Pub Date : 2023-11-01Epub Date: 2021-07-21DOI: 10.1177/15500594211034371
Shunsuke Takagi
Ripples are brief (<150 ms) high-frequency oscillatory neural activities in the brain with a range of 140 to 200 Hz in rodents and 80 to 140 Hz in humans. Ripples are regarded as playing an essential role in several aspects of memory function, mainly in the hippocampus. This type of ripple generally occurs with sharp waves and is called a sharp-wave ripple (SPW-R). Extensive research of SPW-Rs in the rodent brain while actively awake has also linked the function of these SPW-Rs to navigation and decision making. Although many studies with rodents unveiled SPW-R function, research in humans on this subject is still sparse. Therefore, unveiling SPW-R function in the human hippocampus is warranted. A certain type of ripples may also be a biomarker of epilepsy. This type of ripple is called a pathological ripple (p-ripple). p-ripples have a wider range of frequency (80-500 Hz) than SPW-Rs, and the range of frequency is especially higher in brain regions that are intrinsically linked to epilepsy onset. Brain regions producing ripples are too small for scalp electrode recording, and intracranial recording is typically needed to detect ripples. In addition, SPW-Rs in the human hippocampus have been recorded from patients with epilepsy who may have p-ripples. Differentiating SPW-Rs and p-ripples is often not easy. We need to develop more sophisticated methods to record SPW-Rs to differentiate them from p-ripples. This paper reviews the general features and roles of ripple waves.
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{"title":"Exploring Ripple Waves in the Human Brain.","authors":"Shunsuke Takagi","doi":"10.1177/15500594211034371","DOIUrl":"10.1177/15500594211034371","url":null,"abstract":"<p><p>Ripples are brief (<150 ms) high-frequency oscillatory neural activities in the brain with a range of 140 to 200 Hz in rodents and 80 to 140 Hz in humans. Ripples are regarded as playing an essential role in several aspects of memory function, mainly in the hippocampus. This type of ripple generally occurs with sharp waves and is called a sharp-wave ripple (SPW-R). Extensive research of SPW-Rs in the rodent brain while actively awake has also linked the function of these SPW-Rs to navigation and decision making. Although many studies with rodents unveiled SPW-R function, research in humans on this subject is still sparse. Therefore, unveiling SPW-R function in the human hippocampus is warranted. A certain type of ripples may also be a biomarker of epilepsy. This type of ripple is called a pathological ripple (p-ripple). p-ripples have a wider range of frequency (80-500 Hz) than SPW-Rs, and the range of frequency is especially higher in brain regions that are intrinsically linked to epilepsy onset. Brain regions producing ripples are too small for scalp electrode recording, and intracranial recording is typically needed to detect ripples. In addition, SPW-Rs in the human hippocampus have been recorded from patients with epilepsy who may have p-ripples. Differentiating SPW-Rs and p-ripples is often not easy. We need to develop more sophisticated methods to record SPW-Rs to differentiate them from p-ripples. This paper reviews the general features and roles of ripple waves.</p>","PeriodicalId":10682,"journal":{"name":"Clinical EEG and Neuroscience","volume":" ","pages":"594-600"},"PeriodicalIF":2.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/15500594211034371","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39204575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Patients with schizophrenia can exhibit intelligence decline, which is an important element of cognitive impairment. Previous magnetic resonance imaging (MRI) studies have demonstrated that patients with schizophrenia have altered gray matter structures and functional connectivity associated with intelligence decline defined by a difference between premorbid and current intelligence quotients (IQs). However, it has remained unclear whether white matter microstructures are related to intelligence decline. In the present study, the indices of diffusion tensor imaging (DTI) obtained from 138 patients with schizophrenia and 554 healthy controls were analyzed. The patients were classified into three subgroups based on intelligence decline: deteriorated (94 patients), preserved (42 patients), and compromised IQ (2 patients) groups. Given that the DTI of each subject was acquired using either one of two different MRI scanners, we analyzed DTI indices separately for each scanner group. In the comparison between the deteriorated IQ group and the healthy controls, differences in some DTI indices were noted in three regions of interest irrespective of the MRI scanners, whereas differences in only one region of interest were noted between the preserved IQ group and the healthy controls. However, the comparisons between the deteriorated and preserved IQ groups did not show any reproducible differences. Together with the previous findings, it is thought that gray matter structures and functional connectivity are more promising as markers of intelligence decline in schizophrenia than white matter microstructures.
