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Strigaro G, Gori B, Zoccola C, Vinassa A, Cattaneo F, Avino G, Barbero P, Varrasi C, Cantello R. Impaired Visual Inhibition in Amnestic Mild Cognitive Impairment. Clin EEG Neurosci 2024; 55:347-353. [PMID: 36325692 DOI: 10.1177/15500594221136856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Objective.The pathophysiology of amnestic mild cognitive impairment (aMCI) and Alzheimer disease (AD) is still a matter of debate. Visual system might be precociously altered, especially for its cholinergic connections. We thus studied patients with aMCI compared to AD with paired-pulse flash-visual evoked potentials (paired-F-VEPs), a putative marker of cholinergic function. Methods. We enrolled 12 adult patients with aMCI and 12 with AD. 14 normal age- and sex-matched subjects acted as controls (HS). Stimuli were single flashes, with interspersed random flash pairs at critical interstimulus intervals (ISIs, 16.5 to 125 ms) with closed eyes. The "single" (unconditioned) F-VEP was split into a "main complex" (50 to 200 ms after the flash) and a "late response" (200 to 400 ms). As for paired stimulation, the "test" F-VEP emerged from electronic subtraction of the "single" F-VEP from the "paired"-F-VEP. Results. In the single F-VEP, P2 latency was prolonged in patients (aMCI and AD) compared to HS (p < .05). As to the paired F-VEPs, in aMCI the "late response" normal inhibition was abolished at ISIs 50-62.5 ms (p ≤ .016), compared to AD and controls. No changes were detected for the "main complex". Conclusions. Paired-F-VEPs demonstrate a defective neural inhibition in the visual system of patients with aMCI at critical intervals. It may represent a compensatory mechanism against neuronal loss, the failure of which may be involved in AD development. Paired-F-VEPs may warrant inclusion in future preclinical/clinical studies, to evaluate its potential role in the pathophysiology and management of aMCI.
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Affiliation(s)
- Gionata Strigaro
- Neurology Unit, Department of Translational Medicine, University of Piemonte Orientale, and Azienda Ospedaliero-Universitaria "Maggiore della Carità", Novara, Italy
| | - Benedetta Gori
- Neurology Unit, Department of Translational Medicine, University of Piemonte Orientale, and Azienda Ospedaliero-Universitaria "Maggiore della Carità", Novara, Italy
| | - Clara Zoccola
- Neurology Unit, Department of Translational Medicine, University of Piemonte Orientale, and Azienda Ospedaliero-Universitaria "Maggiore della Carità", Novara, Italy
| | - Alessandro Vinassa
- Neurology Unit, Department of Translational Medicine, University of Piemonte Orientale, and Azienda Ospedaliero-Universitaria "Maggiore della Carità", Novara, Italy
| | - Federica Cattaneo
- Neurology Unit, Department of Translational Medicine, University of Piemonte Orientale, and Azienda Ospedaliero-Universitaria "Maggiore della Carità", Novara, Italy
| | - Gianluca Avino
- Neurology Unit, Department of Translational Medicine, University of Piemonte Orientale, and Azienda Ospedaliero-Universitaria "Maggiore della Carità", Novara, Italy
| | - Paolo Barbero
- Neurology Unit, Department of Translational Medicine, University of Piemonte Orientale, and Azienda Ospedaliero-Universitaria "Maggiore della Carità", Novara, Italy
| | - Claudia Varrasi
- Neurology Unit, Department of Translational Medicine, University of Piemonte Orientale, and Azienda Ospedaliero-Universitaria "Maggiore della Carità", Novara, Italy
| | - Roberto Cantello
- Neurology Unit, Department of Translational Medicine, University of Piemonte Orientale, and Azienda Ospedaliero-Universitaria "Maggiore della Carità", Novara, Italy
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Mazzeo A, Cerulli Irelli E, Leodori G, Mancuso M, Morano A, Giallonardo AT, Di Bonaventura C. Resting-state electroencephalography microstates as a marker of photosensitivity in juvenile myoclonic epilepsy. Brain Commun 2024; 6:fcae054. [PMID: 38444911 PMCID: PMC10914451 DOI: 10.1093/braincomms/fcae054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 12/14/2023] [Accepted: 02/16/2024] [Indexed: 03/07/2024] Open
Abstract
Juvenile myoclonic epilepsy is an idiopathic generalized epilepsy syndrome associated with photosensitivity in approximately 30-40% of cases. Microstates consist of a brief period of time during which the topography of the whole resting-state electroencephalography signal is characterized by a specific configuration. Previous neurophysiological and neuroimaging studies have suggested that Microstate B may represent activity within the visual network. In this case-control study, we aimed to investigate whether anatomical and functional alterations in the visual network observed in individuals with photosensitivity could lead to changes in Microstate B dynamics in photosensitive patients with juvenile myoclonic epilepsy. Resting-state electroencephalography microstate analysis was performed on 28 patients with juvenile myoclonic epilepsy. Of these, 15 patients exhibited photosensitivity, while the remaining 13 served as non-photosensitive controls. The two groups were carefully matched in terms of age, sex, seizure control and anti-seizure medications. Multivariate analysis of variance and repeated-measures analysis of variance were performed to assess significant differences in microstate metrics and syntax between the photosensitive and the non-photosensitive group. Post hoc false discovery rate adjusted unpaired t-tests were used to determine differences in specific microstate classes between the two groups. The four classical microstates (Classes A, B, C and D) accounted for 72.8% of the total electroencephalography signal variance in the photosensitive group and 75.64% in the non-photosensitive group. Multivariate analysis of variance revealed a statistically significant class-group interaction on microstate temporal metrics (P = 0.021). False discovery rate adjusted univariate analyses of variance indicated a significant class-group interaction for both mean occurrence (P = 0.002) and coverage (P = 0.03), but not for mean duration (P = 0.14). Post hoc false discovery rate adjusted unpaired t-tests showed significantly higher coverage (P = 0.02) and occurrence (P = 0.04) of Microstate B in photosensitive patients compared with non-photosensitive participants, along with an increased probability of transitioning from Microstates C (P = 0.04) and D (P = 0.02) to Microstate B. No significant differences were found concerning the other microstate classes between the two groups. Our study provides novel insights on resting-state electroencephalography microstate dynamics underlying photosensitivity in patients with juvenile myoclonic epilepsy. The increased representation of Microstate B in these patients might reflect the resting-state overactivation of the visual system underlying photosensitivity. Further research is warranted to investigate microstate dynamics in other photosensitive epilepsy syndromes.
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Affiliation(s)
- Adolfo Mazzeo
- Department of Human Neurosciences, Sapienza University, Rome 00185, Italy
| | | | - Giorgio Leodori
- Department of Human Neurosciences, Sapienza University, Rome 00185, Italy
- IRCCS Neuromed, Pozzilli 86077, Italy
| | - Marco Mancuso
- Department of Human Neurosciences, Sapienza University, Rome 00185, Italy
| | - Alessandra Morano
- Department of Human Neurosciences, Sapienza University, Rome 00185, Italy
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Zhang B, Chen T, Hao X, Xin M, Liang J. Electroclinical characteristics of photosensitive epilepsy: A retrospective study of 31 Chinese children and literature review. Front Pediatr 2023; 11:994817. [PMID: 36969295 PMCID: PMC10034115 DOI: 10.3389/fped.2023.994817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 01/27/2023] [Indexed: 03/29/2023] Open
Abstract
Objective The objective of this study was to better understand the clinical features of photosensitive epilepsy (PSE) in Chinese children. Methods Thirty-one children with PSE were screened out of 398 children with epilepsy who were consecutively diagnosed by the video-electroencephalogram (VEEG) monitoring method and by using an intermittent photic stimulation (IPS) test. Their EEGs and clinical features were retrospectively analyzed, and their treatment outcomes were followed up. Results PSE accounted for 7.79% (31/398) of children with epilepsy during the observation period in our single epilepsy center. The male to female ratio of PSE was 1:3.43, and the average seizure onset age was 7.8 ± 3.28 years. The highest range of frequency sensitivity of the IPS test for the induction of EEG epileptic discharge or electroclinical seizures was within 10-20 Hz. Electroclinical seizures were induced in 41.94% (13/31) of PSE patients by using the IPS test, while EEG discharge without clinical seizures was induced in 58.06% (18/31) of PSE patients. Among all PSE patients, an IPS-positive reaction in the eye-closure state was induced in 83.87% of patients, and this rate was significantly higher than that in the eye-opened state (41.94%) or eye-closed state (35.48%). (Eye-closure IPS stimulation means: make the subjects close their eyes at the beginning of each stimulation, open their eyes at the end of the stimulation, and close their eyes again at the beginning of the next stimulation, and so on. While Eye-closed IPS stimulation means the stimulation is started after 5 s of eye closure, and the subjects are kept closed throughout the whole process.) The common and effective drugs used for single or combined therapy in PSE children were valproic acid and levetiracetam. Conclusion This study provides some useful information about electroclinical characteristics in a cohort of 31 PSE children. It may be beneficial for pediatric neurologists in terms of paying more attention to PSE and correctly dealing with it.
