scholarly journals Localization of Epileptic Foci Based on Simultaneous EEG–fMRI Data

2021 ◽  
Vol 12 ◽  
Author(s):  
Seyyed Mostafa Sadjadi ◽  
Elias Ebrahimzadeh ◽  
Mohammad Shams ◽  
Masoud Seraji ◽  
Hamid Soltanian-Zadeh
Keyword(s):  
Brain Activity ◽  
Epileptiform Activity ◽  
Brain Regions ◽  
Fmri Data ◽  
Clinical Approach ◽  
Hemodynamic Response Function ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
Surgical Evaluation ◽  
Generalized Epilepsy

Combining functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) enables a non-invasive investigation of the human brain function and evaluation of the correlation of these two important modalities of brain activity. This paper explores recent reports on using advanced simultaneous EEG–fMRI methods proposed to map the regions and networks involved in focal epileptic seizure generation. One of the applications of EEG and fMRI combination as a valuable clinical approach is the pre-surgical evaluation of patients with epilepsy to map and localize the precise brain regions associated with epileptiform activity. In the process of conventional analysis using EEG–fMRI data, the interictal epileptiform discharges (IEDs) are visually extracted from the EEG data to be convolved as binary events with a predefined hemodynamic response function (HRF) to provide a model of epileptiform BOLD activity and use as a regressor for general linear model (GLM) analysis of the fMRI data. This review examines the methodologies involved in performing such studies, including techniques used for the recording of EEG inside the scanner, artifact removal, and statistical analysis of the fMRI signal. It then discusses the results reported for patients with primary generalized epilepsy and patients with different types of focal epileptic disorders. An important matter that these results have brought to light is that the brain regions affected by interictal epileptic discharges might not be limited to the ones where they have been generated. The developed methods can help reveal the regions involved in or affected by a seizure onset zone (SOZ). As confirmed by the reviewed literature, EEG–fMRI provides information that comes particularly useful when evaluating patients with refractory epilepsy for surgery.

scholarly journals Musical components important for the Mozart K448 effect in epilepsy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Robert J. Quon ◽  
Michael A. Casey ◽  
Edward J. Camp ◽  
Stephen Meisenhelter ◽  
Sarah A. Steimel ◽  
...  
Keyword(s):  
Refractory Epilepsy ◽  
Focal Epilepsy ◽  
Epileptiform Activity ◽  
Brain Regions ◽  
Original Version ◽  
Pharmacological Intervention ◽  
Theta Power ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
Insight Into

AbstractThere is growing evidence for the efficacy of music, specifically Mozart’s Sonata for Two Pianos in D Major (K448), at reducing ictal and interictal epileptiform activity. Nonetheless, little is known about the mechanism underlying this beneficial “Mozart K448 effect” for persons with epilepsy. Here, we measured the influence that K448 had on intracranial interictal epileptiform discharges (IEDs) in sixteen subjects undergoing intracranial monitoring for refractory focal epilepsy. We found reduced IEDs during the original version of K448 after at least 30-s of exposure. Nonsignificant IED rate reductions were witnessed in all brain regions apart from the bilateral frontal cortices, where we observed increased frontal theta power during transitions from prolonged musical segments. All other presented musical stimuli were associated with nonsignificant IED alterations. These results suggest that the “Mozart K448 effect” is dependent on the duration of exposure and may preferentially modulate activity in frontal emotional networks, providing insight into the mechanism underlying this response. Our findings encourage the continued evaluation of Mozart’s K448 as a noninvasive, non-pharmacological intervention for refractory epilepsy.

scholarly journals Interictal Epileptiform Discharges are Task Dependent and are Associated with Lasting Electrocorticographic Changes

2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Stephen Meisenhelter ◽  
Robert J Quon ◽  
Sarah A Steimel ◽  
Markus E Testorf ◽  
Edward J Camp ◽  
...  
Keyword(s):  
Epileptiform Activity ◽  
Memory Task ◽  
Low Frequency ◽  
Brain Regions ◽  
Blank Screen ◽  
High Frequency Oscillations ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
Task Dependence ◽  
Low Frequency Power

Abstract The factors that control the occurrence of interictal epileptiform discharges (IEDs) are not well understood. We suspected that this phenomenon reflects an attention-dependent suppression of interictal epileptiform activity. We hypothesized that IEDs would occur less frequently when a subject viewed a task-relevant stimulus compared with viewing a blank screen. Furthermore, IEDs have been shown to impair memory when they occur in certain regions during the encoding or recall phases of a memory task. Although these discharges have a short duration, their impact on memory suggests that they have longer lasting electrophysiological effects. We found that IEDs were associated with an increase in low-frequency power and a change in the balance between low- and high-frequency oscillations for several seconds. We found that the occurrence of IEDs is modified by whether a subject is attending to a word displayed on screen or is observing a blank screen. In addition, we found that discharges in brain regions in every lobe impair memory. These findings elucidate the relationship between IEDs and memory impairment and reveal the task dependence of the occurrence of IEDs.

