scholarly journals Node abnormality predicts seizure outcome and relates to long-term relapse after epilepsy surgery

2019 ◽  
Author(s):  
Nishant Sinha ◽  
Yujiang Wang ◽  
Nádia Moreira da Silva ◽  
Anna Miserocchi ◽  
Andrew W. McEvoy ◽  
...  

AbstractObjectiveWe assessed pre-operative structural brain networks and clinical characteristics of patients with drug resistant temporal lobe epilepsy (TLE) to identify correlates of post-surgical seizure outcome at 1 year and seizure relapses up to 5 years.MethodsWe retrospectively examined data from 51 TLE patients who underwent anterior temporal lobe resection (ATLR) and 29 healthy controls. For each patient, using the pre-operative structural, diffusion, and post-operative structural MRI, we generated two networks: ‘pre-surgery’ network and ‘surgically-spared’ network. The pre-surgery network is the whole-brain network before surgery and the surgically-spared network is a subnetwork of the pre-surgery network which is expected to remain unaffected by surgery and hence present post-operatively. Standardising these networks with respect to controls, we determined the number of abnormal nodes before surgery and expected to remain after surgery. We incorporated these 2 abnormality measures and 13 commonly acquired clinical data from each patient in a robust machine learning framework to estimate patient-specific chances of seizures persisting after surgery.ResultsPatients with more abnormal nodes had lower chance of seizure freedom at 1 year and even if seizure free at 1 year, were more likely to relapse within five years. In the surgically-spared networks of poor outcome patients, the number of abnormal nodes was greater and their locations more widespread than in good outcome patients. We achieved 0.84 ± 0.06 AUC and 0.89 ± 0.09 specificity in detecting unsuccessful seizure outcomes at 1-year. Moreover, the model-predicted likelihood of seizure relapse was significantly correlated with the grade of surgical outcome at year-one and associated with relapses up-to five years post-surgery.ConclusionNode abnormality offers a personalised non-invasive marker, that can be combined with clinical data, to better estimate the chances of seizure freedom at 1 year, and subsequent relapse up to 5 years after ATLR.

Neurology ◽  
2020 ◽  
pp. 10.1212/WNL.0000000000011315
Author(s):  
Nishant Sinha ◽  
Yujiang Wang ◽  
Nádia Moreira da Silva ◽  
Anna Miserocchi ◽  
Andrew W. McEvoy ◽  
...  

Objective:We assessed pre-operative structural brain networks and clinical characteristics of patients with drug resistant temporal lobe epilepsy (TLE) to identify correlates of post-surgical seizure recurrences.Methods:We examined data from 51 TLE patients who underwent anterior temporal lobe resection (ATLR) and 29 healthy controls. For each patient, using the pre-operative structural, diffusion, and post-operative structural MRI, we generated two networks: ‘pre-surgery’ network and ‘surgically-spared’ network. Standardising these networks with respect to controls, we determined the number of abnormal nodes before surgery and expected to be spared by surgery. We incorporated these 2 abnormality measures and 13 commonly acquired clinical data from each patient in a robust machine learning framework to estimate patient-specific chances of seizures persisting after surgery.Results:Patients with more abnormal nodes had lower chance of complete seizure freedom at 1 year and even if seizure-free at 1 year, were more likely to relapse within five years. The number of abnormal nodes was greater and their locations more widespread in the surgically-spared networks of poor outcome patients than in good outcome patients. We achieved 0.84±0.06 AUC and 0.89±0.09 specificity in predicting unsuccessful seizure outcomes (ILAE3-5) as opposed to complete seizure freedom (ILAE1) at 1 year. Moreover, the model-predicted likelihood of seizure relapse was significantly correlated with the grade of surgical outcome at year-one and associated with relapses up-to five years post-surgery.Conclusion:Node abnormality offers a personalised non-invasive marker, that can be combined with clinical data, to better estimate the chances of seizure freedom at 1 year, and subsequent relapse up to 5 years after ATLR.Classification of evidence:This study provides Class II evidence that node abnormality predicts post-surgical seizure recurrence.


2015 ◽  
Vol 15 (2) ◽  
pp. 133-143 ◽  
Author(s):  
Jason G. Mandell ◽  
Kenneth L. Hill ◽  
Dan T. D. Nguyen ◽  
Kevin W. Moser ◽  
Robert E. Harbaugh ◽  
...  

