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

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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Outcomes of Disconnective Surgery in Intractable Pediatric Hemispheric and Subhemispheric Epilepsy

International Journal of Pediatrics ◽

10.1155/2012/527891 ◽

2012 ◽

Vol 2012 ◽

pp. 1-7 ◽

Cited By ~ 15

Author(s):

Santhosh George Thomas ◽

Ari George Chacko ◽

Maya Mary Thomas ◽

K. Srinivasa Babu ◽

Paul Swamidhas Sudhakar Russell ◽

...

Keyword(s):

Epilepsy Surgery ◽

Cognitive Skills ◽

Class I ◽

Pediatric Epilepsy ◽

Seizure Outcome ◽

Seizure Onset ◽

Rasmussen’S Encephalitis ◽

Weber Syndrome ◽

Surgical Evaluation

Objectives: To study the outcome of disconnective epilepsy surgery for intractable hemispheric and sub-hemispheric pediatric epilepsy.Methods: A retrospective analysis of the epilepsy surgery database was done in all children (age <18 years) who underwent a peri-insular hemispherotomy (PIH) or a peri-insular posterior quadrantectomy (PIPQ) from April 2000 to March 2011. All patients underwent a detailed pre surgical evaluation. Seizure outcome was assessed by the Engel’s classification and cognitive skills by appropriate measures of intelligence that were repeated annually.Results: There were 34 patients in all. Epilepsy was due to Rasmussen’s encephalitis (RE), Infantile hemiplegia seizure syndrome (IHSS), Hemimegalencephaly (HM), Sturge Weber syndrome (SWS) and due to post encephalitic sequelae (PES). Twenty seven (79.4%) patients underwent PIH and seven (20.6%) underwent PIPQ. The mean follow up was 30.5 months. At the last follow up, 31 (91.1%) were seizure free. The age of seizure onset and etiology of the disease causing epilepsy were predictors of a Class I seizure outcome.Conclusions: There is an excellent seizure outcome following disconnective epilepsy surgery for intractable hemispheric and subhemispheric pediatric epilepsy. An older age of seizure onset, RE, SWS and PES were good predictors of a Class I seizure outcome.

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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.

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Seizure outcome of epilepsy surgery in focal epilepsies associated with temporomesial glioneuronal tumors: lesionectomy compared with tailored resection

Journal of Neurosurgery ◽

10.3171/2009.3.jns081350 ◽

2009 ◽

Vol 111 (6) ◽

pp. 1275-1282 ◽

Cited By ~ 66

Author(s):

Marco Giulioni ◽

Guido Rubboli ◽

Gianluca Marucci ◽

Matteo Martinoni ◽

Lilia Volpi ◽

...

Keyword(s):

Epilepsy Surgery ◽

Seizure Outcome ◽

Epileptogenic Zone ◽

Patients Âgés ◽

Group A ◽

Group B ◽

Postoperative Seizure ◽

The Right ◽

Glioneuronal Tumors

Object The authors retrospectively analyzed and compared seizure outcome in a series of 28 patients with temporomesial glioneuronal tumors associated with epilepsy who underwent 1 of 2 different epilepsy surgery procedures: lesionectomy or tailored resection. Methods The 28 patients were divided into 2 groups, with 14 cases in each group. In Group A, surgery was limited to the tumor (lesionectomy), whereas Group B patients underwent tailored resection involving removal of the tumor and the epileptogenic zone as identified by a neurophysiological noninvasive presurgical study. Results In Group A (10 male and 4 female patients) the interval between onset of seizures and surgery ranged from 1 to 33 years (mean 10.6 years). Patients' ages ranged from 3 to 61 years (mean 23.1 years). The epileptogenic lesion was on the left side in 6 patients and the right in 8 patients. Mean follow-up was 9.8 years (range 6.5–15 years). The Engel classification system, used to determine postoperative seizure outcome, showed 6 patients (42.8%) were Engel Class I and 8 (57.1%) were Engel Class II. In Group B (6 male and 8 female patients) the interval between onset of seizures and surgery ranged from 0.5 to 25 years (mean 8.6 years). Patients' ages ranged from 3 to 48 years (mean 22.3 years). The tumor and associated epileptogenic area was on the right side in 8 patients and the left in 6 patients. Mean follow-up duration was 3.5 years (range 1–6.5 years). Postoperative seizure outcome was Engel Class I in 13 patients (93%) and Engel Class II in 1 (7.1%). Conclusions The authors' results demonstrate a better seizure outcome for temporomesial glioneuronal tumors associated with epilepsy in patients who underwent tailored resection rather than simple lesionectomy (p = 0.005). For temporomesial glioneuronal tumors associated with epilepsy, performing a presurgical noninvasive neurophysiological study intended to identify the epileptogenic zone is necessary for planning a tailored surgery. Using this surgical strategy, the presence of temporomesial glioneuronal tumors constitutes a predictive factor of excellent seizure outcome, and therefore surgical treatment can be offered early to avoid both the consequences of uncontrolled seizures as well as the side effects of pharmacological therapy.

