المؤلفون: Hidenori Sugano, Yasushi Iimura, Takumi Mitsuhashi, Tetsuya Ueda, Hiroharu Suzuki, Kazuki Nishioka, Hiroshi Otsubo

المصدر: Seizure. 94:23-25

مصطلحات موضوعية: Epilepsy, business.industry, General Medicine, Sulcus, Cortical dysplasia, medicine.disease, Epileptogenic zone, Magnetic Resonance Imaging, Electrophysiology, medicine.anatomical_structure, Nuclear magnetic resonance, Neurology, Dysplasia, Malformations of Cortical Development, Group I, medicine, Humans, In patient, Neurology (clinical), business, Subdural electrodes, Phase amplitude coupling

الوصف: Purpose The removal of the bottom of sulcus dysplasia (BOSD) often includes the gyral crown; however, this method has been controversial. We hypothesized that the epileptogenic zone of the BOSD does not include the gyral crown. To reveal the depth and extent of the epileptogenic zone of the BOSD, we applied the two electrophysiological modalities: (1) the occurrence rate (OR) of high-frequency oscillations (HFOs) and (2) modulation index (MI), reflecting the strength of phase-amplitude coupling between HFOs and slow oscillations. Methods We investigated the ripples [80-200 Hz] and fast ripples [200-300 Hz]) in HFOs and MI (HFOs [80-300 Hz] and slow oscillations [3-4 Hz]). We opened the sulcus at the BOSD and implanted the subdural electrodes directly over the MRI visible lesion. All patients (n = 3) underwent lesionectomy and the gyral crown was preserved. Results Pathological findings demonstrated focal cortical dysplasia type IIb and seizure freedom was achieved. The OR of the HFOs was not significantly different between the BOSD and the gyral crown. In contrast, the MI between HFOs and slow oscillations in the BOSD was significantly higher than that in the gyral crown. Conclusion High MI values distinguished the epileptogenic BOSD from the non-epileptogenic gyral crowns. MI could be a more informative biomarker of epileptogenicity than the OR of HFOs in a subset of patients with the BOSD.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::31b50fbea00922bb1d683e8c79ed21d1Test
https://doi.org/10.1016/j.seizure.2021.11.006Test

المؤلفون: Huijuan Ma, Zeyu Wang, Chunsheng Li, Jia Chen, Yuping Wang

المصدر: Frontiers in Neurology
Frontiers in Neurology, Vol 12 (2021)

مصطلحات موضوعية: medicine.medical_specialty, phase-amplitude coupling, frontal lobe epilepsy, modulation index, Electroencephalography, Epilepsy, Internal medicine, medicine, RC346-429, Electrocorticography, Original Research, electrocorticography, Receiver operating characteristic, medicine.diagnostic_test, business.industry, Epileptogenic zone, medicine.disease, Coupling (electronics), Neurology, Cardiology, Neurology. Diseases of the nervous system, Neurology (clinical), Epileptic seizure, medicine.symptom, business, epileptogenic zone, Phase amplitude coupling

الوصف: Objective: This study aimed to explore the characteristics of phase-amplitude coupling in patients with frontal epilepsy based on their electrocorticography data, in order to identify the localization of epileptic regions and further guide clinical resection surgery.Methods: We adopted the modulation index based on the Kullback-Leibler distance, phase-amplitude coupling co-modulogram, and time-varying phase-amplitude modulogram to explore the temporal-spatial patterns and characterization of PAC strength during the period from inter- seizure to post-seizure. Taking the resected area as the gold standard, the epileptogenic zone was located based on MI values of 7 different seizure periods, and the accuracy of localization was measured by the area under the receiver operating curve.Results: (1) The PAC in the inter- and pre-seizure periods was weak and paroxysmal, but strong PAC channels were confined more to the seizure-onset zone and resection region. PAC during the seizure period was intense and persistent, but gradually deviated from the seizure-onset zone. (2) The characteristics of coupling strength of the inter- and pre-seizure EEG can be used to accurately locate the epileptogenic zone, which is better than that in periods after the beginning of a seizure. (3) In an epileptic seizure, the preferred phases of coupling were usually in the rising branches at the pre- and early-seizure stages, while those in the middle- and terminal-seizure were usually in the falling branch. We thus speculate that the coupling occurred in the rising branch can promote the recruitment of abnormal discharge, while the coupling occurred in the falling branch can inhibit the abnormal discharge.Conclusion: The findings suggest that the phase-amplitude coupling during inter- and pre-seizure is a promising marker of epileptic focus location. The preferred phase of coupling changed regularly with the time of epileptic seizure, suggesting that the surge and suppression of abnormal discharges are related to different phases.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::d392692de8f9e8b4ad8fc463b6f6c2bdTest
http://europepmc.org/articles/PMC8458805Test

