Epileptic seizure propagation from the second somatic sensory area to the fronto-medial region, by insular redistribution. A case report and a connectome description

SUMMARY Introduction. The seizure propagation phenomenon by inducing remote symptoms brings several difficulties in finding the seizure onset and delineating the epileptic network which should be taken into consideration in epilepsy surgery. By demonstrating a difficult (MRI negative) epilepsy surgery case explored with invasive presurgical evaluation we highlight the importance to recognise the secondary sensory area and to explore the the parieto-opercular-insular-medial frontal network in certain cases. A further conclusion is the consideration of the redistributory role of the insula as a special structure in the cerebral connectome, having a role in epileptic network organisation. Aims. To support the role of the insula in the organisation of an opercular – medial frontal epileptic network and to confirm Penfield’s the “second somatic sensory leg area” by way of a case report. We try to give an up to date exploration of our patient’s remote epileptic seizures by way of a connectome. Methods. The epileptic disorder was studied with intensive video EEG monitoring and two times 3T MRI. Interictal FDG (fluorodeoxyglucose) PET was also undertaken. Beside the scalp EEG and computerized frequency analysis, the evaluation was performed by invasive EEG with 2 grids and 2 strips and an insular deep electrode in addition. Electrical cortical stimulation and cortical mapping were also undertaken. Results. The video-EEG study revealed the complex seizure semiology. The left sided global somatosesensory aura in the leg, followed supplementary motor area manifestations represented a remote seizure. The seizure onset zone and the symptomatogenic zone were localised by the invasive electrophysiology. With the insular deep electrode we succeeded to explore the propagation of ictal activity to the insula and later to frontal medial surface. The PET, the negative 3T MRI results and the postprocessing morphometry confirmed the lesional origin and localised the epileptogenic area to the second somato-sensory field where a dysgenesis was located. Conclusions. By preoperative invasive video-EEG evaluation, the second somato-sensory leg area was delineated as the seizure onset zone. The resection of this area by IIb type cortical dysgenesis, resulted in a complete relief of the seizures. The invasive video-EEG revealed the peculiar role of the insula in the propagation of the epileptic seizure from the second sensory leg area to the ipsilateral fronto-medial supplemetary motor area. Our results, confirm, that the insula has a relay or node function on the parietal opercular-fronto-medial epileptic network. The connectome of the insula is a further additive of the scale-free features of the remote epileptic networks.

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The proportion of seizure onset zone contacts resected is not associated with outcome following SEEG-guided resective epilepsy surgery in children

10.1101/2021.09.18.21263722 ◽

2021 ◽

Author(s):

Mehdi Khan ◽

Aswin Chari ◽

Kiran Seunarine ◽

Christin Eltze ◽

Friederike Moeller ◽

...

Keyword(s):

Epilepsy Surgery ◽

Univariate Analysis ◽

Seizure Outcome ◽

Epileptogenic Zone ◽

Imaging Data ◽

Seizure Onset ◽

Binary Logistic Regression Model ◽

Primary Analysis ◽

Seizure Onset Zone

AbstractPurposeChildren undergoing stereoelectroencephalography (SEEG)-guided epilepsy surgery represent a complex cohort. We aimed to determine whether the proportion of putative seizure onset zone (SOZ) contacts resected associates with seizure outcome in a cohort of children undergoing SEEG-guided resective epilepsy surgery.MethodsPatients who underwent SEEG-guided resective surgery over a six-year period were included. The proportion of SOZ contacts resected was determined by co-registration of pre- and post-operative imaging. Seizure outcomes were classified as seizure free (SF, Engel class I) or not seizure-free (NSF, Engel class II-IV) at last clinical follow-up.ResultsOf 94 patients undergoing SEEG, 29 underwent subsequent focal resection of whom 22 had sufficient imaging data to be included in the primary analysis (median age at surgery of 10 years, range 5-18). Fifteen (68.2%) were SF and 7 (31.8%) NSF at median follow-up of 19.5 months (range 12-46). On univariate analysis, histopathology, was the only significant factor associated with SF (p<0.05). The percentage of defined SOZ contacts resected ranged from 25-100% and was not associated with SF (p=0.89). In a binary logistic regression model, it was highly likely that histology was the only independent predictor of outcome, although the interpretation was limited by pseudo-complete separation of the data.ConclusionHistopathology is a significant predictor of surgical outcomes in children undergoing SEEG-guided resective epilepsy surgery. The percentage of SOZ contacts resected was not associated with SF. Factors such as spatial organisation of the epileptogenic zone, neurophysiological biomarkers and the prospective identification of pathological tissue may therefore play an important role.

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Mental Retardation in Pediatric Candidates for Epilepsy Surgery: The Role of Early Seizure Onset

Epilepsia ◽

10.1046/j.1528-1157.2001.4220268.x ◽

2003 ◽

Vol 42 ◽

pp. 268-274 ◽

Cited By ~ 2

Author(s):

Elza Vasconcellos ◽

Elaine Wyllie ◽

Shawn Sullivan ◽

Lisa Stanford ◽

Juan Bulacio ◽

...

