Epilepsy duration and seizure outcome in epilepsy surgery: A systematic review and meta-analysis

Disconnection surgery to cure or palliate medically intractable epileptic spasms: a retrospective study

OBJECTIVE

Surgery is a treatment option for medically intractable epileptic spasms (ESs). However, outcomes of ES after surgery are not well understood, especially when surgeries aimed at seizure palliation are included. The purpose of the present study was to 1) investigate the proportion of favorable postoperative ES outcomes, 2) explore the preoperative factors related to favorable postoperative ES outcomes, and 3) examine the timing of ES recurrence after disconnection surgeries, including both curative and palliative indications.

METHODS

This retrospective study included patients who underwent disconnection surgery for medically intractable ES at the authors' institution between May 2015 and April 2021. Patients with suggested focal-onset ES based on preoperative evaluations initially underwent lobar disconnection. Patients with suggested generalized or unknown-onset ES underwent corpus callosotomy (CC). If evaluations after initial CC showed focalized or lateralized change, they were considered secondarily revealed focal-onset ES, and lobar disconnection was performed. ES outcomes were evaluated using the International League Against Epilepsy classification. ES outcomes were divided into classes 1-4 as favorable outcomes and classes 5 and 6 as unfavorable outcomes. The relationship between the favorable postoperative ES outcomes and the following preoperative factors was analyzed: sex, age at onset (< or > 1 year), duration between seizure onset and initial surgery (< or > 2 years), type of seizure at onset (ES or others), presence of other types of seizures, substrate, hypsarrhythmia, and MRI abnormalities. The period between the last surgery and ES recurrence was also analyzed.

RESULTS

A total of 41 patients were included, of whom 75.6% achieved favorable ES outcomes. A longer seizure duration between seizure onset and initial surgery, presence of hypsarrhythmia, and positive MRI findings led to poorer postoperative ES outcomes (p = 0.0028, p = 0.0041, and p = 0.0241, respectively). A total of 60.9% of patients had ES recurrence during the follow-up period, and their ES recurred within 13 months after the last surgery.

CONCLUSIONS

Disconnection surgery is an effective treatment option for medically intractable ES, even when the preoperative evaluation suggests a generalized or unknown onset.

Quantitative Analysis of Visually Reviewed Normal Scalp EEG Predicts Seizure Freedom Following Anterior Temporal Lobectomy

Objective

Anterior temporal lobectomy (ATL) is a widely performed and successful intervention for drug‐resistant temporal lobe epilepsy (TLE). However, up to one third of patients experience seizure recurrence within 1 year after ATL. Despite the extensive literature on presurgical electroencephalography (EEG) and magnetic resonance imaging (MRI) abnormalities to prognosticate seizure freedom following ATL, the value of quantitative analysis of visually reviewed normal interictal EEG in such prognostication remains unclear. In this retrospective multicenter study, we investigate whether machine learning analysis of normal interictal scalp EEG studies can inform the prediction of postoperative seizure freedom outcomes in patients who have undergone ATL.

Methods

We analyzed normal presurgical scalp EEG recordings from 41 Mayo Clinic (MC) and 23 Cleveland Clinic (CC) patients. We used an unbiased automated algorithm to extract eyes closed awake epochs from scalp EEG studies that were free of any epileptiform activity and then extracted spectral EEG features representing (a) spectral power and (b) interhemispheric spectral coherence in frequencies between 1 and 25 Hz across several brain regions. We analyzed the differences between the seizure‐free and non–seizure‐free patients and employed a Naïve Bayes classifier using multiple spectral features to predict surgery outcomes. We trained the classifier using a leave‐one‐patient‐out cross‐validation scheme within the MC data set and then tested using the out‐of‐sample CC data set. Finally, we compared the predictive performance of normal scalp EEG‐derived features against MRI abnormalities.

Results

We found that several spectral power and coherence features showed significant differences correlated with surgical outcomes and that they were most pronounced in the 10–25 Hz range. The Naïve Bayes classification based on those features predicted 1‐year seizure freedom following ATL with area under the curve (AUC) values of 0.78 and 0.76 for the MC and CC data sets, respectively. Subsequent analyses revealed that (a) interhemispheric spectral coherence features in the 10–25 Hz range provided better predictability than other combinations and (b) normal scalp EEG‐derived features provided superior and potentially distinct predictive value when compared with MRI abnormalities (>10% higher F1 score).

Significance

These results support that quantitative analysis of even a normal presurgical scalp EEG may help prognosticate seizure freedom following ATL in patients with drug‐resistant TLE. Although the mechanism for this result is not known, the scalp EEG spectral and coherence properties predicting seizure freedom may represent activity arising from the neocortex or the networks responsible for temporal lobe seizure generation within vs outside the margins of an ATL.

Surgeon-Led Initiatives to Increase Access to Surgical Treatment of Epilepsy at an Academic Level 4 Epilepsy Center: An Observational Cohort Study

BACKGROUND

Underutilization of surgical treatment for epilepsy is multifactorial, and the multidisciplinary nature of caring for these patients represents a significant hurdle in expanding surgical treatment of epilepsy.

OBJECTIVE

To develop internal and external surgical referral relationships for patients with medically refractory epilepsy with the goal of improving access to care.

METHODS

To expand access to surgical epilepsy treatment at University of California (UC)-Irvine, 4 broad approaches focused on developing referral relationships and process improvement of surgical evaluation were undertaken in 2015 and 2016. The authors performed a retrospective review of all surgical epilepsy case referrals of the senior author from 2014 through 2020.

RESULTS

Epilepsy surgical volume at UC-Irvine increased from an average of 5.2 cases annually to 32 cases in the first year (2015) of implementation. There was continued case volume growth from 2015 through 2020 to 52 procedures in the most recent year (P = .03). Hospital payments for epilepsy procedures increased from $1.09M in 2015 to $2.02M and $1.8M in 2019 and 2020 (P < .01), respectively, while maintaining a diverse payer mix. 79.4% of these patients did not have a previously established option for surgical epilepsy care.

