Magnetic resonance-guided laser interstitial thermal therapy for drug-resistant epilepsy: A systematic review and individual participant data meta-analysis

Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) has emerged as a popular minimally invasive alternative to open resective surgery for drug-resistant epilepsy (DRE). We sought to perform a systematic review and individual participant data meta-analysis to identify independent predictors of seizure outcome and complications following MRgLITT for DRE. Eleven databases were searched from January 1, 2010 to February 6, 2021 using the terms “MR-guided ablation therapy” and “epilepsy”. Multivariable mixed-effects Cox and logistic regression identified predictors of time to seizure recurrence, seizure freedom, operative complications, and postoperative neurological deficits. From 8705 citations, 46 studies reporting on 450 MRgLITT DRE patients (mean age = 29.5 ± 18.1 years, 49.6% female) were included. Median postoperative seizure freedom and follow-up duration were 15.5 and 19.0 months, respectively. Overall, 240 (57.8%) of 415 patients (excluding palliative corpus callosotomy) were seizure-free at last follow-up. Generalized seizure semiology (hazard ratio [HR] = 1.78, p = .020) and nonlesional magnetic resonance imaging (MRI) findings (HR = 1.50, p = .032) independently predicted shorter time to seizure recurrence. Cerebral cavernous malformation (CCM; odds ratio [OR] = 7.97, p < .001) and mesial temporal sclerosis/atrophy (MTS/A; OR = 2.21, p = .011) were independently associated with greater odds of seizure freedom at last follow-up. Operative complications occurred in 28 (8.5%) of 330 patients and were independently associated with extratemporal ablations (OR = 5.40, p = .012) and nonlesional MRI studies (OR = 3.25, p = .017). Postoperative neurological deficits were observed in 53 (15.1%) of 352 patients and were independently predicted by hypothalamic hamartoma etiology (OR = 5.93, p = .006) and invasive electroencephalographic monitoring (OR = 4.83, p = .003). Overall, MRgLITT is particularly effective in treating patients with well-circumscribed lesional DRE, such as CCM and MTS/A, but less effective in nonlesional cases or lesional cases with a more diffuse epileptogenic network associated with generalized seizures. This study identifies independent predictors of seizure freedom and complications following MRgLITT that may help further guide patient selection.     

Initial response to antiepileptic drugs in patients with newly diagnosed epilepsy

This study aimed to identify factors predicting the response to antiepileptic drugs in patients with newly diagnosed epilepsy. We prospectively studied 176 patients with newly diagnosed epilepsy. Patients were included if they had a history of two or more clinically definite unprovoked seizures, or had a definite epileptic focus on MRI or epileptiform discharges on electroencephalography if they had suffered only one seizure. The primary endpoint was seizure freedom during the initial 6 months of antiepileptic drug treatment. The secondary endpoint was the time to the first seizure during the maintenance period of antiepileptic drug treatment. A total of 100 patients were included, and seizure freedom for 6 months was achieved in 73 patients. The response to antiepileptic drugs was significantly lower in patients with early age at seizure onset (⩽16 versus >16 years old, odds ratio = 4; 95% confidence interval [CI] 1.5–12.9; relative risk = 1.4; 95% CI 1.1–1.8). In addition, the time to the first seizure during the maintenance period was significantly earlier in patients with age at seizure onset ⩽16 years compared with those with age at seizure onset >16 years on the Kaplan–Meier survival analysis (p = 0.011). Early age at seizure onset is an important factor influencing the response to antiepileptic drugs in patients with newly diagnosed epilepsy.     

Outcomes of resective surgery in children and adolescents with focal lesional epilepsy: The experience of a tertiary epilepsy center