{"title":"Association Study Between White Matter Microstructure and Intelligence Decline in Schizophrenia.","authors":"Junya Matsumoto, Kenichiro Miura, Masaki Fukunaga, Kiyotaka Nemoto, Daisuke Koshiyama, Naohiro Okada, Kentaro Morita, Hidenaga Yamamori, Yuka Yasuda, Michiko Fujimoto, Satsuki Ito, Naomi Hasegawa, Yoshiyuki Watanabe, Kiyoto Kasai, Ryota Hashimoto","doi":"10.1177/15500594211063314","DOIUrl":"10.1177/15500594211063314","url":null,"abstract":"Patients with schizophrenia can exhibit intelligence decline, which is an important element of cognitive impairment. Previous magnetic resonance imaging (MRI) studies have demonstrated that patients with schizophrenia have altered gray matter structures and functional connectivity associated with intelligence decline defined by a difference between premorbid and current intelligence quotients (IQs). However, it has remained unclear whether white matter microstructures are related to intelligence decline. In the present study, the indices of diffusion tensor imaging (DTI) obtained from 138 patients with schizophrenia and 554 healthy controls were analyzed. The patients were classified into three subgroups based on intelligence decline: deteriorated (94 patients), preserved (42 patients), and compromised IQ (2 patients) groups. Given that the DTI of each subject was acquired using either one of two different MRI scanners, we analyzed DTI indices separately for each scanner group. In the comparison between the deteriorated IQ group and the healthy controls, differences in some DTI indices were noted in three regions of interest irrespective of the MRI scanners, whereas differences in only one region of interest were noted between the preserved IQ group and the healthy controls. However, the comparisons between the deteriorated and preserved IQ groups did not show any reproducible differences. Together with the previous findings, it is thought that gray matter structures and functional connectivity are more promising as markers of intelligence decline in schizophrenia than white matter microstructures.","PeriodicalId":10682,"journal":{"name":"Clinical EEG and Neuroscience","volume":" ","pages":"567-573"},"PeriodicalIF":2.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39710810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-01Epub Date: 2021-12-13DOI: 10.1177/15500594211066151
Yuji Yamada, Tomiki Sumiyoshi
Backgrounds. Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique for the treatment of several psychiatric disorders, eg, mood disorders and schizophrenia. Although tDCS provides a promising approach, its neurobiological mechanisms remain to be explored. Objectives. To provide a systematic review of animal studies, and consider how tDCS ameliorates psychiatric conditions. Methods. A literature search was conducted on English articles identified by PubMed. We defined the inclusion criteria as follows: (1) articles published from the original data; (2) experimental studies in animals; (3) studies delivering direct current transcranially, ie, positioning electrodes onto the skull. Results. 138 papers met the inclusion criteria. 62 papers deal with model animals without any dysfunctions, followed by 52 papers for neurological disorder models, and 12 for psychiatric disorder models. The most studied category of functional areas is neurocognition, followed by motor functions and pain. These studies overall suggest the role for the late long-term potentiation (LTP) via anodal stimulation in the therapeutic effects of tDCS. Conclusions. tDCS Anodal stimulation may provide a novel therapeutic strategy to particularly enhance neurocognition in psychiatric disorders. Its mechanisms are likely to involve facilitation of the late LTP.
