Automatic ictal onset source localization in presurgical epilepsy evaluation

Koren, Johannes; Gritsch, G.; Pirker, Susanne; Herta, Johannes; Perko, Hannes; Kluge, Tilmann; Baumgartner, Christoph

doi:10.1016/j.clinph.2018.03.020

Cited by 13 publications

(12 citation statements)

References 39 publications

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“…Our study confirms the feasibility (Koessler et al 2010;Medvedovsky et al 2012;Pellegrino et al 2016;Staljanssens et al 2017;Nemtsas et al 2017;Kuo et al 2018;Koren et al 2018;Sharma et al 2018) of ictal recordings with 64-channel EEG as (i) only 22% (17/78) of patients did not have seizure (in the same range as Sharma et al 2018) and (ii) for the others, a mean of 5.7 seizures per patient (range 1-30) was recorded. Nevertheless, this study does not confirm the superiority of ictal ESI by comparison to Fig.…”

Section: Limitssupporting

confidence: 83%

Respective Contribution of Ictal and Inter-ictal Electrical Source Imaging to Epileptogenic Zone Localization

et al. 2020

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Interictal electrical source imaging (ESI) encompasses a risk of false localization due to complex relationships between irritative and epileptogenic networks. This study aimed to compare the localizing value of ESI derived from ictal and inter-ictal EEG discharges and to evaluate the localizing value of ESI according to three different subgroups: MRI lesion, presumed etiology and morphology of ictal EEG pattern. We prospectively analyzed 54 of 78 enrolled patients undergoing pre-surgical investigation for refractory epilepsy. Ictal and inter-ictal ESI results were interpreted blinded to-and subsequently compared with stereoelectroencephalography as a reference method. Anatomical concordance was assessed at a sub-lobar level. Sensitivity and specificity of ictal, inter-ictal and ictal plus inter-ictal ESI were calculated and compared according to the different subgroups. Inter-ictal and ictal ESI sensitivity (84% and 75% respectively) and specificity (38% and 50% respectively) were not statistically different. Regarding the sensitivity, ictal ESI was never higher than inter-ictal ESI. Regarding the specificity, ictal ESI was higher than inter-ictal ESI in malformations of cortical development (MCD) (60% vs. 43%) and in MRI positive patients (49% vs. 30%). Within the ictal ESI analysis, we showed a higher specificity for ictal spikes (59%) and rhythmic discharges > 13 Hz (50%) than rhythmic discharges < 13 Hz (37%) and (ii) for MCD (60%) than in other etiologies (29%). This prospective study demonstrates the relevance of a combined interpretation of distinct interictal and ictal analysis. Inter-ictal analysis gave the highest sensitivity. Ictal analysis gave the highest specificity especially in patients with MCD or a lesion on MRI.

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Section: Limitssupporting

confidence: 83%

Respective Contribution of Ictal and Inter-ictal Electrical Source Imaging to Epileptogenic Zone Localization

et al. 2020

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“…derived from EEG > 32 channels) compared to low-density (LD) ESI (from 19 to 25 channel EEG) [8,9]. However, there is increasing evidence that adequate diagnostic accuracy in SOZ/IZ localization may be reached through LD ESIat least at a sublobar level [10][11][12][13] and that LD ESI may yield non-redundant information, useful to the phase-I of epilepsy presurgical workup [14]. Developing new methodologies to improve the yield of LD ESI may be valuable especially in the analysis of ictal EEG activity.…”

Section: Introductionmentioning

confidence: 99%

“…Up to date, most studies probing new techniques of ictal ESI have focused on TLE [11,[36][37][38][39][40]. TLE shows rather definite neural networks [41] and presents with homogeneous ictal EEG correlates if compared to the diversity found in ETLE [7].…”

Section: Introductionmentioning

confidence: 99%

Ictal EEG source imaging and connectivity to localize the seizure onset zone in extratemporal lobe epilepsy