ObjectiveThis study aimed to investigate the efficacy of resective surgery in children with focal lesional epilepsy by evaluating the predictive value of pre- and postsurgical factors in terms of seizure freedom.MethodsThis study included 61 children aged between 2 and 18 years who were admitted to the pediatric video-EEG unit for presurgical workup. Each patient was evaluated with a detailed history, video-EEG, neuroimaging, and postsurgical outcomes according to Engel classification to predict postsurgical seizure freedom. All the possible factors including history, etiology, presurgical evaluation, surgical procedures, and postsurgical results were analyzed for their predictive value for postoperative seizure freedom.ResultsOf the 61 patients, 75% were diagnosed as having temporal lobe epilepsy (TLE), and 25% were diagnosed with extra-TLE. Two years after the surgery, 78.6% were seizure-free, of which 89% had TLE, and 50% had extra-TLE (p < 0.05). Patients were more likely to have a favorable outcome for seizure freedom if they had rare seizure frequency, focal EEG findings, and focal seizures; had a temporal epileptogenic zone; or had TLE and hippocampal sclerosis. On the other hand, patients were more likely to have unfavorable results for seizure freedom if they had younger age of seizure onset, frequent seizures before the surgery, a frontal or multilobar epileptogenic zone, secondarily generalized seizures, extra-TLE with frontal lobe surgery, or focal cortical dysplasia.SignificanceResective surgery is one of the most effective treatment methods in children with intractable epilepsy. A history of young age of seizure onset, frequent seizures before surgery, secondarily generalized seizures, a multilobar epileptogenic zone, frontal lobe surgery, and focal cortical dysplasia (FCD) are the most important predictive factors indicating that a patient would continue having seizures after surgery. On the other hand, focal seizure semiologies, temporal lobe localization, and hippocampal sclerosis indicate that a patient would have better results in terms of seizure freedom.     

Comparison of MRI features and surgical outcome among the subtypes of focal cortical dysplasia

PurposeFocal cortical dysplasia (FCD) is the most common pathological diagnosis in patients who have undergone surgical treatment for intractable neocortical epilepsy. However, presurgical identification of MRI abnormalities in FCD patients remains difficult, and there are no highly sensitive imaging parameters available that can reliably differentiate among FCD subtypes. The purpose of our study was to investigate the surgical outcome in FCD patients with identifiable MRI abnormalities and to evaluate the prognostic role of the various MRI features and the characteristics of FCD pathology.MethodsWe retrospectively recruited epilepsy patients who had undergone surgical treatment for refractory epilepsy with focal MRI abnormalities and the pathological diagnosis of FCD. We evaluated the surgical outcome according to the pathological subtypes, and studied the prognostic roles of various MRI features. We used recently proposed three-tiered FCD classification system which included FCD type III when FCD occurs in association with other potentially epileptogenic pathologies.ResultsA total of 69 patients were included, and 68.1% of patients became seizure free. Patients with FCD type III had a lower chance for achieving seizure freedom (7/15) than in patients with isolated FCD (FCD types I and II) (40/54, p = 0.044). Cortical thickness and blurring of gray–white matter junction were more common in isolated FCD than in FCD type III, but most MRI features failed to differentiate between FCD types I and II, and only the transmantle sign was specific for FCD type II. We failed to find a prognostic value of specific MRI abnormalities of prognostic value in terms of post-epilepsy surgery outcome in FCD patients.ConclusionsOur study showed that patients with FCD III have poor surgical outcome. Typical MRI features of isolated FCD such as cortical thickness and blurring of gray–white matter junction were less common in FCD type III and only transmantle sign was helpful in differentiating between FCD types I and II.     

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

ObjectiveTo analyze the significance of intracranial electroencephalography (iEEG) parameters such as seizure onset patterns (SOP) and size of seizure onset zone (SOZ) with respect to prediction of seizure freedom after resective epilepsy surgery.MethodsAll patients who underwent iEEG with subdural electrodes between January 2006 and December 2015 in our epilepsy-center were included. Various iEEG parameters were retrospectively analyzed regarding their predictive value to post-operative seizure freedom. Furthermore, associations of specific SOPs with underlying histopathology and brain regions of the SOZ were examined.ResultsEighty-one patients (34 female) with 324 seizures were assessed. Low-voltage fast activity (37%) and sharp activity <13 Hz (30%) were the most frequent SOPs. Focal SOZ (≤2 cm) was the only iEEG parameter independently associated with 1-year post-operative seizure freedom (OR 4.1, 95% CI 1.433–11.679). While no SOP was linked to specific histopathologies, some associations between SOPs and anatomical regions of SOZ were found.ConclusionsA circumscribed SOZ, but no specific SOP was predictive for seizure freedom after epilepsy surgery.SignificanceIntracranial EEG may be helpful to predict post-operative seizure freedom. Multicenter studies with larger numbers of patients are required to reliably assess the significance of specific SOPs for successful resective epilepsy surgery.     