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Affiliation(s)
- Bo Zhang
- Department of Pediatric Neurology, First Hospital of Jilin University, Changchun, China
- Jilin Provincial Key Laboratory of Pediatric Neurology, Changchun, China
| | - Tianyu Chen
- Department of Pediatric Neurology, First Hospital of Jilin University, Changchun, China
- Department of Pediatrics, The First Affiliated Hospital of Jinzhou Medical University, Jinzhou, China
| | - Xiaosheng Hao
- Department of Pediatric Neurology, First Hospital of Jilin University, Changchun, China
- Jilin Provincial Key Laboratory of Pediatric Neurology, Changchun, China
| | - Meiying Xin
- Department of Pediatric Neurology, First Hospital of Jilin University, Changchun, China
- Jilin Provincial Key Laboratory of Pediatric Neurology, Changchun, China
| | - Jianmin Liang
- Department of Pediatric Neurology, First Hospital of Jilin University, Changchun, China
- Jilin Provincial Key Laboratory of Pediatric Neurology, Changchun, China
- Correspondence: Jianmin Liang
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Aberrant visual-related networks in familial cortical myoclonic tremor with epilepsy. Parkinsonism Relat Disord 2022; 101:105-110. [PMID: 35870251 DOI: 10.1016/j.parkreldis.2022.07.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 07/01/2022] [Accepted: 07/06/2022] [Indexed: 11/20/2022]
Abstract
INTRODUCTION In familial cortical myoclonic tremor with epilepsy, photic stimulation can trigger visual symptoms and induce a photoparoxysmal response, or photosensitivity, on electroencephalography. However, the mechanism is poorly understood. In this study, we aimed to explore the neuroimaging changes related to visual symptoms and photosensitivity in genetically confirmed familial cortical myoclonic tremor with epilepsy type 1. METHODS Resting-state functional magnetic resonance imaging and electroencephalography data were collected from 31 patients carrying the heterozygous pathogenic intronic pentanucleotide (TTTCA)n insertion in the sterile alpha motif domain-containing 12 gene and from 52 age- and sex-matched healthy controls. RESULTS (1) Both regional homogeneity and degree centrality values in the bilateral calcarine sulcus were significantly increased in patients compared with healthy controls. (2) When the calcarine sulcus area with increased regional homogeneity was taken as a seed, increased functional connectivity values were observed in the right precentral gyrus, while decreased functional connectivity values were observed in the right superior frontal gyrus and right inferior parietal lobule. (3) Independent component analysis showed increased connectivity in the left calcarine sulcus inside the medial visual network. (4) Correlation analysis revealed a significant positive correlation between regional homogeneity values and frequency of seizure, and photoparoxysmal response grades were positively correlated with the severity of cortical tremor and duration of epilepsy. CONCLUSION These findings provide strong evidence for the interpretation of visual symptoms and photosensitivity in familial cortical myoclonic tremor with epilepsy. We speculate that functional changes in the primary visual cortex may be an imaging biomarker for the disease.
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Fisher RS, Acharya JN, Baumer FM, French JA, Parisi P, Solodar JH, Szaflarski JP, Thio LL, Tolchin B, Wilkins AJ, Kasteleijn-Nolst Trenité D. Visually sensitive seizures: An updated review by the Epilepsy Foundation. Epilepsia 2022; 63:739-768. [PMID: 35132632 DOI: 10.1111/epi.17175] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 01/10/2022] [Accepted: 01/12/2022] [Indexed: 12/19/2022]
Abstract
Light flashes, patterns, or color changes can provoke seizures in up to 1 in 4000 persons. Prevalence may be higher because of selection bias. The Epilepsy Foundation reviewed light-induced seizures in 2005. Since then, images on social media, virtual reality, three-dimensional (3D) movies, and the Internet have proliferated. Hundreds of studies have explored the mechanisms and presentations of photosensitive seizures, justifying an updated review. This literature summary derives from a nonsystematic literature review via PubMed using the terms "photosensitive" and "epilepsy." The photoparoxysmal response (PPR) is an electroencephalography (EEG) phenomenon, and photosensitive seizures (PS) are seizures provoked by visual stimulation. Photosensitivity is more common in the young and in specific forms of generalized epilepsy. PS can coexist with spontaneous seizures. PS are hereditable and linked to recently identified genes. Brain imaging usually is normal, but special studies imaging white matter tracts demonstrate abnormal connectivity. Occipital cortex and connected regions are hyperexcitable in subjects with light-provoked seizures. Mechanisms remain unclear. Video games, social media clips, occasional movies, and natural stimuli can provoke PS. Virtual reality and 3D images so far appear benign unless they contain specific provocative content, for example, flashes. Images with flashes brighter than 20 candelas/m2 at 3-60 (particularly 15-20) Hz occupying at least 10 to 25% of the visual field are a risk, as are red color flashes or oscillating stripes. Equipment to assay for these characteristics is probably underutilized. Prevention of seizures includes avoiding provocative stimuli, covering one eye, wearing dark glasses, sitting at least two meters from screens, reducing contrast, and taking certain antiseizure drugs. Measurement of PPR suppression in a photosensitivity model can screen putative antiseizure drugs. Some countries regulate media to reduce risk. Visually-induced seizures remain significant public health hazards so they warrant ongoing scientific and regulatory efforts and public education.
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Affiliation(s)
- Robert S Fisher
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California, USA
| | - Jayant N Acharya
- Department of Neurology, Penn State Health, Hershey, Pennsylvania, USA
| | - Fiona Mitchell Baumer
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California, USA
| | - Jacqueline A French
- NYU Comprehensive Epilepsy Center, Epilepsy Foundation, New York, New York, USA
| | - Pasquale Parisi
- Department of Neuroscience, Mental Health, and Sensory Organs, Sapienza University, Rome, Italy
| | - Jessica H Solodar
- American Medical Writers Association-New England Chapter, Boston, Massachusetts, USA
| | - Jerzy P Szaflarski
- Department of Neurology, Neurobiology and Neurosurgery, University of Alabama at Birmingham Heersink School of Medicine, Birmingham, Alabama, USA
| | - Liu Lin Thio
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Benjamin Tolchin
- Department of Neurology, Yale School of Medicine, New Haven, Connecticut, USA
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Differences in visual information processing style between Idiopathic Generalized Epilepsy with and without photosensitivity. Epilepsy Behav 2021; 122:108183. [PMID: 34252831 DOI: 10.1016/j.yebeh.2021.108183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 06/15/2021] [Accepted: 06/15/2021] [Indexed: 11/22/2022]
Abstract
PURPOSE Recently, altered visual cortical processes i.e., lack of habituation to visual evoked potentials (VEP), has been highlighted in both photosensitive epilepsy and in a specific i.e., analytic mode of processing visual inputs. In this study we aimed at evaluating the relationship between photosensitivity (PS) and analytic style of processing visual information, in a sample of 30 patients with Idiopathic Generalized Epilepsy (IGE) and matched healthy controls. METHODS At our Epilepsy unit of the Sapienza University of Rome, we consecutively enrolled 15 patients with IGE with PSand matched them with 15 patients with IGE without PS and 15 Healthy Volunteers. All patients underwent EEG recording in basal conditions during hyperventilation (3 Min), and intermittent light stimulation. The most effective frequencies comprised from 12 to 16 Hz. The instruments used to gather psychological cognitive behavioral data, consisted of participation in two tests: the Sternberg-Wagner Self-Assessment Inventory and the Mariani Learning Style Questionnaire. RESULTS Compared to controls, both IGE groups show significantly higher scores for the analytic style (One-way ANOVA, F(2,44) = 110.3, p < 0.0001). Epilepsy groups thereby showed very distinctive cognitive styles as measured with the Sternberg test. In the visual style, scores of the photosensitive Individuals with IGE were significantly higher than the non-photosensitive individuals with IGE (p < 0.0001, Tukey's post hoc test). CONCLUSIONS An association between analytic style of processing visual information and PS in IGE has been shown. The common neurophysiological features between these two factors, suggest the possibility to evaluate this cognitive behavior as a potential target for nonpharmacological therapeutic strategies in photosensitive epilepsy.