CONCLUSION

We outline strategies that level 4 epilepsy centers may use to strengthen collaborations and improve patient access for surgical epilepsy treatment. Increased collaboration can both improve the number of patients with epilepsy with access to specialized surgical care and produce reimbursement benefits for the centers caring for these patients, regardless of insurance source.

Long-term seizure and psychiatric outcomes following laser ablation of mesial temporal structures

OBJECTIVE

Postsurgical seizure outcome following laser interstitial thermal therapy (LiTT) for the management of drug-resistant mesial temporal lobe epilepsy (MTLE) has been limited to 2 years. Furthermore, its impact on presurgical mood and anxiety disorders has not been investigated. The objectives of this study were (1) to identify seizure outcome changes over a period ranging from 18 to 81 months; (2) to investigate the seizure-free rate in the last follow-up year; (3) to identify the variables associated with seizure freedom; and (4) to identify the impact of LiTT on presurgical mood and anxiety disorders.

METHODS

Medical records of all patients who underwent LiTT for MTLE from 2013 to 2019 at the University of Miami Comprehensive Epilepsy Center were retrospectively reviewed. Demographic, epilepsy-related, cognitive, psychiatric, and LiTT-related data were compared between seizure-free (Engel Class I) and non-seizure-free (Engel Class II + III + IV) patients. Statistical analyses included univariate and multivariate stepwise logistic regression analyses.

RESULTS

Forty-eight patients (mean age = 43 ± 14.2 years, range = 21-78) were followed for a mean period of 50 ± 20.7 months (range = 18-81); 29 (60.4%) achieved an Engel Class I outcome, whereas 11 (22.9%) had one to three seizures/year. Seizure-freedom rate decreased from 77.8% to 50% among patients with 24- and >61-month follow-up periods, respectively. In the last follow-up year, 83% of all patients were seizure-free. Seizure freedom was associated with having mesial temporal sclerosis (MTS), no presurgical focal to bilateral tonic-clonic seizures, and no psychopathology in the last follow-up year. Presurgical mood and/or anxiety disorder were identified in 30 patients (62.5%) and remitted after LiTT in 19 (62%).

SIGNIFICANCE

LiTT appears to be a safe and effective surgical option for treatment-resistant MTLE, particularly among patients with MTS. Remission of presurgical mood and anxiety disorders can also result from LiTT.

Executive deficits in neuropsychological testing differentiate between autoimmune temporal lobe epilepsy caused by limbic encephalitis and temporal lobe epilepsies with non-autoimmune etiologies

OBJECTIVE

Patients with temporal lobe epilepsy caused by autoimmune limbic encephalitis (AI-TLE) clinically resemble patients with temporal lobe epilepsy with non-autoimmune etiologies (NAI-TLE) but have a different prognosis and require specific adjusted therapies. The objective of this study was to investigate whether patients with these forms of TLE can be discerned by means of neuropsychological assessment.

METHODS

Data from 103 patients with TLE (n = 39 with AI-TLE and n = 64 with NAI-TLE, including n = 39 with hippocampal sclerosis [HS] and n = 25 with low-grade epilepsy-associated tumors [LEAT]) and 25 healthy controls who underwent comprehensive neuropsychological assessments were analyzed retrospectively. The neuropsychological characteristics (mean z-scores) were compared between groups using one-way ANOVA, independent-samples t-tests, and discriminant function analysis (DFA).

RESULTS

The groups of patients with TLE showed significantly lower performance in attentional, visuospatial, verbal memory, and nonverbal memory functions compared to the healthy controls. Solely in the domain of executive functions, patients with AI-TLE showed significantly lower performance compared to patients with NAI-TLE regarding cognitive flexibility (p = 0.002) and verbal fluency (p = 0.018). Moreover, the DFA identified cognitive flexibility to be most appropriate to differentiate between patients with AI-TLE and patients with HS. Group membership was correctly predicted through neuropsychological assessment alone in 66.7% of the patients using cross-validation.

SIGNIFICANCE

We were able to identify specific neuropsychological features in our sample of patients with AI-TLE. While all groups of patients with TLE showed the expected TLE-typical memory impairments, significant differences between patients with AI-TLE and NAI-TLE were present only in the cognitive domain of executive functions. This finding facilitates the choice of suitable psychometric tests in clinical routine and, thus, the clinical differential diagnosis between these entities.

Markov modelling of treatment response in a 30-year cohort study of newly diagnosed epilepsy

People with epilepsy have variable and dynamic trajectories in response to antiseizure medications. Accurately modelling long-term treatment response will aid prognostication at the individual level and health resource planning at the societal level. Unfortunately, a robust model is lacking. We aimed to develop a Markov model to predict the probability of future seizure-freedom based on current seizure state and number of antiseizure medication regimens trialled. We included 1,795 people with newly diagnosed epilepsy who attended a specialist clinic in Glasgow, Scotland, between July 1982 and October 2012. They were followed up until October 2014 or death. We developed a simple Markov model, based on current seizure state only, and a more detailed model, based on both current seizure state and number of antiseizure medication regimens trialled. Sensitivity analyses were performed for the regimen-based states model to examine the effect of regimen changes due to adverse effects. The model was externally validated in a separate cohort of 455 newly diagnosis epilepsy patients seen in Perth, Australia, between May 1999 and May 2016. Our models suggested that once seizure-freedom was achieved, it was likely to persist, regardless of the number of antiseizure medications trialled to reach that point. The likelihood of achieving long-term seizure-freedom was highest with the first antiseizure medication regimen, at approximately 50%. The chance of achieving seizure-freedom fell with subsequent regimens. Fluctuations between seizure-free and not seizure-free states were highest earlier on, but decreased with chronicity of epilepsy. Seizure-freedom/recurrence risk tables were constructed with these probability data, similar to cardiovascular risk tables. Sensitivity analyses showed that the general trends and conclusions from the base model were maintained despite perturbing the model and input data with regimen changes due to adverse effects. Quantitative comparison with the external validation cohort showed excellent consistency at year 1, good at year 3 and moderate at year 5. Quantitative models, as used in this study, can provide pertinent clinical insights that are not apparent from simple statistical analysis alone. Attaining seizure freedom at any time in a patient's epilepsy journey will confer durable benefit. Seizure-freedom risk tables may be used to individualise the prediction of future seizure control trajectory.

