Prediction of seizure freedom after epilepsy surgery – Critical reappraisal of significance of intracranial EEG parameters

2020 ◽  
Vol 131 (11) ◽  
pp. 2682-2690
Author(s):  
David Steinbart ◽  
Mirja Steinbrenner ◽  
Frank Oltmanns ◽  
Martin Holtkamp
Keyword(s):  
Epilepsy Surgery ◽  
Seizure Freedom ◽  
Intracranial Eeg

scholarly journals Scalp and Intracranial EEG in Medically Intractable Extratemporal Epilepsy with Normal MRI

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Tarek Zakaria ◽  
Katherine Noe ◽  
Elson So ◽  
Gregory D. Cascino ◽  
Nicholas Wetjen ◽  
...  
Keyword(s):  
Epilepsy Surgery ◽  
Surgical Outcome ◽  
Favorable Outcome ◽  
Rank Test ◽  
Seizure Freedom ◽  
Intracranial Eeg ◽  
Scalp Eeg ◽  
Kaplan Meier ◽  
Postoperative Seizure ◽  
Beta Frequency

Purpose. To investigate EEG and SPECT in the surgical outcome of patients with normal MRI (nonlesional) and extratemporal lobe epilepsy. Methods. We retrospectively identified 41 consecutive patients with nonlesional extratemporal epilepsy who underwent epilepsy surgery between 1997 and 2007. The history, noninvasive diagnostic studies (scalp EEG, MRI, and SPECT) and intracranial EEG (iEEG) monitoring was reviewed. Scalp and iEEG ictal onset patterns were defined. The association of preoperative studies and postoperative seizure freedom was analyzed using Kaplan-Meier analysis, log-rank test, and Cox proportional hazard. Results. Thirty-six of 41 patients had adequate information with a minimum of 1-year followup. Favorable surgical outcome was identified in 49% of patients at 1 year, and 35% at 4-year. On scalp EEG, an ictal onset pattern consisting of focal beta-frequency discharge (>13–125 Hz) was associated with favorable surgical outcome (P=0.02). Similarly, a focal fast-frequency oscillation (>13–125 Hz) on iEEG at ictal onset was associated with favorable outcome (P=0.03). Discussion. A focal fast-frequency discharge at ictal onset identifies nonlesional MRI, extratemporal epilepsy patients likely to have a favorable outcome after resective epilepsy surgery.

scholarly journals Blinded study: prospectively defined high frequency oscillations predict seizure outcome in individual patients

2021 ◽  
Author(s):  
Vasileios Dimakopoulos ◽  
Pierre Mégevand ◽  
Ece Boran ◽  
Shahan Momjian ◽  
Margitta Seeck ◽  
...  
Keyword(s):  
Epilepsy Surgery ◽  
High Frequency ◽  
Dwell Time ◽  
Seizure Outcome ◽  
Seizure Freedom ◽  
Intracranial Eeg ◽  
Retest Reliability ◽  
High Frequency Oscillations ◽  
Test Retest Reliability

Abstract Interictal high frequency oscillations are discussed as biomarkers for epileptogenic brain tissue that should be resected in epilepsy surgery to achieve seizure freedom. The prospective classification of tissue sampled by individual electrode contacts remains a challenge. We have developed an automated, prospective definition of clinically relevant high frequency oscillations in intracranial EEG from Montreal and tested it in recordings from Zurich. We here validated the algorithm on intracranial EEG that was recorded in an independent epilepsy centre so that the analysis was blinded to seizure outcome. We selected consecutive patients who underwent resective epilepsy surgery in Geneva with postsurgical follow-up > 12 months. We analysed long-term recordings during sleep that we segmented into intervals of 5 minutes. High frequency oscillations were defined in the ripple (80-250 Hz) and the fast ripple (250-500 Hz) frequency bands. Contacts with the highest rate of ripples co-occurring with fast ripples designated the relevant area. As a validity criterion, we calculated the test-retest reliability of the high frequency oscillations area between the 5 min intervals (dwell time ≥50%). If the area was not fully resected and the patient suffered from recurrent seizures, this was classified as a true positive prediction. We included recordings from 16 patients (median age 32 years, range 18-53 years) with stereotactic depth electrodes and/or with subdural electrode grids (median follow-up 27 months, range 12-55 months). For each patient, we included several 5 min intervals (median 17 intervals). The relevant area had high test-retest reliability across intervals (median dwell time 95%). In two patients, the test-retest reliability was too low (dwell time < 50%) so that outcome prediction was not possible. The area was fully included in the resected volume in 2/4 patients who achieved postoperative seizure freedom (specificity 50%) and was not fully included in 9/10 patients with recurrent seizures (sensitivity 90%), leading to an accuracy of 79%. An additional exploratory analysis suggested that high frequency oscillations were associated with interictal epileptic discharges only in channels within the relevant area and not associated in channels outside the area. We thereby validated the automated procedure to delineate the clinically relevant area in each individual patient of an independently recorded dataset and achieved the same good accuracy as in our previous studies. The reproducibility of our results across datasets is promising for a multicentre study to test the clinical application of high frequency oscillations to guide epilepsy surgery.