{"title":"Preclinical Evidence for the Mechanisms of Transcranial Direct Current Stimulation in the Treatment of Psychiatric Disorders; A Systematic Review.","authors":"Yuji Yamada, Tomiki Sumiyoshi","doi":"10.1177/15500594211066151","DOIUrl":"10.1177/15500594211066151","url":null,"abstract":"<p><p><i>Backgrounds.</i> Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique for the treatment of several psychiatric disorders, eg, mood disorders and schizophrenia. Although tDCS provides a promising approach, its neurobiological mechanisms remain to be explored. <i>Objectives.</i> To provide a systematic review of animal studies, and consider how tDCS ameliorates psychiatric conditions. <i>Methods.</i> A literature search was conducted on English articles identified by PubMed. We defined the inclusion criteria as follows: (1) articles published from the original data; (2) experimental studies in animals; (3) studies delivering direct current transcranially, ie, positioning electrodes onto the skull. <i>Results.</i> 138 papers met the inclusion criteria. 62 papers deal with model animals without any dysfunctions, followed by 52 papers for neurological disorder models, and 12 for psychiatric disorder models. The most studied category of functional areas is neurocognition, followed by motor functions and pain. These studies overall suggest the role for the late long-term potentiation (LTP) via anodal stimulation in the therapeutic effects of tDCS. <i>Conclusions.</i> tDCS Anodal stimulation may provide a novel therapeutic strategy to particularly enhance neurocognition in psychiatric disorders. Its mechanisms are likely to involve facilitation of the late LTP.</p>","PeriodicalId":10682,"journal":{"name":"Clinical EEG and Neuroscience","volume":" ","pages":"601-610"},"PeriodicalIF":2.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10625720/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39595224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Electroconvulsive therapy (ECT) is the most effective antidepressant treatment, although its mechanisms of action remain unclear. Since 2010, several structural magnetic resonance imaging studies based on a neuroplastic hypothesis have consistently reported increases in the hippocampal volume following ECT. Moreover, volume increases in the human dentate gyrus, where neurogenesis occurs, have also been reported. These results are in line with the preclinical findings of ECT-induced neuroplastic changes, including neurogenesis, gliogenesis, synaptogenesis, and angiogenesis, in rodents and nonhuman primates. Despite this robust evidence of an effect of ECT on hippocampal plasticity, the clinical relevance of these human hippocampal changes continues to be questioned. This narrative review summarizes recent findings regarding ECT-induced hippocampal volume changes. Furthermore, this review also discusses methodological considerations and future directions in this field.
{"title":"What Can We Tell About the Effect of Electroconvulsive Therapy on the Human Hippocampus?","authors":"Akihiro Takamiya, Taishiro Kishimoto, Masaru Mimura","doi":"10.1177/15500594211044066","DOIUrl":"10.1177/15500594211044066","url":null,"abstract":"<p><p>Electroconvulsive therapy (ECT) is the most effective antidepressant treatment, although its mechanisms of action remain unclear. Since 2010, several structural magnetic resonance imaging studies based on a neuroplastic hypothesis have consistently reported increases in the hippocampal volume following ECT. Moreover, volume increases in the human dentate gyrus, where neurogenesis occurs, have also been reported. These results are in line with the preclinical findings of ECT-induced neuroplastic changes, including neurogenesis, gliogenesis, synaptogenesis, and angiogenesis, in rodents and nonhuman primates. Despite this robust evidence of an effect of ECT on hippocampal plasticity, the clinical relevance of these human hippocampal changes continues to be questioned. This narrative review summarizes recent findings regarding ECT-induced hippocampal volume changes. Furthermore, this review also discusses methodological considerations and future directions in this field.</p>","PeriodicalId":10682,"journal":{"name":"Clinical EEG and Neuroscience","volume":" ","pages":"584-593"},"PeriodicalIF":2.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39436562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.1177/15500594211058266
Nivetha Vasudevan, Ranjith Kumar Manokaran, Saji James
Purpose: To investigate whether hyperventilation (HV) for 5 minutes increases the diagnostic yield of electroencephalography (EEG) compared to 3 minutes HV and to determine whether performing HV for 5 minutes is feasible and safe in children. Methods: Data were evaluated from 579 children aged less than 18 years, referred to EEG for epilepsy evaluation. Occurrence of seizures, HV induced interictal epileptiform discharges precipitation and potentiation and adverse events if any were noted during the first 3 minutes and last 2 minutes of HV separately. Results: 398 children (68.7%) completed 5 minutes HV. Seizures were precipitated during the first 3 minutes of HV in 2 children, and during the last 2 minutes in one more child. Inter-ictal EEG abnormalities were precipitated in the first 3 minutes of HV in 31 children, and during the last 2 min in 4 more children. All 398 children completed HV during the last 2 minutes successfully and no adverse events occurred during the last 2 minutes of HV. Conclusion: 33.33% of seizures and 11.5% of inter-ictal EEG abnormalities triggered by HV occurred during the last 2 min of HV. This finding supports the utility of prolonged hyperventilation for 5 minutes. Prolonged HV for 5 minutes increases the diagnostic yield of EEG in paediatric population and it is safe and feasible.
