scholarly journals Imaging the Extent and Location of Spatiotemporally Distributed Epileptiform Sources from MEG Measurements

2021 ◽  
Author(s):  
Xiyuan Jiang ◽  
Shuai Ye ◽  
Abbas Sohrabpour ◽  
Anto Bagic ◽  
Bin He
Keyword(s):  
Focal Epilepsy ◽  
Real Data ◽  
Drug Resistant ◽  
Interictal Spikes ◽  
Source Imaging ◽  
Non Invasive ◽  
Eeg Source Imaging ◽  
Surgical Evaluation ◽  
Extended Sources ◽  
Drug Resistant Epilepsy

Non-invasive MEG/EEG source imaging provides valuable information about the epileptogenic brain areas which can be used to aid presurgical planning in focal epilepsy patients suffering from drug-resistant seizures. However, the source extent estimation for electrophysiological source imaging remains to be a challenge and is usually largely dependent on subjective choice. Our recently developed algorithm, fast spatiotemporal iteratively reweighted edge sparsity minimization (FAST-IRES) strategy, has been shown to objectively estimate extended sources from EEG recording, while it has not been applied to MEG recordings. In this work, through extensive numerical experiments and real data analysis in a group of focal drug-resistant epilepsy patients interictal spikes, we demonstrated the ability of FAST-IRES algorithm to image the location and extent of underlying epilepsy sources from MEG measurements. Our results indicate the merits of FAST-IRES in imaging the location and extent of epilepsy sources for pre-surgical evaluation from MEG measurements.

EEG Source Imaging (ESI) utility in clinical practice

2020 ◽  
Vol 65 (6) ◽  
pp. 673-682
Author(s):  
Pegah Khosropanah ◽  
Eric Tatt-Wei Ho ◽  
Kheng-Seang Lim ◽  
Si-Lei Fong ◽  
Minh-An Thuy Le ◽  
...  
Keyword(s):  
Focal Epilepsy ◽  
Cost Effective ◽  
Head Model ◽  
Computational Technique ◽  
Epileptogenic Zone ◽  
Clinical Tool ◽  
Source Imaging ◽  
Localization Accuracy ◽  
Eeg Source Imaging ◽  
Surgical Evaluation

AbstractEpilepsy surgery is an important treatment modality for medically refractory focal epilepsy. The outcome of surgery usually depends on the localization accuracy of the epileptogenic zone (EZ) during pre-surgical evaluation. Good localization can be achieved with various electrophysiological and neuroimaging approaches. However, each approach has its own merits and limitations. Electroencephalography (EEG) Source Imaging (ESI) is an emerging model-based computational technique to localize cortical sources of electrical activity within the brain volume, three-dimensionally. ESI based pre-surgical evaluation gives an overall clinical yield of 73–91%, depending on choice of head model, inverse solution and EEG electrode density. It is a cost effective, non-invasive method which provides valuable additional information in presurgical evaluation due to its high localizing value specifically in MRI-negative cases, extra or basal temporal lobe epilepsy, multifocal lesions such as tuberous sclerosis or cases with multiple hypotheses. Unfortunately, less than 1% of surgical centers in developing countries use this method as a part of pre-surgical evaluation. This review promotes ESI as a useful clinical tool especially for patients with lesion-negative MRI to determine EZ cost-effectively with high accuracy under the optimized conditions.

scholarly journals Role of Electrical Source Imaging in Pediatric Epilepsy and Pre-Surgical Evaluation

2021 ◽  
pp. 10-14
Author(s):  
Arun Thurairajah
Keyword(s):  
Diagnostic Techniques ◽  
Pediatric Epilepsy ◽  
Source Imaging ◽  
Non Invasive ◽  
Surgical Evaluation ◽  
Invasive Method ◽  
Electric Potentials ◽  
Drug Resistant Epilepsy ◽  
Electrical Source

Children with drug-resistant epilepsy undergo an extensive pre-surgical evaluation to determine the part of the brain thought to be the cause of seizures. The employment of non-invasive diagnostic imaging tools plays an important role in establishing surgical candidacy, preventing the need for invasive procedures. Electrical source imaging (ESI) has been explored as a modern alternative to traditional diagnostic techniques in pre-surgical workup. Through computational analysis of recorded electric potentials and individualized head scans, ESI provides a non-invasive method of obtaining more accurate localizations. However, its use within the clinical setting is limited. The following review looks to examine the literature surrounding ESI and advocates for its inclusion within the pre-surgical workup of children.   