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Factors predicting 10-year seizure freedom after temporal lobe resection

Zeitschrift für Epileptologie ◽

10.1007/s10309-019-00302-x ◽

2020 ◽

Vol 33 (1) ◽

pp. 50-61 ◽

Cited By ~ 2

Author(s):

Friedhelm C. Schmitt ◽

H.‑Joachim Meencke

Keyword(s):

Temporal Lobe ◽

Epilepsy Surgery ◽

Univariate Analysis ◽

Class I ◽

Seizure Outcome ◽

Seizure Freedom ◽

Patient Counseling ◽

Long Term Follow Up

Abstract Background Resective surgery is an established and evidence-based treatment approach in pharmacoresistant temporal lobe epilepsy (TLE). Extra-long-term follow-up data are important to allow for good patient counseling. So far, only few trials provide prospective or retrospective data exceeding 5 years. Objective This study aimed to present data of continuous seizure outcome over an extended time period, with a particular focus on patients who remained seizure free for 10 years. Methods We analyzed seizure outcome after epilepsy surgery for TLE in 46 consecutive patients, who were seen on an annual basis for 10 years in a single center (Epilepsy Center Berlin Brandenburg). Factors for remaining seizure free for 10 years were determined by univariate analysis. Results The class I outcome changed each year by 74–78%. Of the patients, 63% remained continuously in Engel class I (48% Engel Class IA for 10 years) for 10 years. Six patients were never seizure free (12.5%). After 10 years, 35% of the patients were cured (i.e., seizure-free without medication). A higher number of antiepileptic drugs and seizures before surgery as well as the indication for invasive presurgical monitoring were associated with “unsuccessful surgery.” Conclusion With almost half of the patients completely seizure free and more than a third “cured,” epilepsy surgery remains the mainstay of therapy for TLE patients. Analysis in larger cohorts with extra-long-term follow-up is needed to assess good prognostic factors and other postsurgical outcome issues such as neuropsychological, psychiatric, and psychosocial outcomes.

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Interictal high frequency background activity as a biomarker of epileptogenic tissue

Brain Communications ◽

10.1093/braincomms/fcab188 ◽

2021 ◽

Author(s):

Truman Stovall ◽

Brian Hunt ◽

Simon Glynn ◽

William C Stacey ◽

Stephen V Gliske

Keyword(s):