{"title":"Diagnostic Yield of Five Minutes Compared to Three Minutes Hyperventilation During Electroencephalography in Children.","authors":"Nivetha Vasudevan, Ranjith Kumar Manokaran, Saji James","doi":"10.1177/15500594211058266","DOIUrl":"https://doi.org/10.1177/15500594211058266","url":null,"abstract":"<p><p><b><i>Purpose</i>:</b> To investigate whether hyperventilation (HV) for 5 minutes increases the diagnostic yield of electroencephalography (EEG) compared to 3 minutes HV and to determine whether performing HV for 5 minutes is feasible and safe in children. <b><i>Methods</i>:</b> Data were evaluated from 579 children aged less than 18 years, referred to EEG for epilepsy evaluation. Occurrence of seizures, HV induced interictal epileptiform discharges precipitation and potentiation and adverse events if any were noted during the first 3 minutes and last 2 minutes of HV separately. <b><i>Results</i>:</b> 398 children (68.7%) completed 5 minutes HV. Seizures were precipitated during the first 3 minutes of HV in 2 children, and during the last 2 minutes in one more child. Inter-ictal EEG abnormalities were precipitated in the first 3 minutes of HV in 31 children, and during the last 2 min in 4 more children. All 398 children completed HV during the last 2 minutes successfully and no adverse events occurred during the last 2 minutes of HV. <b><i>Conclusion</i>:</b> 33.33% of seizures and 11.5% of inter-ictal EEG abnormalities triggered by HV occurred during the last 2 min of HV. This finding supports the utility of prolonged hyperventilation for 5 minutes. Prolonged HV for 5 minutes increases the diagnostic yield of EEG in paediatric population and it is safe and feasible.</p>","PeriodicalId":10682,"journal":{"name":"Clinical EEG and Neuroscience","volume":"54 5","pages":"522-525"},"PeriodicalIF":2.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10327554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01Epub Date: 2021-10-16DOI: 10.1177/15500594211046703
Teresa López-Castro, Laura Martin, Sean Nickley, Tanya C Saraiya, Robert D Melara
The current study examined frontal alpha asymmetry (FAA) as a marker of approach- and avoidance-related prefrontal activity in participants with and without trauma exposure and posttraumatic stress disorder (PTSD). We investigated FAA in an inhibitory control paradigm (threatening vs nonthreatening cues) under 2 levels of cognitive demand (baseline: images constant within a block of trials; vs filtering: images varied randomly within a block) in 3 groups of participants: individuals with PTSD (n = 16), exposed to trauma but without PTSD (n = 14), and a control group without PTSD or trauma exposure (n = 15). Under low demand (baseline), both PTSD and trauma-exposed participants exhibited significantly greater relative left than right frontal brain activity (approach) to threatening than to nonthreatening images. Under high demand (filtering), no FAA differences were found between threatening and nonthreatening images, but PTSD participants revealed more relative left than right FAA, whereas trauma-exposed participants showed reduced left relative right FAA. In all conditions, healthy controls exhibited reduced left relative to right FAA and no differences between threatening and nonthreatening images. Study findings suggest dysfunctional prefrontal mechanisms of emotion regulation in PTSD, but adaptive prefrontal regulation in trauma-exposed individuals without PTSD.