Keyword(s):

Mental Retardation ◽

Epilepsy Surgery ◽

Seizure Onset ◽

Early Seizure

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Influence analysis for high-dimensional time series with an application to epileptic seizure onset zone detection

Journal of Neuroscience Methods ◽

10.1016/j.jneumeth.2012.12.025 ◽

2013 ◽

Vol 214 (1) ◽

pp. 80-90 ◽

Cited By ~ 7

Author(s):

Christoph Flamm ◽

Andreas Graef ◽

Susanne Pirker ◽

Christoph Baumgartner ◽

Manfred Deistler

Keyword(s):

Time Series ◽

Epileptic Seizure ◽

High Dimensional ◽

Seizure Onset ◽

Influence Analysis ◽

Seizure Onset Zone

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The rate of contradictory lateralization of the epileptic seizure onset zone between ictal and interictal brain perfusion SPECT

10.1055/s-0041-1726755 ◽

2021 ◽

Author(s):

I Apostolova ◽

M Jaber ◽

J Taherpour ◽

S Stodieck ◽

S Klutmann ◽

...

Keyword(s):

Epileptic Seizure ◽

Brain Perfusion ◽

Seizure Onset ◽

Brain Perfusion Spect ◽

Seizure Onset Zone ◽

Perfusion Spect

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SozRank: A new approach for localizing the epileptic seizure onset zone

PLoS Computational Biology ◽

10.1371/journal.pcbi.1005953 ◽

2018 ◽

Vol 14 (1) ◽

pp. e1005953 ◽

Cited By ~ 10

Author(s):

Yonathan Murin ◽

Jeremy Kim ◽

Josef Parvizi ◽

Andrea Goldsmith

Keyword(s):

Epileptic Seizure ◽

Seizure Onset ◽

New Approach ◽

Seizure Onset Zone

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Mental Retardation in Pediatric Candidates for Epilepsy Surgery: The Role of Early Seizure Onset

Epilepsia ◽

10.1046/j.1528-1157.2001.12200.x ◽

2008 ◽

Vol 42 (2) ◽

pp. 268-274 ◽

Cited By ~ 18

Author(s):

Elza Vasconcellos ◽

Elaine Wyllie ◽

Shawn Sullivan ◽

Lisa Stanford ◽

Juan Bulacio ◽

...

Keyword(s):

Mental Retardation ◽

Epilepsy Surgery ◽

Seizure Onset ◽

Early Seizure

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Resting-state functional MRI connectivity impact on epilepsy surgery plan and surgical candidacy: prospective clinical work

Journal of Neurosurgery Pediatrics ◽

10.3171/2020.1.peds19695 ◽

2020 ◽

Vol 25 (6) ◽

pp. 574-581 ◽

Cited By ~ 1

Author(s):

Varina L. Boerwinkle ◽

Lucia Mirea ◽

William D. Gaillard ◽

Bethany L. Sussman ◽

Diana Larocque ◽

...

Keyword(s):

Functional Mri ◽

Epilepsy Surgery ◽

Resting State ◽

Intractable Epilepsy ◽

Pediatric Epilepsy ◽

Seizure Onset ◽

Surgery Planning ◽

Seizure Onset Zone ◽

Pediatric Epilepsy Surgery ◽

The Impact

OBJECTIVEThe authors’ goal was to prospectively quantify the impact of resting-state functional MRI (rs-fMRI) on pediatric epilepsy surgery planning.METHODSFifty-one consecutive patients (3 months to 20 years old) with intractable epilepsy underwent rs-fMRI for presurgical evaluation. The team reviewed the following available diagnostic data: video-electroencephalography (n = 51), structural MRI (n = 51), FDG-PET (n = 42), magnetoencephalography (n = 5), and neuropsychological testing (n = 51) results to formulate an initial surgery plan blinded to the rs-fMRI findings. Subsequent to this discussion, the connectivity results were revealed and final recommendations were established. Changes between pre– and post–rs-fMRI treatment plans were determined, and changes in surgery recommendation were compared using McNemar’s test.RESULTSResting-state fMRI was successfully performed in 50 (98%) of 51 cases and changed the seizure onset zone localization in 44 (88%) of 50 patients. The connectivity results prompted 6 additional studies, eliminated the ordering of 11 further diagnostic studies, and changed the intracranial monitoring plan in 10 cases. The connectivity results significantly altered surgery planning with the addition of 13 surgeries, but it did not eliminate planned surgeries (p = 0.003). Among the 38 epilepsy surgeries performed, the final surgical approach changed due to rs-fMRI findings in 22 cases (58%), including 8 (28%) of 29 in which extraoperative direct electrical stimulation mapping was averted.CONCLUSIONSThis study demonstrates the impact of rs-fMRI connectivity results on the decision-making for pediatric epilepsy surgery by providing new information about the location of eloquent cortex and the seizure onset zone. Additionally, connectivity results may increase the proportion of patients considered eligible for surgery while optimizing the need for further testing.

