Epileptic Discharge Related Functional Connectivity Within and Between Networks in Benign Epilepsy with Centrotemporal Spikes

2017 ◽  
Vol 27 (07) ◽  
pp. 1750018 ◽  
Author(s):  
Rong Li ◽  
Gong-Jun Ji ◽  
Yangyang Yu ◽  
Yang Yu ◽  
Mei-Ping Ding ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Epileptic Activity ◽  
Epilepsy Syndrome ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
Motor Network ◽  
Dorsal Attention Network ◽  
Intrinsic Connectivity Networks ◽  
Positive Correlations ◽  
Benign Epilepsy

Benign epilepsy with centrotemporal spikes (BECTS) is a common childhood epilepsy syndrome associated with abnormalities in neurocognitive domains, particularly during interictal epileptiform discharges (IEDs). Here, we investigated the effects of IEDs on brain’s intrinsic connectivity networks in 43 BECTS patients and 28 matched healthy controls (HCs). Patients were further divided into IED and non-IED subgroups based on simultaneous EEG-fMRI recordings. Functional connectivity within and between five networks, corresponding to seizure origination and cognitive processes, were analyzed to measure IED effects. We found that patients exhibited increased connectivity within the auditory network (AN) and the somato-motor network (SMN), and decreased connectivity within the basal ganglia network and the dorsal attention network, suggesting that both transient and chronic seizure activity may disturb normal network organization. The IED group showed decreased functional connectivity within the default mode network (DMN) compared with the non-IED group and HCs, implying that the DMN was selectively impaired during epileptiform discharges associated with altered self-referential cognitive functions. Moreover, the IED group exhibited increased positive correlations between the AN and the SMN, which suggests a possible excessive influence of centrotemporal spiking on information processing in the auditory system. The association between epileptic activity and network dysfunctions highlights their importance in investigating the pathological mechanism underlying BECTS.

Altered Structural and Functional Feature of Striato-Cortical Circuit in Benign Epilepsy with Centrotemporal Spikes

2015 ◽  
Vol 25 (06) ◽  
pp. 1550027 ◽  
Author(s):  
Cheng Luo ◽  
Yaodan Zhang ◽  
Weifang Cao ◽  
Yue Huang ◽  
Fei Yang ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Focal Epilepsy ◽  
Brain Morphology ◽  
Brain Maturation ◽  
Epilepsy Syndrome ◽  
Healthy Children ◽  
Functional Feature ◽  
Motor Network ◽  
Cortical Circuit ◽  
Benign Epilepsy

Benign epilepsy with centrotemporal spikes (BECT) is the most common form of childhood idiopathic focal epilepsy syndrome. We investigated quantitative evidence regarding brain morphology and functional connectivity features to provide insight into the neuroanatomical foundation of this disorder, using high resolution T1-weighted magnetic resonance imaging (MRI) and resting state functional MRI in 21 patients with BECT and in 20 healthy children. The functional connectivity analysis, seeded at the regions with altered gray-matter (GM) volume in voxel-based morphometry (VBM) analysis, was further performed. Then, the observed structural and functional alteration were investigated for their association with the clinical and behavior manifestations. The increased GM volume in the striatum and fronto-temporo-parietal cortex (striato-cortical circuit) was observed in BECT. The decreased connections were found among the motor network and frontostriatal loop, and between the default mode network (DMN) and language regions. Additionally, the GM of striatum was negatively correlated with age at epilepsy onset. The current observations may contribute to the understanding of the altered structural and functional feature of striato-cortical circuit in patients with BECT. The findings also implied alterations of the motor network and DMN, which were associated with the epileptic activity in patients with BECT. This further suggested that the onset of BECT might have enduring structural and functional effects on brain maturation.