Machine learning models for decision support in epilepsy management: A critical review

PURPOSE

There remain major challenges for the clinician in managing patients with epilepsy effectively. Choosing anti-seizure medications (ASMs) is subject to trial and error. About one-third of patients have drug-resistant epilepsy (DRE). Surgery may be considered for selected patients, but time from diagnosis to surgery averages 20 years. We reviewed the potential use of machine learning (ML) predictive models as clinical decision support tools to help address some of these issues.

METHODS

We conducted a comprehensive search of Medline and Embase of studies that investigated the application of ML in epilepsy management in terms of predicting ASM responsiveness, predicting DRE, identifying surgical candidates, and predicting epilepsy surgery outcomes. Original articles addressing these 4 areas published in English between 2000 and 2020 were included.

RESULTS

We identified 24 relevant articles: 6 on ASM responsiveness, 3 on DRE prediction, 2 on identifying surgical candidates, and 13 on predicting surgical outcomes. A variety of potential predictors were used including clinical, neuropsychological, imaging, electroencephalography, and health system claims data. A number of different ML algorithms and approaches were used for prediction, but only one study utilized deep learning methods. Some models show promising performance with areas under the curve above 0.9. However, most were single setting studies (18 of 24) with small sample sizes (median number of patients 55), with the exception of 3 studies that utilized large databases and 3 studies that performed external validation. There was a lack of standardization in reporting model performance. None of the models reviewed have been prospectively evaluated for their clinical benefits.

CONCLUSION

The utility of ML models for clinical decision support in epilepsy management remains to be determined. Future research should be directed toward conducting larger studies with external validation, standardization of reporting, and prospective evaluation of the ML model on patient outcomes.

Palliative Epilepsy Surgery Procedures in Children

Surgical treatment of epilepsy typically focuses on identification of a seizure focus with subsequent resection and/or disconnection to "cure" the patient's epilepsy and achieve seizure freedom. Palliative epilepsy surgery modalities are efficacious in improving seizure frequency, severity, and quality of life. In this paper, we review palliative epilepsy surgical options for children: vagus nerve stimulation, responsive neurostimulation, deep brain stimulation, hemispherotomy, corpus callosotomy, lobectomy and/or lesionectomy and multiple subpial transection. Reoperation after surgical resection should also be considered. If curative resection is not a viable option for seizure freedom, these methods should be considered with equal emphasis and urgency in the treatment of drug-resistant epilepsy.

Epilepsy surgery in children under 3 years of age: surgical and developmental outcomes

OBJECTIVE

Pediatric epilepsy surgery is known to be effective, but early surgery in infancy is not well characterized. Extensive cortical dysplasia, such as hemimegalencephaly, can cause refractory epilepsy shortly after birth, and early surgical intervention is indicated. However, the complication rate of early pediatric surgery is significant. In this study, the authors assessed the risk-benefit balance of early pediatric epilepsy surgery as relates to developmental outcomes.

METHODS

This is a retrospective descriptive study of 75 patients who underwent their first curative epilepsy surgery at an age under 3 years at the authors' institution between 2006 and 2019 and had a minimum 1-year follow-up of seizure and developmental outcomes. Clinical information including surgical complications, seizure outcomes, and developmental quotient (DQ) was collected from medical records. The effects of clinical factors on DQ at 1 year after surgery were evaluated.

RESULTS

The median age at surgery was 6 months, peaking at between 3 and 4 months. Operative procedures included 27 cases of hemispherotomy, 19 cases of multilobar surgery, and 29 cases of unilobar surgery. Seizure freedom was achieved in 82.7% of patients at 1 year and in 71.0% of patients at a mean follow-up of 62.8 months. The number of antiseizure medications (ASMs) decreased significantly after surgery, and 19 patients (30.6%) had discontinued their ASMs by the last follow-up. Postoperative complications requiring cerebrospinal fluid (CSF) diversion surgery, such as hydrocephalus and cyst formation, were observed in 13 patients (17.3%). The mean DQ values were 74.2 ± 34.3 preoperatively, 60.3 ± 23.3 at 1 year after surgery, and 53.4 ± 25.1 at the last follow-up. Multiple regression analysis revealed that the 1-year postoperative DQ was significantly influenced by preoperative DQ and postoperative seizure freedom but not by the occurrence of any surgical complication requiring CSF diversion surgery.

CONCLUSIONS

Early pediatric epilepsy surgery has an acceptable risk-benefit balance. Seizure control after surgery is important for postoperative development.

Parental experience and decision-making for epilepsy surgery: A systematic review of qualitative and quantitative studies

OBJECTIVE

In selected children with drug-resistant epilepsy (DRE), epilepsy surgery is the most effective treatment option, but unfortunately remains highly underutilized. One of the critical obstacles to pursuing surgical therapy is parents/caregivers' decision against surgery or to delay the surgery until no other treatment option exists. Understanding caregiver decision-making around epilepsy surgery can improve patient/caregiver experience and satisfaction while facilitating appropriate decision-making that optimizes clinical outcomes. The current review systematically explores the existing evidence on caregiver experience and the decision-making process toward epilepsy surgery.

METHODS

The study was conducted as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for systematic literature review. Databases (PubMed Ovid, PubMed Medline, Web of Science, CINHAL, PsycInfo) were systematically searched in February 2021 using a defined search strategy and inclusion/exclusion criteria. Total 1304 articles were screened for titles and abstracts, and 54 full-text articles were retrieved for further assessment. We included 14 articles with critical quality assessment using two different tools for qualitative and questionnaire-based studies. A qualitative content analysis was performed to characterize caregiver experience, perception, and decision-making toward favorable or unfavorable opinions of epilepsy surgery.

RESULTS

Four concepts generated from the analysis may act as enablers or barriers to decision-making around epilepsy surgery: 1. Access to knowledge and information, 2. Communication and coordination issues, 3. Caregiver's emotional state, and 4. Socioeconomic effects. Subsequently, we provided a narrative synthesis of practice recommendations and a conceptual framework to adopt multi-pronged interventions to overcome identified diverse barriers to effective caregiver decision-making.

