scholarly journals Clinical Validation of the Champagne Algorithm for Epilepsy Spike Localization

2021 ◽  
Vol 15 ◽  
Author(s):  
Chang Cai ◽  
Jessie Chen ◽  
Anne M. Findlay ◽  
Danielle Mizuiri ◽  
Kensuke Sekihara ◽  
...  
Keyword(s):  
Refractory Epilepsy ◽  
Focal Epilepsy ◽  
Epileptiform Activity ◽  
Consecutive Series ◽  
Source Reconstruction ◽  
Seizure Onset ◽  
Current Dipole ◽  
Seizure Onset Zone ◽  
Complementary Techniques ◽  
Epilepsy Localization

Magnetoencephalography (MEG) is increasingly used for presurgical planning in people with medically refractory focal epilepsy. Localization of interictal epileptiform activity, a surrogate for the seizure onset zone whose removal may prevent seizures, is challenging and depends on the use of multiple complementary techniques. Accurate and reliable localization of epileptiform activity from spontaneous MEG data has been an elusive goal. One approach toward this goal is to use a novel Bayesian inference algorithm—the Champagne algorithm with noise learning—which has shown tremendous success in source reconstruction, especially for focal brain sources. In this study, we localized sources of manually identified MEG spikes using the Champagne algorithm in a cohort of 16 patients with medically refractory epilepsy collected in two consecutive series. To evaluate the reliability of this approach, we compared the performance to equivalent current dipole (ECD) modeling, a conventional source localization technique that is commonly used in clinical practice. Results suggest that Champagne may be a robust, automated, alternative to manual parametric dipole fitting methods for localization of interictal MEG spikes, in addition to its previously described clinical and research applications.

scholarly journals Interictal epileptiform activity outside the seizure onset zone impacts cognition

Brain ◽  
2017 ◽  
Vol 140 (8) ◽  
pp. 2157-2168 ◽  
Author(s):  
Hoameng Ung ◽  
Christian Cazares ◽  
Ameya Nanivadekar ◽  
Lohith Kini ◽  
Joost Wagenaar ◽  
...  
Keyword(s):  
Epileptiform Activity ◽  
Seizure Onset ◽  
Seizure Onset Zone

scholarly journals Seizure Onset Zone Localization from Ictal High-Density EEG in Refractory Focal Epilepsy

2016 ◽  
Vol 30 (2) ◽  
pp. 257-271 ◽  
Author(s):  
Willeke Staljanssens ◽  
Gregor Strobbe ◽  
Roel Van Holen ◽  
Gwénaël Birot ◽  
Markus Gschwind ◽  
...  
Keyword(s):  
Focal Epilepsy ◽  
High Density ◽  
Seizure Onset ◽  
Seizure Onset Zone

scholarly journals The seizure onset zone drives state-dependent epileptiform activity in susceptible brain regions

2019 ◽  
Vol 130 (9) ◽  
pp. 1628-1641 ◽  
Author(s):  
Joshua M. Diamond ◽  
Julio I. Chapeton ◽  
William H. Theodore ◽  
Sara K. Inati ◽  
Kareem A. Zaghloul
Keyword(s):  
Epileptiform Activity ◽  
Brain Regions ◽  
Seizure Onset ◽  
State Dependent ◽  
Seizure Onset Zone

Prolonged postictal hemianopsia after a focal extraoccipital onset seizure

2021 ◽  
Vol 14 (1) ◽  
pp. e239021
Author(s):  
Vibhangini S Wasade ◽  
Jennifer L Logan
Keyword(s):  
Epileptiform Activity ◽  
Diagnostic Evaluation ◽  
Onset Seizure ◽  
Seizure Onset ◽  
Seizure Termination ◽  
Seizure Onset Zone ◽  
History Of ◽  
Epilepsy Monitoring