Long-term mood, quality of life, and seizure freedom in intracranial EEG epilepsy surgery

2021 ◽  
Vol 123 ◽  
pp. 108241
Author(s):  
Oshi Swarup ◽  
Alexandra Waxmann ◽  
Jocelyn Chu ◽  
Simon Vogrin ◽  
Alan Lai ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Epilepsy Surgery ◽  
Seizure Freedom ◽  
Intracranial Eeg

A historical cohort of temporal lobe surgery for medically refractory epilepsy: a systematic review and meta-analysis to guide future nonrandomized controlled trial studies

2020 ◽  
Vol 133 (1) ◽  
pp. 71-78 ◽  
Author(s):  
Anthony T. Lee ◽  
John F. Burke ◽  
Pranathi Chunduru ◽  
Annette M. Molinaro ◽  
Robert Knowlton ◽  
...  
Keyword(s):  
Systematic Review ◽  
Temporal Lobe ◽  
Epilepsy Surgery ◽  
Refractory Epilepsy ◽  
Meta Analysis ◽  
Small Sample ◽  
Seizure Freedom ◽  
Level I ◽  
Study Designs ◽  
Medically Refractory Epilepsy

OBJECTIVERecent trials for temporal lobe epilepsy (TLE) highlight the challenges of investigating surgical outcomes using randomized controlled trials (RCTs). Although several reviews have examined seizure-freedom outcomes from existing data, there is a need for an overall seizure-freedom rate estimated from level I data as investigators consider other methods besides RCTs to study outcomes related to new surgical interventions.METHODSThe authors performed a systematic review and meta-analysis of the 3 RCTs of TLE in adults and report an overall surgical seizure-freedom rate (Engel class I) composed of level I data. An overall seizure-freedom rate was also collected from level II data (prospective cohort studies) for validation. Eligible studies were identified by filtering a published Cochrane meta-analysis of epilepsy surgery for RCTs and prospective studies, and supplemented by searching indexed terms in MEDLINE (January 1, 2012–April 1, 2018). Retrospective studies were excluded to minimize heterogeneity in patient selection and reporting bias. Data extraction was independently reverified and pooled using a fixed-effects model. The primary outcome was overall seizure freedom following surgery. The historical benchmark was applied in a noninferiority study design to compare its power to a single-study cohort.RESULTSThe overall rate of seizure freedom from level I data was 72.4% (55/76 patients, 3 RCTs), which was nearly identical to the overall seizure-freedom rate of 71.7% (1325/1849 patients, 18 studies) from prospective cohorts (z = 0.134, p = 0.89; z-test). Seizure-freedom rates from level I and II studies were consistent over the years of publication (R2< 0.01, p = 0.73). Surgery resulted in markedly improved seizure-free outcomes compared to medical management (RR 10.82, 95% CI 3.93–29.84, p < 0.01; 2 RCTs). Noninferiority study designs in which the historical benchmark was used had significantly higher power at all difference margins compared to using a single cohort alone (p < 0.001, Bonferroni’s multiple comparison test).CONCLUSIONSThe overall rate of seizure freedom for temporal lobe surgery is approximately 70% for medically refractory epilepsy. The small sample size of the RCT cohort underscores the need to move beyond standard RCTs for epilepsy surgery. This historical seizure-freedom rate may serve as a useful benchmark to guide future study designs for new surgical treatments for refractory TLE.

scholarly journals The Role of KRAS Mutations in Cortical Malformation and Epilepsy Surgery: A Novel Report of Nevus Sebaceous Syndrome and Review of the Literature

2021 ◽  
Vol 11 (6) ◽  
pp. 793
Author(s):  
Chiara Pepi ◽  
Luca de Palma ◽  
Marina Trivisano ◽  
Nicola Pietrafusa ◽  
Francesca Romana Lepri ◽  
...  
Keyword(s):  
Epilepsy Surgery ◽  
Focal Cortical Dysplasia ◽  
Hippocampal Sclerosis ◽  
Brain Mri ◽  
Seizure Freedom ◽  
Histopathological Diagnosis ◽  
Cortical Malformation ◽  
Cognitive Improvement ◽  
Cortical Malformations ◽  
Nevus Sebaceous