scholarly journals Resting-state brain activity can predict target-independent aptitude in fMRI-neurofeedback training

2021 ◽  
Author(s):  
Takashi Nakano ◽  
Masahiro Takamura ◽  
Haruki Nishimura ◽  
Maro Machizawa ◽  
Naho Ichikawa ◽  
...  
Keyword(s):  
Resting State ◽  
Brain Connectivity ◽  
Brain Activity ◽  
Resting State Fmri ◽  
Brain Regions ◽  
Posterior Cingulate Cortex ◽  
Fmri Data ◽  
Independent Test ◽  
The Individual ◽  
The Brain

AbstractNeurofeedback (NF) aptitude, which refers to an individual’s ability to change its brain activity through NF training, has been reported to vary significantly from person to person. The prediction of individual NF aptitudes is critical in clinical NF applications. In the present study, we extracted the resting-state functional brain connectivity (FC) markers of NF aptitude independent of NF-targeting brain regions. We combined the data in fMRI-NF studies targeting four different brain regions at two independent sites (obtained from 59 healthy adults and six patients with major depressive disorder) to collect the resting-state fMRI data associated with aptitude scores in subsequent fMRI-NF training. We then trained the regression models to predict the individual NF aptitude scores from the resting-state fMRI data using a discovery dataset from one site and identified six resting-state FCs that predicted NF aptitude. Next we validated the prediction model using independent test data from another site. The result showed that the posterior cingulate cortex was the functional hub among the brain regions and formed predictive resting-state FCs, suggesting NF aptitude may be involved in the attentional mode-orientation modulation system’s characteristics in task-free resting-state brain activity.

scholarly journals Automated Inter-Ictal Epileptiform Discharge Detection from Routine EEG

2021 ◽  
Author(s):  
Duong Nhu ◽  
Mubeen Janmohamed ◽  
Lubna Shakhatreh ◽  
Ofer Gonen ◽  
Patrick Kwan ◽  
...  
Keyword(s):  
Royal Melbourne Hospital ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
Model Variant ◽  
Eeg Recordings ◽  
Generalized Epilepsy ◽  
Electroencephalogram Eeg ◽  
Health Hospital ◽  
Epilepsy Monitoring

Epilepsy is the most common neurological disorder. The diagnosis commonly requires manual visual electroencephalogram (EEG) analysis which is time-consuming. Deep learning has shown promising performance in detecting interictal epileptiform discharges (IED) and may improve the quality of epilepsy monitoring. However, most of the datasets in the literature are small (n≤100) and collected from single clinical centre, limiting the generalization across different devices and settings. To better automate IED detection, we cross-evaluated a Resnet architecture on 2 sets of routine EEG recordings from patients with idiopathic generalized epilepsy collected at the Alfred Health Hospital and Royal Melbourne Hospital (RMH). We split these EEG recordings into 2s windows with or without IED and evaluated different model variants in terms of how well they classified these windows. The results from our experiment showed that the architecture generalized well across different datasets with an AUC score of 0.894 (95% CI, 0.881–0.907) when trained on Alfred’s dataset and tested on RMH’s dataset, and 0.857 (95% CI, 0.847–0.867) vice versa. In addition, we compared our best model variant with Persyst and observed that the model was comparable.

scholarly journals Influence of Sleep and Sleep Deprivation on Ictal and Interictal Epileptiform Activity

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Antonio Díaz-Negrillo
Keyword(s):  
Sleep Deprivation ◽  
Epileptiform Activity ◽  
Epileptic Seizures ◽  
Future Research ◽  
Reciprocal Relation ◽  
Physiological Factors ◽  
Rigorous Approach ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
The Relationship

Sleep is probably one of the most important physiological factors implicated both in epileptic seizures and interictal epileptiform discharges. The neurophysiology concerning the relationship between sleep and epilepsy is well described in the literature; however, the pathological events that culminate in the seizures are poorly explored. The present paper intends to make a rigorous approach to the main mechanisms involved in this reciprocal relation. Knowledge of sleep and sleep deprivation effects in epilepsy stands as crucial in the understanding of how seizures are produced, their possible lines of treatment, and future research.

Dynamic Statistical Parametric Mapping for Analyzing the Magnetoencephalographic Epileptiform Activity in Patients With Epilepsy

2004 ◽  
Vol 19 (3) ◽  
pp. 363-369
Author(s):  
Hideaki Shiraishi ◽  
Steven M. Stufflebeam ◽  
Susanne Knake ◽  
Seppo P. Ahlfors ◽  
Akira Sudo ◽  
...  
Keyword(s):  
Focal Cortical Dysplasia ◽  
Epileptiform Activity ◽  
Rapid Change ◽  
Statistical Parametric Mapping ◽  
Cortical Dysplasia ◽  
Parametric Mapping ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
L2 Norm ◽  
Patients With Epilepsy