Effect of interictal epileptiform discharges on EEG-based functional connectivity networks

2019 ◽  
Author(s):  
Derek K. Hu ◽  
Daniel W. Shrey ◽  
Beth A. Lopour
Keyword(s):  
Functional Connectivity ◽  
Network Structure ◽  
Infantile Spasms ◽  
List Type ◽  
Interictal Spikes ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
Network Strength ◽  
The Impact ◽  
Connectivity Strength

AbstractObjectiveFunctional connectivity networks (FCNs) based on interictal electroencephalography (EEG) can identify pathological brain networks associated with epilepsy. FCNs are altered by interictal epileptiform discharges (IEDs), but it is unknown whether this is due to the morphology of the IED or the underlying pathological activity. Therefore, we characterized the impact of IEDs on the FCN through simulations and EEG analysis.MethodsWe introduced simulated IEDs to sleep EEG recordings of eight healthy controls and analyzed the effect of IED amplitude and rate on the FCN. We then generated FCNs based on epochs with and without IEDs and compared them to the analogous FCNs from eight subjects with infantile spasms (IS), based on 1,340 visually marked IEDs. Differences in network structure and strength were assessed.ResultsIEDs in IS subjects caused increased connectivity strength but no change in network structure. In controls, simulated IEDs with physiological amplitudes and rates did not alter network strength or structure.ConclusionsIncreases in connectivity strength in IS subjects are not artifacts caused by the interictal spike waveform and may be related to the underlying pathophysiology of IS.SignificanceDynamic changes in EEG-based FCNs during IEDs may be valuable for identification of pathological networks associated with epilepsy.HighlightsInfantile spasms subjects exhibit broadly increased connectivity strength during interictal spikesFunctional connectivity network structure is unaltered by interictal spikes in infantile spasmsSimulated spikes in healthy control EEG did not alter network strength or structure

scholarly journals Temporal Lobe Spikes Affect Distant Intrinsic Connectivity Networks

2021 ◽  
Vol 12 ◽  
Author(s):  
Laura Mirandola ◽  
Daniela Ballotta ◽  
Francesca Talami ◽  
Giada Giovannini ◽  
Giacomo Pavesi ◽  
...  
Keyword(s):  
Temporal Lobe ◽  
Premotor Cortex ◽  
Group Analysis ◽  
Single Subject ◽  
Epileptogenic Zone ◽  
Precentral Gyrus ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
Intrinsic Connectivity ◽  
Intrinsic Connectivity Networks

Objective: To evaluate local and distant blood oxygen level dependent (BOLD) signal changes related to interictal epileptiform discharges (IED) in drug-resistant temporal lobe epilepsy (TLE).Methods: Thirty-three TLE patients undergoing EEG–functional Magnetic Resonance Imaging (fMRI) as part of the presurgical workup were consecutively enrolled. First, a single-subject spike-related analysis was performed: (a) to verify the BOLD concordance with the presumed Epileptogenic Zone (EZ); and (b) to investigate the Intrinsic Connectivity Networks (ICN) involvement. Then, a group analysis was performed to search for common BOLD changes in TLE.Results: Interictal epileptiform discharges were recorded in 25 patients and in 19 (58%), a BOLD response was obtained at the single-subject level. In 42% of the cases, BOLD changes were observed in the temporal lobe, although only one patient had a pure concordant finding, with a single fMRI cluster overlapping (and limited to) the EZ identified by anatomo-electro-clinical correlations. In the remaining 58% of the cases, BOLD responses were localized outside the temporal lobe and the presumed EZ. In every patient, with a spike-related fMRI map, at least one ICN appeared to be involved. Four main ICNs were preferentially involved, namely, motor, visual, auditory/motor speech, and the default mode network. At the single-subject level, EEG–fMRI proved to have high specificity (above 65%) in detecting engagement of an ICN and the corresponding ictal/postictal symptom, and good positive predictive value (above 67%) in all networks except the visual one. Finally, in the group analysis of BOLD changes related to IED revealed common activations at the right precentral gyrus, supplementary motor area, and middle cingulate gyrus.Significance: Interictal temporal spikes affect several distant extra-temporal areas, and specifically the motor/premotor cortex. EEG–fMRI in patients with TLE eligible for surgery is recommended not for strictly localizing purposes rather it might be useful to investigate ICNs alterations at the single-subject level.

scholarly journals The Oscillatory Basis of Working Memory Function and Dysfunction in Epilepsy

2021 ◽  
Vol 14 ◽  
Author(s):  
Olivia N. Arski ◽  
Julia M. Young ◽  
Mary-Lou Smith ◽  
George M. Ibrahim
Keyword(s):  
Working Memory ◽  
High Frequency ◽  
Large Scale ◽  
Memory Function ◽  
Epileptic Activity ◽  
Functional Roles ◽  
High Frequency Oscillations ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges