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Jiang S, Li H, Pei H, Liu L, Li Z, Chen Y, Li X, Li Q, Yao D, Luo C. Connective profiles and antagonism between dynamic and static connectivity underlying generalized epilepsy. Brain Struct Funct 2021; 226:1423-1435. [PMID: 33730218 DOI: 10.1007/s00429-021-02248-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 02/27/2021] [Indexed: 11/28/2022]
Abstract
This study aims to characterize the connective profiles and the coupling relationship between dynamic and static functional connectivity (dFC and sFC) in large-scale brain networks in patients with generalized epilepsy (GE). Functional, structural and diffuse MRI data were collected from 83 patients with GE and 106 matched healthy controls (HC). Resting-state BOLD time course was deconvolved to neural time course using a blind hemodynamic deconvolution method. Then, five connective profiles, including the structural connectivity (SC) and BOLD/neural time course-derived sFC/dFC networks, were constructed based on the proposed whole brain atlas. Network-level weighted correlation probability (NWCP) were proposed to evaluate the association between dFC and sFC. Both the BOLD signal and neural time course showed highly concordant findings and the present study emphasized the consistent findings between two functional approaches. The patients with GE showed hypervariability and enhancement of FC, and notably decreased SC in the subcortical network. Besides, increased dFC, weaker anatomic links, and complex alterations of sFC were observed in the default mode network of GE. Moreover, significantly increased SC and predominantly increased sFC were found in the frontoparietal network. Remarkably, antagonism between dFC and sFC was observed in large-scale networks in HC, while patients with GE showed significantly decreased antagonism in core epileptic networks. In sum, our study revealed distinct connective profiles in different epileptic networks and provided new clues to the brain network mechanism of epilepsy from the perspective of antagonism between dynamic and static functional connectivity.
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Affiliation(s)
- Sisi Jiang
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, School of Life Science and Technology, University of Electronic Science and Technology of China, Qingshuihe Campus: No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, 611731, People's Republic of China
| | - Hechun Li
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, School of Life Science and Technology, University of Electronic Science and Technology of China, Qingshuihe Campus: No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, 611731, People's Republic of China
| | - Haonan Pei
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, School of Life Science and Technology, University of Electronic Science and Technology of China, Qingshuihe Campus: No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, 611731, People's Republic of China
| | - Linli Liu
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, School of Life Science and Technology, University of Electronic Science and Technology of China, Qingshuihe Campus: No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, 611731, People's Republic of China
| | - Zhiliang Li
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, School of Life Science and Technology, University of Electronic Science and Technology of China, Qingshuihe Campus: No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, 611731, People's Republic of China
| | - Yan Chen
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, School of Life Science and Technology, University of Electronic Science and Technology of China, Qingshuihe Campus: No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, 611731, People's Republic of China
| | - Xiangkui Li
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, School of Life Science and Technology, University of Electronic Science and Technology of China, Qingshuihe Campus: No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, 611731, People's Republic of China
| | - Qifu Li
- Department of Neurology, First Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Dezhong Yao
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, School of Life Science and Technology, University of Electronic Science and Technology of China, Qingshuihe Campus: No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, 611731, People's Republic of China.,Department of Neurology, First Affiliated Hospital of Hainan Medical University, Haikou, China.,Research Unit of NeuroInformation, Chinese Academy of Medical Sciences, 2019RU035, Chengdu, China.,High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, Center for Information in Medicine, University of Electronic Science and Technology of China, Chengdu, People's Republic of China
| | - Cheng Luo
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, School of Life Science and Technology, University of Electronic Science and Technology of China, Qingshuihe Campus: No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, 611731, People's Republic of China. .,Research Unit of NeuroInformation, Chinese Academy of Medical Sciences, 2019RU035, Chengdu, China. .,High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, Center for Information in Medicine, University of Electronic Science and Technology of China, Chengdu, People's Republic of China.
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Strigaro G, Gori B, Varrasi C, Fleetwood T, Cantello G, Cantello R. Flash-evoked high-frequency EEG oscillations in photosensitive epilepsies. Epilepsy Res 2021; 172:106597. [PMID: 33714866 DOI: 10.1016/j.eplepsyres.2021.106597] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 02/03/2021] [Accepted: 02/27/2021] [Indexed: 10/22/2022]
Abstract
OBJECTIVE To determine the feasibility of measuring scalp-recorded, flash-evoked, high-frequency EEG oscillations (F-HFOs) using a relatively simple technique. Furthermore, to assess whether F-HFOs are enhanced in photosensitive epileptic patients and if they might be proposed as a putative non-provocative biomarker of photosensitivity. METHODS We studied 19 photosensitive patients with idiopathic generalized epilepsy, and 22 controls matched for demographic features. We extracted F-HFOs from the broadband scalp flash-visual evoked potential (b F-VEP) through appropriate filtering. We measured F-HFO amplitude, number and latency. Also, we carried out a time-frequency domain spectral F-HFO analysis. Inter-group statistics was performed. Within-groups, F-HFO features were correlated to the b F-VEP. RESULTS The N3-N3I wave of the b F-VEP was significantly (p = 0.01) larger in patients compared to controls. The same was true for the inter-group F-HFO amplitude (p = 0.01). F-HFOs showed two main spectral peaks (∼88 and ∼125 Hz), whose power was greater (p = 0.001) in patients than in controls. The ∼88 Hz peak power exceeded the upper normal range in 15/19 patients. Patients showed a significant (p = 0.04) correlation between the ∼88 Hz peak power and the size of the N3-N3I wave. SIGNIFICANCE A simplified F-HFO measurement proved feasible. In patients, F-HFOs were enhanced in terms of both size and spectral power, suggesting a role in the generation of the photoparoxysmal response. Some spectral features of the F-HFOs may be proposed as a putative non-provocative marker of epileptic photosensitivity.
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Affiliation(s)
- Gionata Strigaro
- Neurology Unit, Department of Translational Medicine, University of Piemonte Orientale, Azienda Ospedaliero-Universitaria "Maggiore della Carità", Novara, Italy.
| | - Benedetta Gori
- Neurology Unit, Department of Translational Medicine, University of Piemonte Orientale, Azienda Ospedaliero-Universitaria "Maggiore della Carità", Novara, Italy
| | - Claudia Varrasi
- Neurology Unit, Department of Translational Medicine, University of Piemonte Orientale, Azienda Ospedaliero-Universitaria "Maggiore della Carità", Novara, Italy
| | - Thomas Fleetwood
- Neurology Unit, Department of Translational Medicine, University of Piemonte Orientale, Azienda Ospedaliero-Universitaria "Maggiore della Carità", Novara, Italy
| | - Giorgio Cantello
- Neurology Unit, Department of Translational Medicine, University of Piemonte Orientale, Azienda Ospedaliero-Universitaria "Maggiore della Carità", Novara, Italy
| | - Roberto Cantello
- Neurology Unit, Department of Translational Medicine, University of Piemonte Orientale, Azienda Ospedaliero-Universitaria "Maggiore della Carità", Novara, Italy
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Yuan Y, Yang F, Huo L, Fan Y, Liu X, Wu Q, Wang H. Case Report: A Case of Eyelid Myoclonic Status With Tonic-Clonic Seizure and Literature Review. Front Pediatr 2021; 9:671732. [PMID: 33968862 PMCID: PMC8100049 DOI: 10.3389/fped.2021.671732] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 03/15/2021] [Indexed: 11/29/2022] Open
Abstract
Eyelid myoclonus with or without absence epilepsy is a rare and usually misdiagnosed disease in the neurology department. It is an idiopathic general epileptic syndrome, the onset period is 6-8 years, and is more common in girls. It is characterized by rapid abnormal eye blinking, accompanied by upward rolling of the eye and slight backward movement of the head, with eye closure sensitivity and photosensitivity. The seizure is frequent and short, dozens or even hundreds of times a day; a small number of patients may have eyelid myoclonus status. We report a patient who visits the hospital for the first time with eyelid myoclonic problem; the patient continued to wink the eyes, eye rolled up, and backward movement of the head, accompanied by impairment of consciousness. Video electroencephalography (VEEG) suggests continued spike slow-wave, polyspike slow-wave. After the patient had 2, 4, 6, 8, 10, 12, and 14 Hz of intermittent photic stimulation (IPS), her seizures and epileptic discharges reduced or stopped. Seven min after giving stimulation at 20 Hz, the child developed an occipital-initiated tonic-clonic seizure, which demonstrated that after sufficient IPS stimulation, the occiput cortex became excited and initiated a brain network, leading to diffuse brain discharge and tonic-clonic seizures. At 1 h after onset, the child developed a nonconvulsive state, with impairment of consciousness despite no eyelid myoclonic movements, and VEEG suggested a large number of epileptic discharges. After 10 min of administrating midazolam, the patient's EEG immediately became normal, and the patient regained consciousness. Therefore, this paper presents an eyelid myoclonus status patient with occipital origin seizure, we recorded the whole course of the disease and the treatment effect, and reviewed the literature accordingly.