المؤلفون: Gregory A. Worrell, Federico Raimondo, Zachary J. Waldman, Diego Fernández Slezak, Jerome Engel, Anatol Bragin, Michael R. Sperling, Mustafa Donmez, Shennan A. Weiss, Richard J. Staba

المصدر: Biomarkers in medicine, vol 13, iss 5

مصطلحات موضوعية: phase–amplitude coupling, Clinical Biochemistry, Review, Brain tissue, Neurodegenerative, Medical Biochemistry and Metabolomics, 030204 cardiovascular system & hematology, HFO, computer.software_genre, Machine Learning, Epilepsy, 0302 clinical medicine, Drug Discovery, Medicine, Epilepsy surgery, ripple, Brain, artificial intelligence, fast ripple, 030220 oncology & carcinogenesis, Neurological, epilepsy surgery, CIENCIAS NATURALES Y EXACTAS, high frequency oscillation, PHASE-AMPLITUDE COUPLING, seizure, Clinical Sciences, High frequency oscillation, Machine learning, Medicinal and Biomolecular Chemistry, 03 medical and health sciences, high-frequency oscillation, wavelet, Humans, Oncology & Carcinogenesis, epileptiform spike, business.industry, phase amplitude coupling, Biochemistry (medical), Neurosciences, Neurophysiology, medicine.disease, Ciencias de la Computación, Brain Disorders, Ciencias de la Computación e Información, Refractory epilepsy, Artificial intelligence, business, computer, Medical Informatics, Biomarkers, Phase amplitude coupling

الوصف: Pathological high frequency oscillations (HFOs) are putative neurophysiological biomarkers of epileptogenic brain tissue. Utilizing HFOs for epilepsy surgery planning offers the promise of improved seizure outcomes for patients with medically refractory epilepsy. This review discusses possible machine learning strategies that can be applied to HFO biomarkers to better identify epileptogenic regions. We discuss the role of HFO rate, and utilizing features such as explicit HFO properties (spectral content, duration, and power) and phase-amplitude coupling for distinguishing pathological HFO (pHFO) events from physiological HFO events. In addition, the review highlights the importance of neuroanatomical localization in machine learning strategies. Fil: Weiss, Shennan A.. Thomas Jefferson University; Estados Unidos Fil: Waldman, Zachary. Thomas Jefferson University; Estados Unidos Fil: Raimondo, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Investigación en Ciencias de la Computación. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Investigación en Ciencias de la Computación; Argentina Fil: Fernandez Slezak, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Investigación en Ciencias de la Computación. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Investigación en Ciencias de la Computación; Argentina Fil: Donmez, Mustafa. Thomas Jefferson University; Estados Unidos Fil: Worrell, Gregory. Mayo Systems Electrophysiology Laboratory; Estados Unidos Fil: Bragin, Anatol. David Geffen School of Medicine at UCLA; Estados Unidos Fil: Engel, Jerome. David Geffen School of Medicine at UCLA; Estados Unidos Fil: Staba, Richard. David Geffen School of Medicine at UCLA; Estados Unidos Fil: Sperling, Michael. Thomas Jefferson University; Estados Unidos

وصف الملف: application/pdf

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b9efdc47a9d37dc720c94948817a3a9dTest
https://doi.org/10.2217/bmm-2018-0335Test

المؤلفون: Nuria Campora, Camilo J. Mininni, Sara Silvia Kochen, Sergio E. Lew

المصدر: Scientific Reports, Vol 9, Iss 1, Pp 1-8 (2019)
CONICET Digital (CONICET)
Consejo Nacional de Investigaciones Científicas y Técnicas
instacron:CONICET
Scientific Reports