{"title":"Frontal Alpha Asymmetry in Posttraumatic Stress Disorder: Group Differences Among Individuals With and Without PTSD During an Inhibitory Control Task.","authors":"Teresa López-Castro, Laura Martin, Sean Nickley, Tanya C Saraiya, Robert D Melara","doi":"10.1177/15500594211046703","DOIUrl":"10.1177/15500594211046703","url":null,"abstract":"<p><p>The current study examined frontal alpha asymmetry (FAA) as a marker of approach- and avoidance-related prefrontal activity in participants with and without trauma exposure and posttraumatic stress disorder (PTSD). We investigated FAA in an inhibitory control paradigm (threatening vs nonthreatening cues) under 2 levels of cognitive demand (baseline: images constant within a block of trials; vs filtering: images varied randomly within a block) in 3 groups of participants: individuals with PTSD (<i>n</i> = 16), exposed to trauma but without PTSD (<i>n</i> = 14), and a control group without PTSD or trauma exposure (<i>n</i> = 15). Under low demand (baseline), both PTSD and trauma-exposed participants exhibited significantly greater relative left than right frontal brain activity (approach) to threatening than to nonthreatening images. Under high demand (filtering), no FAA differences were found between threatening and nonthreatening images, but PTSD participants revealed more relative left than right FAA, whereas trauma-exposed participants showed reduced left relative right FAA. In all conditions, healthy controls exhibited reduced left relative to right FAA and no differences between threatening and nonthreatening images. Study findings suggest dysfunctional prefrontal mechanisms of emotion regulation in PTSD, but adaptive prefrontal regulation in trauma-exposed individuals without PTSD.</p>","PeriodicalId":10682,"journal":{"name":"Clinical EEG and Neuroscience","volume":"54 5","pages":"472-482"},"PeriodicalIF":2.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9022109/pdf/nihms-1789773.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10504047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.1177/15500594221129962
Valentina Barone, Johannes P van Dijk, Mariette H J A Debeij-van Hall, Michel J A M van Putten
Attention is an important aspect of human brain function and often affected in neurological disorders. Objective assessment of attention may assist in patient care, both for diagnostics and prognostication. We present a compact test using a combination of a choice reaction time task, eye-tracking and EEG for assessment of visual attention in the clinic. The system quantifies reaction time, parameters of eye movements (i.e. saccade metrics and fixations) and event related potentials (ERPs) in a single and fast (15 min) experimental design. We present pilot data from controls, patients with mild traumatic brain injury and epilepsy, to illustrate its potential use in assessing attention in neurological patients. Reaction times and eye metrics such as fixation duration, saccade duration and latency show significant differences (p < .05) between neurological patients and controls. Late ERP components (200-800 ms) can be detected in the central line channels for all subjects, but no significant group differences could be found in the peak latencies and mean amplitudes. Our system has potential to assess key features of visual attention in the clinic. Pilot data show significant differences in reaction times and eye metrics between controls and patients, illustrating its promising use for diagnostics and prognostication.