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Affiliation(s)
- Yujun Yuan
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, China
| | - Fenghua Yang
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, China
| | - Liang Huo
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, China
| | - Yuying Fan
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, China
| | - Xueyan Liu
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, China
| | - Qiong Wu
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, China
| | - Hua Wang
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, China
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Brinciotti M, Mittica A, Matricardi M. Characteristics of visual evoked potentials related to the electro-clinical expression of reflex seizures in photosensitive patients with idiopathic occipital lobe epilepsy. Epilepsy Res 2020; 164:106345. [DOI: 10.1016/j.eplepsyres.2020.106345] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 03/30/2020] [Accepted: 04/22/2020] [Indexed: 11/24/2022]
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11
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Sysoeva OV, Smirnov K, Stroganova TA. Sensory evoked potentials in patients with Rett syndrome through the lens of animal studies: Systematic review. Clin Neurophysiol 2019; 131:213-224. [PMID: 31812082 DOI: 10.1016/j.clinph.2019.11.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 11/07/2019] [Accepted: 11/11/2019] [Indexed: 01/04/2023]
Abstract
OBJECTIVE Systematically review the abnormalities in event related potential (ERP) recorded in Rett Syndrome (RTT) patients and animals in search of translational biomarkers of deficits related to the particular neurophysiological processes of known genetic origin (MECP2 mutations). METHODS Pubmed, ISI Web of Knowledge and BIORXIV were searched for the relevant articles according to PRISMA standards. RESULTS ERP components are generally delayed across all sensory modalities both in RTT patients and its animal model, while findings on ERPs amplitude strongly depend on stimulus properties and presentation rate. Studies on RTT animal models uncovered the abnormalities in the excitatory and inhibitory transmission as critical mechanisms underlying the ERPs changes, but showed that even similar ERP alterations in auditory and visual domains have a diverse neural basis. A range of novel approaches has been developed in animal studies bringing along the meaningful neurophysiological interpretation of ERP measures in RTT patients. CONCLUSIONS While there is a clear evidence for sensory ERPs abnormalities in RTT, to further advance the field there is a need in a large-scale ERP studies with the functionally-relevant experimental paradigms. SIGNIFICANCE The review provides insights into domain-specific neural basis of the ERP abnormalities and promotes clinical application of the ERP measures as the non-invasive functional biomarkers of RTT pathophysiology.
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Affiliation(s)
- Olga V Sysoeva
- The Cognitive Neurophysiology Laboratory, Department of Pediatrics, Albert Einstein College of Medicine & Montefiore Medical Center, Bronx, New York, USA; The Cognitive Neurophysiology Laboratory, Ernest J. Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA; The Laboratory of Human Higher Nervous Activity, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia.
| | - Kirill Smirnov
- Department of Neuroontogenesis, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Science, Moscow, Russia.
| | - Tatiana A Stroganova
- Center for Neurocognitive Research (MEG-Center), Moscow State University of Psychology and Education (MSUPE), Moscow, Russia; Autism Research Laboratory, Moscow State University of Psychology and Education (MSUPE), Moscow, Russia.
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13
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Padmanaban V, Inati S, Ksendzovsky A, Zaghloul K. Clinical advances in photosensitive epilepsy. Brain Res 2019; 1703:18-25. [DOI: 10.1016/j.brainres.2018.07.025] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 06/21/2018] [Accepted: 07/26/2018] [Indexed: 12/12/2022]
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Pojda-Wilczek D, Maruszczyk W, Sirek S. Flash visual evoked potentials (FVEP) in various stimulation conditions. Doc Ophthalmol 2018; 138:35-42. [PMID: 30470955 PMCID: PMC6349809 DOI: 10.1007/s10633-018-9663-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Accepted: 11/06/2018] [Indexed: 11/28/2022]
Abstract
Aim To compare flash visual evoked potentials (FVEP) elicited using a Ganzfeld bowl (G), Mini Ganzfeld (MG) and Flash Goggles (GG) with eyes open and closed. Patients and method The study group comprised 17 volunteers with mean age of 30 years; all of them were examined with the Roland Consult electrophysiological diagnostic system. Active electrodes were placed at O1 and O2. With the G and MG stimulators, the flash generated by white-light-emitting diodes (LEDs) presented standard flash of 3 cd s m−2. The GG used red LED flash of 3 cd s m−2. Stimulus frequency of 1.0 Hz, low-pass filter of 1.0 Hz and high-pass filters of 100 Hz (G); 50 Hz (MG); 30 Hz (GG) were used. P2 amplitude and latency were compared by the means of the Wilcoxon matched-pairs signed-rank test. Results After right eye stimulation (from O1; n = 17), the mean amplitudes of P2, elicited with the G, MG and GG, were 13, 7 and 10 µV, respectively. The respective latencies were 129, 114 and 110 ms. Hence, the difference between the results obtained with these stimulators was statistically significant (p < 0.05). The mean P2 amplitudes, acquired by the means of the G, MG and GG, were 13 µV, 7 µV and 10 µV for open eyes, and 11 µV, 8 µV and 8 µV for closed eyes. The respective latencies were 129, 114 and 110 ms for eyes open, and 127, 125 and 121 ms for eyes closed. These results of the MG (latency only) and GG (latency and amplitude) stimulation differed significantly (p < 0.05). Conclusion The amplitudes and latencies of the FVEP P2 elicited with different stimulators are not suitable for comparison. Closing the eye during the examination had a significant effect on the components of FVEP waveform elicited with the Flash Goggle and on the latency of P2 elicited with the MG.
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Affiliation(s)
- Dorota Pojda-Wilczek
- Ophthalmology Clinic and Department of Ophthalmology, University Clinical Centre, School of Medicine in Katowice, Medical University of Silesia in Katowice, Ceglana 35, 40-514, Katowice, Poland.
| | - Wojciech Maruszczyk
- Ophthalmology Clinic and Department of Ophthalmology, University Clinical Centre, School of Medicine in Katowice, Medical University of Silesia in Katowice, Ceglana 35, 40-514, Katowice, Poland
| | - Sebastian Sirek
- Ophthalmology Clinic and Department of Ophthalmology, University Clinical Centre, School of Medicine in Katowice, Medical University of Silesia in Katowice, Ceglana 35, 40-514, Katowice, Poland
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Abstract
INTRODUCTION Photosensitivity, which is a main feature of Jeavons syndrome, can be seen in other types of idiopathic or genetic epilepsies with focal or generalized seizures and tends to disappear spontaneously usually in the second decade. Although it responds well to antiepileptic treatment, especially to valproic acid, it may continue into adulthood in rare cases. CASE REPORT We describe a 63-year-old male patient with eyelid myoclonia with absences, generalized tonic-clonic seizures, and severe photosensitivity accompanied by eyelid myoclonia. Seizures were treated with antiepileptic treatment, whereas photosensitivity still continued on electroencephalogram without clinical findings. CONCLUSION Our elderly patient with Jeavons syndrome with ongoing remarkable photosensitivity demonstrated that it may continue to older ages, although it is uncommon.