مصطلحات موضوعية: 0301 basic medicine, Adult, Male, CIENCIAS MÉDICAS Y DE LA SALUD, Neurociencias, SEIZURE LOCATION, lcsh:Medicine, Seizure onset zone, Intracranial Electroencephalography, Stereoelectroencephalography, Article, 03 medical and health sciences, Epilepsy, Young Adult, 0302 clinical medicine, Seizures, Medicine, Humans, Epilepsy surgery, In patient, Ictal, lcsh:Science, Brain Mapping, PHASE AMPLITUDE COUPLING, Multidisciplinary, business.industry, lcsh:R, Brain, Electroencephalography, purl.org/becyt/ford/3.1 [https], medicine.disease, Electrodes, Implanted, Coupling (electronics), Medicina Básica, 030104 developmental biology, SEIZURE PREDICTION, Female, purl.org/becyt/ford/3 [https], lcsh:Q, business, Neuroscience, 030217 neurology & neurosurgery

الوصف: Understanding changes in brain rhythms provides useful information to predict the onset of a seizure and to localize its onset zone in epileptic patients. Brain rhythms dynamics in general, and phaseamplitude coupling in particular, are known to be drastically altered during epileptic seizures. However, the neural processes that take place before a seizure are not well understood. We analysed the phaseamplitude coupling dynamics of stereoelectroencephalography recordings (30 seizures, 5 patients) before and after seizure onset. Electrodes near the seizure onset zone showed higher phase-amplitude coupling. Immediately before the beginning of the seizure, phase-amplitude coupling dropped to values similar to the observed in electrodes far from the seizure onset zone. Thus, our results bring accurate information to detect epileptic events during pre-ictal periods and to delimit the zone of seizure onset in patients undergoing epilepsy surgery Fil: Cámpora, Nuria Elide. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Ingeniería Biomédica; Argentina Fil: Mininni, Camilo Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina Fil: Kochen, Sara Silvia. Universidad Nacional Arturo Jauretche. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Provincia de Buenos Aires. Ministerio de Salud. Hospital Alta Complejidad en Red El Cruce Dr. Néstor Carlos Kirchner Samic. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos; Argentina Fil: Lew, Sergio Eduardo. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Ingeniería Biomédica; Argentina

وصف الملف: application/pdf

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::da505a1f2f06e596bd0c2275bb65a331Test
http://link.springer.com/article/10.1038/s41598-019-56548-yTest

المؤلفون: Gerard Gooding-Williams, Jan-Mathijs Schoffelen, Georgina Rippon, Klaus Kessler, Robert A. Seymour

المصدر: Brain
Brain, 142, 10, pp. 3294-3305
Brain, 142, 3294-3305

مصطلحات موضوعية: Male, phase-amplitude coupling, 110 000 Neurocognition of Language, Adolescent, Sensory processing, Autism Spectrum Disorder, media_common.quotation_subject, medicine.medical_treatment, ASD, Visual processing, 03 medical and health sciences, 0302 clinical medicine, Perception, Neural Pathways, Connectome, medicine, Gamma Rhythm, Humans, Gray Matter, Visual hierarchy, media_common, 030304 developmental biology, Granger causality connectivity, 0303 health sciences, medicine.diagnostic_test, Brain, Magnetoencephalography, Electroencephalography, Original Articles, medicine.disease, Alpha Rhythm, Autism spectrum disorder, oscillations, Visual Perception, visual system, Autism, Female, Occipital Lobe, Neurology (clinical), Psychology, Occipital lobe, Neuroscience, 030217 neurology & neurosurgery, Neurotypical