The rare nevus sebaceous (NS) syndrome (NSS) includes cortical malformations and drug-resistant epilepsy. Somatic RAS-pathway genetic variants are pathogenetic in NS, but not yet described within the brain of patients with NSS. We report on a 5-year-old boy with mild psychomotor delay. A brown-yellow linear skin lesion suggestive of NS in the left temporo-occipital area was evident at birth. Epileptic spasms presented at aged six months. EEG showed continuous left temporo-occipital epileptiform abnormalities. Brain MRI revealed a similarly located diffuse cortical malformation with temporal pole volume reduction and a small hippocampus. We performed a left temporo-occipital resection with histopathological diagnosis of focal cortical dysplasia type Ia in the occipital region and hippocampal sclerosis type 1. Three years after surgery, he is seizure-and drug-free (Engel class Ia) and showed cognitive improvement. Genetic examination of brain and skin specimens revealed the c.35G > T (p.Gly12Val) KRAS somatic missense mutation. Literature review suggests epilepsy surgery in patients with NSS is highly efficacious, with 73% probability of seizure freedom. The few histological analyses reported evidenced disorganized cortex, occasionally with cytomegalic neurons. This is the first reported association of a KRAS genetic variant with cortical malformations associated with epilepsy, and suggests a possible genetic substrate for hippocampal sclerosis.

scholarly journals The influence of lesion volume, perilesion resection volume, and completeness of resection on seizure outcome after resective epilepsy surgery for cortical dysplasia in children

2015 ◽  
Vol 15 (6) ◽  
pp. 644-650 ◽  
Author(s):  
Chima O. Oluigbo ◽  
Jichuan Wang ◽  
Matthew T. Whitehead ◽  
Suresh Magge ◽  
John S. Myseros ◽  
...  
Keyword(s):  
Epilepsy Surgery ◽  
Seizure Control ◽  
Brain Mri ◽  
Age At Onset ◽  
Cortical Dysplasia ◽  
Complete Resection ◽  
Seizure Outcome ◽  
Seizure Freedom ◽  
Lesion Volume ◽  
Resection Volume

OBJECT Focal cortical dysplasia (FCD) is one of the most common causes of intractable epilepsy leading to surgery in children. The predictors of seizure freedom after surgical management for FCD are still unclear. The objective of this study was to perform a volumetric analysis of factors shown on the preresection and postresection brain MRI scans of patients who had undergone resective epilepsy surgery for cortical dysplasia and to determine the influence of these factors on seizure outcome. METHODS The authors reviewed the medical records and brain images of 43 consecutive patients with focal MRI-documented abnormalities and a pathological diagnosis of FCD who had undergone surgical treatment for refractory epilepsy. Preoperative lesion volume and postoperative resection volume were calculated by manual segmentation using OsiriX PRO software. RESULTS Forty-three patients underwent first-time surgery for resection of an FCD. The age range of these patients at the time of surgery ranged from 2 months to 21.8 years (mean age 7.3 years). The median duration of follow-up was 20 months. The mean age at onset was 31.6 months (range 1 day to 168 months). Complete resection of the area of an FCD, as adjudged from the postoperative brain MR images, was significantly associated with seizure control (p = 0.0005). The odds of having good seizure control among those who underwent complete resection were about 6 times higher than those among the patients who did not undergo complete resection. Seizure control was not significantly associated with lesion volume (p = 0.46) or perilesion resection volume (p = 0.86). CONCLUSIONS The completeness of FCD resection in children is a significant predictor of seizure freedom. Neither lesion volume nor the further resection of perilesional tissue is predictive of seizure freedom.

Forecasting Seizure Freedom After Epilepsy Surgery Assessing Concordance Between Noninvasive and StereoEEG Findings

Neurosurgery ◽  
2021 ◽  
Vol 89 (Supplement_2) ◽  
pp. S65-S65
Author(s):  
Reinaldo Uribe San Martin ◽  
Roberta Di Giacomo ◽  
Roberto Mai ◽  
Francesca Gozzo ◽  
Veronica Pelliccia ◽  
...  
Keyword(s):  
Epilepsy Surgery ◽  
Seizure Freedom

European trends in epilepsy surgery

Neurology ◽  
2018 ◽  
Vol 91 (2) ◽  
pp. e96-e106 ◽  
Author(s):  
Maxime O. Baud ◽  
Thomas Perneger ◽  
Attila Rácz ◽  
Max C. Pensel ◽  
Christian Elger ◽  
...  
Keyword(s):  
Epilepsy Surgery ◽  
Disease Duration ◽  
Focal Epilepsy ◽  
Seizure Freedom ◽  
Early Referral ◽  
Temporal Epilepsy ◽  
Included Patient ◽  
Class 1 ◽  
Postsurgical Outcomes ◽  
Over Time