The impact of stereotactic laser ablation at a typical epilepsy center

PurposeStereotactic laser ablation (SLA) is a novel form of epilepsy surgery for patients with drug-resistant focal epilepsy. We evaluated one hundred consecutive surgeries performed for patients with epilepsy to address the impact of SLA on our therapeutic approach, as well as patient outcomes.MethodsA retrospective, single center analysis of the last one hundred neurosurgeries for epilepsy was performed from 2013 to 2015. Demographics, surgical procedures, and postoperative measures were assessed up to 5 years to compare the effect of SLA on outcome. Confidence intervals (CI) and comparative tests of proportions compared outcomes for SLA and resective surgery. Procedural categorical comparison used Chi-square and Kaplan–Meier curves. Student t-test was utilized for single variables such as age at procedure and seizure onset.ResultsOne hundred surgeries for epilepsy yielded thirty-three SLAs and twenty-one resections with a mean of 21.7-month and 21.3-month follow-up, respectively. The temporal lobe was the most common target for SLA (92.6%) and resection (75%). A discrete lesion was present on brain magnetic resonance imaging (MRI) in 27/32 (84.4%) of SLA patients compared with 7/20 (35%) of resection patients with a normal MRI. Overall, 55–60% of patients became seizure-free (SF). Four of five patients with initial failure to SLA became SF with subsequent resection surgery. Complications were more frequent with resection although SF outcomes did not differ (Chi square; p = 0.79). Stereotactic laser ablation patients were older than those with resections (47.0 years vs. 35.4 years, p = 0.001). The mean length of hospitalization prior to discharge was shorter for SLA (1.18 days) compared with open resection (3.43 days; SD: 3.16 days) (p = 0.0002).ConclusionWe now use SLA as a first line therapy at our center in patients with lesional temporal lobe epilepsy (TLE) before resection. Seizure-free outcome with SLA and resection was similar but with a shorter length of stay. Long-term follow-up is recommended to determine sustained SF status from SLA.     

Long-term seizure and psychosocial outcomes after resective surgery for intractable epilepsy

Resective surgery is considered an effective treatment for refractory localization-related epilepsy. Most studies have reported seizure and psychosocial outcomes of 2–5 years postsurgery and a few up to 10 years. Our study aimed to assess long-term (up to 15 years) postsurgical seizure and psychosocial outcomes at our epilepsy center. The Henry Ford Health System Corporate Data Store was accessed to identify patients who had undergone surgical resection for localization-related epilepsy from 1993 to 2011. Demographics including age at epilepsy onset and surgery, seizure frequency before surgery, and pathology were gathered from electronic medical records. Phone surveys were conducted from May 2012 to January 2013 to determine patients' current seizure frequency and psychosocial metrics including driving and employment status and use of antidepressants. Surgical outcomes were based on Engel's classification (classes I and II = favorable outcomes). McNemar's tests, chi-square tests, two sample t-tests, and Wilcoxon two sample tests were used to analyze the relationships of psychosocial and surgical outcomes with demographic and surgical characteristics. A total of 470 patients had resective epilepsy surgery, and of those, 50 (11%) had died since surgery. Of the remaining, 253 (60%) were contacted with mean follow-up of 10.6 ± 5.0 years (27% of patients had follow-up of 15 years or longer). Of the patients surveyed, 32% were seizure-free and 75% had a favorable outcome (classes I and II). Favorable outcomes had significant associations with temporal resection (78% temporal vs 58% extratemporal, p = 0.01) and when surgery was performed after scalp EEG only (85% vs 65%, p < 0.001). Most importantly, favorable and seizure-free outcome rates remained stable after surgery over long-term follow-up [i.e., < 5 years (77%, 41%), 5–10 years (67%, 29%), 10–15 years (78%, 38%), and > 15 years (78%, 26%)]. Compared to before surgery, patients at the time of the survey were more likely to be driving (51% vs 35%, p < 0.001) and using antidepressants (30% vs 22%, p = 0.013) but less likely to be working full-time (23% vs 42%, p < 0.001). A large majority of patients (92%) considered epilepsy surgery worthwhile regardless of the resection site, and this was associated with favorable outcomes (favorable = 98% vs unfavorable = 74%, p < 0.001). The findings suggest that resective epilepsy surgery yields favorable long-term postoperative seizure and psychosocial outcomes.     