الوصف: Autism Spectrum Disorder is often accompanied by sensory symptoms. Using magnetoencephalography to measure gamma and alpha band cortical activity in affected individuals, Seymour et al. corroborate the hypothesis that aberrant sensory processing is linked to atypical functional connectivity within and between areas of the visual system.
Autism spectrum disorder is increasingly associated with atypical perceptual and sensory symptoms. Here we explore the hypothesis that aberrant sensory processing in autism spectrum disorder could be linked to atypical intra- (local) and interregional (global) brain connectivity. To elucidate oscillatory dynamics and connectivity in the visual domain we used magnetoencephalography and a simple visual grating paradigm with a group of 18 adolescent autistic participants and 18 typically developing control subjects. Both groups showed similar increases in gamma (40–80 Hz) and decreases in alpha (8–13 Hz) frequency power in occipital cortex. However, systematic group differences emerged when analysing intra- and interregional connectivity in detail. First, directed connectivity was estimated using non-parametric Granger causality between visual areas V1 and V4. Feedforward V1-to-V4 connectivity, mediated by gamma oscillations, was equivalent between autism spectrum disorder and control groups, but importantly, feedback V4-to-V1 connectivity, mediated by alpha (8–13 Hz) oscillations, was significantly reduced in the autism spectrum disorder group. This reduction was positively correlated with autistic quotient scores, consistent with an atypical visual hierarchy in autism, characterized by reduced top-down modulation of visual input via alpha-band oscillations. Second, at the local level in V1, coupling of alpha-phase to gamma amplitude (alpha-gamma phase amplitude coupling) was reduced in the autism spectrum disorder group. This implies dysregulated local visual processing, with gamma oscillations decoupled from patterns of wider alpha-band phase synchrony (i.e. reduced phase amplitude coupling), possibly due to an excitation-inhibition imbalance. More generally, these results are in agreement with predictive coding accounts of neurotypical perception and indicate that visual processes in autism are less modulated by contextual feedback information.

وصف الملف: application/pdf

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e223e7cb10c012d9d30ad282a474a0b9Test
https://doi.org/10.1093/brain/awz214Test

المؤلفون: Takahiro Mihara, Takahisa Goto, Eishi Asano, Yutaro Takayama, Naoto Kuroda, Tomoyuki Miyazaki, Ethan Firestone, Keiko Wada, Kazuki Sakakura, Keiya Iijima, Masaki Iwasaki, Masaki Sonoda

المصدر: Clin Neurophysiol

مصطلحات موضوعية: Drug Resistant Epilepsy, Minimum alveolar concentration, Adolescent, Modulation index, Anesthesia, General, Article, Neurosurgical Procedures, Sevoflurane, Young Adult, Epilepsy, Physiology (medical), Seizure control, medicine, Humans, Prospective Studies, Child, business.industry, Brain, Epileptogenic zone, medicine.disease, Brain Waves, Sensory Systems, Neurology, Child, Preschool, Anesthesia, Anesthetics, Inhalation, Anesthetic, Neurology (clinical), Electrocorticography, Epilepsies, Partial, business, Phase amplitude coupling, Sevoflurane anesthesia, medicine.drug

الوصف: ObjectivePhase-amplitude coupling between high-frequency (≥150 Hz) and delta (3-4 Hz) oscillations - modulation index (MI) - is a promising, objective biomarker of epileptogenicity. We determined whether sevoflurane anesthesia preferentially enhances this metric within the epileptogenic zone.MethodsThis is an observational study of intraoperative electrocorticography data from 621 electrodes chronically implanted into eight patients with drug-resistant, focal epilepsy. All patients were anesthetized with sevoflurane during resective surgery, which subsequently resulted in seizure control. We classified ‘removed’ and ‘retained’ brain sites as epileptogenic and non-epileptogenic, respectively. Mixed model analysis determined which anesthetic stage optimized MI-based classification of epileptogenic sites.ResultsMI increased as a function of anesthetic stage, ranging from baseline (i.e., oxygen alone) to 2 minimum alveolar concentration (MAC) of sevoflurane, preferentially at sites showing higher initial MI values. This phenomenon was accentuated just prior to sevoflurane reaching 2 MAC, at which time, the odds of a site being classified as epileptogenic were enhanced by 86.6 times for every increase of 1 MI.ConclusionsIntraoperative MI best localized the epileptogenic zone immediately before sevoflurane reaching 2 MAC in this small cohort of patients.SignificanceProspective, large cohort studies are warranted to determine whether sevoflurane anesthesia can reduce the need for extraoperative, invasive evaluation.Highlights-We measured the modulation index on intraoperative electrocorticography recording.-Sevoflurane enhanced the modulation index differentially across the epileptogenic and non- epileptogenic sites.-The modulation index best discriminated these two groups of sites before sevoflurane reached 2 minimum alveolar concentration.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::6089f8ed3f74279f5dc6482e5831321dTest
https://doi.org/10.1101/2021.10.21.21265330Test