Our current purpose is to evaluate the applicability of dynamic statistical parametric mapping, a novel method for localizing epileptiform activity recorded with magnetoencephalography in patients with epilepsy. We report four pediatric patients with focal epilepsies. Magnetoencephalographic data were collected with a 306-channel whole-head helmet-shaped sensor array. We calculated equivalent current dipoles and dynamic statistical parametric mapping movies of the interictal epileptiform discharges that were based in the minimum-L2 norm estimate, minimizing the square sum of the dipole element amplitudes. The dynamic statistical parametric mapping analysis of interictal epileptiform discharges can demonstrate the rapid change and propagation of interical epileptiform discharges. According to these findings, specific epileptogenic lesion—focal cortical dysplasia could be found and patients could be operated on successfully. The presurgical analysis of interictal epileptiform discharges using dynamic statistical parametric mapping seems to be promising in patients with a possible underlying focal cortical dysplasia and might help to guide the placement of invasive electrodes. ( J Child Neurol 2005;20:363—369).

A diffusional kurtosis imaging study of idiopathic generalized epilepsy with unilateral interictal epileptiform discharges in children

2016 ◽  
Vol 43 (5) ◽  
pp. 339-345 ◽  
Author(s):  
Yuzhen Zhang ◽  
Yu Gao ◽  
Minxiong Zhou ◽  
Jie Wu ◽  
Chishing Zee ◽  
...  
Keyword(s):  
Imaging Study ◽  
Idiopathic Generalized Epilepsy ◽  
Diffusional Kurtosis Imaging ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
Generalized Epilepsy

scholarly journals P119 Brain function and fatigue in patients with inflammatory bowel disease

2020 ◽  
Vol 14 (Supplement_1) ◽  
pp. S195-S196
Author(s):  
A Thomann ◽  
M Schmitgen ◽  
D Kmuche ◽  
M Griebe ◽  
M Ebert ◽  
...  
Keyword(s):  
Resting State ◽  
Brain Function ◽  
Brain Activity ◽  
Low Frequency ◽  
Peak Level ◽  
Brain Regions ◽  
Fmri Data ◽  
Considerable Proportion ◽  
Functional Studies ◽  
Inflammatory Bowel

Abstract Background Fatigue is common in patients with inflammatory bowel diseases (IBD). It occurs in up to 80% of patients with active disease, but also a considerable proportion of patients in remission, and significantly affects quality of life. The underlying mechanisms are still poorly understood, and it is still unclear which patients will suffer from fatigue even in luminally quiescent disease. Task-based brain functional studies have examined neural correlates of fatigueability and found changes in the orbitofrontal cortex (OFC), among other regions. To the best our knowledge, the relationship between brain function and fatigue in IBD has not been investigated. This study aimed to examine the association between fatigue and resting-state brain function in remitted IBD patients. Methods We obtained resting-state-functional MRI (rs-fMRI) data from 45 IBD patients in stable remission without current steroid or biological therapy and 17 healthy controls (HCs). Fatigue was assessed with Würzburger Erschöpfungsinventar Multiple Sklerose (WEIMuS). Preprocessing of rs-fMRI-data and calculation of amplitude of low frequency fluctuations (ALFF) was performed using the Data Processing Assistant for rs-fMRI. The resulting individual maps were analysed via second-level SPM multiple regression models in patients and HC to test for correlations between ALFF data and WEIMuS scores. Age, gender and mean framewise displacement were included as covariates of no interest and results were displayed at p < 0.001 (peak level) with a threshold of spatial extent (k) according to the expected voxels per cluster estimated by SPM. Results Fatigue scores did not differ significantly between patients and controls (mean WEIMuS-scores 17.9 (SD 13.9) vs. 12.3 (SD 16.5), p = .17). Proportions of participants with fatigue scores above the cutoff (>32P.) were nearly identical in patients and HC (8/45 vs. 3/17). In patients, fatigue scores correlated positively with ALFF in the right central operculum and negatively with ALFF in the left OFC and left cerebellum (all p < .001, Figure 1). Fatigue and ALFF in the left cerebellum were also found to correlate in HC. Conclusion This study shows fatigue-associated changes in brain activity in several brain regions. The negative association between fatigue and ALFF in the left OFC of IBD patients was not seen in HC, indicating that reduced ALFF in the OFC may represent a neural correlate of IBD-related fatigue. The OFC is thought to be involved in decision-making, which is described to be impaired in many fatigued IBD patients. If the association between fatigue and brain function detected in our study is confirmed in longitudinal IBD studies, these regions could serve as biomarkers when targeting fatigue in IBD.

Focal interictal epileptiform discharges in idiopathic generalized epilepsy

2016 ◽  
Vol 37 (7) ◽  
pp. 1071-1077 ◽  
Author(s):  
Eman H. Esmail ◽  
Amani M. Nawito ◽  
Dalia M. Labib ◽  
Mye A. Basheer
Keyword(s):  
Idiopathic Generalized Epilepsy ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
Generalized Epilepsy
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