scholarly journals The Onset of Interictal Spike-Related Ripples Facilitates Detection of the Epileptogenic Zone

2021 ◽  
Vol 12 ◽  
Author(s):  
Yurika Numata-Uematsu ◽  
Mitsugu Uematsu ◽  
Rie Sakuraba ◽  
Masaki Iwasaki ◽  
Shinichiro Osawa ◽  
...  
Keyword(s):  
Epilepsy Surgery ◽  
Preoperative Evaluation ◽  
Accurate Estimation ◽  
Epileptogenic Zone ◽  
Interictal Spikes ◽  
Simple Method ◽  
Interictal Spike ◽  
High Frequency Oscillations ◽  
Surgery Outcomes ◽  
Resection Area

Objective: Accurate estimation of the epileptogenic zone (EZ) is essential for favorable outcomes in epilepsy surgery. Conventional ictal electrocorticography (ECoG) onset is generally used to detect the EZ but is insufficient in achieving seizure-free outcomes. By contrast, high-frequency oscillations (HFOs) could be useful markers of the EZ. Hence, we aimed to detect the EZ using interictal spikes and investigated whether the onset area of interictal spike-related HFOs was within the EZ.Methods: The EZ is considered to be included in the resection area among patients with seizure-free outcomes after surgery. Using a complex demodulation technique, we developed a method to determine the onset channels of interictal spike-related ripples (HFOs of 80–200 Hz) and investigated whether they are within the resection area.Results: We retrospectively examined 12 serial patients who achieved seizure-free status after focal resection surgery. Using the method that we developed, we determined the onset channels of interictal spike-related ripples and found that for all 12 patients, they were among the resection channels. The onset frequencies of ripples were in the range of 80–150 Hz. However, the ictal onset channels (evaluated based on ictal ECoG patterns) and ripple onset channels coincided in only 3 of 12 patients.Conclusions: Determining the onset area of interictal spike-related ripples could facilitate EZ estimation. This simple method that utilizes interictal ECoG may aid in preoperative evaluation and improve epilepsy surgery outcomes.

scholarly journals A spiking neural network (SNN) for detecting high frequency oscillations (HFOs) in the intraoperative ECoG

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Karla Burelo ◽  
Mohammadali Sharifshazileh ◽  
Niklaus Krayenbühl ◽  
Georgia Ramantani ◽  
Giacomo Indiveri ◽  
...  
Keyword(s):  
Neural Network ◽  
Real Time ◽  
Epilepsy Surgery ◽  
High Frequency ◽  
Seizure Outcome ◽  
Seizure Freedom ◽  
Epileptogenic Zone ◽  
Spiking Neural Network ◽  
High Frequency Oscillations ◽  
Neuromorphic Hardware

AbstractTo achieve seizure freedom, epilepsy surgery requires the complete resection of the epileptogenic brain tissue. In intraoperative electrocorticography (ECoG) recordings, high frequency oscillations (HFOs) generated by epileptogenic tissue can be used to tailor the resection margin. However, automatic detection of HFOs in real-time remains an open challenge. Here we present a spiking neural network (SNN) for automatic HFO detection that is optimally suited for neuromorphic hardware implementation. We trained the SNN to detect HFO signals measured from intraoperative ECoG on-line, using an independently labeled dataset (58 min, 16 recordings). We targeted the detection of HFOs in the fast ripple frequency range (250-500 Hz) and compared the network results with the labeled HFO data. We endowed the SNN with a novel artifact rejection mechanism to suppress sharp transients and demonstrate its effectiveness on the ECoG dataset. The HFO rates (median 6.6 HFO/min in pre-resection recordings) detected by this SNN are comparable to those published in the dataset (Spearman’s $$\rho$$ ρ = 0.81). The postsurgical seizure outcome was “predicted” with 100% (CI [63 100%]) accuracy for all 8 patients. These results provide a further step towards the construction of a real-time portable battery-operated HFO detection system that can be used during epilepsy surgery to guide the resection of the epileptogenic zone.

scholarly journals Can we use intraoperative high‐frequency oscillations to guide tumor‐related epilepsy surgery?