المؤلفون: Charles Quairiaux, Shahan Momjian, Laurent Spinelli, Andreas Kleinschmidt, M. Seeck, Pierre Mégevand, Christian Bénar, Serge Vulliemoz, Laurent Sheybani

المساهمون: Geneva University Hospital (HUG), University of Geneva [Switzerland], Institut de Neurosciences des Systèmes (INS), Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM), Hôpitaux Universitaires de Genève (HUG), Swiss National Science Foundation Grants 167836, CRSII5 170873 and 192749, CRS115- 180365 and 163398, ANR-17-HBPR-0005,SCALES,Mesures à plusieurs échelles dans des protocoles cognitifs grâce à des enregistrements simultanés de surface et de profondeur(2017), Université de Genève = University of Geneva (UNIGE)

المصدر: Epilepsia
Epilepsia, Wiley, 2021, 62 (10), pp.2357-2371. ⟨10.1111/epi.17020⟩
Epilepsia (2021)

مصطلحات موضوعية: Human epilepsy, Phase– amplitude coupling, Slow oscillations, Brain activity and meditation, Interictal epileptic discharges, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, [SDV.MHEP.CHI]Life Sciences [q-bio]/Human health and pathology/Surgery, 03 medical and health sciences, Epilepsy, Epileptic discharge, 0302 clinical medicine, Temporal lobe seizure, Medicine, Premovement neuronal activity, Humans, Ictal, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, Neurons, 0303 health sciences, business.industry, Intracranial recording, Electroencephalography, medicine.disease, Phase synchronization, Neuromodulation (medicine), ddc:616.8, Neurology, Epilepsy, Temporal Lobe, Neurology (clinical), Disease Susceptibility, business, Neuroscience, 030217 neurology & neurosurgery

الوصف: Objective: In patients with epilepsy, interictal epileptic discharges are a diag-nostic hallmark of epilepsy and represent abnormal, so- called “irritative” activity that disrupts normal cognitive functions. Despite their clinical relevance, their mechanisms of generation remain poorly understood. It is assumed that brain activity switches abruptly, unpredictably, and supposedly randomly to these epi-leptic transients. We aim to study the period preceding these epileptic discharges, to extract potential proepileptogenic mechanisms supporting their expression.Methods: We used multisite intracortical recordings from patients who under-went intracranial monitoring for refractory epilepsy, the majority of whom had a mesial temporal lobe seizure onset zone. Our objective was to evaluate the ex-istence of proepileptogenic windows before interictal epileptic discharges. We tested whether the amplitude and phase synchronization of slow oscillations (.5– 4Hz and 4– 7Hz) increase before epileptic discharges and whether the latter are phase- locked to slow oscillations. Then, we tested whether the phase- locking of neuronal activity (assessed by high- gamma activity, 60– 160Hz) to slow oscil-lations increases before epileptic discharges to provide a potential mechanism linking slow oscillations to interictal activities.Results: Changes in widespread slow oscillations anticipate upcoming epileptic discharges. The network extends beyond the irritative zone, but the increase in amplitude and phase synchronization is rather specific to the irritative zone. In contrast, epileptic discharges are phase- locked to widespread slow oscillations and the degree of phase- locking tends to be higher outside the irritative zone. Then, within the irritative zone only, we observe an increased coupling between slow oscillations and neuronal discharges before epileptic discharges.Significance: Our results show that epileptic discharges occur during vulnerable time windows set up by a specific phase of slow oscillations. The specificity of these permissive windows is further reinforced by the increased coupling of neu-ronal activity to slow oscillations. These findings contribute to our understanding of epilepsy as a distributed oscillopathy and open avenues for future neuromodu-lation strategies aiming at disrupting proepileptic mechanisms.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::7e9a790333d0872d2cf274626462b582Test
https://hal.archives-ouvertes.fr/hal-03509397Test