We report a case of a prolonged postictal hemianopsia occurring after a focal extraoccipital seizure. A 55-year-old man with a history of neurosyphilis, treated with penicillin, presented to our epilepsy monitoring unit (EMU) for diagnostic evaluation of his spells occurring for 2 years. The spell semiology was stereotypical, described as oral and manual automatisms, speech difficulty and unresponsiveness. During the EMU stay, after his typical seizure was recorded, he experienced right hemianopsia lasting for 2 hours. Electrographically, the ictal pattern was prominent over the left temporal derivation and propagated to the left occipital derivation as the seizure progressed. Interictal epileptiform activity was over the left temporal derivations. We support the view that postictal phenomenon may represent merely a seizure termination zone and not be necessarily localising to the seizure onset zone. Furthermore, prolonged isolated postictal symptom of hemianopsia could also be noted in rare situations.

scholarly journals Contribution of ictal source imaging for localizing seizure onset zone in patients with focal epilepsy patients

Neurology ◽  
2020 ◽  
pp. 10.1212/WNL.0000000000011109
Author(s):  
Shuai Ye ◽  
Lin Yang ◽  
Yunfeng Lu ◽  
Michal T. Kucewicz ◽  
Benjamin Brinkmann ◽  
...  
Keyword(s):  
Surgical Resection ◽  
Focal Epilepsy ◽  
High Density ◽  
Concordance Rate ◽  
Added Value ◽  
Seizure Onset ◽  
Source Imaging ◽  
Intracranial Eeg ◽  
Seizure Onset Zone ◽  
Eeg Recordings

ObjectiveTo determine whether seizure onset zone can be accurately localized prior to surgical planning in focal epilepsy patients, we performed non-invasive EEG recordings and source localization analyses on 39 patients.MethodsIn a total of 39 focal epilepsy patients, we recorded and extracted 138 seizures and 1,325 interictal epileptic discharges using high-density EEG. We have investigated a novel approach for directly imaging sources of seizures and interictal spikes from high density EEG recordings, and rigorously validated it for noninvasive localization of seizure onset zone (SOZ) determined from intracranial EEG findings and surgical resection volume. Conventional source imaging analyses were also performed for comparison.ResultsIctal source imaging showed a concordance rate of 95% when compared to intracranial EEG or resection results. The average distance from estimation to seizure onset (intracranial) electrodes is 1.35 cm in patients with concordant results, and 0.74 cm to surgical resection boundary in patients with successful surgery. About 41% of the patients were found to have multiple types of interictal activities; coincidentally, a lower concordance rate and a significantly worse performance in localizing SOZ were observed in these patients.ConclusionNoninvasive ictal source imaging with high-density EEG recording can provide highly concordant results with clinical decisions obtained by invasive monitoring or confirmed by resective surgery. By means of direct seizure imaging using high-density scalp EEG recordings, the added value of ictal source imaging is particularly high in patients with complex interictal activity patterns, who may represent the most challenging cases with poor prognosis.

scholarly journals Statistical Features in High-Frequency Bands of Interictal iEEG Work Efficiently in Identifying the Seizure Onset Zone in Patients with Focal Epilepsy

Entropy ◽  
2020 ◽  
Vol 22 (12) ◽  
pp. 1415
Author(s):  
Most. Sheuli Akter ◽  
Md. Rabiul Islam ◽  
Toshihisa Tanaka ◽  
Yasushi Iimura ◽  
Takumi Mitsuhashi ◽  
...  
Keyword(s):  
High Frequency ◽  
State Of The Art ◽  
Focal Epilepsy ◽  
Epileptic Seizures ◽  
Gradient Boosting ◽  
Statistical Features ◽  
Seizure Onset ◽  
Seizure Onset Zone ◽  
Frequency Components ◽  
Final Score

The design of a computer-aided system for identifying the seizure onset zone (SOZ) from interictal and ictal electroencephalograms (EEGs) is desired by epileptologists. This study aims to introduce the statistical features of high-frequency components (HFCs) in interictal intracranial electroencephalograms (iEEGs) to identify the possible seizure onset zone (SOZ) channels. It is known that the activity of HFCs in interictal iEEGs, including ripple and fast ripple bands, is associated with epileptic seizures. This paper proposes to decompose multi-channel interictal iEEG signals into a number of subbands. For every 20 s segment, twelve features are computed from each subband. A mutual information (MI)-based method with grid search was applied to select the most prominent bands and features. A gradient-boosting decision tree-based algorithm called LightGBM was used to score each segment of the channels and these were averaged together to achieve a final score for each channel. The possible SOZ channels were localized based on the higher value channels. The experimental results with eleven epilepsy patients were tested to observe the efficiency of the proposed design compared to the state-of-the-art methods.