{"title":"A Potential Multimodal Test for Clinical Assessment of Visual Attention in Neurological Disorders.","authors":"Valentina Barone, Johannes P van Dijk, Mariette H J A Debeij-van Hall, Michel J A M van Putten","doi":"10.1177/15500594221129962","DOIUrl":"https://doi.org/10.1177/15500594221129962","url":null,"abstract":"<p><p>Attention is an important aspect of human brain function and often affected in neurological disorders. Objective assessment of attention may assist in patient care, both for diagnostics and prognostication. We present a compact test using a combination of a choice reaction time task, eye-tracking and EEG for assessment of visual attention in the clinic. The system quantifies reaction time, parameters of eye movements (i.e. saccade metrics and fixations) and event related potentials (ERPs) in a single and fast (15 min) experimental design. We present pilot data from controls, patients with mild traumatic brain injury and epilepsy, to illustrate its potential use in assessing attention in neurological patients. Reaction times and eye metrics such as fixation duration, saccade duration and latency show significant differences (p < .05) between neurological patients and controls. Late ERP components (200-800 ms) can be detected in the central line channels for all subjects, but no significant group differences could be found in the peak latencies and mean amplitudes. Our system has potential to assess key features of visual attention in the clinic. Pilot data show significant differences in reaction times and eye metrics between controls and patients, illustrating its promising use for diagnostics and prognostication.</p>","PeriodicalId":10682,"journal":{"name":"Clinical EEG and Neuroscience","volume":"54 5","pages":"512-521"},"PeriodicalIF":2.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10411032/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9965880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.1177/15500594211070800
Ayse Nur Ozdag Acarli, Ayse Deniz Elmali, Nermin Gorkem Sirin, Betul Baykan, Nerses Bebek
Introduction. Although ictal blinking is significantly more frequent in generalized epilepsy, it has been reported as a rare but useful lateralizing sign in focal seizures when it is not associated with facial clonic twitching. This study aimed to raise awareness of eye blinking as a semiological lateralizing sign. Method. Our database over an 11-year period reviewed retrospectively to assess patients who had ictal blinking associated with focal seizures. Results. Among 632 patients, 14 (2.2%), who had 3 to 13 (7 ± 3) seizures during video-EEG monitoring, were included. Twenty-five percent of all 92 seizures displayed ictal blinking and each patient had one to five seizures with ictal blinking. Ictal blinking was unilateral in 17%, asymmetrical in 22% and symmetrical in 61%. The blinking appeared with a mean latency of 6.3 s (range 0-39) after the clinical seizure-onset, localized most often to fronto-temporal, then in frontal or occipital regions. Blinking was ipsilateral to ictal scalp EEG lateralization side in 83% (5/6) of the patients with unilateral/asymmetrical blinking. The exact lateralization and localization of ictal activity could not have been determined via EEG in most of the patients with symmetrical blinking, remarkably. Conclusions. Unilateral/asymmetrical blinking is one of the early components of the seizures and appears as a useful lateralizing sign, often associated with fronto-temporal seizure-onset. Symmetrical blinking, on the other hand, did not seem to be valuable in lateralization and localization of focal seizures. Future studies using invasive recordings and periocular electrodes are needed to evaluate the value of blinking in lateralization and localization.
{"title":"Ictal Blinking: Reappraisal of the Lateralization and Localization Value in Focal Seizures.","authors":"Ayse Nur Ozdag Acarli, Ayse Deniz Elmali, Nermin Gorkem Sirin, Betul Baykan, Nerses Bebek","doi":"10.1177/15500594211070800","DOIUrl":"https://doi.org/10.1177/15500594211070800","url":null,"abstract":"<p><p><i>Introduction.</i> Although ictal blinking is significantly more frequent in generalized epilepsy, it has been reported as a rare but useful lateralizing sign in focal seizures when it is not associated with facial clonic twitching. This study aimed to raise awareness of eye blinking as a semiological lateralizing sign. <i>Method.