Predictors of intellectual functioning after epilepsy surgery in childhood: The role of socioeconomic status

ObjectiveThe objective of this study was to evaluate the association between socioeconomic status and intellectual functioning in children with medically refractory epilepsy, before and after resective epilepsy surgery. Family environment is a strong contributor to cognitive development in children and has been recently shown to play a significant role in intellectual outcome after surgery in children with epilepsy.MethodsOne hundred children who had undergone resective epilepsy surgery and completed preoperative and postoperative assessments of IQ as part of clinical care were included in the study. We evaluated the impact of epilepsy-related variables, income quintile, and residence location on IQ.ResultsGreater improvements in IQ after surgery were associated with an older age at surgery (β = .235, p = .018). Higher IQ scores at follow-up were associated with an older age of seizure onset (β = .371, p < .001), older age at surgery (β = .356, p < .001), unilobar epileptogenic focus (β = .394, p < .001), and mesial temporal sclerosis (β = .338, p = .001) or tumor (β = .457, p < .001) in comparison with malformation of cortical development; age at seizure onset did not remain as a significant predictor in multivariable regression analysis. Income quintile, residence location, seizure control, and antiepileptic medication use were not significant predictors.ConclusionsEpilepsy-related variables were the strongest predictors of IQ and postoperative change in IQ. We were unable to identify a significant association between IQ and socioeconomic status. Future research should evaluate the impact of multiple aspects of family environment.     

Intraoperative magnetic resonance imaging in epilepsy surgery: A systematic review and meta-analysis

This systematic review investigated the added value of intraoperative magnetic resonance imaging (iMRI)-guidance in epilepsy surgery, compared to conventional non-iMRI surgery, with respect to the rate of gross total resection (GTR), postoperative seizure freedom, neurological deficits, non-neurological complications and reoperations. A comprehensive literature search was conducted using Medline, Embase, PubMed, and Cochrane Reviews databases. Randomized control trials, case control or cohort studies, and surgical case series published from January 1993 to February 2021 that reported on iMRI-guided epilepsy surgery outcomes for either adults or children were eligible for inclusion. Studies comparing iMRI-guided epilepsy surgery to non-iMRI surgery controls were selected for meta-analysis using random-effects models. Forty-two studies matched the selection criteria and were used for qualitative synthesis and ten of these were suitable for meta-analysis. Overall, studies included various 0.2–3.0 Tesla iMRI systems, contained small numbers with heterogenous clinical characteristics, utilized subjective GTR reporting, and had variable follow-up durations. Meta-analysis demonstrated that the use of iMRI-guidance led to statistically significant higher rates of GTR (RR = 1.31 [95% CI = 1.10–1.57]) and seizure freedom (RR = 1.44 [95% CI = 1.12–1.84]), but this was undermined by moderate to significant statistical heterogeneity between studies (I² = 55% and I² = 71% respectively). Currently, there is only level III-2 evidence supporting the use of iMRI-guidance over conventional non-iMRI epilepsy surgery, with respect to the studied outcomes.     

Acute postoperative seizures and long-term outcome following pediatric epilepsy surgery