Multimodal approach in the pre-surgical evaluation of focal epilepsy surgery candidates: how far are we from a non-invasive ESI-based “sourcectomy”?

2021 ◽  
Vol 23 (4) ◽  
pp. 661-666
Author(s):  
Giulia Nobile ◽  
Alessandro Consales ◽  
Domenico Tortora ◽  
Mattia Pacetti ◽  
Francesca Gianno ◽  
...  
Keyword(s):  
Epilepsy Surgery ◽  
Focal Epilepsy ◽  
Multimodal Approach ◽  
Non Invasive ◽  
Surgical Evaluation

scholarly journals Chronic subthreshold cortical stimulation for adult drug-resistant focal epilepsy: safety, feasibility, and technique

2018 ◽  
Vol 129 (2) ◽  
pp. 533-543 ◽  
Author(s):  
Panagiotis Kerezoudis ◽  
Sanjeet S. Grewal ◽  
Matthew Stead ◽  
Brian Nils Lundstrom ◽  
Jeffrey W. Britton ◽  
...  
Keyword(s):  
Focal Epilepsy ◽  
Cortical Stimulation ◽  
Adult Patients ◽  
Therapeutic Trial ◽  
Drug Resistant ◽  
Surgical Safety ◽  
Institutional Experience ◽  
Eloquent Cortex ◽  
Drug Resistant Epilepsy ◽  
Seizure Foci

OBJECTIVEEpilepsy surgery is effective for lesional epilepsy, but it can be associated with significant morbidity when seizures originate from eloquent cortex that is resected. Here, the objective was to describe chronic subthreshold cortical stimulation and evaluate its early surgical safety profile in adult patients with epilepsy originating from seizure foci in cortex that is not amenable to resection.METHODSAdult patients with focal drug-resistant epilepsy underwent intracranial electroencephalography monitoring for evaluation of resection. Those with seizure foci in eloquent cortex were not candidates for resection and were offered a short therapeutic trial of continuous subthreshold cortical stimulation via intracranial monitoring electrodes. After a successful trial, electrodes were explanted and permanent stimulation hardware was implanted.RESULTSTen patients (6 males) who underwent chronic subthreshold cortical stimulation between 2014 and 2016 were included. Based on radiographic imaging, intracranial pathologies included cortical dysplasia (n = 3), encephalomalacia (n = 3), cortical tubers (n = 1), Rasmussen encephalitis (n = 1), and linear migrational anomaly (n = 1). The duration of intracranial monitoring ranged from 3 to 20 days. All patients experienced an uneventful postoperative course and were discharged home with a median length of stay of 10 days. No postoperative surgical complications developed (median follow-up length 7.7 months). Seizure severity and seizure frequency improved in all patients.CONCLUSIONSThe authors’ institutional experience with this small group shows that chronic subthreshold cortical stimulation can be safely and effectively performed in appropriately selected patients without postoperative complications. Future investigation will provide further insight to recently published results regarding mechanism and efficacy of this novel and promising intervention.

scholarly journals Current approaches to neurosurgical treatment for drug-resistant focal epilepsy in adults

2018 ◽  
Vol 10 (1S) ◽  
pp. 81-88
Author(s):  
E. A. Narodova ◽  
A. A. Narodov ◽  
N. A. Shnayder ◽  
D. V. Dmitrenko ◽  
I. G. Strotskaya
Keyword(s):  
Focal Epilepsy ◽  
Rapid Development ◽  
Adult Population ◽  
Infectious Complications ◽  
High Rate ◽  
Drug Resistant ◽  
Postoperative Rehabilitation ◽  
Foreign Countries ◽  
Neurosurgical Treatment ◽  
Drug Resistant Epilepsy