Epilepsia ◽  
2021 ◽  
Author(s):  
Nicole E. C. Klink ◽  
Willemiek J. E. M. Zweiphenning ◽  
Cyrille H. Ferrier ◽  
Peter H. Gosselaar ◽  
Kai J. Miller ◽  
...  
Keyword(s):  
Epilepsy Surgery ◽  
High Frequency ◽  
High Frequency Oscillations

PP482 Invasive Electroencephalography In The Pre-Surgical Diagnosis Of Pharmacoresistant Epilepsy

2020 ◽  
Vol 36 (S1) ◽  
pp. 38-38
Author(s):  
Andrey Avdeyev ◽  
Azat Shpekov ◽  
Valeriy Benberin ◽  
Nasrulla Shanazarov ◽  
Leilya Ismailova ◽  
...  
Keyword(s):  
Cost Effectiveness ◽  
Meta Analysis ◽  
Epileptogenic Zone ◽  
Pharmacoresistant Epilepsy ◽  
Simple Method ◽  
Integrated Method ◽  
Accurate Localization ◽  
Functional Zones ◽  
Severity Of The Disease ◽  
Government Reimbursement

IntroductionWorldwide, more than 50 million people suffer from epilepsy, and there are 16–51 new cases per 100,000 population each year. Up to 30 percent of patients with epilepsy are pharmacoresistant, who are candidates for surgical treatment. Invasive electroencephalography (iEEG) is a mandatory method in the arsenal of epileptic centers, and is gradually becoming the gold standard for invasive determination of boundaries between the affected and functional zones of the cortex and subcortical brain. Treatment costs correlate with the severity of the disease, with patients having uncontrolled seizures incurring eight times the costs compared to those with controlled epilepsy.MethodsTo assess the clinical and cost-effectiveness of the iEEG in the pre-surgical diagnosis of pharmacoresistant epilepsy, a systematic search of literature by keywords in the MEDLINE database was conducted. The search resulted in sixty-six articles. The analysis included twenty studies that met the search criteria.ResultsMost studies including meta-analysis show very low rates of complications of iEEG. Literature data demonstrate cost-effectiveness of the method in patients with pharmacoresistant epilepsy in comparison with continued antiepileptic drug therapy. As an integrated method, rather than a simple method, it takes maximum account of clinical, neurophysiological and anatomical-functional data to achieve accurate localization of the epileptogenic zone. Currently, iEEG is a clinically effective method to improve the safety and specificity of resective surgery.ConclusionsWith the use of iEEG, mortality and disability of patients with pharmacoresistant epilepsy will be significantly reduced. It has also been proven that epilepsy surgery leads to significant financial savings in the treatment of pharmacoresistant epilepsy. The results of the clinical and economic evaluation (mini-HTA report) have been submitted to the Ministry of Healthcare for decision-making on including iEEG in government reimbursement system.

Interictal spike localization for epilepsy surgery using magnetoencephalography beamforming

2021 ◽  
Vol 132 (4) ◽  
pp. 928-937
Author(s):  
Rui Li ◽  
Chris Plummer ◽  
Simon J. Vogrin ◽  
William P. Woods ◽  
Levin Kuhlmann ◽  
...  
Keyword(s):  
Epilepsy Surgery ◽  
Interictal Spike

Selection of children with drug resistant epilepsy who are candidates for epilepsy surgery: pre and post-operative evaluation

QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Osama Salah Mohamed El Sharkawy ◽  
Zeinab Anwar El kabbany ◽  
Neveen Tawakol Younis ◽  
Khaled Aboulfotouh Ahmad ◽  
Ahmed Darwish Mahmoud ◽  
...  
Keyword(s):  
Epilepsy Surgery ◽  
Preoperative Evaluation ◽  
Drug Resistant ◽  
Surgery Outcome ◽  
Class 1 ◽  
Operative Evaluation ◽  
Drug Resistant Epilepsy ◽  
Stage 1 ◽  
International League ◽  
Selection Of

Abstract Objective To select patients with drug resistant epilepsy following up in Pediatrics Neurology Outpatient Clinic of Children's Hospital, Ain Shams University who are candidates for epilepsy surgery and to detect outcome of epilepsy surgery in such children as regards seizures control. Methods This prospective study was conducted over a period of 36 months and comprises of 3 stages. Stage 1 includes selection of candidates for epilepsy surgery and preoperative evaluation. Evaluation included clinical assessment, video EEG, MRI epilepsy protocol. Stage 2 include surgery phase where decision of surgery was made by a multidisciplinary team. Stage 3 includes post-operative evaluation as regards Seizures frequency, Seizures Severity using Chalfont score, Engel Epilepsy Surgery Outcome Scale and the International League Against Epilepsy (ILAE) outcome classification. Data was tabulated and analyzed with SSPS package for windows. Results 17 patients underwent epilepsy surgery. Results revealed significant decrease in seizures frequency and severity at 6 and 12 months after surgery. As regards Engel Epilepsy Surgery Outcome Scale 11 (64.7%) patients were class I at 12 months. As regards the ILAE outcome classification 10 (58.8%) patients are class 1 at 12 months. Conclusions epilepsy surgery can be a hope for patients with drug resistant epilepsy who are well selected and evaluated preoperatively. New studies on larger number and for longer duration are recommended.

