Postoperative seizure freedom does not normalize altered connectivity in temporal lobe epilepsy

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.

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Resection of Temporal Neocortex During Multiple Hippocampal Transections for Mesial Temporal Lobe Epilepsy Does not Affect Seizure or Memory Outcome

Operative Neurosurgery ◽

10.1093/ons/opx031 ◽

2017 ◽

Vol 13 (6) ◽

pp. 711-717 ◽

Cited By ~ 2

Author(s):

Fady Girgis ◽

Madeline E Greil ◽

Philip S Fastenau ◽

Jennifer Sweet ◽

Hans Lüders ◽

...

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Visual Memory ◽

Mesial Temporal Lobe Epilepsy ◽

Seizure Outcome ◽

Seizure Freedom ◽

Visual Spatial ◽

Mesial Temporal Lobe ◽

Postoperative Seizure ◽

Temporal Neocortex

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.

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Hippocampography Guides Consistent Mesial Resections in Neocortical Temporal Lobe Epilepsy

Epilepsy Research and Treatment ◽

10.1155/2016/3581358 ◽

2016 ◽

Vol 2016 ◽

pp. 1-8

Author(s):

Marcus C. Ng ◽

Ronan Kilbride ◽

Mirela Simon ◽

Emad Eskandar ◽

Andrew J. Cole

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Primary Outcome ◽

Group Versus ◽

Temporal Lobectomy ◽

Seizure Freedom ◽

Neuropsychological Deficit ◽

Lateral Group ◽

Postoperative Seizure

Background. The optimal surgery in lesional neocortical temporal lobe epilepsy is unknown. Hippocampal electrocorticography maximizes seizure freedom by identifying normal-appearing epileptogenic tissue for resection and minimizes neuropsychological deficit by limiting resection to demonstrably epileptogenic tissue. We examined whether standardized hippocampal electrocorticography (hippocampography) guides resection for more consistent hippocampectomy than unguided resection in conventional electrocorticography focused on the lesion. Methods. Retrospective chart reviews any kind of electrocorticography (including hippocampography) as part of combined lesionectomy, anterolateral temporal lobectomy, and hippocampectomy over 8 years . Patients were divided into mesial (i.e., hippocampography) and lateral electrocorticography groups. Primary outcome was deviation from mean hippocampectomy length. Results. Of 26 patients, fourteen underwent hippocampography-guided mesial temporal resection. Hippocampography was associated with 2.6 times more consistent resection. The range of hippocampal resection was 0.7 cm in the mesial group and 1.8 cm in the lateral group (p=0.01). 86% of mesial group versus 42% of lateral group patients achieved seizure freedom (p=0.02). Conclusions. By rationally tailoring excision to demonstrably epileptogenic tissue, hippocampography significantly reduces resection variability for more consistent hippocampectomy than unguided resection in conventional electrocorticography. More consistent hippocampal resection may avoid overresection, which poses greater neuropsychological risk, and underresection, which jeopardizes postoperative seizure freedom.

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Resective temporal lobe surgery in refractory temporal lobe epilepsy: prognostic factors of postoperative seizure outcome

Journal of Neurosurgery ◽

10.3171/2020.7.jns20284 ◽

2021 ◽

pp. 1-10

Author(s):

Valeri Borger ◽

Motaz Hamed ◽

Julia Taube ◽

Gülsah Aydin ◽

Inja Ilic ◽

...

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Multivariate Logistic Regression Analysis ◽