Logistic Regression ◽

Confidence Interval ◽

High Frequency ◽

High Frequency Oscillation ◽

Epileptogenic Zone ◽

Odds Ratios ◽

Seizure Onset ◽

High Frequency Oscillations ◽

Seizure Onset Zone ◽

Background Data

Abstract High Frequency Oscillations are very brief events that are a well-established biomarker of the epileptogenic zone, but are rare and comprise only a tiny fraction of the total recorded EEG. We hypothesize that the interictal high frequency “background” data, which has received little attention but represents the majority of the EEG record, also may contain additional, novel information for identifying the epileptogenic zone. We analyzed intracranial EEG (30–500 Hz frequency range) acquired from 24 patients who underwent resective surgery. We computed 38 quantitative features based on all usable, interictal data (63–307 hours per subject), excluding all detected high frequency oscillations. We assessed association between each feature and the seizure onset zone and resected volume using logistic regression. A pathology score per channel was also created via principle component analysis and logistic regression, using hold-out-one-patient cross validation to avoid in-sample training. Association of the pathology score with the seizure onset zone and resected volume was quantified using an asymmetry measure. Many features were associated with the seizure onset zone: 23/38 features had odds ratios >1.3 or < 0.7 and 17/38 had odds ratios different than zero with high significance (p < 0.001/39, logistic regression with Bonferroni Correction). The pathology score, the rate of high frequency oscillations, and their channel-wise product were each strongly associated with the seizure onset zone (median asymmetry > =0.44, good surgery outcome patients; median asymmetry > =0.40, patients with other outcomes; 95% confidence interval > 0.27 in both cases). The pathology score and the channel-wise product also had higher asymmetry with respect to the seizure onset zone than the high frequency oscillation rate alone (median difference in asymmetry > =0.18, 95% confidence interval >0.05). These results support that the high frequency background data contains useful information for determining the epileptogenic zone, distinct and complementary to information from detected high frequency oscillations. The concordance between the high frequency activity pathology score and the rate of high frequency oscillations appears to be a better biomarker of epileptic tissue than either measure alone.

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Association of fast ripples on intracranial EEG and outcomes after epilepsy surgery

Neurology ◽

10.1212/wnl.0000000000010468 ◽

2020 ◽

Vol 95 (16) ◽

pp. e2235-e2245

Author(s):

Päivi Nevalainen ◽

Nicolás von Ellenrieder ◽

Petr Klimeš ◽

François Dubeau ◽

Birgit Frauscher ◽

...

Keyword(s):

Epilepsy Surgery ◽

Slow Wave Sleep ◽

Seizure Outcome ◽

Incomplete Resection ◽

Epileptogenic Zone ◽

Poor Prognostic Factor ◽

Individual Level ◽

Poor Outcome ◽

Surgery Outcome ◽

The Individual

ObjectiveTo examine whether fast ripples (FRs) are an accurate marker of the epileptogenic zone, we analyzed overnight stereo-EEG recordings from 43 patients and hypothesized that FR resection ratio, maximal FR rate, and FR distribution predict postsurgical seizure outcome.MethodsWe detected FRs automatically from an overnight recording edited for artifacts and visually from a 5-minute period of slow-wave sleep. We examined primarily the accuracy of removing ≥50% of total FR events or of channels with FRs to predict postsurgical seizure outcome (Engel class I = good, classes II–IV = poor) according to the whole-night and 5-minute analysis approaches. Secondarily, we examined the association of low overall FR rates or absence or incomplete resection of 1 dominant FR area with poor outcome.ResultsThe accuracy of outcome prediction was highest (81%, 95% confidence interval [CI] 67%–92%) with the use of the FR event resection ratio and whole-night recording (vs 72%, 95% CI 56%–85%, for the visual 5-minute approach). Absence of channels with FR rates >6/min (p = 0.001) and absence or incomplete resection of 1 dominant FR area (p < 0.001) were associated with poor outcome.ConclusionsFRs are accurate in predicting epilepsy surgery outcome at the individual level when overnight recordings are used. Absence of channels with high FR rates or absence of 1 dominant FR area is a poor prognostic factor that may reflect suboptimal spatial sampling of the epileptogenic zone or multifocality, rather than an inherently low sensitivity of FRs.Classification of evidenceThis study provides Class II evidence that FRs are accurate in predicting epilepsy surgery outcome.

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Rasmussen Encephalitis: longterm outcome after surgery

Journal of Epilepsy and Clinical Neurophysiology ◽

10.1590/s1676-26492010000200004 ◽

2010 ◽

Vol 16 (2) ◽

pp. 59-63 ◽

Cited By ~ 1

Author(s):

Vera C. Terra ◽

Helio R. Machado ◽

Ricardo dos Santos Oliveira ◽

Luciano N Serafini ◽

Cecília Souza-Oliveira ◽

...

