Seizure Outcome of Temporal Lobe Epilepsy Surgery in Adults and Children: A Systematic Review and Meta-Analysis

Do acute postoperative seizures predict epilepsy surgery outcome? a scoping review

BACKGROUND

Acute postoperative seizures (APOS) are common phenomena following resective epilepsy surgery and can be categorized as running-down (RDS) or running-up seizures (RUS). This differentiation is made retrospectively, considering their classification is based on seizure recurrence. However, early differentiation of RDS from RUS may prevent unnecessary escalation of anti-seizure medication or reoperation. This review provides an overview of the available literature on variables influencing the evolution to RDS/RUS in patients exhibiting acute or early postoperative seizures.

METHODS

A database search was performed addressing studies related to the running-down phenomenon and postoperative seizures in PubMed and Embase. Eligibility required a clear definition of acute or early postoperative seizures. Studies concerning any type of epilepsy surgery or pathology were accepted, excluding those related to high-grade malignancies.

RESULTS

The search yielded a total of n = 1,690 records. We included n = 21 studies with a total of n = 1,496 patients, which examined variables associated with long-term seizure outcome. Interictal epileptiform discharge presence/laterality, epileptogenic zone size, APOS frequency, and history of generalized tonic-clonic seizures, head trauma, or encephalitis were associated with seizure outcome. Ictal expression and timing of seizure recurrence appeared less relevant. However, these associations are uncertain due to conflicting results between studies, likely due to small sample sizes, a limited reporting of secondary variables, and heterogeneity in study population and methodology.

CONCLUSIONS

The variability in clinical outcome following APOS highlights the need for a refined classification of postoperative seizures. Future research should focus on constructing and validating a multifactorial model integrating EEG-derived variables, APOS frequency, and medical history to more accurately predict long-term seizure outcome following resective epilepsy surgery.

Predictors of Surgical Failure in Pediatric Lesional Temporal Lobe Epilepsy Surgery

BACKGROUND

Epilepsy surgery can potentially cure pharmacoresistant temporal lobe epilepsy (TLE) in children. However, surgical failures, where patients continue to experience seizures, still exist. We evaluated outcomes in pediatric patients after resective temporal lobe surgery to identify risk factors for failure.

METHODS

Data on pediatric patients with TLE who underwent surgery were prospectively collected at our institution. Minimum follow-up (FU) was three years after surgery. Resections were stratified into extended resections, i.e., anterior temporal lobectomies, and sparing resections, i.e., lesionectomies and selective amygdalohippocampectomies. Ongoing seizures and relapses within the first three years were considered surgical failures.

RESULTS

We included 96 patients after 43 sparing and 52 extended resections from 1993 to 2019 with a median FU of 10.1 years (range 3.0 to 28.3 years). Pathohistology most frequently revealed epilepsy-associated tumors (44.8%), hippocampal sclerosis (37.5%), and focal cortical dysplasias (12.5%). One year postoperatively, 69.8% were seizure free, increasing to 78.5% after five and 72.9% after 10 years. Sparing resections increased the odds for surgical failure in a multivariate analysis (odds ratio: 4.63, P = 0.006). Preoperative focal onset to bilateral tonic-clonic seizures increased the likelihood of seizure relapses (hazard ratio: 3.89, P = 0.006) and contributed to higher odds of surgical failure (odds ratio: 2.79, P = 0.002).

CONCLUSIONS

Pediatric patients with TLE undergoing surgery have high rates of long-lasting favorable seizure outcomes. Resection strategy is a prognostic factor for early surgical success in favor of larger resections. Relapses were more frequent in children with focal onset to bilateral tonic-clonic seizures beforesurgery.

Outcome predictors in patients with temporal lobe epilepsy after temporal resective surgery

BACKGROUND

Temporal lobe epilepsy is one of the most common types of partial epilepsy. Although surgical treatment has led to significant improvements in seizure-free rates, nearly one-third of patients still have poor seizure control after surgery. Moreover, the long-term outcome is less favorable compared to short-term outcome, with 48-58% of patients experiencing seizures five years after surgery. The aim of this study was to investigate the surgical outcomes and the predictive value of prognostic factors associated with poor surgical outcomes in temporal lobe epilepsy patients receiving surgery.