PurposeAcute post-operative seizures (APOS) after epilepsy surgery, previously believed to be benign, are increasingly associated with poor long-term prognosis. Prior literature has focused primarily on adult temporal lobe epilepsy. This retrospective study aimed to identify the prevalence, prognostic significance and risk factors for APOS in pediatric epilepsy surgery at a single center.MethodRetrospective chart review of all children aged 0–21 years undergoing resective surgery for epilepsy between 2009 and 2012 at a single center. APOS were defined as seizures within 30 days of resection. Surgical outcome was determined, using a minimum of 12 months postoperative follow-up for inclusion.ResultsAPOS, defined as a seizure within 30 days of resection, were identified in 50/112 (44%) of patients. APOS were a significant predictor of poor postoperative seizure outcome (ILAE 4–6); only 26% of those with APOS had a good outcome (ILAE 1–3), compared to 76% without APOS. Timing of postoperative seizure was not correlated with outcome. Most (54%) with APOS and good outcome had continued seizures between 14-30 days postoperatively. Patients with APOS after temporal (p = 0.05) and extratemporal (p < 0.001) resections had a significantly worse prognosis. APOS after hemispherectomy were not associated with a worse prognosis (p = 0.22). Key risk factors for APOS include lack of ictal EEG lateralization to operated hemisphere/side of MRI abnormality.ConclusionThis study shows an association between APOS and poor outcome in both temporal and extratemporal pediatric epilepsy surgery. Findings support the expansion of APOS duration to 30 days.     

Socioeconomic status influences time to surgery and surgical outcome in pediatric epilepsy surgery

The aims of this study were to evaluate the influence of socioeconomic status (SES) on time-to-surgery (TTS) and surgical outcome in children with treatment-resistant epilepsy in a universal health care system. The cohort consisted of children who had undergone resective epilepsy surgery between 2001 and 2013 in Canada. The patients' postal codes were linked to Statistics Canada National Household Survey data to obtain dissemination area income, which was used to infer SES. Time-to-surgery was defined as the interval from date of epilepsy onset to date of surgery. Seizure outcome was classified using ILAE classification. The associations between SES and TTS, as well as SES and surgical outcome, were assessed. Two hundred eighty-four children who had epilepsy surgery were included. Patients in the lowest income quintile had a significantly higher TTS relative to the highest income quintile (β = 0.121, p = 0.044). There were no significant associations between income quintiles and seizure-free surgical outcome (odds ratio (OR) = 0.746–1.494, all p > 0.05). However, patients in the lowest income quintile had a significantly lower odds of an improvement in seizure frequency relative to the highest income quintile (OR = 0.262, p = 0.046). The TTS was not uniform across SES in spite of the existence of a universal health care system. This finding highlights the need to address social and economic barriers for epilepsy surgery to improve access to this potentially curative treatment. Those with lower SES had lower likelihood of improvement in seizure control following epilepsy surgery and may require additional support including social and financial support to mitigate the discrepancies in seizure control following surgery between SES levels.     

Minimal access keyhole surgery for mesial temporal lobe epilepsy

A keyhole surgical approach for the treatment of medically intractable temporal lobe epilepsy is described. Additionally, patients who had keyhole surgery are contrasted with individuals who underwent a non-keyhole approach for outcome parameters of seizure freedom, complications, and speed of recovery. Patients who had a keyhole approach for temporal lobe epilepsy with over 2 years follow-up were compared with all patients who had selective amygdalohippocampectomy performed in a non-keyhole fashion over the same time period. Rates of seizure freedom were comparable in the 17 patients with keyhole surgery and the 34 individuals who had a non-keyhole approach. However, patients treated with keyhole surgery were discharged from the hospital earlier than non-keyhole patients (p = 0.04), and with a shorter operative time (p = 0.0001). The restricted keyhole surgical exposure has not limited the ability to perform surgery for temporal lobe epilepsy with favorable results on reducing the seizure tendency, and patients may be benefited by a minimal access technique with a more rapid recovery from surgery.     

Should substitution monotherapy or combination therapy be used after failure of the first antiseizure medication? Observations from a 30-year cohort study

Objectives

To assess the temporal trends in the use of second antiseizure (ASM) regimens and compare the efficacy of substitution monotherapy and combination therapy after failure of initial monotherapy in people with epilepsy.

Methods

This was a longitudinal observational cohort study conducted at the Epilepsy Unit of the Western Infirmary in Glasgow, Scotland. We included patients who were newly treated for epilepsy with ASMs between July 1982, and October 2012. All patients were followed up for a minimum of 2 years. Seizure freedom was defined as no seizure for at least 1 year on unchanged medication at the last follow up.