The review is dedicated to the problems of current neurosurgical treatment for drug-resistant epilepsy in the adult population of Russia and foreign countries. The literature published in the period  2010–2017 was sought in Russian and foreign databases. This  review included 58 only full-text publications. The search results  have shown that despite advances in neurosurgery for drug-resistant epilepsy and the development of new surgical procedures, the  problem of this disease has not yet been fully resolved today. This is  evidenced by fairly high global prevalence rates in patients with  postoperative epilepsy resistant to antiepileptic therapy. The  literature analysis has revealed that the mean prevalence of postoperative epilepsy is 69%. This indicator may vary according  to the type of an epileptogenic structural lesion and its location in  the brain. However, despite the rapid development of epilepsy  surgery, currently there is still a low surgical activity in the treatment  of patients with drugresistant epilepsy. Of importance is  also the presence of postoperative complications, including various  infectious complications and neurological deficit. Taking into account  the high rate of postoperative epilepsy, it is concluded that it is  appropriate to develop postoperative rehabilitation methods for patients with drug-resistant epilepsy.

scholarly journals Drug-resistant focal epilepsy in children is associated with increased modal controllability of the whole brain and epileptogenic regions

2021 ◽  
Author(s):  
Kiran Seunarine ◽  
Xiaosong He ◽  
Martin Tisdall ◽  
Christopher Clark ◽  
Danielle S Bassett ◽  
...  
Keyword(s):  
Diffusion Mri ◽  
Focal Epilepsy ◽  
Brain Network ◽  
Structure And Function ◽  
Network Control ◽  
Drug Resistant ◽  
Drug Resistant Epilepsy ◽  
And Function ◽  
The Brain ◽  
Disease Understanding

Network control theory provides a framework by which neurophysiological dynamics of the brain can be modelled as a function of the structural connectome constructed from diffusion MRI. Average controllability describes the ability of a region to drive the brain to easy-to-reach neurophysiological states whilst modal controllability describes the ability of a region to drive the brain to difficult-to-reach states. In this study, we identify increases in mean average and modal controllability in children with drug-resistant epilepsy compared to healthy controls. Using simulations, we purport that these changes may be a result of increased thalamocortical connectivity. At the node level, we demonstrate decreased modal controllability in the thalamus and posterior cingulate regions. In those undergoing resective surgery, we also demonstrate increased modal controllability of the resected parcels, a finding specific to patients who were rendered seizure free following surgery. Changes in controllability are a manifestation of brain network dysfunction in epilepsy and may be a useful construct to understand the pathophysiology of this archetypical network disease. Understanding the mechanisms underlying these controllability changes may also facilitate the design of network-focussed interventions that seek to normalise network structure and function.

Surgical decision-making among patients with uncontrolled epilepsy: “Making important decisions about my brain, which I happen to love”

2020 ◽  
pp. 174239532096862
Author(s):  
Huibrie C Pieters ◽  
Sandra R Dewar ◽  
Lizza Ranit ◽  
Tomoko J Iwaki ◽  
Jerome Engel
Keyword(s):  
Decision Making ◽  
Focal Epilepsy ◽  
Treatment Options ◽  
Visual Image ◽  
Constructivist Grounded Theory ◽  
Thought Processes ◽  
Risks And Benefits ◽  
Surgical Evaluation ◽  
Drug Resistant Epilepsy ◽  
The Impact

Objective To explore decision-making from patients’ perceptions of risks and benefits of epilepsy surgery for refractory focal seizures. Methods Using constructivist grounded theory, in-person interviews were conducted with 35 adults with refractory focal epilepsy who were undergoing a pre-surgical evaluation or who had consented for surgery. Results For this sample of participants decision-making about surgery was complex, centering on the meaning of illness for the self and the impact of epilepsy and its treatment for significant others. Two interrelated categories crystalized from our data: the unique context of brain surgery and how the decisional counterweights of risks and benefits were considered. Discussion Exploring components of decision-making from the patients’ perspective afforded an opportunity to describe thought processes intrinsic to how people with drug-resistant epilepsy weighed their treatment options. Tensions were evident in how decisions were made. We use the analogy of an imaginary tightrope-walker to create a visual image of what patients face as they consider the illness experience (past and present), their hopes for the future, and the simultaneous uncertainty centered around balancing the counterweights of treatment risks and benefits.

Sign in / Sign up

Export Citation Format

Share Document