METHODS

We retrospectively reviewed 94 patients undergoing temporal resective surgery in the Epilepsy Center of Guangdong Provincial Hospital of Traditional Chinese Medicine between July 2016 and July 2020. Patient information including age, gender, personal and family history, as well as preoperative and postoperative clinical data (clinical type and duration of disease) was collected.

RESULTS

The differences of postoperative clinical efficacy in both seizure free group and non-seizure free group patients were observed. A log-rank test was used for univariate analysis, and a Cox proportional hazard model was used for multivariate analysis. Ninety-four patients were followed up for at least 1 years. At 12 months of follow-up, 71 (75.5%) patients achieved Engel class I, 5 (5.3%) patients were classified as Engel class II, 5 (5.3%) patients were classified as Engel class III, and 13 (13.8%) patients were classified as Engel class IV. Univariate analysis and multivariate Cox regression analysis indicated that the postoperative EEG abnormalities were significantly correlated with seizure recurrence and were significant independent predictive factors, with a hazard ratio of 12.940.

CONCLUSIONS

The relapse rate in our study was similar to commonly reported overall rates in temporal lobe epilepsy patients receiving surgery. Anterior temporal lobectomy is a reliable treatment option for temporal lobe epilepsy patients. Postoperative electroencephalograph abnormalities are independent risk factors for poor surgical prognosis.

Defining benchmark outcomes for mesial temporal lobe epilepsy surgery: A global multicenter analysis of 1119 cases

OBJECTIVE

Benchmarking has been proposed to reflect surgical quality and represents the highest standard reference values for desirable results. We sought to determine benchmark outcomes in patients after surgery for drug-resistant mesial temporal lobe epilepsy (MTLE).

METHODS

This retrospective multicenter study included patients who underwent MTLE surgery at 19 expert centers on five continents. Benchmarks were defined for 15 endpoints covering surgery and epilepsy outcome at discharge, 1 year after surgery, and the last available follow-up. Patients were risk-stratified by applying outcome-relevant comorbidities, and benchmarks were calculated for low-risk ("benchmark") cases. Respective measures were derived from the median value at each center, and the 75th percentile was considered the benchmark cutoff.

RESULTS

A total of 1119 patients with a mean age (range) of 36.7 (1-74) years and a male-to-female ratio of 1:1.1 were included. Most patients (59.2%) underwent anterior temporal lobe resection with amygdalohippocampectomy. The overall rate of complications or neurological deficits was 14.4%, with no in-hospital death. After risk stratification, 377 (33.7%) benchmark cases of 1119 patients were identified, representing 13.6%-72.9% of cases per center and leaving 742 patients in the high-risk cohort. Benchmark cutoffs for any complication, clinically apparent stroke, and reoperation rate at discharge were ≤24.6%, ≤.5%, and ≤3.9%, respectively. A favorable seizure outcome (defined as International League Against Epilepsy class I and II) was reached in 83.6% at 1 year and 79.0% at the last follow-up in benchmark cases, leading to benchmark cutoffs of ≥75.2% (1-year follow-up) and ≥69.5% (mean follow-up of 39.0 months).

SIGNIFICANCE

This study presents internationally applicable benchmark outcomes for the efficacy and safety of MTLE surgery. It may allow for comparison between centers, patient registries, and novel surgical and interventional techniques.

Long-term outcomes of mesial temporal laser interstitial thermal therapy for drug-resistant epilepsy and subsequent surgery for seizure recurrence: a multi-centre cohort study

BACKGROUND

Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) is a minimally invasive alternative to surgical resection for drug-resistant mesial temporal lobe epilepsy (mTLE). Reported rates of seizure freedom are variable and long-term durability is largely unproven. Anterior temporal lobectomy (ATL) remains an option for patients with MRgLITT treatment failure. However, the safety and efficacy of this staged strategy is unknown.