المؤلفون: Masayuki Hirata, Naoki Tani, Takufumi Yanagisawa, Hiroaki Hashimoto, Hui Ming Khoo, Satoru Oshino, Haruhiko Kishima

المصدر: Scientific Reports
Scientific Reports, Vol 11, Iss 1, Pp 1-13 (2021)

مصطلحات موضوعية: Adult, Male, medicine.medical_specialty, Adolescent, genetic structures, Science, Seizure onset zone, behavioral disciplines and activities, Article, Young Adult, Epilepsy, Seizure onset, Seizures, Internal medicine, mental disorders, medicine, Humans, Ictal, Electrode placement, Multidisciplinary, business.industry, Electroencephalography, Middle Aged, medicine.disease, Cardiology, Medicine, Female, business, Biomarkers, Phase amplitude coupling

الوصف: Infraslow activity (ISA) and high-frequency activity (HFA) are key biomarkers for studying epileptic seizures. We aimed to elucidate the relationship between ISA and HFA around seizure onset. We enrolled seven patients with drug-resistant focal epilepsy who underwent intracranial electrode placement. We comparatively analyzed the ISA, HFA, and ISA-HFA phase-amplitude coupling (PAC) in the seizure onset zone (SOZ) or non-SOZ (nSOZ) in the interictal, preictal, and ictal states. We recorded 15 seizures. HFA and ISA were larger in the ictal states than in the interictal or preictal state. During seizures, the HFA and ISA of the SOZ were larger and occurred earlier than those of nSOZ. In the preictal state, the ISA-HFA PAC of the SOZ was larger than that of the interictal state, and it began increasing at approximately 87 s before the seizure onset. The receiver-operating characteristic curve revealed that the ISA-HFA PAC of the SOZ showed the highest discrimination performance in the preictal and interictal states, with an area under the curve of 0.926. This study demonstrated the novel insight that ISA-HFA PAC increases before the onset of seizures. Our findings indicate that ISA-HFA PAC could be a useful biomarker for discriminating between the preictal and interictal states.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::add2df1d94a1d41b3e0fcd3585f0ea1fTest
http://europepmc.org/articles/PMC8408139Test

المؤلفون: Yasushi Iimura, Hidenori Sugano, Takumi Mitsuhashi, Tetsuya Ueda, Kostadin Karagiozov, Shimpei Abe, Hiroshi Otsubo

المصدر: Frontiers in Neurology, Vol 12 (2021)
Frontiers in Neurology

مصطلحات موضوعية: 0301 basic medicine, phase-amplitude coupling, Fetal ultrasonography, modulation index, epileptic spasms, Case Report, high frequency oscillations, Aicardi syndrome, 03 medical and health sciences, 0302 clinical medicine, medicine, subtotal hemispherotomy, RC346-429, Choroid plexus cyst, Corpus Callosum Agenesis, business.industry, Ventricular dilatation, medicine.disease, Epileptic spasms, 030104 developmental biology, Neurology, Anesthesia, Phenobarbital, Neurology (clinical), Neurology. Diseases of the nervous system, Vitamin b6, business, 030217 neurology & neurosurgery, medicine.drug

الوصف: The mechanism of epileptic spasms (ES) in Aicardi syndrome (AS) remains obscure. We compared intraoperative high-frequency oscillations (HFOs) and phase-amplitude coupling (PAC) before and after subtotal hemispherotomy in a 3-month-old girl with drug-resistant ES secondary to AS. Fetal ultrasonography showing corpus callosum agenesis, bilateral ventricular dilatation, and a large choroid plexus cyst confirmed AS diagnosis. Her ES started when she was 1 month old and had ten series of clustered ES per day despite phenobarbital and vitamin B6 treatment. After subtotal hemispherotomy, her ES dramatically improved. We analyzed two intraoperative electrocorticography modalities: (1), occurrence rate (OR) of HFOs; (2), PAC of HFOs and slow wave bands in the frontal, central, and parietal areas. We hypothesized that HFOs and PAC could be the biomarkers for efficacy of subtotal hemispherotomy in AS with ES. PAC in all three areas and OR of HFOs in the frontal and parietal areas significantly decreased, while OR of HFOs in the central area remained unchanged after subtotal hemispherotomy. We have demonstrated the usefulness of evaluating intraoperative HFOs and PAC to assess subtotal hemispherotomy effectiveness in AS patients with ES. Disconnecting the thalamocortical and subcortical pathways in the epileptic network plays a role in controlling ES generation.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::2ee714b32f6be879756dc75455890ed1Test
https://www.frontiersin.org/articles/10.3389/fneur.2021.683729/fullTest