CONCLUSION

Multiple influences impact how caregivers decide about epilepsy surgery for their children, with no single factor identified as the primary driver for or against surgery. However, limited research has explored these influences. Future studies should focus on quantitatively examining factors to identify significant variables most likely to influence caregiver decision-making, ultimately overcoming barriers that limit utilization of epilepsy surgery as a treatment tool.

Knowledge, attitude, and barriers for epilepsy surgery: A survey among resident doctors in a tertiary care center in India

BACKGROUND

Knowledge and attitude of doctors toward epilepsy surgery are essential for management and timely referral of people with Drug refractory epilepsy (DRE). This study aimed at analyzing knowledge, attitude, and barriers for epilepsy surgery among medical residents.

METHODS

A survey consisting of 16 statements in a Likert-like scale and one open-ended question was conducted among residents joining different postgraduate courses after MBBS (GR) and super-specialty courses after MD (PG) within 2 months of joining the institute. PGs with a postgraduate degree in internal medicine, pediatrics, or psychiatry were included. Demographic data were analyzed using descriptive statistics. Difference in response to the survey statements was analyzed using independent t test.

RESULTS

115 participated in the survey of which 97 were GRs. Participants belonged to 22 different states and 3 were foreign nationals. 45% of participants did not know the definition of DRE. There was a difference of opinion among GRs and PGs regarding surgery as a treatment option for epilepsy and feasibility of epilepsy surgery in children (p < .05). PGs were more confident in treating PWE and preferred to refer people with DRE to a higher center early (p < .05). Lack of knowledge was the commonest barrier for epilepsy surgery.

CONCLUSION

A substantial number of participants lacked the basic knowledge of DRE and epilepsy surgery. Lack of knowledge was perceived to be the commonest barrier for epilepsy surgery. Dissemination of basic knowledge and development of protocols for identification and referral of people with DRE are the need of the hour.

Data-driven electrophysiological feature based on deep learning to detect epileptic seizures

Objective. To identify a new electrophysiological feature characterising the epileptic seizures, which is commonly observed in different types of epilepsy.Methods. We recorded the intracranial electroencephalogram (iEEG) of 21 patients (12 women and 9 men) with multiple types of refractory epilepsy. The raw iEEG signals of the early phase of epileptic seizures and interictal states were classified by a convolutional neural network (Epi-Net). For comparison, the same signals were classified by a support vector machine (SVM) using the spectral power and phase-amplitude coupling. The features learned by Epi-Net were derived by a modified integrated gradients method. We considered the product of powers multiplied by the relative contribution of each frequency amplitude as a data-driven epileptogenicity index (d-EI). We compared the d-EI and other conventional features in terms of accuracy to detect the epileptic seizures. Finally, we compared the d-EI among the electrodes to evaluate its relationship with the resected area and the Engel classification.Results. Epi-Net successfully identified the epileptic seizures, with an area under the receiver operating characteristic curve of 0.944 ± 0.067, which was significantly larger than that of the SVM (0.808 ± 0.253,n =21;p =0.025). The learned iEEG signals were characterised by increased powers of 17-92 Hz and >180 Hz in addition to decreased powers of other frequencies. The proposed d-EI detected them with better accuracy than the other iEEG features. Moreover, the surgical resection of areas with a larger increase in d-EI was observed for all nine patients with Engel class ⩽1, but not for the 4 of 12 patients with Engel class >1, demonstrating the significant association with seizure outcomes.Significance.We derived an iEEG feature from the trained Epi-Net, which identified the epileptic seizures with improved accuracy and might contribute to identification of the epileptogenic zone.

Long-Term Neuropsychological Outcomes Following Temporal Lobe Epilepsy Surgery: An Update of the Literature

We present an update of the literature concerning long-term neuropsychological outcomes following surgery for refractory temporal lobe epilepsy (TLE). A thorough search was conducted through the PubMed and Medline electronic databases for studies investigating neuropsychological function in adult patients undergoing resective TLE surgery and followed for a mean/median > five years period. Two independent reviewers screened citations for eligibility and assessed relevant studies for the risk of bias. We found eleven studies fulfilling the above requirements. Cognitive function remained stable through long-term follow up despite immediate post-surgery decline; a negative relation between seizure control and memory impairment has emerged and a possible role of more selective surgery procedures is highlighted.

Outcome of epilepsy surgery in lesional epilepsy: Experiences from a developing country

BACKGROUND

Our aim was to report the postoperative seizure outcome and associated factors in patients with lesional epilepsy, in a low-income setting.

METHODS

This longitudinal prospective study included patients who underwent epilepsy surgery at Kashani Comprehensive Epilepsy Center between 2014 and 2019. Post-surgical outcomes were reported according to the Engel score, and patients were classified into two groups of seizure free (SF) and not-seizure free (NSF).

RESULTS

A total of 148 adult patients, with a mean age of 30.45 ± 9.23 years were included. The SF outcome was reported in 86.5% of patients and antiepileptic drugs (AEDs) were reduced or discontinued in 45.9%. The mean follow-up duration was 26.7 ± 14.9 months. Temporal lobe lesions (76.3%) and mesial temporal sclerosis (MTS) (56.7%) were the most frequent etiologies. Temporal lesion (Incidence relative risk (IRR): 1.76, 95% CI [1.08-2.87], p = 0.023), prior history of CNS infection (IRR:1.18, 95% CI [1.03-1.35], p = 0.019), use of intra-operative ECoG (IRR:1.73, 95% CI [1.06-2.81], p = 0.028), and absence of IEDs in postoperative EEG (IRR: 1.41, 95% CI [1.18-1.70], p < 0.001) were positive predictors for a favorable outcome.

CONCLUSION

Many patients with drug-resistant lesional epilepsy showed a favorable response to surgery. We believe that resective epilepsy surgery in low-income settings is a major treatment option. The high frequency of patients with drug-resistant epilepsy in developing countries is associated with high rates of morbidity and mortality. Hence, strategies to increase access to epilepsy surgery in these settings are urgently needed.