METHODS

This multicentre, retrospective cohort study included 268 patients consecutively treated with mesial temporal MRgLITT at 11 centres between 2012 and 2018. Seizure outcomes and complications of MRgLITT and any subsequent surgery are reported. Predictive value of preoperative variables for seizure outcome was assessed.

RESULTS

Engel I seizure freedom was achieved in 55.8% (149/267) at 1 year, 52.5% (126/240) at 2 years and 49.3% (132/268) at the last follow-up ≥1 year (median 47 months). Engel I or II outcomes were achieved in 74.2% (198/267) at 1 year, 75.0% (180/240) at 2 years and 66.0% (177/268) at the last follow-up. Preoperative focal to bilateral tonic-clonic seizures were independently associated with seizure recurrence. Among patients with seizure recurrence, 14/21 (66.7%) became seizure-free after subsequent ATL and 5/10 (50%) after repeat MRgLITT at last follow-up≥1 year.

CONCLUSIONS

MRgLITT is a viable treatment with durable outcomes for patients with drug-resistant mTLE evaluated at a comprehensive epilepsy centre. Although seizure freedom rates were lower than reported with ATL, this series represents the early experience of each centre and a heterogeneous cohort. ATL remains a safe and effective treatment for well-selected patients who fail MRgLITT.

Extent of piriform cortex resection in children with temporal lobe epilepsy

OBJECTIVE

A greater extent of resection of the temporal portion of the piriform cortex (PC) has been shown to be associated with higher likelihood of seizure freedom in adults undergoing anterior temporal lobe resection (ATLR) for drug-resistant temporal lobe epilepsy (TLE). There have been no such studies in children, therefore this study aimed to investigate this association in a pediatric cohort.

METHODS

A retrospective, neuroimaging cohort study of children with TLE who underwent ATLR between 2012 and 2021 was undertaken. The PC, hippocampal and amygdala volumes were measured on the preoperative and postoperative T1-weighted MRI. Using these volumes, the extent of resection per region was compared between the seizure-free and not seizure-free groups.

RESULTS

In 50 children (median age 9.5 years) there was no significant difference between the extent of resection of the temporal PC in the seizure-free (median = 50%, n = 33/50) versus not seizure-free (median = 40%, n = 17/50) groups (p = 0.26). In a sub-group of 19 with ipsilateral hippocampal atrophy (quantitatively defined by ipsilateral-to-contralateral asymmetry), the median extent of temporal PC resection was greater in children who were seizure-free (53%) versus those not seizure-free (19%) (p = 0.009).

INTERPRETATION

This is the first study demonstrating that, in children with TLE and hippocampal atrophy, more extensive temporal PC resection is associated with a greater chance of seizure freedom-compatible with an adult series in which 85% of patients had hippocampal sclerosis. In a combined group of children with and without hippocampal atrophy, the extent of PC resection was not associated with seizure outcome, suggesting different epileptogenic networks within this cohort.

Opinions about epilepsy surgery in adults with epilepsy

OBJECTIVE

The goal of the current study was to investigate the opinions of adult patients with epilepsy (PWE) with regard to the application of epilepsy surgery for their condition.

METHODS

We surveyed all the consecutive adult PWE with at least one year history of epilepsy who were referred to our neurology clinics (Shiraz University of Medical Sciences) from September 2022 until January 2023. Using a questionnaire, the degree of acceptance of epilepsy surgery was measured depending on the chance of seizure freedom and risk for surgery complications.

RESULTS

In total, 393 adult PWE participated in the study; 180 patients (45.8%) expressed that they would be willing to have surgery if their epilepsy doctor told them that brain surgery was guaranteed to stop their seizures, without regard to the potential surgery complications. The most common reasons for the patients to be willing to have epilepsy surgery were as follows: to become seizure-free and to be able to discontinue their antiseizure medications. The most common reasons for the patients not to be willing to have epilepsy surgery were as follows: feeling of having the seizures under the control with antiseizure medications and fear of surgery complications.