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Algin Dİ, Erdinç OO. Impaired Visual Habituation in Idiopathic Generalized Epilepsy with Photosensitivity Patients. ACTA ACUST UNITED AC 2018; 57:108-112. [PMID: 32550775 DOI: 10.29399/npa.23047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 03/16/2018] [Indexed: 11/07/2022]
Abstract
Introduction In this study, our goal was to analyze further the cortical excitability levels in idiopathic generalized epilepsy (IGE) patients with and without photosensitivity. Methods Forty-two patients (16 men and 26 women; mean age 30±8 years; range: 18-43 years) with IGE and thirty healthy age-matched control subjects (15 men and 15 women; mean age 35±3 years; range: 20-45 years) were enrolled for the investigation. We investigated the following two groups: 18 subjects with IGE with photosensitivity (IGE+PS), and 24 patients with IGE without photosensitivity (IGE-PS). Pattern reversal and potential inter-peak amplitudes, N75-P100 and P100-N145, as well as the corresponding latencies (N75, P100, and N145) for one hundred responses were measured 6 times. A linear regression slope was used for N75-P100 and P100-N145. Results Statistical analysis showed difference between groups where the IGE+PS had reduced N75-P100 compared to IGE-PS and controls. In IGE+PS group, the amplitude of N75-P100 was drastically reduced receiving antiepileptic therapy compared to those not receiving any anti-epileptic treatment (p=0.035). Conclusion These results show that the IGE+PS group has a different photoparoxysmal response phenotype driven by an unknown and distinct molecular mechanism. Pre-activation cortical excitability may be increased in IGE+PS patients compared to the IGE-PS or in healthy group. PR-VEP habituation may project the pathophysiological mechanisms underlying photosensitivity and it may be potential biomarker in patients with IGE+PS.
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Affiliation(s)
- Demet İlhan Algin
- Department of Neurology, Eskişehir Osmangazi University Faculty of Medicine, Eskişehir, Turkey
| | - Oğuz Osman Erdinç
- Department of Neurology, Eskişehir Osmangazi University Faculty of Medicine, Eskişehir, Turkey
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Vaudano AE, Ruggieri A, Avanzini P, Gessaroli G, Cantalupo G, Coppola A, Sisodiya SM, Meletti S. Photosensitive epilepsy is associated with reduced inhibition of alpha rhythm generating networks. Brain 2017; 140:981-997. [PMID: 28334965 DOI: 10.1093/brain/awx009] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 12/11/2016] [Indexed: 12/19/2022] Open
Abstract
See Hamandi (doi:10.1093/awx049) for a scientific commentary on this article.Photosensitivity is a condition in which lights induce epileptiform activities. This abnormal electroencephalographic response has been associated with hyperexcitability of the visuo-motor system. Here, we evaluate if intrinsic dysfunction of this network is present in brain activity at rest, independently of any stimulus and of any paroxysmal electroencephalographic activity. To address this issue, we investigated the haemodynamic correlates of the spontaneous alpha rhythm, which is considered the hallmark of the brain resting state, in photosensitive patients and in people without photosensitivity. Second, we evaluated the whole-brain functional connectivity of the visual thalamic nuclei in the various populations of subjects under investigation. Forty-four patients with epilepsy and 16 healthy control subjects underwent an electroencephalography-correlated functional magnetic resonance imaging study, during an eyes-closed condition. The following patient groups were included: (i) genetic generalized epilepsy with photosensitivity, 16 subjects (mean age 25 ± 10 years); (ii) genetic generalized epilepsy without photosensitivity, 13 patients (mean age 25 ± 11 years); (iii) focal epilepsy, 15 patients (mean age 25 ± 9 years). For each subject, the posterior alpha power variations were convolved with the standard haemodynamic response function and used as a regressor. Within- and between-groups second level analyses were performed. Whole brain functional connectivity was evaluated for two thalamic regions of interest, based on the haemodynamic findings, which included the posterior thalamus (pulvinar) and the medio-dorsal thalamic nuclei. Genetic generalized epilepsy with photosensitivity demonstrated significantly greater mean alpha-power with respect to controls and other epilepsy groups. In photosensitive epilepsy, alpha-related blood oxygen level-dependent signal changes demonstrated lower decreases relative to all other groups in the occipital, sensory-motor, anterior cingulate and supplementary motor cortices. Coherently, the same brain regions demonstrated abnormal connectivity with the visual thalamus only in epilepsy patients with photosensitivity. As predicted, our findings indicate that the cortical-subcortical network generating the alpha oscillation at rest is different in people with epilepsy and visual sensitivity. This difference consists of a decreased alpha-related inhibition of the visual cortex and sensory-motor networks at rest. These findings represent the substrate of the clinical manifestations (i.e. myoclonus) of the photoparoxysmal response. Moreover, our results provide the first evidence of the existence of a functional link between the circuits that trigger the visual sensitivity phenomenon and those that generate the posterior alpha rhythm.
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Affiliation(s)
- Anna Elisabetta Vaudano
- Department of Biomedical, Metabolic, and Neural Science, Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, OCSE Hospital, Modena, Italy.,Neurology Unit, OCSAE Hospital, Azienda Ospedaliera Universitaria, Modena, Italy
| | - Andrea Ruggieri
- Department of Biomedical, Metabolic, and Neural Science, Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, OCSE Hospital, Modena, Italy.,Neurology Unit, OCSAE Hospital, Azienda Ospedaliera Universitaria, Modena, Italy
| | - Pietro Avanzini
- Department of Neuroscience, University of Parma, Consiglio nazionale delle Ricerche - CNR, Parma, Italy
| | - Giuliana Gessaroli
- Neurology Unit, OCSAE Hospital, Azienda Ospedaliera Universitaria, Modena, Italy
| | - Gaetano Cantalupo
- Department of Life and Reproduction Sciences, University of Verona, Verona, Italy
| | - Antonietta Coppola
- Epilepsy Centre, Department of Neuroscience, Odontostomatology and Reproductive Sciences, Federico II University, Naples, Italy
| | - Sanjay M Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, LondonWC1N 3BG, UK.,Epilepsy Society, Chalfont-St-Peter, Bucks SL9 0RJ, UK
| | - Stefano Meletti
- Department of Biomedical, Metabolic, and Neural Science, Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, OCSE Hospital, Modena, Italy.,Neurology Unit, OCSAE Hospital, Azienda Ospedaliera Universitaria, Modena, Italy
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18
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Poleon S, Szaflarski JP. Photosensitivity in generalized epilepsies. Epilepsy Behav 2017; 68:225-233. [PMID: 28215998 DOI: 10.1016/j.yebeh.2016.10.040] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 10/26/2016] [Accepted: 10/29/2016] [Indexed: 11/24/2022]
Abstract
Photosensitivity, which is the hallmark of photosensitive epilepsy (PSE), is described as an abnormal EEG response to visual stimuli known as a photoparoxysmal response (PPR). The PPR is a well-recognized phenomenon, occurring in 2-14% of patients with epilepsy but its pathophysiology is not clearly understood. PPR is electrographically described as 2-5Hz spike, spike-wave, or slow wave complexes with frontal and paracentral prevalence. Diagnosis of PPR is confirmed using intermittent photic stimulation (IPS) as well as video monitoring. The PPR can be elicited by certain types of visual stimuli including flicker, high contrast gratings, moving patterns, and rapidly modulating luminance patterns which may be encountered during e.g., watching television, playing video games, or attending discotheques. Photosensitivity may present in different idiopathic (genetic) epilepsy syndromes e.g. juvenile myoclonic epilepsy (JME) as well as non-IGE syndromes e.g. severe myoclonic epilepsy of infancy. Consequently, PPR is present in patients with diverse seizure types including absence, myoclonic, and generalized tonic-clonic (GTC) seizures. Across syndromes, abnormalities in structural connectivity, functional connectivity, cortical excitability, cortical morphology, and behavioral and neuropsychological function have been reported. Treatment of photosensitivity includes antiepileptic drug administration, and the use of non-pharmacological agents, e.g. tinted or polarizing glasses, as well as occupational measures, e.g. avoidance of certain stimuli.
