Objective: The goal of this study was to investigate the spatial extent and functional organization of the epileptogenic network through cortico-cortical evoked potentials (CCEPs) in patients being evaluated with intracranial stereoelectroencephalography.
Methods: We retrospectively included 25 patients. We divided the recorded sites into three regions: epileptogenic zone (EZ); propagation zone (PZ); and noninvolved zone (NIZ). The root mean square of the amplitudes was calculated to reconstruct effective connectivity network. We also analyzed the N1/N2 amplitudes to explore the responsiveness influenced by epileptogenicity. Prognostic analysis was performed by comparing intra-region and inter-region connectivity between seizure-free and non-seizure-free groups.
Results: Our results confirmed that stimulation of the EZ caused the strongest responses on other sites within and outside the EZ. Moreover, we found a hierarchical connectivity pattern showing the highest connectivity strength within EZ, and decreasing connectivity gradient from EZ, PZ to NIZ. Prognostic analysis indicated a stronger intra-EZ connection in the seizure-free group.
Conclusion: The EZ showed highest excitability and dominantly influenced other regions. Quantitative CCEPs can be useful in mapping epileptic networks and predicting surgical outcome.
Significance: The generated computational connectivity model may enhance our understanding of epileptogenic networks and provide useful information for surgical planning and prognosis prediction.
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http://dx.doi.org/10.1016/j.clinph.2020.08.012 | DOI Listing |
Chaos
January 2025
Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China.
Generally, epilepsy is considered as abnormally enhanced neuronal excitability and synchronization. So far, previous studies on the synchronization of epileptic brain networks mainly focused on the synchronization strength, but the synchronization stability has not yet been explored as deserved. In this paper, we propose a novel idea to construct a hypergraph brain network (HGBN) based on phase synchronization.
View Article and Find Full Text PDFEpilepsia
January 2025
Department of Neurology, The University of Alabama at Birmingham, Birmingham, Alabama, USA.
Objective: Temporal encephaloceles (TEs) are seen in patients with drug-resistant epilepsy (DRE); yet they are also common incidental findings. Variability in institutional pre-surgical epilepsy practices and interpretation of epileptogenic network localization contributes to bias in existing epilepsy cohorts with TE, and therefore the relevance of TE in DRE remains controversial. We sought to estimate effect sizes and sample sizes necessary to demonstrate clinically relevant improvements in seizure outcome with different surgical approaches.
View Article and Find Full Text PDFJ Neurol
January 2025
Epilepsy Unit - Sleep Disorders Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.
Background: Temporal lobe epilepsy with isolated amygdala enlargement (TLE-AE) still lacks a definite characterization and controversies exist.
Methods: We conducted a retrospective study identifying brain MRI scans with isolated AE between 2015 and 2021. We collected clinical and paraclinical data of patients with TLE-AE and evaluated the outcome.
Eur J Neurol
January 2025
Department of Neurosurgery, Medical University of Vienna, Vienna, Austria.
Background: Temporal lobe epilepsy (TLE) can lead to structural brain abnormalities, with thalamus atrophy being the most common extratemporal alteration. This study used probabilistic tractography to investigate the structural connectivity between individual thalamic nuclei and the hippocampus in TLE.
Methods: Thirty-six TLE patients who underwent pre-surgical 3 Tesla magnetic resonance imaging (MRI) and 18 healthy controls were enrolled in this study.
Neurophysiol Clin
January 2025
Neuroscience and Human Genetics Department, Meyer Children's Hospital IRCCS, Full Member of European Reference Network on Rare and Complex Epilepsies, EpiCARE, viale Pieraccini 24, 50139, Florence, Italy; Neurofarba Department, University of Florence, viale Pieraccini 6, 50139, Florence, Italy.
Stereo-EEG is not just a diagnostic examination but a complex methodology, requiring an accurate synthesis of many data (anatomical, clinical, neurophysiological, cognitive, metabolic, and genetic). The implantation scheme is decided based on a hypothesis (or hypotheses) of epileptogenic zone localization. Subsequently, intracerebral electrical stimulation is used to define the extent of highly functional cortical regions and to reproduce the clinical symptoms and signs associated with seizures.
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