analyses. The morphological seizure pattern at the ictal onset remained globally unchanged over time in seizures arising from the frontal lobe for each patient. Isolated sharp waves were the most frequent waveforms in the expression of IED. Frontal lobe seizures are frequently short and sometimes appear grouped in clusters within the same recording. Often the ictal expression of the electrical activity in frontal lobe seizure is subtle and challenging to interpret. A description of the main ﬁndings is summarized to identify seizures arising from the frontal lobe and avoid false negatives ﬁndings in EEG interpretations. Keywords: EEG; frontal lobe seizures; electroencephalography; EEG discharges in focal epilepsy; EEG morphology 1. Introduction Frontal lobe epilepsy (FLE) is the second most frequent type of focal epilepsy. Most series are surgical, which may introduce se

FAQs

What was the main objective of the study on frontal lobe epilepsy EEG?

To describe interictal and ictal EEG activity and identify variables that could help differentiate and diagnose cases of frontal lobe epilepsy.

How stable was the morphological seizure pattern at ictal onset over time?

The morphological seizure pattern at ictal onset remained globally unchanged over time in seizures arising from the frontal lobe for each patient.

What EEG features were most frequent and why is interpretation challenging?

Isolated sharp waves were the most frequent waveforms for IED expression. Interpretation is challenging because ictal electrical activity in frontal lobe seizures is often subtle and can be obscured by artifacts, leading to false negatives if not carefully assessed.

Sep 10, 2026

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