Keyword(s):

Epilepsy Surgery ◽

Language Impairment ◽

Seizure Control ◽

Demographic Data ◽

Intractable Epilepsy ◽

Seizure Outcome ◽

Rasmussen Encephalitis ◽

Eeg Abnormalities ◽

Clonic Seizures

BACKGROUND AND PURPOSE: Rasmussen Encephalitis (RE) is characterized by intractable epilepsy, progressive hemiparesis and unilateral hemispheric atrophy. The progression of the symptoms usually occurs within months to few years. Antiepileptic drugs are usually not effective to control disease progression and epilepsy surgery in the form of hemispheric disconnection has been considered the treatment of choice. This work describes the clinical and electrographic analyses, as well as the post-operative evolution of patients with RE. PATIENTS AND METHODS: This work includes all the patients with RE evaluated from January 1995 to January 2008 by the Ribeirão Preto Epilepsy Surgery Program (CIREP) considering demographic data, interictal and ictal electroencephalographic (EEG) findings; anatomo-pathological findings and clinical outcome. RESULTS: Twenty-five patients were evaluated, thirteen were female. Mean age of epilepsy onset was 4.4±2.0 years. There were no differences between patients with slow and fast evolution with respect to age of epilepsy onset (p=0.79), age at surgery (p=0.24), duration of epilepsy (0.06), and follow-up (p=0.40). There were no correlations between the presence of bilateral EEG abnormalities or the absence of spikes and post-operative seizure outcome (p=0.06). Twenty-three patients underwent surgery. The mean follow-up was 75.3 months. Eleven patients had total seizure control. Twelve individuals persisted with seizures consisting of mild facial jerks (6 patients), occasional hemigeneralized tonic-clonic seizures (3 patients), and frequent tonic-clonic seizures (3 patients). Mental and language impairment was observed in 15 and 12 patients, after surgery, respectively. CONCLUSIONS: This retrospective study reported the clinical and electrographic analysis, as well as the evolution of 23 patients with RE. Fourteen patients achieved satisfactory seizure control, three patients had partial response to surgery, and five patients had maintenance of the pre-operative condition. All patients with left side involvement presented with some language and cognitive disturbance.

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Stereotactic laser ablation for nonlesional cingulate epilepsy: case report

Journal of Neurosurgery Pediatrics ◽

10.3171/2018.5.peds18120 ◽

2018 ◽

Vol 22 (5) ◽

pp. 481-488 ◽

Cited By ~ 3

Author(s):

Ahmad Marashly ◽

Michelle M. Loman ◽

Sean M. Lew

Keyword(s):

Laser Ablation ◽

Right Hemisphere ◽

Focal Epilepsy ◽

Mesial Temporal Lobe Epilepsy ◽

Epileptogenic Zone ◽

Seizure Onset Zone ◽

The Right ◽

Invasive Evaluation ◽

Motor Areas

Stereotactic laser ablation (SLA) is being increasingly used to treat refractory focal epilepsy, especially mesial temporal lobe epilepsy. However, emerging evidence suggests it can be used for extratemporal lobe epilepsy as well.The authors report the case of a 17-year-old male who presented with refractory nocturnal seizures characterized by bilateral arms stiffening or rhythmic jerking lasting several seconds. Semiology suggested an epileptogenic zone close to one of the supplementary sensory motor areas. Electroencephalography showed seizures arising from the central region without consistent lateralization. Brain imaging showed no abnormality. An invasive evaluation using bilateral stereoelectroencephalography (SEEG) was utilized in 2 steps, first to establish the laterality of seizures, and second to further cover the mesial cingulate region of the right hemisphere. Seizures arose from the middle portion of the right cingulate gyrus. Extraoperative electrical mapping revealed that the seizure onset zone was adjacent to eloquent motor areas. SLA targeting the right midcingulate gyrus was performed. The patient has remained seizure free since immediately after the procedure with no postoperative deficits (follow-up of 17 months).This case highlights the utility of SEEG in evaluating difficult-to-localize, focal epilepsy. It also demonstrates that the use of SLA can be extended to nonlesional, extratemporal epilepsies.