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Affiliation(s)
- Shervonne Poleon
- University of Alabama at Birmingham, Department of Neurology and UAB Epilepsy Center, Birmingham, AL, USA.
| | - Jerzy P Szaflarski
- University of Alabama at Birmingham, Department of Neurology and UAB Epilepsy Center, Birmingham, AL, USA
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19
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Single and paired pulse transcranial magnetic stimulation in drug naïve epilepsy. Clin Neurophysiol 2016; 127:3140-3155. [DOI: 10.1016/j.clinph.2016.06.025] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 06/03/2016] [Accepted: 06/26/2016] [Indexed: 01/06/2023]
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20
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Altered recovery from inhibitory repetitive transcranial magnetic stimulation (rTMS) in subjects with photosensitive epilepsy. Clin Neurophysiol 2016; 127:3353-61. [PMID: 27407061 DOI: 10.1016/j.clinph.2016.06.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 06/08/2016] [Accepted: 06/18/2016] [Indexed: 01/07/2023]
Abstract
OBJECTIVE To investigate functional changes underlying photosensitivity, we studied the response of the visual cortex to low-frequency, inhibitory repetitive transcranial magnetic stimulation (rTMS) in drug-free patients with photosensitive seizures and healthy volunteers. METHODS Visual evoked potentials (VEPs) triggered by grating stimuli of different contrasts were recorded in both hemispheres before and after transient functional inactivation of the occipital cortex of one side via low-frequency rTMS (0.5Hz for 20'). VEPs were recorded before (T0), immediately after (T1) and 45' following the completion of rTMS (T2). RESULTS Baseline amplitudes of the early VEP components (N1 and P1) were enhanced in photosensitive patients. At T1, rTMS produced an inhibitory effect on VEPs amplitudes at all contrasts in the targeted side and a concurrent facilitation of responses in the contralateral hemisphere. Compared with PSE subjects, VEP amplitudes remained persistently dampened in the stimulated hemisphere of controls (Holm-Sidak post-hoc method, p<0.05). In the contralateral hemisphere, we found a clear enhancement of VEP amplitude in photosensitive subjects but not controls at T2 (Holm-Sidak test, p<0.001). CONCLUSIONS Visual responses recovered more quickly in the stimulated hemisphere, and disinhibition persisted in the contralateral side of photosensitive subjects. SIGNIFICANCE The rapid recovery of excitability and the persistent transcallosal disinhibition following perturbation of cortical activity may play a role in the pathophysiology of photosensitive epilepsy.
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21
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Koepp MJ, Caciagli L, Pressler RM, Lehnertz K, Beniczky S. Reflex seizures, traits, and epilepsies: from physiology to pathology. Lancet Neurol 2015; 15:92-105. [PMID: 26627365 DOI: 10.1016/s1474-4422(15)00219-7] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 08/11/2015] [Accepted: 08/13/2015] [Indexed: 10/22/2022]
Abstract
Epileptic seizures are generally unpredictable and arise spontaneously. Patients often report non-specific triggers such as stress or sleep deprivation, but only rarely do seizures occur as a reflex event, in which they are objectively and consistently modulated, precipitated, or inhibited by external sensory stimuli or specific cognitive processes. The seizures triggered by such stimuli and processes in susceptible individuals can have different latencies. Once seizure-suppressing mechanisms fail and a critical mass (the so-called tipping point) of cortical activation is reached, reflex seizures stereotypically manifest with common motor features independent of the physiological network involved. The complexity of stimuli increases from simple sensory to complex cognitive-emotional with increasing age of onset. The topography of physiological networks involved follows the posterior-to-anterior trajectory of brain development, reflecting age-related changes in brain excitability. Reflex seizures and traits probably represent the extremes of a continuum, and understanding of their underlying mechanisms might help to elucidate the transition of normal physiological function to paroxysmal epileptic activity.
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Affiliation(s)
- Matthias J Koepp
- Department of Clinical and Experimental Epilepsy, University College London (UCL) Institute of Neurology, London, UK; National Hospital for Neurology and Neurosurgery, Queen Square, UK.
| | - Lorenzo Caciagli
- Department of Clinical and Experimental Epilepsy, University College London (UCL) Institute of Neurology, London, UK; National Hospital for Neurology and Neurosurgery, Queen Square, UK
| | - Ronit M Pressler
- Department of Clinical Neurophysiology, Great Ormond Street Hospital, London, UK; Clinical Neuroscience, UCL Institute of Child Health, London, UK
| | - Klaus Lehnertz
- Department of Epileptology, University Hospital of Bonn, Bonn, Germany
| | - Sándor Beniczky
- Department of Clinical Neurophysiology, Danish Epilepsy Centre, Dianalund, Denmark; Department of Clinical Neurophysiology, Aarhus University, Aarhus, Denmark
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Strigaro G, Cerino A, Falletta L, Mittino D, Comi C, Varrasi C, Cantello R. Impaired visual inhibition in migraine with aura. Clin Neurophysiol 2015; 126:1988-93. [DOI: 10.1016/j.clinph.2014.12.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 12/09/2014] [Accepted: 12/16/2014] [Indexed: 10/24/2022]
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Strigaro G, Falletta L, Varrasi C, Rothwell JC, Cantello R. Overactive visuomotor connections underlie the photoparoxysmal response. A TMS study. Epilepsia 2015; 56:1828-35. [DOI: 10.1111/epi.13190] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/11/2015] [Indexed: 11/30/2022]
Affiliation(s)
- Gionata Strigaro
- Department of Translational Medicine; Section of Neurology; University of Piemonte Orientale; Novara Italy
| | - Lina Falletta
- Department of Translational Medicine; Section of Neurology; University of Piemonte Orientale; Novara Italy
| | - Claudia Varrasi
- Department of Translational Medicine; Section of Neurology; University of Piemonte Orientale; Novara Italy
| | - John C. Rothwell
- Sobell Department of Motor Neuroscience and Movement Disorders; University College London Institute of Neurology; London United Kingdom
| | - Roberto Cantello
- Department of Translational Medicine; Section of Neurology; University of Piemonte Orientale; Novara Italy
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Strigaro G, Falletta L, Cerino A, Pizzamiglio C, Tondo G, Varrasi C, Cantello R. Abnormal motor cortex plasticity in juvenile myoclonic epilepsy. Seizure 2015. [DOI: 10.1016/j.seizure.2015.06.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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Strigaro G, Mayer I, Chen JC, Cantello R, Rothwell JC. Transcranial Direct Current Stimulation Effects on Single and Paired Flash Visual Evoked Potentials. Clin EEG Neurosci 2015; 46:208-13. [PMID: 25253432 DOI: 10.1177/1550059414539481] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 05/20/2014] [Indexed: 11/16/2022]
Abstract
Transcranial direct current stimulation (tDCS) applied over the occipital cortex has a controversial effect on the visual cortex excitability. Paired flash visual evoked potentials (paired F-VEPs) offer a unique method to express neural inhibition within the visual system. However, no studies have explored the effects of tDCS on F-VEPs in humans. The aim of this study was to evaluate the changes of single- and paired-F-VEPs during and after tDCS in healthy humans. Twenty-six healthy volunteers participated. F-VEPs were recorded from occipital electrodes with closed eyes. Stimuli were single flashes, intermingled to flash pairs at the interstimulus interval of 125, 62.5, 50, 33.3, 16.6, and 11.1 ms (internal frequency of 8, 16, 20, 30, 60, and 90 Hz). The single F-VEP was split into a "main complex" and a "late response." As to paired stimuli, the "test" F-VEP emerged from electronic subtraction of the single-F-VEP to the paired-F-VEP. In experiment 1, the return electrode was located on the scalp and we studied changes in F-VEPs after anodal, cathodal (1 mA, 15 min) and sham stimulation. A second experiment was performed in which F-VEPs were recorded before, during and after tDCS stimulation (anodal and cathodal) with the return electrode on the neck. F-VEPs recorded in experiment 1 did not detect any significant change after tDCS. In experiment 2 anodal polarization significantly increased the P2 latency (P = .031) and reduced the amplitude of the "late response" of the single F-VEP (P = .008). As for the paired F-VEPs, no significant changes were detected. In conclusion, low-intensity anodal tDCS has weak inhibitory aftereffects on the single F-VEP and no effects on the paired F-VEPs. Further methodological studies are needed to improve polarization efficacy.
