Overnight ictal magnetoencephalography

The added value of magnetoencephalography (MEG) in the presurgical evaluation for drug-resistant epilepsy is well-recognised 1-4. However, MEG remains mostly limited to analysis of interictal epileptic activity 1,5. Seizures are uncommonly captured due to logistical considerations despite mounting evidence of the value of ictal MEG in localising the seizure onset zone 5-7. Here we report the recording and analysis of ictal MEG recordings in two drug-resistant epilepsy presurgical candidates that spent a night sleeping in the MEG.

Download Full-text

A novel HFO-based method for unsupervised localization of the seizure onset zone in drug-resistant epilepsy

2017 39th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) ◽

10.1109/embc.2017.8037008 ◽

2017 ◽

Cited By ~ 5

Author(s):

Paige M. Murphy ◽

Adam J. von Paternos ◽

Sabato Santaniello

Keyword(s):

Drug Resistant ◽

Seizure Onset ◽

Seizure Onset Zone ◽

Drug Resistant Epilepsy

Download Full-text

Comparison of Ictal Brain Perfusion SPECT With 99mTc-HMPAO Versus 99mTc-ECD for Identification of The Epileptic Seizure Onset Zone

10.21203/rs.3.rs-104415/v1 ◽

2020 ◽

Author(s):

Mariam Jaber ◽

Jila Taherpour ◽

Berthold Voges ◽

Ivayla Apostolova ◽

Thomas Sauvigny ◽

...

Keyword(s):

Brain Perfusion ◽

Drug Resistant ◽

Seizure Onset ◽

Tracer Injection ◽

Brain Perfusion Spect ◽

Temporal Epilepsy ◽

Large Patient ◽

Seizure Onset Zone ◽

Perfusion Spect ◽

Drug Resistant Epilepsy

Abstract Background: The chemical microspheres 99mTc-HMPAO and 99mTc-ECD are widely used as tracers in ictal brain perfusion SPECT for identification of the seizure onset zone (SOZ) in presurgical evaluation of patients with drug-resistant epilepsy and uncertainty of SOZ localization after standard diagnostic workup. For both tracers there are theoretical arguments to favor it over the other for this task. The aim of this study was to compare the performance of ictal brain perfusion SPECT between 99mTc-HMPAO and 99mTc-ECD in a rather large patient sample.Methods: The study retrospectively included 196 patients from clinical routine in whom ictal perfusion SPECT had been performed with stabilized 99mTc-HMPAO (n = 110) or 99mTc-ECD (n = 86). Lateralization and localization of the SOZ was obtained by the consensus of two independent readers who visually inspected the SPECT images retrospectively. Results: The 99mTc-HMPAO group and the 99mTc-ECD group were well matched with respect to age, sex, age at first seizure, duration of disease, seizure frequency, history of previous brain surgery, and findings of presurgical MRI. The tracer groups differed significantly with respect to the latency of tracer injection (median latency 4 s longer in the 99mTc-HMPAO group), duration of the seizure after tracer injection (25 s shorter in the 99mTc-HMPAO group), tracer dose (70 MBq higher in the 99mTc-HMPAO group), and delay of the SPECT acquisition after tracer injection (63 min longer in the 99mTc-HMPAO group). The fraction of lateralising ictal SPECT did not differ significantly between the 99mTc-HMPAO and the 99mTc-ECD group (65.5% versus 72.1%, p = 0.355). Sensitivity of ictal perfusion SPECT (independent of the tracer) for correct localization of the SOZ in 62 patients with temporal lobe epilepsy and at least worthwhile improvement (Engel scale ≤ III) 12 months after temporal epilepsy surgery was 63%.Conclusions: This study does not provide evidence to favor 99mTc-HMPAO or 99mTc-ECD for identification of the SOZ by ictal perfusion SPECT in patients with drug resistant epilepsy.

Download Full-text

Localizing Seizure-Onset Zones in Presurgical Evaluation of Drug-Resistant Epilepsy by Electroencephalography/fMRI: Effectiveness of Alternative Thresholding Strategies

American Journal of Neuroradiology ◽

10.3174/ajnr.a3052 ◽

2012 ◽

Vol 33 (9) ◽

pp. 1818-1824 ◽

Cited By ~ 12

Author(s):

M. Hauf ◽

K. Jann ◽

K. Schindler ◽

O. Scheidegger ◽

K. Meyer ◽

...

Keyword(s):

Drug Resistant ◽

Seizure Onset ◽

Presurgical Evaluation ◽

Drug Resistant Epilepsy ◽

Seizure Onset Zones

Download Full-text

A probabilistic approach for lateralization of seizure onset zone in drug-resistant epilepsy with bilateral cerebral pathology

Mathematical Biosciences ◽

10.1016/j.mbs.2016.04.006 ◽

2016 ◽

Vol 277 ◽

pp. 136-140

Author(s):

Ravindra Arya ◽

Siva Sivaganesan ◽

Katherine D. Holland ◽

Hansel M. Greiner ◽

Francesco T. Mangano ◽

...

Keyword(s):

Probabilistic Approach ◽

Drug Resistant ◽

Seizure Onset ◽

Seizure Onset Zone ◽

Cerebral Pathology ◽

Drug Resistant Epilepsy

Download Full-text

Use of Innovative SPECT Techniques in the Presurgical Evaluation of Patients with Nonlesional Extratemporal Drug-Resistant Epilepsy

Molecular Imaging ◽

10.1155/2021/6614356 ◽

2021 ◽

Vol 2021 ◽

pp. 1-9

Author(s):

Ahmed Yassin ◽

Khalid El-Salem ◽

Abdel-Hameed Al-Mistarehi ◽

Aiman Momani ◽

Anas M. Zein Alaabdin ◽

...