Working memory (WM) deficits are pervasive co-morbidities of epilepsy. Although the pathophysiological mechanisms underpinning these impairments remain elusive, it is thought that WM depends on oscillatory interactions within and between nodes of large-scale functional networks. These include the hippocampus and default mode network as well as the prefrontal cortex and frontoparietal central executive network. Here, we review the functional roles of neural oscillations in subserving WM and the putative mechanisms by which epilepsy disrupts normative activity, leading to aberrant oscillatory signatures. We highlight the particular role of interictal epileptic activity, including interictal epileptiform discharges and high frequency oscillations (HFOs) in WM deficits. We also discuss the translational opportunities presented by greater understanding of the oscillatory basis of WM function and dysfunction in epilepsy, including potential targets for neuromodulation.

scholarly journals Effect of interictal epileptiform discharges on EEG-based functional connectivity networks

2020 ◽  
Vol 131 (5) ◽  
pp. 1087-1098
Author(s):  
Derek K. Hu ◽  
Andrew Mower ◽  
Daniel W. Shrey ◽  
Beth A. Lopour
Keyword(s):  
Functional Connectivity ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges

scholarly journals Interictal Epileptiform Discharge Dynamics in Peri-sylvian Polymicrogyria Using EEG-fMRI

2021 ◽  
Vol 12 ◽  
Author(s):  
Noa Cohen ◽  
Yoram Ebrahimi ◽  
Mordekhay Medvedovsky ◽  
Guy Gurevitch ◽  
Orna Aizenstein ◽  
...  
Keyword(s):  
Case Series ◽  
Epileptic Seizures ◽  
Epileptic Activity ◽  
Scalp Eeg ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
Malformation Of Cortical Development ◽  
Interictal Epileptiform Discharge ◽  
Drug Resistant Epilepsy ◽  
Patients With Epilepsy

Polymicrogyria (PMG) is a common malformation of cortical development associated with a higher susceptibility to epileptic seizures. Seizures secondary to PMG are characterized by difficult-to-localize cerebral sources due to the complex and widespread lesion structure. Tracing the dynamics of interictal epileptiform discharges (IEDs) in patients with epilepsy has been shown to reveal the location of epileptic activity sources, crucial for successful treatment in cases of focal drug-resistant epilepsy. In this case series IED dynamics were evaluated with simultaneous EEG-fMRI recordings in four patients with unilateral peri-sylvian polymicrogyria (PSPMG) by tracking BOLD activations over time: before, during and following IED appearance on scalp EEG. In all cases, focal BOLD activations within the lesion itself preceded the activity associated with the time of IED appearance on EEG, which showed stronger and more widespread activations. We therefore propose that early hemodynamic activity corresponding to IEDs may hold important localizing information potentially leading to the cerebral sources of epileptic activity. IEDs are suggested to develop within a small area in the PSPMG lesion with structural properties obscuring the appearance of their electric field on the scalp and only later engage widespread structures which allow the production of large currents which are recognized as IEDs on EEG.

scholarly journals Improved mapping of interictal epileptiform discharges with EEG-fMRI and voxel-wise functional connectivity analysis

Epilepsia ◽  
2014 ◽  
Vol 55 (9) ◽  
pp. 1380-1388 ◽  
Author(s):  
Junjie V. Liu ◽  
Erik J. Kobylarz ◽  
Terrance M. Darcey ◽  
Zhengang Lu ◽  
Yu-Chien Wu ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Connectivity Analysis ◽  
Functional Connectivity Analysis ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges

Cognitive Enhancement in Epilepsy

2017 ◽  
Author(s):  
Beth A. Leeman-Markowski ◽  
Kimford J. Meador
Keyword(s):  
Quality Of Life ◽  
Cognitive Deficits ◽  
Cognitive Enhancement ◽  
Psychiatric Disease ◽  
Epilepsy Syndrome ◽  
Surgical Interventions ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
Underlying Mechanisms

Cognitive deficits, including attention, language, and memory dysfunction, are common in the setting of epilepsy and can greatly impair quality of life. Cognitive dysfunction in epilepsy is often multifactorial and may relate to the underlying etiology or epilepsy syndrome, comorbid psychiatric disease, interictal epileptiform discharges, effects of seizures, antiepileptic drugs, and surgical interventions. Studies have addressed the prevention of impairment and, less commonly, methods for cognitive enhancement. This chapter examines the possible underlying mechanisms of cognitive deficits in epilepsy, methods for prevention of dysfunction, issues in study design, and data regarding cognitive enhancement.

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