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Affiliation(s)
- Gionata Strigaro
- Sobell Department of Motor Neuroscience and Movement Disorders, University College London Institute of Neurology, London, UK Department of Translational Medicine, Section of Neurology, University of Piemonte Orientale "A. Avogadro", Novara, Italy
| | - Isabella Mayer
- Sobell Department of Motor Neuroscience and Movement Disorders, University College London Institute of Neurology, London, UK Department of Neurology, University Clinic Ulm, Ulm, Germany
| | - Jui-Cheng Chen
- Sobell Department of Motor Neuroscience and Movement Disorders, University College London Institute of Neurology, London, UK Neuroscience Laboratory, Department of Neurology, China Medical University Hospital, Taichung, Taiwan School of Medicine, China Medical University, Taichung, Taiwan
| | - Roberto Cantello
- Department of Translational Medicine, Section of Neurology, University of Piemonte Orientale "A. Avogadro", Novara, Italy
| | - John C Rothwell
- Sobell Department of Motor Neuroscience and Movement Disorders, University College London Institute of Neurology, London, UK
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Strigaro G, Ruge D, Chen JC, Marshall L, Desikan M, Cantello R, Rothwell JC. Interaction between visual and motor cortex: a transcranial magnetic stimulation study. J Physiol 2015; 593:2365-77. [PMID: 25762215 DOI: 10.1113/jp270135] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 03/04/2015] [Indexed: 11/08/2022] Open
Abstract
The major link between the visual and motor systems is via the dorsal stream pathways from visual to parietal and frontal areas of the cortex. Although the pathway appears to be indirect, there is evidence that visual input can reach the motor cortex at relatively short latency. To shed some light on its neural basis, we studied the visuomotor interaction using paired transcranial magnetic stimulation (TMS). Motor-evoked potentials (MEPs) were recorded from the right first dorsal interosseous in sixteen healthy volunteers. A conditioning stimulus (CS) was applied over the phosphene hotspot of the visual cortex, followed by a test stimulus over the left primary motor cortex (M1) with a random interstimulus interval (ISI) in range 12-40 ms. The effects of paired stimulation were retested during visual and auditory reaction-time tasks (RT). Finally, we measured the effects of a CS on short-interval intracortical inhibition (SICI). At rest, a CS over the occiput significantly (P < 0.001) suppressed test MEPs with an ISI in the range 18-40 ms. In the visual RT, inhibition with an ISI of 40 ms (but not 18 ms) was replaced by a time-specific facilitation (P < 0.001), whereas, in the auditory RT, the CS no longer had any effect on MEPs. Finally, an occipital CS facilitated SICI with an ISI of 40 ms (P < 0.01). We conclude that it is possible to study separate functional connections from visual to motor cortices using paired-TMS with an ISI in the range 18-40 ms. The connections are inhibitory at rest and possibly mediated by inhibitory interneurones in the motor cortex. The effect with an ISI of 40 ms reverses into facilitation during a visuomotor RT but not an audiomotor RT. This suggests that it plays a role in visuomotor integration.
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Affiliation(s)
- Gionata Strigaro
- Sobell Department of Motor Neuroscience and Movement Disorders, University College London Institute of Neurology, London, UK.,Department of Translational Medicine, Section of Neurology, University of Piemonte Orientale 'A. Avogadro', Novara, Italy
| | - Diane Ruge
- Sobell Department of Motor Neuroscience and Movement Disorders, University College London Institute of Neurology, London, UK
| | - Jui-Cheng Chen
- Sobell Department of Motor Neuroscience and Movement Disorders, University College London Institute of Neurology, London, UK.,Neuroscience Laboratory, Department of Neurology, China Medical University Hospital, Taichung, Taiwan.,School of Medicine, China Medical University, Taichung, Taiwan
| | - Louise Marshall
- Sobell Department of Motor Neuroscience and Movement Disorders, University College London Institute of Neurology, London, UK
| | - Mahalekshmi Desikan
- Sobell Department of Motor Neuroscience and Movement Disorders, University College London Institute of Neurology, London, UK
| | - Roberto Cantello
- Department of Translational Medicine, Section of Neurology, University of Piemonte Orientale 'A. Avogadro', Novara, Italy
| | - John C Rothwell
- Sobell Department of Motor Neuroscience and Movement Disorders, University College London Institute of Neurology, London, UK
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Irmen F, Wehner T, Lemieux L. Do reflex seizures and spontaneous seizures form a continuum? - triggering factors and possible common mechanisms. Seizure 2014; 25:72-9. [PMID: 25645641 DOI: 10.1016/j.seizure.2014.12.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 12/06/2014] [Accepted: 12/14/2014] [Indexed: 11/26/2022] Open
Abstract
Recent changes in the understanding and classification of reflex seizures have fuelled a debate on triggering mechanisms of seizures and their conceptual organization. Previous studies and patient reports have listed extrinsic and intrinsic triggers, albeit their multifactorial and dynamic nature is poorly understood. This paper aims to review literature on extrinsic and intrinsic seizure triggers and to discuss common mechanisms among them. Among self-reported seizure triggers, emotional stress is most frequently named. Reflex seizures are typically associated with extrinsic sensory triggers; however, intrinsic cognitive or proprioceptive triggers have also been assessed. The identification of a trigger underlying a seizure may be more difficult if it is intrinsic and complex, and if triggering mechanisms are multifactorial. Therefore, since observability of triggers varies and triggers are also found in non-reflex seizures, the present concept of reflex seizures may be questioned. We suggest the possibility of a conceptual continuum between reflex and spontaneous seizures rather than a dichotomy and discuss evidence to the notion that to some extent most seizures might be triggered.
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Affiliation(s)
- Friederike Irmen
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, United Kingdom
| | - Tim Wehner
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, United Kingdom; National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - Louis Lemieux
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, United Kingdom.
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Vaudano AE, Ruggieri A, Tondelli M, Avanzini P, Benuzzi F, Gessaroli G, Cantalupo G, Mastrangelo M, Vignoli A, Bonaventura CD, Canevini MP, Bernardina BD, Nichelli PF, Meletti S. The visual system in eyelid myoclonia with absences. Ann Neurol 2014; 76:412-27. [DOI: 10.1002/ana.24236] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2014] [Revised: 07/15/2014] [Accepted: 07/21/2014] [Indexed: 12/22/2022]
Affiliation(s)
- Anna Elisabetta Vaudano
- Department of Biomedical, Metabolic, and Neural Science; University of Modena and Reggio Emilia; Nuovo Ospedale Civile S. Agostino Estense (NOCSAE) Hospital, AUSL Modena, NOCSE Hospital Modena
| | - Andrea Ruggieri
- Department of Biomedical, Metabolic, and Neural Science; University of Modena and Reggio Emilia; Nuovo Ospedale Civile S. Agostino Estense (NOCSAE) Hospital, AUSL Modena, NOCSE Hospital Modena
| | - Manuela Tondelli
- Department of Biomedical, Metabolic, and Neural Science; University of Modena and Reggio Emilia; Nuovo Ospedale Civile S. Agostino Estense (NOCSAE) Hospital, AUSL Modena, NOCSE Hospital Modena
| | - Pietro Avanzini
- Department of Biomedical, Metabolic, and Neural Science; University of Modena and Reggio Emilia; Nuovo Ospedale Civile S. Agostino Estense (NOCSAE) Hospital, AUSL Modena, NOCSE Hospital Modena
- Department of Neuroscience; University of Parma; Parma
| | - Francesca Benuzzi
- Department of Biomedical, Metabolic, and Neural Science; University of Modena and Reggio Emilia; Nuovo Ospedale Civile S. Agostino Estense (NOCSAE) Hospital, AUSL Modena, NOCSE Hospital Modena
| | - Giuliana Gessaroli
- Department of Biomedical, Metabolic, and Neural Science; University of Modena and Reggio Emilia; Nuovo Ospedale Civile S. Agostino Estense (NOCSAE) Hospital, AUSL Modena, NOCSE Hospital Modena
| | - Gaetano Cantalupo
- Department of Life and Reproduction Sciences; University of Verona; Verona
| | | | - Aglaia Vignoli
- Department of Health Sciences, Epilepsy Center, San Paolo Hospital; University of Milan; Milan
| | - Carlo Di Bonaventura
- Department of Neurological Sciences; University of Rome “La Sapienza,”; Rome Italy
| | - Maria Paola Canevini
- Department of Health Sciences, Epilepsy Center, San Paolo Hospital; University of Milan; Milan
| | | | - Paolo Frigio Nichelli
- Department of Biomedical, Metabolic, and Neural Science; University of Modena and Reggio Emilia; Nuovo Ospedale Civile S. Agostino Estense (NOCSAE) Hospital, AUSL Modena, NOCSE Hospital Modena
| | - Stefano Meletti
- Department of Biomedical, Metabolic, and Neural Science; University of Modena and Reggio Emilia; Nuovo Ospedale Civile S. Agostino Estense (NOCSAE) Hospital, AUSL Modena, NOCSE Hospital Modena