OBJECT The incidence of temporal lobe epilepsy (TLE) due to mesial temporal sclerosis (MTS) can be high in developing countries. Current diagnosis of MTS relies on structural MRI, which is generally unavailable in developing world settings. Given widespread effects on temporal lobe structure beyond hippocampal atrophy in TLE, the authors propose that CT volumetric analysis can be used in patient selection to help predict outcomes following resection. METHODS Ten pediatric patients received preoperative CT scans and temporal resections at the CURE Children's Hospital of Uganda. Engel classification of seizure control was determined 12 months postoperatively. Temporal lobe volumes were measured from CT and from normative MR images using the Cavalieri method. Whole brain and fluid volumes were measured using particle filter segmentation. Linear discrimination analysis (LDA) was used to classify seizure outcome by temporal lobe volumes and normalized brain volume. RESULTS Epilepsy patients showed normal to small brain volumes and small temporal lobes bilaterally. A multivariate measure of the volume of each temporal lobe separated patients who were seizure free (Engel Class IA) from those with incomplete seizure control (Engel Class IB/IIB) with LDA (p < 0.01). Temporal lobe volumes also separate normal subjects, patients with Engel Class IA outcomes, and patients with Class IB/IIB outcomes (p < 0.01). Additionally, the authors demonstrated that age-normalized whole brain volume, in combination with temporal lobe volumes, may further improve outcome prediction (p < 0.01). CONCLUSIONS This study shows strong evidence that temporal lobe and brain volume can be predictive of seizure outcome following temporal lobe resection, and that volumetric CT analysis of the temporal lobe may be feasible in lieu of structural MRI when the latter is unavailable. Furthermore, since the authors' methods are modality independent, these findings suggest that temporal lobe and normative brain volumes may further be useful in the selection of patients for temporal lobe resection when structural MRI is available.


2020 ◽  
Vol 27 ◽  
pp. 102320 ◽  
Author(s):  
Nádia Moreira da Silva ◽  
Rob Forsyth ◽  
Andrew McEvoy ◽  
Anna Miserocchi ◽  
Jane de Tisi ◽  
...  

Neurosurgery ◽  
2019 ◽  
Vol 66 (Supplement_1) ◽  
Author(s):  
Long Di ◽  
Elliot G Neal ◽  
Stephanie Maciver ◽  
Fernando L Vale

Abstract INTRODUCTION Surgery remains an essential option for the treatment of medically intractable temporal lobe epilepsy. However, only 66% of patients achieve postoperative seizure freedom, perhaps attributable to an incomplete understanding of brain network alterations in surgical candidates. Here, we present a novel network modeling algorithm that may be used to identify key characteristics of epileptic networks correlated with improved surgical outcome. METHODS Twenty-nine patients were prospectively included, and relevant demographic information was attained. Resting-state functional magnetic resonance imaging (MRI) and electroencephalography (EEG) data were recorded and preprocessed. Using our novel algorithm, patient-specific epileptic networks were mapped preoperatively and geographic spread was quantified. Global functional connectivity was also determined using a volumetric functional atlas. Key demographic data and features of epileptic networks were then correlated with surgical outcome using Pearson's product-moment correlation. RESULTS At an average follow-up of 19 mo, 20/29 (69%) patients were seizure-free. Higher rates of seizure recurrence correlated with the localization of the epilepsy network to either temporal lobe (R = –0.415, P = .039), with the stronger correlation found with the localization to the contralateral temporal lobe (R = –0.566, P = .003). When the volumetric functional atlas connectivity was measured, increased connectivity globally was correlated with seizure recurrence (R = –0.541, P = .006). Seizure recurrence also correlated with greater atlas-based connectivity within the contralateral hemisphere (R = –0.390, P = .049). CONCLUSION Network localization to the temporal lobes, in particular the contralateral temporal lobe, and increased atlas-defined connectivity contralateral to the surgery side are associated with seizure recurrence. These findings may reflect network-level disruption that has infiltrated the contralateral temporal lobe contributing to relatively worse surgical outcomes. Further identification of network parameters that predict patient outcomes may aid in patient selection, resection planning, and ultimately the efficacy of epilepsy surgery.


Neurology ◽  
2021 ◽  
pp. 10.1212/WNL.0000000000013033
Author(s):  
Ezequiel Gleichgerrcht ◽  
Daniel L. Drane ◽  
Simon Sean Keller ◽  
Kathryn A. Davis ◽  
Robert Gross ◽  
...  