What is the effect of delays in access to specialist epilepsy care on patient outcomes? A systematic review and meta-analysis

OBJECTIVE

To determine the association between delays in access to specialist epilepsy care and patient outcomes.

METHODS

Three databases were searched using eligibility criteria related to the concepts of timely access, epilepsy, and clinical outcome. Comparative data on patient outcomes by time to treatment was required for inclusion. Studies were selected independently by two researchers who reviewed title/abstract, then full text articles. Data were extracted and risk of bias was evaluated. Results were synthesized in random effects model meta-analyses, and strength of the body of evidence was evaluated. Descriptive analysis was conducted for studies not included in meta-analyses.

RESULTS

Thirty-five studies, reported in 40 papers, were included. The studies investigated impact of delays in diagnosis, commencement of medication, or surgery for children and adults. Early diagnosis and access to specialist neurology care was associated with improvements in seizure status, development, and/or intelligence quotients. Meta-analyses provided low to high certainty evidence of increased odds of improved seizure outcome with early commencement of medication depending on follow-up period and individual risk factors. There was moderate certainty evidence that people with favorable seizure outcomes wait less time (MD 2.8 years, 95% CI 1.7-3.9) for surgery compared to those with unfavorable outcomes.

SIGNIFICANCE

This review provides evidence that earlier access to specialist epilepsy care for diagnosis, commencement of medication, and surgery is associated with better patient outcomes.

Association of Epilepsy Surgery With Changes in Imaging-Defined Brain Age

Objective

To determine whether surgery in patients with mesial temporal lobe epilepsy (mTLE) is associated with reduced brain-predicted age as a neural marker overall brain health, we compared brain-predicted and chronologic age difference (brain age gap estimation [BrainAGE]) in patients before and after surgery with healthy controls.

Methods

We acquired 3D T1-weighted MRI scans for 48 patients with mTLE before and after temporal lobe surgery to estimate brain age using a gaussian processes regression model. We examined BrainAGE before and after surgery controlling for brain volume change, comparing patients to 37 age- and sex-matched controls.

Results

Preoperatively, patients showed an increased BrainAGE of more than 7 years compared to controls. However, surgery was associated with a mean BrainAGE reduction of 5 years irrespective of whether or not surgery resulted in complete seizure freedom. We observed a lateralization effect as patients with left mTLE had BrainAGE values that more closely resembled control group values following surgery.

Conclusions

Our findings suggest that while morphologic brain alterations linked to accelerated aging have been observed in mTLE, surgery may be associated with changes that reverse such alterations in some patients. This work highlights the advantages of resective surgery on overall brain health in patients with refractory focal epilepsy.

Connectivity within regions characterizes epilepsy duration and treatment outcome

Finding clear connectome biomarkers for temporal lobe epilepsy (TLE) patients, in particular at early disease stages, remains a challenge. Currently, the whole-brain structural connectomes are analyzed based on coarse parcellations (up to 1,000 nodes). However, such global parcellation-based connectomes may be unsuitable for detecting more localized changes in patients. Here, we use a high-resolution network (~50,000-nodes overall) to identify changes at the local level (within brain regions) and test its relation with duration and surgical outcome. Patients with TLE (n = 33) and age-, sex-matched healthy subjects (n = 36) underwent high-resolution (~50,000 nodes) structural network construction based on deterministic tracking of diffusion tensor imaging. Nodes were allocated to 68 cortical regions according to the Desikan-Killany atlas. The connectivity within regions was then used to predict surgical outcome. MRI processing, network reconstruction, and visualization of network changes were integrated into the NICARA (https://nicara.eu). Lower clustering coefficient and higher edge density were found for local connectivity within regions in patients, but were absent for the global network between regions (68 cortical regions). Local connectivity changes, in terms of the number of changed regions and the magnitude of changes, increased with disease duration. Local connectivity yielded a better surgical outcome prediction (Mean value: 95.39% accuracy, 92.76% sensitivity, and 100% specificity) than global connectivity. Connectivity within regions, compared to structural connectivity between brain regions, can be a more efficient biomarker for epilepsy assessment and surgery outcome prediction of medically intractable TLE.

MRI network progression in mesial temporal lobe epilepsy related to healthy brain architecture

We measured MRI network progression in mesial temporal lobe epilepsy (mTLE) patients as a function of healthy brain architecture. Resting-state functional MRI and diffusion-weighted MRI were acquired in 40 unilateral mTLE patients and 70 healthy controls. Data were used to construct region-to-region functional connectivity, structural connectivity, and streamline length connectomes per subject. Three models of distance from the presumed seizure focus in the anterior hippocampus in the healthy brain were computed using the average connectome across controls. A fourth model was defined using regions of transmodal (higher cognitive function) to unimodal (perceptual) networks across a published functional gradient in the healthy brain. These models were used to test whether network progression in patients increased when distance from the anterior hippocampus or along a functional gradient in the healthy brain decreases. Results showed that alterations of structural and functional networks in mTLE occur in greater magnitude in regions of the brain closer to the seizure focus based on healthy brain topology, and decrease as distance from the focus increases over duration of disease. Overall, this work provides evidence that changes across the brain in focal epilepsy occur along healthy brain architecture.

A meta-analysis on potential modifiers of LITT efficacy for mesial temporal lobe epilepsy: Seizure-freedom seems to fade with time

BACKGROUND

The efficacy of laser interstitial thermal therapy (LITT) in mesial temporal lobe epilepsy (MTLE) has not been clearly established yet.

OBJECTIVE

We conducted a meta-analysis to estimate the efficacy of LITT for TLE (Q1). We also examined the effect of the patient's age (Q2), the total ablation volume (TAV) (Q3), the strength of the MRI unit (Q4), the type of the utilized stereotactic platform (Q5), and the follow up period (Q6) on the patient's outcome.

METHODS

Fixed- and random-effects model meta-analysis was conducted to assess the proportion estimate for each parameter individually. Kaplan-Meier survival-analysis was performed on the available individual patient time-to-first seizure data.