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Bartolini E, Pesaresi I, Fabbri S, Cecchi P, Giorgi FS, Sartucci F, Bonuccelli U, Cosottini M. Abnormal response to photic stimulation in Juvenile Myoclonic Epilepsy: An EEG-fMRI study. Epilepsia 2014; 55:1038-47. [DOI: 10.1111/epi.12634] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/19/2014] [Indexed: 12/01/2022]
Affiliation(s)
- Emanuele Bartolini
- Department of Clinical and Experimental Medicine; University of Pisa; Italy
| | | | - Serena Fabbri
- Department of Clinical and Experimental Medicine; University of Pisa; Italy
| | - Paolo Cecchi
- Department of Clinical and Experimental Medicine; University of Pisa; Italy
| | | | | | - Ubaldo Bonuccelli
- Department of Clinical and Experimental Medicine; University of Pisa; Italy
| | - Mirco Cosottini
- Department of Translational Research and New Technologies in Medicine and Surgery; University of Pisa; Pisa Italy
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30
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Kimura T, Ogata K, Nakazono H, Tobimatsu S. Repetitive Paired-pulse Transcranial Magnetic Stimulation Over the Visual Cortex Selectively Inhibits Focal Flash VEPs. Brain Stimul 2014; 7:275-80. [DOI: 10.1016/j.brs.2013.12.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Revised: 11/13/2013] [Accepted: 12/17/2013] [Indexed: 10/25/2022] Open
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Visual cortex hyperexcitability in idiopathic generalized epilepsies with photosensitivity: a TMS pilot study. Epilepsy Behav 2013; 27:301-6. [PMID: 23518608 DOI: 10.1016/j.yebeh.2013.02.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2012] [Revised: 02/11/2013] [Accepted: 02/13/2013] [Indexed: 11/22/2022]
Abstract
BACKGROUND The current understanding of the mechanisms underlying photosensitivity is still limited, although most studies point to a hyperexcitability of the visual cortex. METHODS Using transcranial magnetic stimulation, we determined the resting motor threshold (rMT) and the phosphene threshold (PT) in 33 patients with IGEs (8 with photosensitivity) compared with 12 healthy controls. RESULTS Eleven controls (92%) reported phosphenes compared with fifteen (46%) patients with idiopathic generalized epilepsy (p=0.015). Phosphenes were reported more frequently among patients with epilepsy with photosensitivity (87.5%) than in patients with active epilepsy without photosensitivity (30.8%) (p=0.038) and patients with epilepsy in remission without photosensitivity (33.3%) (p=0.054); no differences were found between patients with epilepsy with photosensitivity and controls (p=0.648). Resting motor threshold and phosphene threshold were significantly higher among patients with epilepsy (active epilepsy or epilepsy in remission without photosensitivity) compared to healthy controls (p<0.01). Conversely, patients with active epilepsy and photosensitivity had significantly lower values than controls (p=0.03). CONCLUSIONS The marked decrease in PT and the high phosphene prevalence in patients with IGE with photosensitivity indicate a regional hyperexcitability of the primary visual cortex. Results of this study also suggest that the PT may serve as a biomarker for excitability in patients with IGE and photosensitivity.
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Lim JH, Hwang HJ, Han CH, Jung KY, Im CH. Classification of binary intentions for individuals with impaired oculomotor function: 'eyes-closed' SSVEP-based brain-computer interface (BCI). J Neural Eng 2013; 10:026021. [PMID: 23528484 DOI: 10.1088/1741-2560/10/2/026021] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Some patients suffering from severe neuromuscular diseases have difficulty controlling not only their bodies but also their eyes. Since these patients have difficulty gazing at specific visual stimuli or keeping their eyes open for a long time, they are unable to use the typical steady-state visual evoked potential (SSVEP)-based brain-computer interface (BCI) systems. In this study, we introduce a new paradigm for SSVEP-based BCI, which can be potentially suitable for disabled individuals with impaired oculomotor function. APPROACH The proposed electroencephalography (EEG)-based BCI system allows users to express their binary intentions without needing to open their eyes. A pair of glasses with two light emitting diodes flickering at different frequencies was used to present visual stimuli to participants with their eyes closed, and we classified the recorded EEG patterns in the online experiments conducted with five healthy participants and one patient with severe amyotrophic lateral sclerosis (ALS). MAIN RESULTS Through offline experiments performed with 11 participants, we confirmed that human SSVEP could be modulated by visual selective attention to a specific light stimulus penetrating through the eyelids. Furthermore, the recorded EEG patterns could be classified with accuracy high enough for use in a practical BCI system. After customizing the parameters of the proposed SSVEP-based BCI paradigm based on the offline analysis results, binary intentions of five healthy participants were classified in real time. The average information transfer rate of our online experiments reached 10.83 bits min(-1). A preliminary online experiment conducted with an ALS patient showed a classification accuracy of 80%. SIGNIFICANCE The results of our offline and online experiments demonstrated the feasibility of our proposed SSVEP-based BCI paradigm. It is expected that our 'eyes-closed' SSVEP-based BCI system can be potentially used for communication of disabled individuals with impaired oculomotor function.
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Affiliation(s)
- Jeong-Hwan Lim
- Department of Biomedical Engineering, Hanyang University, Seoul 133-731, Korea
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Strigaro G, Prandi P, Varrasi C, Magistrelli L, Falletta L, Cantello R. Intermittent photic stimulation affects motor cortex excitability in photosensitive idiopathic generalized epilepsy. Epilepsy Res 2013; 104:78-83. [DOI: 10.1016/j.eplepsyres.2012.08.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2012] [Revised: 08/19/2012] [Accepted: 08/26/2012] [Indexed: 10/27/2022]
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Brigo F, Rossini F, Stefani A, Nardone R, Tezzon F, Fiaschi A, Manganotti P, Bongiovanni L. Fixation-off sensitivity. Clin Neurophysiol 2013; 124:221-7. [DOI: 10.1016/j.clinph.2012.07.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Revised: 07/19/2012] [Accepted: 07/30/2012] [Indexed: 11/24/2022]
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35
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Wang Z, Zhang Z, Jiao Q, Liao W, Chen G, Sun K, Shen L, Wang M, Li K, Liu Y, Lu G. Impairments of thalamic nuclei in idiopathic generalized epilepsy revealed by a study combining morphological and functional connectivity MRI. PLoS One 2012; 7:e39701. [PMID: 22808050 PMCID: PMC3394762 DOI: 10.1371/journal.pone.0039701] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Accepted: 05/24/2012] [Indexed: 12/22/2022] Open
Abstract
OBJECTIVE Neuroimaging evidence suggested that the thalamic nuclei may play different roles in the progress of idiopathic generalized epilepsy (IGE). This study aimed to demonstrate the alterations in morphometry and functional connectivity in the thalamic nuclei in IGE. METHODS Fifty-two patients with IGE characterized by generalized tonic-clonic seizures and 67 healthy controls were involved in the study. The three-dimensional high-resolution T1-weighted MRI data were acquired for voxel-based morphometry (VBM) analysis, and resting-state blood-oxygenation level functional MRI data were acquired for functional connectivity analysis. The thalamic nuclei of bilateral medial dorsal nucleus (MDN) and pulvinar, as detected with decreased gray matter volumes in patients with IGE through VBM analysis, were selected as seed regions for functional connectivity analysis. RESULTS Different alteration patterns were found in functional connectivity of the thalamic nuclei with decreased gray matter volumes in IGE. Seeding at the MDN, decreased connectivity in the bilateral orbital frontal cortex, caudate nucleus, putamen and amygdala were found in the patients (P<0.05 with correction). However, seeding at the pulvinar, no significant alteration of functional connectivity was found in the patients (P<0.05 with correction). CONCLUSIONS Some specific impairment of thalamic nuclei in IGE was identified using morphological and functional connectivity MRI approaches. These findings may strongly support the different involvement of the thalamocortical networks in IGE.
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Affiliation(s)
- Zhengge Wang
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Zhiqiang Zhang
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Qing Jiao
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Wei Liao
- Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University, Hangzhou, China
| | - Guanghui Chen
- Department of Neurology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Kangjian Sun
- Department of Neurosurgery, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Lianfang Shen
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Maoxue Wang
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Kai Li
- Department of Pharmacology, Suzhou University, Suzhou, China
| | - Yijun Liu
- Department of Psychiatry and McKnight Brain Institute, University of Florida, Gainesville, Florida, United States of America
| | - Guangming Lu
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
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