Seizure Outcome ◽

Seizure Freedom ◽

Depth Electrodes ◽

Group I ◽

Significant Difference ◽

Class 1 ◽

Postoperative Seizure

OBJECTIVETemporal lobe epilepsy (TLE) is one of the most common forms of epilepsy. In approximately 30% of patients, seizures are refractory to drug treatment. Despite the achievements of modern presurgical evaluation in recent years, the presurgical prediction of seizure outcome remains difficult. The aim of this study was to evaluate the seizure outcome in patients with drug-refractory TLE who underwent resective temporal lobe surgery (rTLS) and to determine features associated with unfavorable postsurgical seizure outcome.METHODSPatients with medically refractory TLE who underwent rTLS between 2012 and 2017 were reviewed from the prospectively collected epilepsy surgery database. A retrospective analysis of clinical, radiological, neuropsychological, histopathological, and perioperative findings of 161 patients was performed. The patients were divided into two groups according to seizure outcome (group I, International League Against Epilepsy [ILAE] class 1; group II, ILAE class ≥ 2). For identification of independent risk factors for unfavorable postoperative seizure outcome (ILAE class ≥ 2), a multivariate logistic regression analysis was performed.RESULTSSeizure freedom (ILAE class 1) was achieved in 121 patients (75.2%). The neuropsychological evaluation demonstrated that losses in cognitive performance were more pronounced in verbal memory after resections in the left temporal lobe and in nonverbal memory after right-sided resections, whereas attention improved after surgery. Overall, postoperative visual field deficits (VFDs) were common and occurred in 51% of patients. There was no statistically significant difference in the incidence of VFD in patients with selective surgical procedures compared to the patients with nonselective procedures. The lack of MRI lesions and placement of depth electrodes were preoperatively identified as predictors for unfavorable seizure outcome.CONCLUSIONSrTLS is an effective treatment method in patients with refractory TLE. However, patients with a lack of MRI lesions and placement of depth electrodes prior to rTLS are at higher risk for an unfavorable postsurgical seizure outcome.

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Side of Lesions Predicts Surgical Outcomes in Patients With Drug-Resistant Temporal Lobe Epilepsy Secondary to Focal Cortical Dysplasia Type IIIa

Frontiers in Neurology ◽

10.3389/fneur.2020.580221 ◽

2020 ◽

Vol 11 ◽

Author(s):

Xinghui He ◽

Dingyang Liu ◽

Zhuanyi Yang ◽

Junmei Zhang ◽

Sushan Li ◽

...

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Surgical Outcomes ◽

Focal Cortical Dysplasia ◽

Cortical Dysplasia ◽

Seizure Freedom ◽

Drug Resistant ◽

Type Iiia ◽

Postoperative Seizure ◽

The Right

Objective: This study aims to evaluate the surgical outcomes and analyze the predictors of surgical outcomes in patients undergoing anterior temporal lobectomy (ATL) for drug-resistant temporal lobe epilepsy (TLE) secondary to focal cortical dysplasia (FCD) type IIIa.Methods: Data on patients with drug-resistant TLE secondary to FCD type IIIa who had undergone ATL at Xiangya Hospital, Central South University from January 2014 to April 2018, were collected retrospectively. International League Against Epilepsy (ILAE) classification was used to evaluate postoperative seizure outcomes. Predictors of surgical outcomes were identified by using univariate and multivariate analyses.Results: A total of 43 patients with drug-resistant TLE secondary to FCD type IIIa who had undergone ATL were included in this study. Twenty patients had right ATL, and 23 patients had left ATL. With a follow-up of 2–6 years, 76.7% (33 of 43) of patients were seizure-free. Univariate and multivariate analysis results indicated that lesions on the right side independently predict postoperative seizure freedom (OR, 0.08; 95% CI, 0.01–0.72; P = 0.024).Conclusion: ATL is an effective therapy for patients with drug-resistant TLE secondary to FCD type IIIa. Patients with lesions on the right side are more likely to achieve postoperative seizure freedom.

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P6-6 Is interictal EEG enough to predict seizure freedom in mesial temporal lobe epilepsy with hippocampal sclerosis?

Clinical Neurophysiology ◽

10.1016/s1388-2457(10)60554-8 ◽

2010 ◽

Vol 121 ◽

pp. S135

Author(s):

J.M. Chung ◽

J.R. Soss ◽

J. Engel

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Hippocampal Sclerosis ◽

Mesial Temporal Lobe Epilepsy ◽

Seizure Freedom ◽

Interictal Eeg ◽

Mesial Temporal Lobe

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Do psychiatric comorbidities predict postoperative seizure outcome in temporal lobe epilepsy surgery?