RESULTS

Sixteen studies with 575 patients fulfilled our eligibility criteria. The efficacy of LITT was 0.547 (95%CI: 0.506-0.588). Our statistical analysis had robust results after stratification according to the study population (Q2; p = 0.3418), and the type of the utilized stereotactic platform (Q5; p = 0.286), whereas the role of the TAV (Q3; p = 0.058) and strength of the magnetic field (Q4; p = 0.062) in seizure control remained unclear. The median seizure-free period (Q6) was 0.643 (0.569-0.726) and 0.467 (0.385-0.566) for the one- and the two-year follow up.

CONCLUSIONS

LITT seems to offer a viable alternative to resective surgery, with a moderate efficacy and enduring results. Higher ablation volumes may be associated with improved seizure control, although our current study provided no statistically significant data. More high-quality studies are required to highlight the role of LITT in epilepsy surgery, particularly in the pediatric population.

Postoperative outcomes and surgical ratio at a newly established epilepsy center: The first 100 procedures

PURPOSE

To describe the patients' characteristics, surgical ratio, and outcomes following epilepsy surgery at the newly established Epilepsy Center Frankfurt Rhine-Main.

METHODS

We retrospectively studied the first 100 consecutive patients, including adult (n = 77) and pediatric (n = 23) patients, with drug-resistant epilepsy who underwent resective or ablative surgical procedures at a single, newly established epilepsy center. Patient characteristics, seizure and neuropsychological outcomes, histopathology, complications, and surgical ratio were analyzed.

RESULTS

The mean patient age was 28.8 years (children 10.6 years, adults 34.2 years). The mean epilepsy duration was 11.9 years (children 3.9 years, adults 14.3 years), and the mean follow-up was 1.5 years. At the most recent visit, 64% of patients remained completely seizure free [Engel IA]. The rates of perioperative complications and unexpected new neurological deficits were 5%, each. The proportion of patients showing deficits in one or more cognitive domains increased six months after surgery and decreased to presurgical proportions after two years. Symptoms of depression were significantly decreased and quality of life was significantly increased after surgery. The surgical ratio was 25.3%.

CONCLUSION

Similar postsurgical outcomes were achieved at a newly established epilepsy center compared with long-standing epilepsy centers. The lower time to surgery may reflect a general decrease in time to surgery over the last decade or the improved accessibility of a new epilepsy center in a previously underserved area. The surgical ratio was not lower than reported for established centers.

Epilepsy, dissociative seizures, and mixed: Associations with time to video-EEG

PURPOSE

Video-electroencephalographic monitoring (VEM) is a core component to the diagnosis and evaluation of epilepsy and dissociative seizures (DS)-also known as functional or psychogenic seizures-but VEM evaluation often occurs later than recommended. To understand why delays occur, we compared how patient-reported clinical factors were associated with time from first seizure to VEM (TVEM) in patients with epilepsy, DS or mixed.

METHODS

We acquired data from 1245 consecutive patients with epilepsy, VEM-documented DS or mixed epilepsy and DS. We used multivariate log-normal regression with recursive feature elimination (RFE) to evaluate which of 76 clinical factors interacting with patients' diagnoses were associated with TVEM.

RESULTS

The mean and median TVEM were 14.6 years and 10 years, respectively (IQR 3-23 years). In the multivariate RFE model, the factors associated with longer TVEM in all patients included unemployment and not student status, more antiseizure medications (current and past), concussion, and ictal behavior suggestive of temporal lobe epilepsy. Average TVEM was shorter for DS than epilepsy, particularly for patients with depression, anxiety, migraines, and eye closure. Average TVEM was longer specifically for patients with DS taking more medications, more seizure types, non-metastatic cancer, and with other psychiatric comorbidities.

CONCLUSIONS

In all patients with seizures, trials of numerous antiseizure medications, unemployment and non-student status was associated with longer TVEM. These associations highlight a disconnect between International League Against Epilepsy practice parameters and observed referral patterns in epilepsy. In patients with dissociative seizures, some but not all factors classically associated with DS reduced TVEM.

Recommendations for the treatment of epilepsy in adult and pediatric patients in Belgium: 2020 update

To guide health care professionals in Belgium in selecting the appropriate antiepileptic drugs (AEDs) for their epilepsy patients, a group of Belgian epilepsy experts developed recommendations for AED treatment in adults and children (initial recommendations in 2008, updated in 2012). As new drugs have become available, others have been withdrawn, new indications have been approved and recommendations for pregnant women have changed, a new update was pertinent. A group of Belgian epilepsy experts (partly overlapping with the group in charge of the 2008/2012 recommendations) evaluated the most recent international guidelines and relevant literature for their applicability to the Belgian situation (registration status, reimbursement, clinical practice) and updated the recommendations for initial monotherapy in adults and children and add-on treatment in adults. Recommendations for add-on treatment in children were also included (not covered in the 2008/2012 publications). Like the 2008/2012 publications, the current update also covers other important aspects related to the management of epilepsy, including the importance of early referral in drug-resistant epilepsy, pharmacokinetic properties and tolerability of AEDs, comorbidities, specific considerations in elderly and pregnant patients, generic substitution and the rapidly evolving field of precision medicine.

Regional abnormality of functional connectivity is associated with clinical manifestations in individuals with intractable focal epilepsy

We explored regional functional connectivity alterations in intractable focal epilepsy brains using resting-state functional MRI. Distributions of the network parameters (corresponding to degree and eigenvector centrality) measured at each brain region for all 25 patients were significantly different from age- and sex-matched control data that were estimated by a healthy control dataset (n = 582, 18-84 years old). The number of abnormal regions whose parameters exceeded the mean + 2 SD of age- and sex-matched data for each patient were associated with various clinical parameters such as the duration of illness and seizure severity. Furthermore, abnormal regions for each patient tended to have functional connections with each other (mean ± SD = 58.6 ± 20.2%), the magnitude of which was negatively related to the quality of life. The abnormal regions distributed within the default mode network with significantly higher probability (p < 0.05) in 7 of 25 patients. We consider that the detection of abnormal regions by functional connectivity analysis using a large number of control datasets is useful for the numerical assessment of each patient's clinical conditions, although further study is necessary to elucidate etiology-specific abnormalities.