CONCLUSION

Many patients with epilepsy are willing to have epilepsy surgery if their physician presented epilepsy surgery to them as an established safe and effective treatment option. The important values and priorities of PWE must be considered when designing epilepsy surgery educational materials and programs for preoperative counseling for PWE with drug-resistant seizures.

Predictors of surgical outcomes in patients with drug-resistant temporal lobe epilepsy

Aim. To identify predictors of surgical outcomes in patients with drug-resistant temporal lobe epilepsy in a multivariate model.

Materials and methods. Aretrospective study included 69 patients with drug-resistant temporal lobe epilepsy who underwent microsurgical anterior temporal lobectomy. The study included 31 (45%) men and 38 (55%) women. The median age was 28 (21; 36). Surgical treatment outcomes were assessed at 6, 12, 36, and 60 months after surgical intervention according to the Engel Epilepsy Surgery Outcome Scale. Logistic regression equations were calculated, a ROC curve was constructed, and odds ratio (OR) with 95% confidence interval (CI), sensitivity, specificity, area under the ROC curve (AUC) were calculated.

Results. In all assessed time periods, 88.3–93.0% of patients had outcomes consistent with Engel classes I and II. The distribution of patients by outcome classes did not change statistically significantly over the entire follow-up period. There were the following predictors of high efficacy of surgical treatment at 6 months after surgery: relatively shorter duration of active disease course (OR 0.719, 95%, CI: 0.437–0.966, p < 0.05), absence of status epilepticus (OR 0.048, 95% CI: 0.002–0.472, p < 0.05), absence of subdominant foci of irritative activity (OR 0.123, 95% CI: 0.012–0.845, p < 0.01), presence of mesial temporal sclerosis (OR 1008, 95% CI: 21.59–1310851, p < 0.01), a relatively longer resection margin on the temporal lobe (OR 637.32, 95% CI: 5.43–1960062, p < 0.05), lateralization of epileptogenic zone in subdominant hemisphere (OR 0.103, 95% CI 0.004–0.937, p = 0.0532). AUC was 0.957 (0.917–0.997), p < 0.0001; sensitivity 87.5%, and specificity 82.8%.

Conclusion. Independent predictors of the efficacy of microsurgical anterior temporal lobectomy in patients with drug-resistant temporal lobe epilepsy are the following: shorter duration of active disease course, absence of status epilepticus in the history, absence of subdominant foci, presence of mesial temporal sclerosis, a relatively longer resection margin on the temporal lobe, and lateralization of the epileptogenic zone in the temporal lobe of the subdominant hemisphere.

Parents' opinions about epilepsy surgery in children with epilepsy

OBJECTIVE

This survey aimed to investigate the opinions of the parents of children with epilepsy with regard to the application of epilepsy surgery for their children.

METHODS

We surveyed all the parents of children with epilepsy referred to our neurology clinic (Shiraz University of Medical Sciences) in April-July 2022. We collected their opinions about epilepsy surgery based on a predesigned questionnaire. The inclusion criteria included parents of all children with epilepsy (1 to 16 years of age, with at least one-year history of epilepsy, and with at least one drug used in the past 12 months).

RESULTS

In total, 472 people participated in the study; 277 participants (58.7%) were willing to have epilepsy surgery for their child; the most common reason was to be able to discontinue the drugs. Sex (male), age (younger), and education (college) of the parents had significant associations with the parental willingness to have surgery for their children. The patient's drug regimen (polytherapy) and history of ictal injury (in the child) also had significant associations with the parental willingness to have surgery for the children.

CONCLUSION

Most parents of children with epilepsy are willing to have epilepsy surgery for their children if their physician presents epilepsy surgery to them as an established, safe, and effective treatment option. Patient and parental-related factors should be considered when designing educational materials and programs for preoperative counseling for the parents of children with drug-resistant seizures.