Epilepsy & Behavior ◽

10.1016/j.yebeh.2009.01.002 ◽

2009 ◽

Vol 14 (3) ◽

pp. 529-534 ◽

Cited By ~ 57

Author(s):

Ricardo Guarnieri ◽

Roger Walz ◽

Jaime E.C. Hallak ◽

Érica Coimbra ◽

Edna de Almeida ◽

...

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Epilepsy Surgery ◽

Seizure Outcome ◽

Psychiatric Comorbidities ◽

Postoperative Seizure

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The “Natural” History of Medically Treated Temporal Lobe Epilepsy: What Can an Evidence-Based Approach Tell Us?

Epilepsy Research and Treatment ◽

10.1155/2012/216510 ◽

2012 ◽

Vol 2012 ◽

pp. 1-8

Author(s):

Colin Bruce Josephson ◽

Bernhard Pohlmann-Eden

Keyword(s):

Natural History ◽

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Population Based ◽

Seizure Freedom ◽

History Of ◽

Prospective Cohorts ◽

Eeg Recordings ◽

Incident Cases ◽

Treatment Prognosis

We systematically reviewed the literature to describe the “natural” history of medically treated temporal lobe epilepsy (TLE). No population-based studies recruiting incident cases of TLE irrespective of age exist. Prospective, population-based studies were limited to those recruiting only childhood-onset TLE or those reporting TLE as a subgroup of cohorts of focal epilepsies. Few studies have been performed in the “MRI era” limiting information on natural history secondary to specific pathologies. Available data suggests that TLE is highly variable, with unpredictable transient remissions and low rates of seizure freedom (30 to 50%). Etiology and failure of first and second drug seem to be the most important predictors for treatment prognosis. The role of initial precipitating injuries remains speculative, as imaging information of related events is either missing or conflicting. Prospective cohorts of new-onset TLE with long-term followup using advanced MRI techniques, timely EEG recordings, and assessments of psychiatric comorbidities are needed.

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Surgical Outcomes and EEG Prognostic Factors After Stereotactic Laser Amygdalohippocampectomy for Mesial Temporal Lobe Epilepsy

Frontiers in Neurology ◽

10.3389/fneur.2021.654668 ◽

2021 ◽

Vol 12 ◽

Author(s):

Shasha Wu ◽

Naoum P. Issa ◽

Maureen Lacy ◽

David Satzer ◽

Sandra L. Rose ◽

...

Keyword(s):

Temporal Lobe Epilepsy ◽

Temporal Lobe ◽

Surgical Outcomes ◽

Mesial Temporal Lobe Epilepsy ◽

Seizure Freedom ◽

Seizure Recurrence ◽

Factors Associated ◽

Scalp Eeg ◽

Mesial Temporal Lobe

Objective: To assess the seizure outcomes of stereotactic laser amygdalohippocampectomy (SLAH) in consecutive patients with mesial temporal lobe epilepsy (mTLE) in a single center and identify scalp EEG and imaging factors in the presurgical evaluation that correlate with post-surgical seizure recurrence.Methods: We retrospectively reviewed the medical and EEG records of 30 patients with drug-resistant mTLE who underwent SLAH and had at least 1 year of follow-up. Surgical outcomes were classified using the Engel scale. Univariate hazard ratios were used to evaluate the risk factors associated with seizure recurrence after SLAH.Results: The overall Engel class I outcome after SLAH was 13/30 (43%), with a mean postoperative follow-up of 48.9 ± 17.6 months. Scalp EEG findings of interictal regional slow activity (IRSA) on the side of surgery (HR = 4.05, p = 0.005) and non-lateralizing or contra-lateralizing seizure onset (HR = 4.31, p = 0.006) were negatively correlated with postsurgical seizure freedom. Scalp EEG with either one of the above features strongly predicted seizure recurrence after surgery (HR = 7.13, p < 0.001) with 100% sensitivity and 71% specificity.Significance: Understanding the factors associated with good or poor surgical outcomes can help choose the best candidates for SLAH. Of the variables assessed, scalp EEG findings were the most clearly associated with seizure outcomes after SLAH.

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