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The critical role of spiny stellate cells in seizure onset based on dynamic analysis of a neural mass model

10.1101/2021.07.19.452876 ◽

2021 ◽

Author(s):

Saba Tabatabaee ◽

Fariba Bahrami ◽

Mahyar Janahmadi

Keyword(s):

Bifurcation Analysis ◽

Epileptic Seizure ◽

Critical Role ◽

Stellate Cells ◽

Neural Mass Model ◽

Seizure Onset ◽

Mass Model ◽

Neural Mass ◽

The Brain

Increasing evidence has shown that excitatory neurons in the brain play a significant role in seizure generation. However, spiny stellate cells are cortical excitatory non-pyramidal neurons in the brain which their basic role in seizure occurrence is not well understood. In the present research, we study the critical role of spiny stellate cells or the excitatory interneurons (EI), for the first time, in epileptic seizure generation using an extended neural mass model introduced originally by Taylor and colleagues in 2014. Applying bifurcation analysis on this modified model, we investigated the rich dynamics corresponding to the epileptic seizure onset and transition between interictal and ictal states due to the EI. Our results indicate that the transition is described by a supercritical Hopf bifurcation which shapes the preictal activity in the model and suggests why before seizure onset, the amplitude and frequency of neural activities increase gradually. Moreover, we showed that 1) the altered function of GABAergic and glutamatergic receptors of EI can cause seizure, and 2) the pathway between the thalamic relay nucleus and EI facilitates the transition from interictal to the ictal activity by decreasing the preictal period. Thereafter, we considered both sensory and cortical periodic inputs to drive the model responses to various harmonic stimulations. Our results from the bifurcation analysis of the model suggest that the initial stage of the brain might be the main cause for the transition between interictal and ictal states as the stimulus frequency changes. The extended thalamocortical model shows also that the amplitude jump phenomenon and nonlinear resonance behavior result from the preictal stage of the brain. These results can be considered as a step forward to a deeper understanding of the mechanisms underlying the transition from brain normal activities to epileptic activities.

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The UK experience of stereoelectroencephalography in children: An analysis of factors predicting the identification of a seizure onset zone and subsequent seizure freedom

10.1101/2021.03.05.21252613 ◽

2021 ◽

Author(s):

Keyword(s):

Epilepsy Surgery ◽

Surgical Intervention ◽

Focal Epilepsy ◽

Neurological Deficits ◽

Seizure Freedom ◽

Seizure Onset ◽

Operative Outcomes ◽

Seizure Onset Zone ◽

Nationally Representative ◽

The Uk

AbstractImportanceStereoelectroencephalography (SEEG) is more frequently being used in the pre-surgical evaluation of children with focal epilepsy. Many factors affect the rate of identification of a definable seizure onset zone (SOZ) and subsequent seizure freedom following SEEG-guided epilepsy surgery, which have not been systematically examined in multi-centre studies.ObjectivesDetermine the rates and factors that predict (a) whether or not a definable putative SOZ was identified on SEEG and (b) subsequent seizure freedom following surgical intervention.DesignRetrospective cohort studySettingMulticentre study involving 6 of 7 UK Children’s Epilepsy Surgery Service centres that perform paediatric SEEG in the UK.ParticipantsAll children undergoing SEEG from 2014 - March 2019 were included. Demographic, non-invasive evaluation, SEEG and operative factors were collected retrospectively from patient records.Main OutcomesThe two main outcome measures were (a) whether or not a definable putative SOZ was identified on SEEG (binary yes/no outcome) and (b) subsequent seizure freedom following surgical intervention (Engel classification)FindingsOne hundred and thirty-five patients underwent 139 SEEG explorations using a total of 1767 electrodes. A definable SOZ was identified in 117 patients (85.7%); odds of successfully finding a SOZ were 6.4x greater for non-motor seizures compared to motor seizures (p=0.02) and 3.6x more if ≥ 4 seizures were recorded during SEEG (p=0.03). Of 100 patients undergoing surgical treatment, 47 (47.0%) had an Engel class I outcome at a median follow-up of 1.3 years; the only factor associated with outcome was indication for SEEG (p=0.03). SEEG was safe with one (0.7%) haematoma requiring surgical evacuation and no long-term neurological deficits as a result of the procedure.Conclusions and RelevanceThis large nationally representative cohort illustrates that, in these patients who may not have otherwise been offered resective surgery, SEEG-guided surgery can still achieve high rates of seizure freedom. Seizure semiology and the number of seizures recorded during SEEG are important factors in the identification of a definable SOZ and the indication for SEEG is an important factor in post-operative outcomes.

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