Results

During the study period, 498 patients were treated with a second ASM regimen after failure of the initial ASM monotherapy, of whom 346 (69%) were prescribed combination therapy and 152 (31%) were given substitution monotherapy. The proportion of patients receiving second regimen as combination therapy increased during the study period from 46% in first epoch (1985–1994) to 78% in the last (2005–2015) (RR = 1.66, 95% CI: 1.17–2.36, corrected-p = .010). Overall, 21% (104/498) of the patients achieved seizure freedom on the second ASM regimen, which was less than half of the seizure-free rate on the initial ASM monotherapy (45%, p < .001). Patients who received substitution monotherapy had similar seizure-free rate compared with those who received combination therapy (RR = 1.17, 95% CI: 0.81–1.69, p = .41). Individual ASMs used, either alone or in combination, had similar efficacy. However, the subgroup analysis was limited by small sample sizes.

Significance

The choice of second regimen used based on clinical judgment was not associated with treatment outcome in patients whose initial monotherapy failed due to poor seizure control. Alternative approaches such as machine learning should be explored to aid individualized selection of the second ASM regimen.     

MEG abnormalities and mechanisms of surgical failure in neocortical epilepsy

Objective

Epilepsy surgery fails to achieve seizure freedom in 30%–40% of cases. It is not fully understood why some surgeries are unsuccessful. By comparing interictal magnetoencephalography (MEG) band power from patient data to normative maps, which describe healthy spatial and population variability, we identify patient-specific abnormalities relating to surgical failure. We propose three mechanisms contributing to poor surgical outcome: (1) not resecting the epileptogenic abnormalities (mislocalization), (2) failing to remove all epileptogenic abnormalities (partial resection), and (3) insufficiently impacting the overall cortical abnormality. Herein we develop markers of these mechanisms, validating them against patient outcomes.

Methods

Resting-state MEG recordings were acquired for 70 healthy controls and 32 patients with refractory neocortical epilepsy. Relative band-power spatial maps were computed using source-localized recordings. Patient and region-specific band-power abnormalities were estimated as the maximum absolute z-score across five frequency bands using healthy data as a baseline. Resected regions were identified using postoperative magnetic resonance imaging (MRI). We hypothesized that our mechanistically interpretable markers would discriminate patients with and without postoperative seizure freedom.

Results

Our markers discriminated surgical outcome groups (abnormalities not targeted: area under the curve [AUC] = 0.80, p = .003; partial resection of epileptogenic zone: AUC = 0.68, p = .053; and insufficient cortical abnormality impact: AUC = 0.64, p = .096). Furthermore, 95% of those patients who were not seizure-free had markers of surgical failure for at least one of the three proposed mechanisms. In contrast, of those patients without markers for any mechanism, 80% were ultimately seizure-free.

Significance

The mapping of abnormalities across the brain is important for a wide range of neurological conditions. Here we have demonstrated that interictal MEG band-power mapping has merit for the localization of pathology and improving our mechanistic understanding of epilepsy. Our markers for mechanisms of surgical failure could be used in the future to construct predictive models of surgical outcome, aiding clinical teams during patient pre-surgical evaluations.     

Investigation of bias in an epilepsy machine learning algorithm trained on physician notes

Racial disparities in the utilization of epilepsy surgery are well documented, but it is unknown whether a natural language processing (NLP) algorithm trained on physician notes would produce biased recommendations for epilepsy presurgical evaluations. To assess this, an NLP algorithm was trained to identify potential surgical candidates using 1097 notes from 175 epilepsy patients with a history of resective epilepsy surgery and 268 patients who achieved seizure freedom without surgery (total N = 443 patients). The model was tested on 8340 notes from 3776 patients with epilepsy whose surgical candidacy status was unknown (2029 male, 1747 female, median age = 9 years; age range = 0‐60 years). Multiple linear regression using demographic variables as covariates was used to test for correlations between patient race and surgical candidacy scores. After accounting for other demographic and socioeconomic variables, patient race, gender, and primary language did not influence surgical candidacy scores (P > .35 for all). Higher scores were given to patients >18 years old who traveled farther to receive care, and those who had a higher family income and public insurance (P < .001, .001, .001, and .01, respectively). Demographic effects on surgical candidacy scores appeared to reflect patterns in patient referrals.     