Objective:To determine the association between surgical lesions of distinct grey and white structures and connections with favorable post-operative seizure outcomes.Methods:Patients with drug-resistant temporal lobe epilepsy (TLE) from three epilepsy centers were included. We employed a voxel-based and connectome-based mapping approach to determine the association between favorable outcomes and surgery-induced temporal lesions. Analyses were conducted controlling for multiple confounders, including total surgical resection/ablation volume, hippocampal volumes, side of surgery, and site where the patient was treated.Results:The cohort included 113 patients with TLE [54 women; 86 right-handed; 16.5 (SD = 11.9) age at seizure onset, 54.9% left] who were 61.1% free of disabling seizures (Engel class 1) at follow-up. Postoperative seizure freedom in TLE was associated with 1) surgical lesions that targeted the hippocampus as well as the amygdala-piriform cortex complex and entorhinal cortices; 2) disconnection of temporal, frontal, and limbic regions through loss of white matter tracts within the uncinate fasciculus, anterior commissure, and fornix; and 3) functional disconnection of the frontal (superior and middle frontal gyri, orbitofrontal region) and temporal (superior and middle pole) lobes.Conclusions:Better postoperative seizure freedom are associated with surgical lesions of specific structures and connections throughout the temporal lobes. These findings shed light on the key components of epileptogenic networks in TLE and constitute a promising source of new evidence for future improvements in surgical interventions.Classification of Evidence:This study provides Class II evidence that for patients with temporal lobe epilepsy, postoperative seizure freedom is associated with surgical lesions of specific temporal lobe structures and connections.


2017 ◽  
Vol 13 (6) ◽  
pp. 711-717 ◽  
Author(s):  
Fady Girgis ◽  
Madeline E Greil ◽  
Philip S Fastenau ◽  
Jennifer Sweet ◽  
Hans Lüders ◽  
...  

Abstract BACKGROUND Multiple hippocampal transection (MHT) is a surgical treatment for mesial temporal lobe epilepsy associated with improved postoperative neuropsychological outcomes compared with lobectomy. OBJECTIVE To determine whether resection of the amygdala and anterior temporal neocortex during MHT affects postoperative seizure/memory outcome. METHODS Seventeen patients with normal magnetic resonance imaging and stereo-electroencephalogram-proven drug-resistant dominant mesial temporal lobe epilepsy were treated with MHT. Nine patients underwent MHT alone (MHT–) and 8 patients underwent MHT plus removal of the amygdala and anterior 4.5 cm of temporal neocortex lateral to the fusiform gyrus (MHT+). Verbal and visual-spatial memory were assessed in all patients preoperatively and in 14 patients postoperatively using the Wechsler Memory Scale. Postoperative seizure control was assessed at 12 months for all patients. RESULTS Overall, 11 of 17 patients (64.7%) were Engel class 1 at 1 year (6/9 MHT–, 5/8 MHT+, P = .38), and 10 of 14 patients (71.4%) had no significant postoperative decline in either verbal or visual memory (6/8 MHT–, 4/6 MHT+, P = .42). Verbal memory declined in 2 of 8 MHT– and 1 of 6 MHT+ patients, and visual memory declined in 1 of 8 MHT– and 2 of 6 MHT+ patients. Two patients had improved visual memory postoperatively, both in the MHT+ group. CONCLUSION MHT on the dominant side is associated with high rates of seizure freedom and favorable memory preservation outcomes regardless of the extent of neocortical resection. Preservation of the temporal neocortex and amygdala during MHT does not appear to decrease the risk of postoperative memory decline, nor does it alter seizure outcome.


2017 ◽  
Vol 127 (5) ◽  
pp. 1147-1152 ◽  
Author(s):  
Veronica Pelliccia ◽  
Francesco Deleo ◽  
Francesca Gozzo ◽  
Ivana Sartori ◽  
Roberto Mai ◽  
...  