المؤلفون: Berj L. Bardakjian, Peter L. Carlen, Richard Wennberg, Vasily Grigorovsky, Vanessa L. Breton, Yotin Chinvarun, Uilki Tufa, Jose Martin del Campo, Christopher Lucasius, Daniel Jacobs

المصدر: Brain Communications

مصطلحات موضوعية: 0301 basic medicine, phase-amplitude coupling, SUDEP, seizure, Electroencephalography, 03 medical and health sciences, Epilepsy, 0302 clinical medicine, Rhythm, medicine, Ictal, PGES, medicine.diagnostic_test, business.industry, AcademicSubjects/SCI01870, General Engineering, medicine.disease, 030104 developmental biology, medicine.anatomical_structure, Scalp, Connectome, epilepsy, Original Article, AcademicSubjects/MED00310, business, Neuroscience, 030217 neurology & neurosurgery, Phase amplitude coupling, Postictal state

الوصف: Postictal generalized EEG suppression is the state of suppression of electrical activity at the end of a seizure. Prolongation of this state has been associated with increased risk of sudden unexpected death in epilepsy, making characterization of underlying electrical rhythmic activity during postictal suppression an important step in improving epilepsy treatment. Phase-amplitude coupling in EEG reflects cognitive coding within brain networks and some of those codes highlight epileptic activity; therefore, we hypothesized that there are distinct phase-amplitude coupling features in the postictal suppression state that can provide an improved estimate of this state in the context of patient risk for sudden unexpected death in epilepsy. We used both intracranial and scalp EEG data from eleven patients (six male, five female; age range 21–41 years) containing 25 seizures, to identify frequency dynamics, both in the ictal and postictal EEG suppression states. Cross-frequency coupling analysis identified that during seizures there was a gradual decrease of phase frequency in the coupling between delta (0.5–4 Hz) and gamma (30+ Hz), which was followed by an increased coupling between the phase of 0.5–1.5 Hz signal and amplitude of 30–50 Hz signal in the postictal state as compared to the pre-seizure baseline. This marker was consistent across patients. Then, using these postictal-specific features, an unsupervised state classifier—a hidden Markov model—was able to reliably classify four distinct states of seizure episodes, including a postictal suppression state. Furthermore, a connectome analysis of the postictal suppression states showed increased information flow within the network during postictal suppression states as compared to the pre-seizure baseline, suggesting enhanced network communication. When the same tools were applied to the EEG of an epilepsy patient who died unexpectedly, ictal coupling dynamics disappeared and postictal phase-amplitude coupling remained constant throughout. Overall, our findings suggest that there are active postictal networks, as defined through coupling dynamics that can be used to objectively classify the postictal suppression state; furthermore, in a case study of sudden unexpected death in epilepsy, the network does not show ictal-like phase-amplitude coupling features despite the presence of convulsive seizures, and instead demonstrates activity similar to postictal. The postictal suppression state is a period of elevated network activity as compared to the baseline activity which can provide key insights into the epileptic pathology.
Phase-amplitude coupling analysis shows that a state of postictal generalized EEG suppression has increased delta-gamma coupling. These coupling features, used with an unsupervised hidden Markov model, reliably differentiated four substates in seizure episodes. A sudden unexpected death in epilepsy case study showed coupling activity similar to a postictal state.
Graphical Abstract Graphical Abstract

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b41ff015491806768f0728dc9f62b3e6Test
https://pubmed.ncbi.nlm.nih.gov/33376988Test