Comparing the effects of cortical resection and vagus nerve stimulation in patients with nonlesional extratemporal epilepsy

The main purpose of this retrospective study was to compare the effects of resective surgery (RESgr—26 patients) and vagus nerve stimulation (VNSgr—35 patients) on seizure frequency (2 and 5 years after surgery) in patients with nonlesional extratemporal epilepsy (NLexTLE). We analyzed hospital admission costs directly associated with epilepsy (HACE) in both groups at the same follow-up. The decrease in seizure frequency from the preoperative levels, in both VNSgr and RESgr, was statistically significant (p < 0.001). The seizure frequency reduction did not differ significantly between the follow-up visits for either group (p = 0.221 at 2 years and 0.218 at 5 years). A significantly higher number of Engel I and Engel I + II patients were found in RESgr than in VNSgr at both follow-up visits (p = 0.04 and 0.007, respectively). Using McHugh classification, we did not find statistically significant differences between both groups at both follow-up visits. Hospital admission costs directly associated with epilepsy/patient/year in both RESgr and VNSgr dropped significantly at 2- and 5-year follow-up visit and this reduction was not statistically different between RESgr and VNSgr (p = 0.232).Both VNS and resective surgery cause comparably significant seizure reduction in NLexTLE. Resective surgery leads to a greater number of patients with excellent postoperative outcome (Engel I + II). The HACE reduction is statistically comparable between both groups.     

Predictive factors of postoperative outcome in the elderly after resective epilepsy surgery

ObjectiveTo evaluate the efficiency of resective epilepsy surgery (RES) in patients over 50 years and determine prognostic factors.ResultsOver the 147 patients over 50 years (54.9 ± 3.8 years [50–69]) coming from 8 specialized French centres for epilepsy surgery, 72.1%, patients were seizure-free and 91.2% had a good outcome 12 months after RES. Seizure freedom was not associated with the age at surgery or duration of epilepsy. In multivariate analysis, seizure freedom was associated with MRI and neuropathological hippocampal sclerosis (HS) (P = 0.009 and P = 0.028 respectively), PET hypometabolism (P = 0.013), temporal epilepsy (P = 0.01). On the contrary, the need for intracranial exploration was associated with a poorer prognosis (P = 0.001). Postoperative number of antiepileptic drugs was significantly lower in the seizure-free group (P = 0.001). Neurological adverse event rate after surgery was 21.1% and 11.7% of patients had neuropsychological adverse effects overall transient.ConclusionsRES is effective procedure in the elderly. Even safe it remains at higher risk of complication and population should be carefully selected. Nevertheless, age should not be considered as a limiting factor, especially when good prognostic factors are identified.     

External validation of the Epilepsy Surgery Grading Scale in a Japanese cohort of patients with epilepsy

Objective: The Epilepsy Surgery Grading Scale (ESGS) is a simple method to predict the likelihood of a patient with epilepsy proceeding to surgery and achieving seizure freedom. Usefulness of the ESGS has been confirmed in established epilepsy centres in the United States and Belgium for adult patients with drug‐resistant focal epilepsy undergoing presurgical evaluation. However, the applicability of the ESGS has not yet been evaluated in a wider range of epilepsy patients that may reflect the general spectrum of epilepsy. The present study validated the ESGS in a Japanese epilepsy centre in which admission‐based comprehensive epilepsy studies were indicated beyond presurgical evaluation. Methods: This single‐centre retrospective study included adult patients with epilepsy admitted to the Epilepsy Monitoring Unit from 2010 to June 2019. Patients were classified as ESGS Grade 1 (most favorable), Grade 2 (intermediate), and Grade 3 (least favourable). Patients were grouped into three cohorts: all patients, patients with drug‐resistant focal epilepsy, and patients who underwent resective epilepsy surgery. We assessed progression to surgery and seizure freedom at one year after surgery. Results: Of the 1,158 total admissions, 670 patients met the inclusion criteria and formed the total cohort. Of these, 435 (64.9%) had drug‐resistant focal epilepsy and 78 (11.6%) proceeded to resective surgery. Overall, progression to surgery was observed in 41.3%, 16.6%, and 4.8% of patients with Grade 1, 2, and 3, respectively. In the surgical cohort, seizure freedom was observed in 85.2%, 65.2%, and 31.3% of patients with Grade 1, 2, and 3, respectively. Significance: Our results indicate that the ESGS is effective in predicting whether a patient proceeds to epilepsy surgery and achieves seizure freedom even in the general population of epilepsy patients, regardless of type or resistance to antiepileptic drugs.     