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Epilepsy Surgery of the Cingulate Gyrus and the Frontomesial Cortex

Neurosurgery ◽

10.1227/neu.0b013e318237aaa3 ◽

2011 ◽

Vol 70 (4) ◽

pp. 900-910 ◽

Cited By ~ 15

Author(s):

Marec von Lehe ◽

Jan Wagner ◽

Joerg Wellmer ◽

Hans Clusmann ◽

Thomas Kral

Keyword(s):

Epilepsy Surgery ◽

Supplementary Motor Area ◽

Focal Epilepsy ◽

Case Reports ◽

Motor Area ◽

Seizure Outcome ◽

Cingulate Gyrus ◽

Long Term Follow Up ◽

Magnetic Resonance Imaging Mri

Abstract BACKGROUND: Epilepsy surgery involving the cingulate gyrus has been mostly presented as case reports, and larger series with long-term follow-up are not published yet. OBJECTIVE: To report our experience with focal epilepsy arising from the cingulate gyrus and surrounding structures and its surgical treatment. METHODS: Twenty-two patients (mean age, 36; range, 12–63) with a mean seizure history of 23 years (range, 2–52) were retrospectively analyzed. We report presurgical diagnostics, surgical strategy, and postoperative follow-up concerning functional morbidity and seizures (mean follow-up, 86 months; range, 25–174). RESULTS: Nineteen patients showed potential epileptogenic lesions on preoperative magnetic resonance imaging (MRI). All patients had noninvasive presurgical workup; 15 (68%) underwent invasive Video-electroencephalogram (EEG)-Monitoring. In 12 patients we performed extended lesionectomy according to MRI; an extension with regard to EEG results was done in 6 patients. In 4 patients, the resection was incomplete because of the involvement of eloquent areas according to functional mapping results. Eight pure cingulate resections (36%, 3 in the posterior cingulate gyrus) and 14 extended supracingular frontal resections were performed. Nine patients experienced temporary postoperative supplementary motor area syndrome after resection in the superior frontal gyrus. Two patients retained a persistent mild hand or leg paresis, respectively. Postoperatively, 62% of patients were seizure-free (International League Against Epilepsy [ILAE] 1), and 76% had a satisfactory seizure outcome (ILAE 1–3). CONCLUSION: Epilepsy surgery for lesions involving the cingulate gyrus represents a small fraction of all epilepsy surgery cases, with good seizure outcome and low rates of postoperative permanent deficits. In case of extended supracingular resection, supplementary motor area syndrome should be considered.

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Stereoelectroencephalography in Children and Adolescents With Difficult-to-Localize Refractory Focal Epilepsy

Neurosurgery ◽

10.1227/neu.0000000000000453 ◽

2014 ◽

Vol 75 (3) ◽

pp. 258-268 ◽

Cited By ~ 50

Author(s):

Jorge Gonzalez-Martinez ◽

Jeffrey Mullin ◽

Juan Bulacio ◽

Ajay Gupta ◽

Rei Enatsu ◽

...

Keyword(s):

Children And Adolescents ◽

Pediatric Patients ◽

Focal Epilepsy ◽

Early Experience ◽

Morbidity Rate ◽

Seizure Outcome ◽

Seizure Freedom ◽

Epileptogenic Zone ◽

Eloquent Cortex

Abstract BACKGROUND: Although stereoelectroencephalography (SEEG) has been shown to be a valuable tool for preoperative decision making in focal epilepsy, there are few reports addressing the utility and safety of SEEG methodology applied to children and adolescents. OBJECTIVE: To present the results of our early experience using SEEG in pediatric patients with difficult-to-localize epilepsy who were not considered candidates for subdural grid evaluation. METHODS: Thirty children and adolescents with the diagnosis of medically refractory focal epilepsy (not considered ideal candidates for subdural grids and strip placement) underwent SEEG implantation. Demographics, electrophysiological localization of the hypothetical epileptogenic zone, complications, and seizure outcome after resections were analyzed. RESULTS: Eighteen patients (60%) underwent resections after SEEG implantations. In patients who did not undergo resections (12 patients), reasons included failure to localize the epileptogenic zone (4 patients); multifocal epileptogenic zone (4 patients); epileptogenic zone located in eloquent cortex, preventing resection (3 patients); and improvement in seizures after the implantation (1 patient). In patients who subsequently underwent resections, 10 patients (55.5%) were seizure free (Engel class I) and 5 patients (27.7%) experienced seizure improvement (Engel class II or III) at the end of the follow-up period (mean, 25.9 months; range, 12 to 47 months). The complication rate in SEEG implantations was 3%. CONCLUSION: The SEEG methodology is safe and should be considered in children/adolescents with difficult-to-localize epilepsy. When applied to highly complex and difficult-to-localize pediatric patients, SEEG may provide an additional opportunity for seizure freedom in association with a low morbidity rate.

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