Would people living with epilepsy benefit from palliative care?

Palliative care (PC) is an approach to the care of persons living with serious illness and their families that focuses on improving quality of life and reducing suffering by addressing complex medical symptoms, psychosocial needs, spiritual well-being, and advance care planning. While PC has traditionally been associated with hospice care for persons with cancer, there is now recognition that PC is relevant to many noncancer diagnoses, including neurologic illness, and at multiple points along the illness journey, not just end of life. Despite the recent growth of the field of neuropalliative care there has been scant attention paid to the relevance of PC principles in epilepsy or the potential for PC approaches to improve outcomes for persons living with epilepsy and their families. We believe this has been a significant oversight and that PC may provide a useful framework for addressing the many sources of suffering facing persons living with epilepsy, for engaging patients and families in challenging conversations, and to focus efforts to improve models of care for this population. In this manuscript we review areas of significant unmet needs where a PC approach may improve patient and family-centered outcomes, including complex symptom management, goals of care, advance care planning, psychosocial support for patient and family and spiritual well-being. When relevant we highlight areas where epilepsy patients may have unique PC needs compared to other patient populations and conclude with suggestions for future research, clinical, and educational efforts.

Temporal lobe epilepsy surgery in children and adults: A multicenter study

OBJECTIVE

To assess seizure and cognitive outcomes and their predictors in children (<16 years at surgery) and adults undergoing temporal lobe epilepsy (TLE) surgery in eight Italian centers.

METHODS

This is a retrospective multicenter study. We performed a descriptive analysis and subsequently carried out multivariable mixed-effect models corrected for multiple comparisons.

RESULTS

We analyzed data from 511 patients (114 children) and observed significant differences in several clinical features between adults and children. The possibility of achieving Engel class IA outcome and discontinuing antiepileptic drugs (AEDs) at last follow-up (FU) was significantly higher in children (P = .006 and < .0001). However, percentages of children and adults in Engel class I at last FU (mean ± SD, 45.9 ± 17 months in children; 45.9 ± 20.6 months in adults) did not differ significantly. We identified different predictors of seizure outcome in children vs adults and at short- vs long-term FU. The only variables consistently associated with class I outcome over time were postoperative electroencephalography (EEG) in adults (abnormal, improved,odds ratio [OR] = 0.414, P = .023, Q = 0.046 vs normal, at 2-year FU and abnormal, improved, OR = 0.301, P = .001, Q = 0.002 vs normal, at last FU) and the completeness of resection of temporal magnetic resonance (MR) abnormalities other than hippocampal sclerosis in children (OR = 7.93, P = .001, Q = 0.003, at 2-year FU and OR = 45.03, P < .0001, Q < 0.0001, at last FU). Cognitive outcome was best predicted by preoperative performances in either age group.

SIGNIFICANCE

Clinical differences between adult and pediatric patients undergoing TLE surgery are reflected in differences in long-term outcomes and predictors of failures. Children are more likely to achieve sustained seizure freedom and withdraw AEDs after TLE surgery. Earlier referral should be encouraged as it can improve surgical outcome.

Epilepsy: Workup and Management in Adults

When managing epilepsy, there is a temptation to focus care with respect to the last and the next seizure. However, epilepsy is a multifaceted chronic condition and should be treated as such. Epilepsy comes with many physical risks, psychological effects, and socioeconomic ramifications, demanding a long-term commitment from the treating physician. Patients with epilepsy, compared to other chronically ill patient populations, have a worse quality of life, family function, and less social support. The majority of patients are well controlled on antiseizure drugs. However, approximately one-third will continue to have seizures despite optimized medical management. The primary aim of this article is to explore the long-term management of chronic epilepsy, and to address some of the particular needs of patients with chronic epilepsy.

Addressing the epilepsy surgery gap: Impact of community/tertiary epilepsy center collaboration

•

Collaboration agreements can improve epilepsy surgery referral volumes.

•

Standardized referral pathways may help address epilepsy surgery gap.

•

Internal and external process changes can improve referral process.

•

Sociodemographic variables continue to influence referral completion.

To assess whether a formal collaboration between a non-surgical, community epilepsy center and a surgical, tertiary-care epilepsy center can improve patient progress throughout the pre-surgical referral process, and to elucidate predictors of referral completion among inter-center referrals.

The inter-center referral process was tracked, and the number of patients completing surgical conference (primary outcome) and epilepsy surgery at the tertiary center were collected and compared in the 45-month immediate pre/post-collaboration periods. Demographic and clinical variables were collected on post-collaboration inter-center patient referrals to explore factors associated with completion of the referral process.

Compared to the pre-collaboration period, the proportion of tertiary center epilepsy surgery conference patients referred from the community epilepsy center increased from 3/88 to 14/113 (263% increase, p = .01) during the post-collaboration period. The proportion of patients completing surgery via the community to tertiary referral process increased from 2/63 pre-collaboration to 8/71 post-collaboration (254% increase, p = .04). Referral completion was associated with higher seizure frequency, shorter travel distance, private insurance status and positive employment status (p < 0.05).

Collaboration agreements between community and tertiary-care epilepsy centers may improve patient completion of the epilepsy surgery referral process. Implementation of similar programs at other centers may be beneficial in reducing the epilepsy surgery gap.

New era of personalised epilepsy management

The trial and error approach to epilepsy treatment has not changed for over a century but machine learning and patient derived stem cells promise a personalised and more effective strategy, argue Patrick Kwan and colleagues

Preoperative sensory aura predicts risk for seizure in temporal lobe epilepsy surgery

BACKGROUND

Patients with temporal lobe epilepsy (TLE) often report viscerosensory and experiential auras, with substantial epilepsy localization. However, few previous studies have investigated the epileptic preoperative aura, particularly with regard to its effect on surgical outcomes in patients with drug-resistant epilepsy.

OBJECTIVE

This study investigated the potential role of preoperative aura in predicting outcomes after surgery for TLE.

