Utilizing Excitatory and Inhibitory Activity Derived from Interictal Intracranial Electroencephalography as Potential Biomarkers for Epileptogenicity
Epileptogenic zones (EZs), where epileptic seizures cease after resection, are localized by assessing the seizure-onset zone using ictal electroencephalography (EEG). Owing to the difficulty in capturing unpredictable seizures, biomarkers capable of identifying EZs from interictal EEG are anticipate...
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| Format: | Article |
| Language: | English |
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The Japan Neurosurgical Society
2024-02-01
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| Series: | Neurologia Medico-Chirurgica |
| Subjects: | |
| Online Access: | https://www.jstage.jst.go.jp/article/nmc/64/2/64_2023-0207/_pdf/-char/en |
| _version_ | 1797269120313458688 |
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| author | Keisuke NAGATA Naoto KUNII Seijiro SHIMADA Nobuhito SAITO |
| author_facet | Keisuke NAGATA Naoto KUNII Seijiro SHIMADA Nobuhito SAITO |
| author_sort | Keisuke NAGATA |
| collection | DOAJ |
| description | Epileptogenic zones (EZs), where epileptic seizures cease after resection, are localized by assessing the seizure-onset zone using ictal electroencephalography (EEG). Owing to the difficulty in capturing unpredictable seizures, biomarkers capable of identifying EZs from interictal EEG are anticipated. Recent studies using intracranial EEG have identified several potential candidate biomarkers for epileptogenicity. High-frequency oscillation (HFO) was initially expected to be a robust biomarker of abnormal excitatory activity in the ictogenic region. However, HFO-guided resection failed to improve seizure prognosis. Meanwhile, the regularity of low-gamma oscillations (30-80 Hz) indicates inhibitory interneurons' hypersynchronization, which could be used to localize the EZ. Besides resting-state EEG assessments, evoked potentials elicited by single-pulse electrical stimulation, such as corticocortical evoked potentials (CCEP), became valuable tools for assessing epileptogenic regions. CCEP responses recorded in the cortex remote from the stimulation site indicate functional connectivity, revealing increased internal connectivity within the ictogenic region and elevated inhibitory input from the non-involved regions to the ictogenic region. Conversely, large responses close to the stimulation site reflect local excitability, manifesting as an increased N1 amplitude and overriding HFO. Further research is required to establish whether these novel electrophysiological methods, either individually or in combination, can function as robust biomarkers of epileptogenicity and hold promise for improving seizure prognosis. |
| first_indexed | 2024-04-25T01:43:19Z |
| format | Article |
| id | doaj.art-8f924b5529d5412b8df5a6affffef8b5 |
| institution | Directory Open Access Journal |
| issn | 1349-8029 |
| language | English |
| last_indexed | 2024-04-25T01:43:19Z |
| publishDate | 2024-02-01 |
| publisher | The Japan Neurosurgical Society |
| record_format | Article |
| series | Neurologia Medico-Chirurgica |
| spelling | doaj.art-8f924b5529d5412b8df5a6affffef8b52024-03-08T00:46:57ZengThe Japan Neurosurgical SocietyNeurologia Medico-Chirurgica1349-80292024-02-01642657010.2176/jns-nmc.2023-02072023-0207Utilizing Excitatory and Inhibitory Activity Derived from Interictal Intracranial Electroencephalography as Potential Biomarkers for EpileptogenicityKeisuke NAGATA0Naoto KUNII1Seijiro SHIMADA2Nobuhito SAITO3Department of Neurosurgery, The University of TokyoDepartment of Neurosurgery, Jichi Medical UniversityDepartment of Neurosurgery, The University of TokyoDepartment of Neurosurgery, The University of TokyoEpileptogenic zones (EZs), where epileptic seizures cease after resection, are localized by assessing the seizure-onset zone using ictal electroencephalography (EEG). Owing to the difficulty in capturing unpredictable seizures, biomarkers capable of identifying EZs from interictal EEG are anticipated. Recent studies using intracranial EEG have identified several potential candidate biomarkers for epileptogenicity. High-frequency oscillation (HFO) was initially expected to be a robust biomarker of abnormal excitatory activity in the ictogenic region. However, HFO-guided resection failed to improve seizure prognosis. Meanwhile, the regularity of low-gamma oscillations (30-80 Hz) indicates inhibitory interneurons' hypersynchronization, which could be used to localize the EZ. Besides resting-state EEG assessments, evoked potentials elicited by single-pulse electrical stimulation, such as corticocortical evoked potentials (CCEP), became valuable tools for assessing epileptogenic regions. CCEP responses recorded in the cortex remote from the stimulation site indicate functional connectivity, revealing increased internal connectivity within the ictogenic region and elevated inhibitory input from the non-involved regions to the ictogenic region. Conversely, large responses close to the stimulation site reflect local excitability, manifesting as an increased N1 amplitude and overriding HFO. Further research is required to establish whether these novel electrophysiological methods, either individually or in combination, can function as robust biomarkers of epileptogenicity and hold promise for improving seizure prognosis.https://www.jstage.jst.go.jp/article/nmc/64/2/64_2023-0207/_pdf/-char/enepilepsyepileptogenic zonegamma oscillationccepexcitatory-inhibitory balance |
| spellingShingle | Keisuke NAGATA Naoto KUNII Seijiro SHIMADA Nobuhito SAITO Utilizing Excitatory and Inhibitory Activity Derived from Interictal Intracranial Electroencephalography as Potential Biomarkers for Epileptogenicity Neurologia Medico-Chirurgica epilepsy epileptogenic zone gamma oscillation ccep excitatory-inhibitory balance |
| title | Utilizing Excitatory and Inhibitory Activity Derived from Interictal Intracranial Electroencephalography as Potential Biomarkers for Epileptogenicity |
| title_full | Utilizing Excitatory and Inhibitory Activity Derived from Interictal Intracranial Electroencephalography as Potential Biomarkers for Epileptogenicity |
| title_fullStr | Utilizing Excitatory and Inhibitory Activity Derived from Interictal Intracranial Electroencephalography as Potential Biomarkers for Epileptogenicity |
| title_full_unstemmed | Utilizing Excitatory and Inhibitory Activity Derived from Interictal Intracranial Electroencephalography as Potential Biomarkers for Epileptogenicity |
| title_short | Utilizing Excitatory and Inhibitory Activity Derived from Interictal Intracranial Electroencephalography as Potential Biomarkers for Epileptogenicity |
| title_sort | utilizing excitatory and inhibitory activity derived from interictal intracranial electroencephalography as potential biomarkers for epileptogenicity |
| topic | epilepsy epileptogenic zone gamma oscillation ccep excitatory-inhibitory balance |
| url | https://www.jstage.jst.go.jp/article/nmc/64/2/64_2023-0207/_pdf/-char/en |
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