scholarly journals Temporal Lobe Epilepsy Semiology

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Robert D. G. Blair
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Focal Epilepsy ◽  
Intractable Epilepsy ◽  
Febrile Seizures ◽  
Mesial Temporal Sclerosis ◽  
Careful Study ◽  
Seizure Onset ◽  
Seizure Semiology ◽  
Seizure Onset Zone

Epilepsy represents a multifaceted group of disorders divided into two broad categories, partial and generalized, based on the seizure onset zone. The identification of the neuroanatomic site of seizure onset depends on delineation of seizure semiology by a careful history together with video-EEG, and a variety of neuroimaging technologies such as MRI, fMRI, FDG-PET, MEG, or invasive intracranial EEG recording. Temporal lobe epilepsy (TLE) is the commonest form of focal epilepsy and represents almost 2/3 of cases of intractable epilepsy managed surgically. A history of febrile seizures (especially complex febrile seizures) is common in TLE and is frequently associated with mesial temporal sclerosis (the commonest form of TLE). Seizure auras occur in many TLE patients and often exhibit features that are relatively specific for TLE but few are of lateralizing value. Automatisms, however, often have lateralizing significance. Careful study of seizure semiology remains invaluable in addressing the search for the seizure onset zone.

scholarly journals Localizing Epileptic Foci Using Simultaneous EEG-fMRI Recording: Template Component Cross-Correlation

2021 ◽  
Vol 12 ◽  
Author(s):  
Elias Ebrahimzadeh ◽  
Mohammad Shams ◽  
Masoud Seraji ◽  
Seyyed Mostafa Sadjadi ◽  
Lila Rajabion ◽  
...  
Keyword(s):  
Medical Records ◽  
Generalized Linear Model ◽  
Cross Correlation ◽  
Refractory Epilepsy ◽  
Brain Structures ◽  
Seizure Onset ◽  
Future Behavior ◽  
Seizure Onset Zone ◽  
Conventional Methods ◽  
Deep Brain

Conventional EEG-fMRI methods have been proven to be of limited use in the sense that they cannot reveal the information existing in between the spikes. To resolve this issue, the current study obtains the epileptic components time series detected on EEG and uses them to fit the Generalized Linear Model (GLM), as a substitution for classical regressors. This approach allows for a more precise localization, and equally importantly, the prediction of the future behavior of the epileptic generators. The proposed method approaches the localization process in the component domain, rather than the electrode domain (EEG), and localizes the generators through investigating the spatial correlation between the candidate components and the spike template, as well as the medical records of the patient. To evaluate the contribution of EEG-fMRI and concordance between fMRI and EEG, this method was applied on the data of 30 patients with refractory epilepsy. The results demonstrated the significant numbers of 29 and 24 for concordance and contribution, respectively, which mark improvement as compared to the existing literature. This study also shows that while conventional methods often fail to properly localize the epileptogenic zones in deep brain structures, the proposed method can be of particular use. For further evaluation, the concordance level between IED-related BOLD clusters and Seizure Onset Zone (SOZ) has been quantitatively investigated by measuring the distance between IED/SOZ locations and the BOLD clusters in all patients. The results showed the superiority of the proposed method in delineating the spike-generating network compared to conventional EEG-fMRI approaches. In all, the proposed method goes beyond the conventional methods by breaking the dependency on spikes and using the outside-the-scanner spike templates and the selected components, achieving an accuracy of 97%. Doing so, this method contributes to improving the yield of EEG-fMRI and creates a more realistic perception of the neural behavior of epileptic generators which is almost without precedent in the literature.

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.

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