ObjectiveResective surgery is effective in treating drug-resistant focal epilepsy, but it remains unclear whether improved diagnostics influence postsurgical outcomes. Here, we compared practice and outcomes over 2 periods 15 years apart.MethodsSixteen European centers retrospectively identified 2 cohorts of children and adults who underwent epilepsy surgery in the period of 1997 to 1998 (n = 562) or 2012 to 2013 (n = 736). Data collected included patient (sex, age) and disease (duration, localization and diagnosis) characteristics, type of surgery, histopathology, Engel postsurgical outcome, and complications, as well as imaging and electrophysiologic tests performed for each case. Postsurgical outcome predictors were included in a multivariate logistic regression to assess the strength of date of surgery as an independent predictor.ResultsOver time, the number of operated cases per center increased from a median of 31 to 50 per 2-year period (p = 0.02). Mean disease duration at surgery decreased by 5.2 years (p < 0.001). Overall seizure freedom (Engel class 1) increased from 66.7% to 70.9% (adjusted p = 0.04), despite an increase in complex surgeries (extratemporal and/or MRI negative). Surgeries performed during the later period were 1.34 times (adjusted odds ratio; 95% confidence interval 1.02–1.77) more likely to yield a favorable outcome (Engel class I) than earlier surgeries, and improvement was more marked in extratemporal and MRI-negative temporal epilepsy. The rate of persistent neurologic complications remained stable (4.6%–5.3%, p = 0.7).ConclusionImprovements in European epilepsy surgery over time are modest but significant, including higher surgical volume, shorter disease duration, and improved postsurgical seizure outcomes. Early referral for evaluation is required to continue on this encouraging trend.

Outcomes of cingulate epilepsy surgery: insights from an institutional and patient-level systematic review and meta-analysis

2021 ◽  
pp. 1-10
Author(s):  
Panagiotis Kerezoudis ◽  
Rohin Singh ◽  
Gregory A. Worrell ◽  
Jamie J. Van Gompel
Keyword(s):  
Epilepsy Surgery ◽  
Literature Search ◽  
Anterior Cingulate ◽  
Postoperative Outcomes ◽  
Cochrane Library ◽  
Rank Test ◽  
Seizure Freedom ◽  
Low Grade ◽  
Cingulate Gyrus

OBJECTIVE Due to their deep and medial location, range of seizure semiologies, and poor localization on ictal electroencephalography (EEG), cingulate gyrus seizures can be difficult to diagnose and treat. The aim of this study was to review the available evidence on postoperative outcomes after cingulate epilepsy surgery. METHODS A comprehensive literature search of the PubMed/MEDLINE, Ovid Embase, Ovid Scopus, and Cochrane Library databases was conducted to identify studies that investigated postoperative outcomes of patients with cingulate epilepsy. Seizure freedom at the last follow-up (at least 12 months) was the primary endpoint. The literature search was supplemented by the authors’ institutional series (4 patients). RESULTS Twenty-one studies were identified, yielding a total of 105 patients (68 with lesional epilepsy [65%]). Median age at surgery was 23 years, and 56% of patients were male. Median epilepsy duration was 7.5 years. Invasive EEG recording was performed on 69% of patients (53% of patients with lesional epilepsy and 97% of those with nonlesional epilepsy, p < 0.001). The most commonly resected region was the anterior cingulate (55%), followed by the posterior (17%) and middle (14%) cingulate. Lesionectomy alone was performed in 9% of patients. Additional extracingulate treatment was performed in 54% of patients (53% of patients with lesional epilepsy vs 57% of those with nonlesional epilepsy, p = 0.87). The most common pathology was cortical dysplasia (54%), followed by low-grade neoplasm (29%) and gliosis (8%). Seizure freedom was noted in 72% of patients (median follow-up 24 months). A neurological deficit was noted in 27% of patients (24% had temporary deficit), with the most common deficit being motor weakness (13%) followed by supplementary motor area syndrome (9.5%). Univariate survival analysis revealed significantly greater probability of seizure freedom in patients with lesional epilepsy (p = 0.015, log-rank test). CONCLUSIONS Surgical treatment of drug-resistant focal epilepsy originating from the cingulate gyrus is safe, leads to low rates of permanent adverse effects, and leads to high rates of long-term seizure freedom in carefully selected patients. These data may serve as a benchmark for surgical counseling of patients with cingulate epilepsy.

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