OBJECTIVEEpilepsy surgery is an effective means of treating focal epilepsy associated with long-term epilepsy-associated tumors. This study evaluated a large population of surgically treated patients with childhood onset of epilepsy and a histologically confirmed diagnosis of long-term epilepsy-associated tumors. The authors analyzed long-term seizure outcomes to establish whether the time of surgery and patients' ages were determinant factors.METHODSThe authors separately investigated several presurgical, surgical, and postsurgical variables in patients operated on before (pediatric group) and at or after (adult group) the age of 18 years. Patients with < 24 months of postsurgical follow-up were excluded from the analysis.RESULTSThe patients who underwent surgery before 18 years of age showed better seizure outcomes than those after 18 years of age (80% vs 53.3% Engel Class Ia outcome, respectively; p < 0.001). Multivariate analysis showed that the only variables significantly associated with seizure freedom were complete resection of the lesion, a shorter duration of epilepsy, and temporal lobe resection.CONCLUSIONSThe findings of this study indicate that pediatric patients are more responsive to epilepsy surgery and that a shorter duration of epilepsy, complete resection, and a temporal lobe localization are determinant factors for a positive seizure outcome.


Neurosurgery ◽  
2012 ◽  
Vol 71 (3) ◽  
pp. 703-709 ◽  
Author(s):  
Steven M. Falowski ◽  
David Wallace ◽  
Andres Kanner ◽  
Michael Smith ◽  
Michael Rossi ◽  
...  

Abstract BACKGROUND: There have been only a few large series that have used a tailored temporal lobectomy. OBJECTIVE: To clarify whether tailoring a temporal lobe resection will lead to equivalent epilepsy outcomes or have the same predictive factors for success when compared with standard resections. METHODS: Retrospective analysis of 222 patients undergoing a tailored temporal lobe resection. Demographic measures and typical factors influencing outcome were evaluated. RESULTS: Pathology included 222 cases. With a mean follow-up of 5.4 years, 70% of patients achieved Engel class I outcome. A significant factor predicting Engel class I outcome on multivariate analysis was lesional pathology (P = .04). Among patients with hippocampal sclerosis, extent of lateral neocortical resection and hippocampal resection were not statistically associated with Engel class I outcome (P = .93 and P = .24). However, an analysis of Engel class subgroups a to d showed that patients who had a complete hippocampectomy in the total series were more likely to achieve an Engel class Ia outcome (P = .04). This was also true among patients with hippocampal sclerosis (P = .03). Secondarily, generalized seizure (P = .01) predicted outcome less than Engel class I. Predictive of poor outcome was the need for preoperative electrodes (P = .02). Complications included superior quadrant visual field defects, 2 cases of permanent dysphasia, and 3 wound infections. CONCLUSION: Predictors of successful seizure outcome for a tailored temporal lobectomy are similar to standard lobectomy. Patients with secondarily generalized epilepsy and cases in which preoperative subdural electrodes were thought necessary were less likely to achieve class I outcome. Among Engel class I cases, those who had a complete hippocampectomy were more likely to achieve Engel class Ia outcome.


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Jugoslav Ivanović ◽  
Kristin Åshild Alfstad ◽  
Pål Bache Marthinsen ◽  
Ketil Berg Olsen ◽  
Pål Gunnar Larsson ◽  
...  

ABSTRACT BACKGROUND Treatment of patients with pharmacoresistant temporal lobe epilepsy with hippocampal sclerosis and nonspecific pathology who failed initial resection is challenging, although selected patients may benefit from repeated surgery. OBJECTIVE To determine seizure outcome, postoperative morbidity, and possible predictors of seizure freedom after repeated ipsitemporal resection. METHODS We reviewed the results of comprehensive epilepsy evaluations performed before the initial and repeated resections in 10 patients with hippocampal sclerosis and 13 with nonspecific pathology. We assessed the Engel classification of seizure outcome 2 yr after repeated resection, evaluated postoperative morbidity, and examined the association of epilepsy and surgical characteristics with seizure freedom before and after reoperation. RESULTS After reoperation, in patients with hippocampal sclerosis, seizure freedom (Engel class I) was achieved in 2 (20%), 1 (10%) experienced surgical complications, and 1 (10%) experienced permanent neurological impairment. Following reoperation in patients with nonspecific pathology, seizure freedom was achieved in 1 (8%), 3 (23%) experienced surgical complications, and 4 (31%) experienced permanent neurological impairment. Epilepsy and surgical characteristics before and after reoperation were not associated with seizure freedom. CONCLUSION Patients with hippocampal sclerosis and nonspecific pathology who underwent a comprehensive initial work-up and failed original temporal lobe resection rarely become seizure-free after repeated ipsitemporal reoperation. Reoperations carry a high risk of surgical complications and neurological impairment. Predictors for seizure freedom could not be defined.


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