Does adherence to epilepsy quality measures correlate with reduced epilepsy‐related adverse hospitalizations? A retrospective experience

In 2011, the American Academy of Neurology (AAN) established eight epilepsy quality measures (EQMs) for chronic epilepsy treatment to address deficits in quality of care. This study assesses the relationship between adherence to these EQMs and epilepsy‐related adverse hospitalizations (ERAHs). A retrospective chart review of 475 new epilepsy clinic patients with an ICD‐9 code 345.1‐9 between 2010 and 2012 was conducted. Patient demographics, adherence to AAN guidelines, and annual number of ERAHs were assessed. Fisher's exact test was used to assess the relationship between adherence to guidelines (as well as socioeconomic variables) and the presence of one or more ERAH per year. Of the eight measures, only documentation of seizure frequency, but not seizure type, correlated with ERAH (relative risk [RR] 0.343, 95% confidence interval [CI] 0.176–0.673, p = 0.010). Among patients in the intellectually disabled population (n = 70), only review/request of neuroimaging correlated with ERAH (RR 0.128, 95% CI 0.016–1.009, p = 0.004). ERAHs were more likely in African American patients (RR 2.451, 95% CI 1.377–4.348, p = 0.008), Hispanic/Latino patients (RR 4.016, 95% CI 1.721–9.346, p = 0.016), Medicaid patients (RR 2.217, 95% CI 1.258–3.712, p = 0.009), and uninsured patients (RR 2.667, 95% CI 1.332–5.348, p = 0.013). In this retrospective series, adherence to the eight AAN quality measures did not strongly correlate with annual ERAH.     

Pediatric epilepsy surgery from 2000 to 2018: Changes in referral and surgical volumes,patient characteristics,genetic testing,and postsurgical outcomes

Objective

Neurosurgery is a safe and effective form of treatment for select children with drug-resistant epilepsy. Still, there is concern that it remains underutilized, and that seizure freedom rates have not improved over time. We investigated referral and surgical practices, patient characteristics, and postoperative outcomes over the past two decades.

Methods

We performed a retrospective cohort study of children referred for epilepsy surgery at a tertiary center between 2000 and 2018. We extracted information from medical records and analyzed temporal trends using regression analyses.

Results

A total of 1443 children were evaluated for surgery. Of these, 859 (402 females) underwent surgical resection or disconnection at a median age of 8.5 years (interquartile range [IQR] = 4.6–13.4). Excluding palliative procedures, 67% of patients were seizure-free and 15% were on no antiseizure medication (ASM) at 1-year follow-up. There was an annual increase in the number of referrals (7%, 95% confidence interval [CI] = 5.3–8.6; p < .001) and surgeries (4% [95% CI = 2.9–5.6], p < .001) over time. Duration of epilepsy and total number of different ASMs trialed from epilepsy onset to surgery were, however, unchanged, and continued to exceed guidelines. Seizure freedom rates were also unchanged overall but showed improvement (odds ratio [OR] 1.09, 95% CI = 1.01–1.18; p = .027) after adjustment for an observed increase in complex cases. Children who underwent surgery more recently were more likely to be off ASMs postoperatively (OR 1.04, 95% CI = 1.01–1.08; p = .013). There was a 17% annual increase (95% CI = 8.4–28.4, p < .001) in children identified to have a genetic cause of epilepsy, which was associated with poor outcome.

Significance

Children with drug-resistant epilepsy continue to be put forward for surgery late, despite national and international guidelines urging prompt referral. Seizure freedom rates have improved over the past decades, but only after adjustment for a concurrent increase in complex cases. Finally, genetic testing in epilepsy surgery patients has expanded considerably over time and shows promise in identifying patients in whom surgery is less likely to be successful.