scholarly journals Pediatric Epilepsy Surgery

2017 ◽  
Vol 32 (5) ◽  
pp. 467-474 ◽  
Author(s):  
Krista J. Qualmann ◽  
Christine G. Spaeth ◽  
Melanie F. Myers ◽  
Paul S. Horn ◽  
Katherine Holland ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
General Population ◽  
Epilepsy Surgery ◽  
Pediatric Epilepsy ◽  
Seizure Outcome ◽  
Cognitive Disability ◽  
Pediatric Epilepsy Surgery ◽  
Surgery Outcomes

Central nervous system comorbidities have been identified in patients with epilepsy. Several of these comorbidities have been correlated with poor surgery outcomes in patient cohorts. The authors sought to determine if prevalence of comorbidities in pediatric epilepsy surgery patients and their families correlate with long-term seizure outcome in a cross-sectional analysis. Three-generation pedigrees were elicited to compare family history of epilepsy, ADHD, anxiety, autism, bipolar disorder, cognitive disability, depression, migraine, and motor disability to surgery outcomes in 52 patients. Proportions of affected patients and relatives were compared to general population comorbidity rates and the patients’ most recent seizure outcome classification. Patients and families had significantly higher rates of comorbidities than the general population. Poorer long-term seizure outcomes following resective surgery were associated with autism or cognitive disability in patients. Together these data support evidence for a common pathophysiological mechanism between epilepsy and central nervous system comorbidities.

scholarly journals Medically resistant pediatric insular-opercular/perisylvian epilepsy. Part 1: invasive monitoring using the parasagittal transinsular apex depth electrode

2016 ◽  
Vol 18 (5) ◽  
pp. 511-522 ◽  
Author(s):  
Alexander G. Weil ◽  
Aria Fallah ◽  
Evan C. Lewis ◽  
Sanjiv Bhatia
Keyword(s):  
Epilepsy Surgery ◽  
Electrode Placement ◽  
Epileptogenic Zone ◽  
Drug Resistant ◽  
Depth Electrodes ◽  
Depth Electrode ◽  
Age At Surgery ◽  
Feasible Alternative ◽  
The Mean ◽  
Drug Resistant Epilepsy

OBJECTIVE Insular lobe epilepsy (ILE) is an under-recognized cause of extratemporal epilepsy and explains some epilepsy surgery failures in children with drug-resistant epilepsy. The diagnosis of ILE usually requires invasive investigation with insular sampling; however, the location of the insula below the opercula and the dense middle cerebral artery vasculature renders its sampling challenging. Several techniques have been described, ranging from open direct placement of orthogonal subpial depth and strip electrodes through a craniotomy to frame-based stereotactic placement of orthogonal or oblique electrodes using stereo-electroencephalography principles. The authors describe an alternative method for sampling the insula, which involves placing insular depth electrodes along the long axis of the insula through the insular apex following dissection of the sylvian fissure in conjunction with subdural electrodes over the lateral hemispheric/opercular region. The authors report the feasibility, advantages, disadvantages, and role of this approach in investigating pediatric insular-opercular refractory epilepsy. METHODS The authors performed a retrospective analysis of all children (< 18 years old) who underwent invasive intracranial studies involving the insula between 2002 and 2015. RESULTS Eleven patients were included in the study (5 boys). The mean age at surgery was 7.6 years (range 0.5–16 years). All patients had drug-resistant epilepsy as defined by the International League Against Epilepsy and underwent comprehensive noninvasive epilepsy surgery workup. Intracranial monitoring was performed in all patients using 1 parasagittal insular electrode (1 patient had 2 electrodes) in addition to subdural grids and strips tailored to the suspected epileptogenic zone. In 10 patients, extraoperative monitoring was used; in 1 patient, intraoperative electrocorticography was used alone without extraoperative monitoring. The mean number of insular contacts was 6.8 (range 4–8), and the mean number of fronto-parieto-temporal hemispheric contacts was 61.7 (range 40–92). There were no complications related to placement of these depth electrodes. All 11 patients underwent subsequent resective surgery involving the insula. CONCLUSIONS Parasagittal transinsular apex depth electrode placement is a feasible alternative to orthogonally placed open or oblique-placed stereotactic methodologies. This method is safe and best suited for suspected unilateral cases with a possible extensive insular-opercular epileptogenic zone.

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