</i> Our database over an 11-year period reviewed retrospectively to assess patients who had ictal blinking associated with focal seizures. <i>Results.</i> Among 632 patients, 14 (2.2%), who had 3 to 13 (7 ± 3) seizures during video-EEG monitoring, were included. Twenty-five percent of all 92 seizures displayed ictal blinking and each patient had one to five seizures with ictal blinking. Ictal blinking was unilateral in 17%, asymmetrical in 22% and symmetrical in 61%. The blinking appeared with a mean latency of 6.3 s (range 0-39) after the clinical seizure-onset, localized most often to fronto-temporal, then in frontal or occipital regions. Blinking was ipsilateral to ictal scalp EEG lateralization side in 83% (5/6) of the patients with unilateral/asymmetrical blinking. The exact lateralization and localization of ictal activity could not have been determined via EEG in most of the patients with symmetrical blinking, remarkably. <i>Conclusions.</i> Unilateral/asymmetrical blinking is one of the early components of the seizures and appears as a useful lateralizing sign, often associated with fronto-temporal seizure-onset. Symmetrical blinking, on the other hand, did not seem to be valuable in lateralization and localization of focal seizures. Future studies using invasive recordings and periocular electrodes are needed to evaluate the value of blinking in lateralization and localization.</p>","PeriodicalId":10682,"journal":{"name":"Clinical EEG and Neuroscience","volume":"54 5","pages":"497-504"},"PeriodicalIF":2.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10009372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.1177/15500594211054990
Thanga Aarthy Manoharan, Menaka Radhakrishnan
AbstractAutism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairment in sensory modulation. These sensory modulation deficits would ultimately lead them to difficulties in adaptive behavior and intellectual functioning. The purpose of this study was to observe changes in the nervous system with responses to auditory/visual and only audio stimuli in children with autism and typically developing (TD) through electroencephalography (EEG). In this study, 20 children with ASD and 20 children with TD were considered to investigate the difference in the neural dynamics. The neural dynamics could be understood by non-linear analysis of the EEG signal. In this research to reveal the underlying nonlinear EEG dynamics, recurrence quantification analysis (RQA) is applied. RQA measures were analyzed using various parameter changes in RQA computations. In this research, the cosine distance metric was considered due to its capability of information retrieval and the other distance metrics parameters are compared for identifying the best biomarker. Each computational combination of the RQA measure and the responding channel was analyzed and discussed. To classify ASD and TD, the resulting features from RQA were fed to the designed BiLSTM (bi-long short-term memory) network. The classification accuracy was tested channel-wise for each combination. T3 and T5 channels with neighborhood selection as FAN (fixed amount of nearest neighbors) and distance metric as cosine is considered as the best-suited combination to discriminate between ASD and TD with the classification accuracy of 91.86%, respectively.
摘要自闭症谱系障碍是一种以感觉调节功能障碍为特征的神经发育障碍。这些感觉调节缺陷最终会导致他们在适应行为和智力功能方面出现困难。本研究目的是通过脑电图(EEG)观察自闭症和典型发育(TD)儿童在听觉/视觉和仅听觉刺激下神经系统的变化。本研究以20名ASD患儿和20名TD患儿为研究对象,探讨其神经动力学的差异。通过对脑电信号的非线性分析,可以理解脑电信号的神经动力学。在本研究中,应用递归量化分析(RQA)来揭示潜在的非线性脑电动力学。利用RQA计算中的各种参数变化对RQA度量进行了分析。在本研究中,考虑余弦距离度量,因为它的信息检索能力和其他距离度量参数进行比较,以确定最佳的生物标志物。对RQA度量和响应信道的各种计算组合进行了分析和讨论。为了对ASD和TD进行分类,RQA得到的特征被输入到设计的BiLSTM(双长短期记忆)网络中。对每个组合的分类精度进行了通道测试。以邻域选择为FAN (fixed amount of nearest neighbors),距离度量为余弦的T3和T5通道被认为是区分ASD和TD的最合适组合,分类准确率分别为91.86%。
{"title":"Region-Wise Brain Response Classification of ASD Children Using EEG and BiLSTM RNN.","authors":"Thanga Aarthy Manoharan, Menaka Radhakrishnan","doi":"10.1177/15500594211054990","DOIUrl":"https://doi.org/10.1177/15500594211054990","url":null,"abstract":"<p><p><b>Abstract</b>Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairment in sensory modulation. These sensory modulation deficits would ultimately lead them to difficulties in adaptive behavior and intellectual functioning. The purpose of this study was to observe changes in the nervous system with responses to auditory/visual and only audio stimuli in children with autism and typically developing (TD) through electroencephalography (EEG). In this study, 20 children with ASD and 20 children with TD were considered to investigate the difference in the neural dynamics. The neural dynamics could be understood by non-linear analysis of the EEG signal. In this research to reveal the underlying nonlinear EEG dynamics, recurrence quantification analysis (RQA) is applied. RQA measures were analyzed using various parameter changes in RQA computations. In this research, the cosine distance metric was considered due to its capability of information retrieval and the other distance metrics parameters are compared for identifying the best biomarker. Each computational combination of the RQA measure and the responding channel was analyzed and discussed. To classify ASD and TD, the resulting features from RQA were fed to the designed BiLSTM (bi-long short-term memory) network. The classification accuracy was tested channel-wise for each combination. T3 and T5 channels with neighborhood selection as FAN (fixed amount of nearest neighbors) and distance metric as cosine is considered as the best-suited combination to discriminate between ASD and TD with the classification accuracy of 91.86%, respectively.</p>","PeriodicalId":10682,"journal":{"name":"Clinical EEG and Neuroscience","volume":"54 5","pages":"461-471"},"PeriodicalIF":2.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10327557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.1177/15500594221083256
Mustafa Emir Tavşanlı, Demet Kınay
Background. It is known that sleep and sleep deprivation affect the EEG findings, onset, frequency and semiology of the seizures. Generalized spike and wave discharges were found more common in drowsiness and sleep states, especially in childhood and juvenile absence epilepsy syndromes. Aim. In this study we aimed to show the effects of short sleep on the interictal and ictal discharges of the patients with genetic generalized epileptic seizures and to show the effects of treatment on the discharges during awake and sleep states. Method. 37 patients (29 females and 8 males) with a diagnosis of genetic generalized epilepsy syndrome were included. All the patients were investigated with video-EEG recording during awake, sleep and post sleep states. Epileptic discharges were counted manually. Discharge numbers and their relation with triggers were analyzed to see the difference between different vigilance states. Results. Number of ictal discharges is found to be increased after sleep. There was no difference in the control EEGs, which were taken under treatment. Conclusion. Sleep is a trigger of epileptic discharges in ictal nature, but an effective antiepileptic treatment prevents this effect.
{"title":"Effect of Sleep on Epileptic Discharges in Patients with Idiopathic Generalized Epilepsy.","authors":"Mustafa Emir Tavşanlı, Demet Kınay","doi":"10.1177/15500594221083256","DOIUrl":"https://doi.org/10.1177/15500594221083256","url":null,"abstract":"<p><p><i>Background.</i> It is known that sleep and sleep deprivation affect the EEG findings, onset, frequency and semiology of the seizures. Generalized spike and wave discharges were found more common in drowsiness and sleep states, especially in childhood and juvenile absence epilepsy syndromes. <i>Aim.</i> In this study we aimed to show the effects of short sleep on the interictal and ictal discharges of the patients with genetic generalized epileptic seizures and to show the effects of treatment on the discharges during awake and sleep states. <i>Method.</i> 37 patients (29 females and 8 males) with a diagnosis of genetic generalized epilepsy syndrome were included. All the patients were investigated with video-EEG recording during awake, sleep and post sleep states. Epileptic discharges were counted manually. Discharge numbers and their relation with triggers were analyzed to see the difference between different vigilance states. <i>Results.</i> Number of ictal discharges is found to be increased after sleep. There was no difference in the control EEGs, which were taken under treatment. <i>Conclusion.</i> Sleep is a trigger of epileptic discharges in ictal nature, but an effective antiepileptic treatment prevents this effect.</p>","PeriodicalId":10682,"journal":{"name":"Clinical EEG and Neuroscience","volume":"54 5","pages":"489-496"},"PeriodicalIF":2.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9946861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}