Vespa

Baroumand

Santos

et al. 2020

Seizure

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To evaluate the yield of Functional Connectivity (FC) in addition to low-density ictal Electrical Source Imaging (ESI) in extratemporal lobe epilepsy (ETLE), using an automated algorithm for analysis. Method: Long-term EEG monitoring of consecutive ETLE patients who underwent surgery was reviewed by epileptologists, and seizure onsets characterized by rhythmical activity were identified. A spectrogram-based algorithm was developed to select objectively the parameters of ESI analysis. Two methods for SOZ localization were compared: i) ESI power, based on LORETA exclusively; ii) ESI + FC, including a Granger causality-based connectivity analysis. Results were determined at a sublobar level. The resection zone, in relation to 1-year follow-up surgical outcome, was considered as reference standard for diagnostic accuracy analyses. Results: Ninety-four seizures from 24 patients were analyzed. At seizure-level, ESI power showed 36 % sensitivity and 72 % specificity (accuracy: 45 %). ESI + FC significantly improved the accuracy, with 52 % sensitivity and 84 % specificity (accuracy: 61 %, p = 0.04). Results of ESI + FC were equally valuable in patients with lateralized or bilateral/generalized visual interpretation of ictal EEG. In a patient level sub-analysis, upon blinded clinical interpretation, ESI + FC showed a correct localization in 67 % of patients and substantial interrater agreement (kappa = 0.64), against 27 % achieved by ESI power, with fair inter-rater agreement (kappa = 0.37). Conclusion: FC significantly improves SOZ localization compared to ESI solely in ETLE. Ictal ESI + FC could represent a novel option in the armamentarium of presurgical evaluation, aiding also in patients with visually non-localizable scalp ictal EEG. Prospective studies evaluating the clinical added value of automated low-density ictal ESI may be justified.

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“…Recently, ictal ESI was successfully applied for localization of the ictal onset zone 42– 50 . Ictal MSI is also feasible but is limited by the fact that long-term MEG recordings cannot be performed and it remains difficult to catch seizures during short-term MEG recordings 51– 54 .…”

Section: Neurophysiological Techniquesmentioning

confidence: 99%

“…It should be noted that automated techniques exist to perform both interictal and ictal ESI 25, 42 .…”

Section: Neurophysiological Techniquesmentioning

confidence: 99%

Presurgical epilepsy evaluation and epilepsy surgery

et al. 2019

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F1000 Faculty Reviews are written by members of the prestigious . They are F1000 Faculty commissioned and are peer reviewed before publication to ensure that the final, published version is comprehensive and accessible. The reviewers who approved the final version are listed with their names and affiliations. AbstractWith a prevalence of 0.8 to 1.2%, epilepsy represents one of the most frequent chronic neurological disorders; 30 to 40% of patients suffer from drug-resistant epilepsy (that is, seizures cannot be controlled adequately with antiepileptic drugs). Epilepsy surgery represents a valuable treatment option for 10 to 50% of these patients. Epilepsy surgery aims to control seizures by resection of the epileptogenic tissue while avoiding neuropsychological and other neurological deficits by sparing essential brain areas. The most common histopathological findings in epilepsy surgery specimens are hippocampal sclerosis in adults and focal cortical dysplasia in children. Whereas presurgical evaluations and surgeries in patients with mesial temporal sclerosis and benign tumors recently decreased in most centers, non-lesional patients, patients requiring intracranial recordings, and neocortical resections increased. Recent developments in neurophysiological techniques (high-density electroencephalography [EEG], magnetoencephalography, electrical and magnetic source imaging, EEG-functional magnetic resonance imaging [EEG-fMRI], and recording of pathological high-frequency oscillations), structural magnetic resonance imaging (MRI) (ultra-high-field imaging at 7 Tesla, novel imaging acquisition protocols, and advanced image analysis [post-processing] techniques), functional imaging (positron emission tomography and single-photon emission computed tomography co-registered to MRI), and fMRI significantly improved non-invasive presurgical evaluation and have opened the option of epilepsy surgery to patients previously not considered surgical candidates. Technical improvements of resective surgery techniques facilitate successful and safe operations in highly delicate brain areas like the perisylvian area in operculoinsular epilepsy. Novel less-invasive surgical techniques include stereotactic radiosurgery, MR-guided laser interstitial thermal therapy, and stereotactic intracerebral EEG-guided radiofrequency thermocoagulation. PubMed Abstract | Publisher Full Text 18. Cloppenborg T, May TW, Blümcke I, et al.: Trends in epilepsy surgery: stable surgical numbers despite increasing presurgical volumes. J Neurol Neurosurg Psychiatr. 2016; 87(12): 1322-9. PubMed Abstract | Publisher Full Text 19. Dugan P, Carlson C, Jetté N, et al.: Derivation and initial validation of a surgical grading scale for the preliminary evaluation of adult patients with drug-resistant focal epilepsy. Epilepsia. 2017; 58(5): 792-800. PubMed Abstract | Publisher Full Text | F1000 Recommendation 20. Butler TA, Dugan P, French J: Why is mesial temporal lobe epilepsy with Ammon's horn sclerosis becoming less common? Eur J Neurol. 2015; 22(1): e12.PubMe...

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Automatic ictal onset source localization in presurgical epilepsy evaluation

Cited by 13 publications

References 39 publications

Respective Contribution of Ictal and Inter-ictal Electrical Source Imaging to Epileptogenic Zone Localization

Respective Contribution of Ictal and Inter-ictal Electrical Source Imaging to Epileptogenic Zone Localization

Ictal EEG source imaging and connectivity to localize the seizure onset zone in extratemporal lobe epilepsy

Presurgical epilepsy evaluation and epilepsy surgery

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