MATERIAL AND METHODS

This study included consecutive patients diagnosed with TLE who underwent anterior temporal lobectomy (ATL) for drug-resistant TLE during the period from January 1999 to December 2017. Data pertaining to patient age at the time of surgery, sex, age at initial seizure onset, duration of epilepsy, presence of preoperative aura, comprehensive clinical semiology, side of surgery, and type of pathology were analyzed. Preoperative auras were classified as autonomic, sensory, mental and affective, or multiple manifestations. Patients were followed at 3 and 12 months after surgery and at regular intervals thereafter.

RESULTS AND CONCLUSIONS

A total of 498 patients were included in the study. Positive preoperative aura was observed in 386 patients (77.51%). The correlation of each variable with seizure outcomes was analyzed, and the only variable found to correlate with seizure outcome was the presence of preoperative aura. Compared with those with negative preoperative aura, those with positive preoperative aura were 1.74-fold more likely to be seizure-free after surgery for TLE. The analysis of patient data suggested a later onset of initial seizure in those with positive preoperative aura, compared with those without (p = 0.04, 95% confidence interval (CI): 0.55-3.24). Patients with a shorter duration of disease prior to TLE surgery were more likely to achieve seizure-free status postoperatively. Preoperative sensory aura was a good predictor that a patient would be seizure-free during follow-up (p = 0.022).

Seizure outcome and use of antiepileptic drugs after epilepsy surgery according to histopathological diagnosis: a retrospective multicentre cohort study

BACKGROUND

Surgery is a widely accepted treatment option for drug-resistant focal epilepsy. A detailed analysis of longitudinal postoperative seizure outcomes and use of antiepileptic drugs for different brain lesions causing epilepsy is not available. We aimed to analyse the association between histopathology and seizure outcome and drug freedom up to 5 years after epilepsy surgery, to improve presurgical decision making and counselling.

METHODS

In this retrospective, multicentre, longitudinal, cohort study, patients who had epilepsy surgery between Jan 1, 2000, and Dec 31, 2012, at 37 collaborating tertiary referral centres across 18 European countries of the European Epilepsy Brain Bank consortium were assessed. We included patients of all ages with histopathology available after epilepsy surgery. Histopathological diagnoses and a minimal dataset of clinical variables were collected from existing local databases and patient records. The primary outcomes were freedom from disabling seizures (Engel class 1) and drug freedom at 1, 2, and 5 years after surgery. Proportions of individuals who were Engel class 1 and drug-free were reported for the 11 main categories of histopathological diagnosis. We analysed the association between histopathology, duration of epilepsy, and age at surgery, and the primary outcomes using random effects multivariable logistic regression to control for confounding.

FINDINGS

9147 patients were included, of whom seizure outcomes were available for 8191 (89·5%) participants at 2 years, and for 5577 (61·0%) at 5 years. The diagnoses of low-grade epilepsy associated neuroepithelial tumour (LEAT), vascular malformation, and hippocampal sclerosis had the best seizure outcome at 2 years after surgery, with 77·5% (1027 of 1325) of patients free from disabling seizures for LEAT, 74·0% (328 of 443) for vascular malformation, and 71·5% (2108 of 2948) for hippocampal sclerosis. The worst seizure outcomes at 2 years were seen for patients with focal cortical dysplasia type I or mild malformation of cortical development (50·0%, 213 of 426 free from disabling seizures), those with malformation of cortical development-other (52·3%, 212 of 405 free from disabling seizures), and for those with no histopathological lesion (53·5%, 396 of 740 free from disabling seizures). The proportion of patients being both Engel class 1 and drug-free was 0-14% at 1 year and increased to 14-51% at 5 years. Children were more often drug-free; temporal lobe surgeries had the best seizure outcomes; and a longer duration of epilepsy was associated with reduced chance of favourable seizure outcomes and drug freedom. This effect of duration was evident for all lesions, except for hippocampal sclerosis.

INTERPRETATION

Histopathological diagnosis, age at surgery, and duration of epilepsy are important prognostic factors for outcomes of epilepsy surgery. In every patient with refractory focal epilepsy presumed to be lesional, evaluation for surgery should be considered.

FUNDING

None.

Social functioning and health-related quality of life trajectories in people with epilepsy after epilepsy surgery

OBJECTIVE

An improvement in quality of life (QoL) over time after epilepsy surgery has been demonstrated in people with epilepsy; however, social functioning has been less investigated. We conducted this study to examine whether postsurgical improvement is parallel between QoL and social functioning in patients with epilepsy.

METHODS

We retrospectively reviewed patients who underwent epilepsy surgery. All participants completed a comprehensive neuropsychological assessment, the Quality of Life in Epilepsy Inventory (QOLIE-89) questionnaire, and the Social and Occupational Functioning Scale for Epilepsy (SOFSE) before surgery and at 3 months, 6 months, and 1 year after surgery. Demographic and epilepsy-related information was also collected. Generalized estimating equations with identity links were used to model the QOLIE-89 and SOFSE over time and possible associated factors. A p < 0.05 was considered statistically significant.

RESULTS

A total of 76 patients, including 36 males and 43 females aged 18 to 62 years were collected. Both total QOLIE-89 and overall SOFSE improved over time after epilepsy surgery (adjusted p value < 0.001 and 0.002, respectively, with Bonferroni's correction). Total QOLIE-89 improved 3 months after surgery, while overall SOFSE showed no significant improvement until 6 months after surgery. The presurgical Full-Scale Intelligence Quotient (FSIQ) of the Wechsler Adult Intelligence Scale-III and years of education were significantly associated with time-dependent improvement for both total QOLIE-89 and overall SOFSE (p value < 0.001). At one year after surgery, overall SOFSE and total QOLIE-89 scores were significantly higher in the seizure-free group than in the nonseizure-free group (p value = 0.040 and 0.032, respectively).

CONCLUSION

Social functioning significantly improved in people with epilepsy after surgery as QoL, but it took more time to exhibit improvement. People with better FSIQ and more years of education had better improvement in social functioning over time. The early intervention of rehabilitation programs after epilepsy surgery might be necessary to facilitate the improvement in social functioning.