Keyword(s):

Single Photon ◽

Photon Emission ◽

Vital Role ◽

Emission Computed Tomography ◽

Drug Resistant ◽

Presurgical Evaluation ◽

Ictal Spect ◽

Seizure Onset Zone ◽

Drug Resistant Epilepsy ◽

Patients With Epilepsy

Up to 30% of patients with epilepsy may not respond to antiepileptic drugs. Patients with drug-resistant epilepsy (DRE) should undergo evaluation for seizure onset zone (SOZ) localization to consider surgical treatment. Cases of drug-resistant nonlesional extratemporal lobe epilepsy (ETLE) pose the biggest challenge in localizing the SOZ and require multiple noninvasive diagnostic investigations before planning the intracranial monitoring (ICM) or direct resection. Ictal Single Photon Emission Computed Tomography (i-SPECT) is a unique functional diagnostic tool that assesses the SOZ using the localized hyperperfusion that occurs early in the seizure. Subtraction ictal SPECT coregistered to MRI (SISCOM), statistical ictal SPECT coregistered to MRI (STATISCOM), and PET interictal subtracted ictal SPECT coregistered with MRI (PISCOM) are innovative SPECT methods for the determination of the SOZ. This article comprehensively reviews SPECT and sheds light on its vital role in the presurgical evaluation of the nonlesional extratemporal DRE.

Download Full-text

Neural Fragility as an EEG Marker of the Seizure Onset Zone

10.1101/862797 ◽

2019 ◽

Author(s):

Adam Li ◽

Chester Huynh ◽

Zachary Fitzgerald ◽

Iahn Cajigas ◽

Damian Brusko ◽

...

Keyword(s):

Surgical Outcomes ◽

Predictive Power ◽

Biological Marker ◽

Complete Removal ◽

Drug Resistant ◽

Success Rates ◽

Seizure Onset ◽

Intracranial Eeg ◽

Seizure Onset Zone ◽

Drug Resistant Epilepsy

AbstractOver 15 million epilepsy patients worldwide do not respond to drugs. Successful surgical treatment requires complete removal, or disconnection of the seizure onset zone (SOZ), brain region(s) where seizures originate. Unfortunately, surgical success rates vary between 30%-70% because no clinically validated biological marker of the SOZ exists. We develop and retrospectively validate a new EEG marker - neural fragility. We validate this new marker in a retrospective analysis of 91 patients by using neural fragility of the annotated SOZ as a metric to predict surgical outcomes. Fragility predicts 43/47 surgical failures with an overall prediction accuracy of 76%, compared to the accuracy of clinicians being 48% (successful outcomes). In failed outcomes, we identify fragile regions that were untreated. When compared to 20 EEG features proposed as SOZ markers, fragility outperformed in predictive power and interpretability suggesting neural fragility as an EEG fingerprint of the SOZ.One Sentence SummaryNeural fragility, an intracranial EEG biomarker for the seizure onset zone in drug-resistant epilepsy, predicts surgical outcomes with high accuracy.

Download Full-text

Interictal SEEG resting-state connectivity localizes seizure onset zone and predicts seizure outcome

10.1101/2021.12.30.21268524 ◽

2022 ◽

Author(s):

Haiteng Jiang ◽

Vasileios Kokkinos ◽

Shuai Ye ◽

Alexandra Urban ◽

Anto Bagic ◽

...

Keyword(s):

Information Flow ◽

Resting State ◽

Inhibitory Input ◽

Seizure Outcome ◽

Epileptogenic Zone ◽

Drug Resistant ◽

Seizure Onset ◽

Seizure Onset Zone ◽

Drug Resistant Epilepsy ◽

Resting State Connectivity

Stereotactic-electroencephalography (SEEG) is a common neurosurgical method to localize epileptogenic zone in drug resistant epilepsy patients and inform treatment recommendations. In the current clinical practice, localization of epileptogenic zone typically requires prolonged recordings to capture seizure, which may take days to weeks. Although epilepsy surgery has been proven to be effective in general, the percentage of unsatisfactory seizure outcomes is still concerning. We developed a method to identify the seizure onset zone (SOZ) and predict seizure outcome using short-time resting-state SEEG data. In a cohort of 43 drug resistant epilepsy patients, we estimated the information flow via directional connectivity and inferred the excitation-inhibition ratio from the 1/f power slope. We hypothesized that the antagonism of information flow at multiple frequencies between SOZ and non-SOZ underlying the relatively stable epilepsy resting state could be related to the disrupted excitation-inhibition balance. We found higher excitability in non-SOZ regions compared to the SOZ, with dominant information flow from non-SOZ to SOZ regions, probably reflecting inhibitory input from non-SOZ to prevent seizure initiation. Greater differences in information flow between SOZ and non-SOZ regions were associated with favorable seizure outcome. By integrating a balanced random forest model with resting-state connectivity, our method localized the SOZ with an accuracy of 85% and predicted the seizure outcome with an accuracy of 77% using clinically determined SOZ. Overall, our study suggests that brief resting-state SEEG data can significantly facilitate the identification of SOZ and may eventually predict seizure outcomes without requiring long-term ictal recordings.

Download Full-text