Stimulation of the bilateral anterior nuclei of the thalamus in the treatment of refractory epilepsy: two cases of subcortical band heterotopia

Subcortical band heterotopia is a neuronal migration disorder that may cause refractory epilepsy. In these patients, resective surgery has yielded inadequate results. Deep brain stimulation of the anterior nuclei of the thalamus has been used for the treatment of refractory epilepsy with good results. We describe the first two patients with subcortical band heterotopia who were submitted to deep brain stimulation of the anterior nuclei of the thalamus, with evaluation of seizure outcome after 12 and 18 months of follow‐up. At these times, both showed a >50% decrease in seizure frequency and an increase in seizure freedom. Both patients had a depressive syndrome after surgery that responded fully to anti‐depressive medication in one patient and partly in the other. In both, deep brain stimulation of the anterior nuclei of the thalamus was associated with good seizure outcome. This procedure can therefore be considered in the treatment of patients with subcortical band heterotopia and refractory epilepsy. Depression may be a transient adverse event of the surgery or stimulation, however, its aetiology is probably multifactorial.     

Ultimate success in epilepsy – the patient's perspective

Most people with epilepsy can live outwardly normal lives, but fear about impending seizures, driving restrictions, lack of independence, employment and social problems, medication-related adverse effects and the presence of cognitive or psychiatric complications are all concerns readily identified by affected individuals. While seizure control is the overriding goal of treatment, it is essential to realize the importance that patients place on other aspects of daily functioning. While many of the concerns identified by patients can only be managed by improved social support, others (e.g. neuropsychological impairment, medication-related adverse events, cognitive impairment, sleep disturbance) may be amenable to therapy (if available) or to the selection of a more appropriate antiepileptic drug. Each antiepileptic drug has a unique pharmacodynamic and tolerability profile. Awareness by the treating clinician of the pharmacological profile of each drug may help to minimize unwanted treatment-related effects and possibly improve the outcome of treatment from an epilepsy patient's perspective. Therefore, in order to achieve true treatment success, clinicians need to understand how individuals perceive their disorder and, where possible, address those factors that adversely affect patient quality of life. For the person with epilepsy, successful treatment involves beneficial effects on social, vocational and psychological function. This extends beyond seizure control to freedom from the fear associated with seizures, confidence in pharmacological therapy and improvements in health-related quality of life.     

Complications and consequences of epilepsy surgery, ketogenic diet, and vagus nerve stimulation

Children with medically intractable epilepsy may be candidates for nonpharmacologic therapies such as resective and disconnection epilepsy surgery, the ketogenic diet and its variants, and vagus nerve stimulation. Each of these therapies offers unique advantages and disadvantages, and careful consideration of the risk-benefit analysis must be tailored to each child. The hopeful outcome from each of these therapies is seizure freedom or at least a very significant improvement in seizure control, with few or no adverse effects. However, unfortunate adverse consequences can and do occur. These may be serious and irreversible or more commonly mild and transient. An appreciation of these complications and consequences is necessary for the comprehensive management of these complex patients.     

Impact of epilepsy surgery on seizure control and quality of life: a 26-year follow-up study

Purpose: The short‐term efficacy and safety of epilepsy surgery relative to medical therapy has been established, but it remains underutilized. There is a lack of data regarding the long‐term seizure‐control rates and quality of life outcomes after epilepsy surgery. This study represents the longest follow‐up study to date, with a mean follow‐up duration of 26 years. Methods: We studied the seizure and health‐related quality of life outcomes of patients who underwent epilepsy surgery by Dr. Sidney Goldring from 1967 to 1990. Retrospective clinical chart reviews gathered perioperative data and surveys obtained follow‐up data. Seizure outcome was evaluated using the Engel classification system. Key Findings: Of 361 patients, 117 (32.4%) completed follow‐up interviews. Fifty‐six patients (48%) were Engel class I. Mean overall Quality of Life in Epilepsy (QOLIE‐31) questionnaire score for the cohort was 68.2 ± 16. Eighty percent of patients reported their overall quality of life now as being better than before surgery. Seizure freedom was associated with better quality of life. We did not observe a statistically significant association between postoperative complications and long‐term outcome. Patients who underwent temporal lobe resection achieved better seizure outcomes than those who underwent other types of procedures. Astatic seizures and bilateral surgery were associated with a worse Engel class outcome. Significance: Our study demonstrates that the beneficial effects of epilepsy surgery are sustained over decades, and that these beneficial effects are correlated with an improved quality of life. The confirmation of its durability makes us optimistic that the outcomes from modern epilepsy surgery will be even better and that our present enthusiasm for this treatment modality is not misplaced.     

Prognosis of Intractable Epilepsy: Is Long-Term Seizure Freedom Possible with Medical Management?

Until recently, very little data existed on long-term seizure prognosis of patients with intractable epilepsy. We review recent work that assessed seizure remission in patients with intractable epilepsy during medical management. Recent prevalence cohort studies among adults with longstanding intractable epilepsy have demonstrated notable proportions of patients attaining at least 1-year seizure freedom, ranging from more than 10% to nearly 30% of patients, when followed for mean duration of 18 months to 6 years. Additionally, a recent prospective cohort study of pediatric-onset intractable epilepsy (followed prospectively for seizure outcome from onset of intractability) revealed minimum 1-year seizure remission among more than half of study patients. Despite the notable rates of remission seen among patients with intractable epilepsy, many individuals experienced subsequent seizure relapse. These findings highlight the continued importance of surgical therapy for those who are good candidates and the need for further development of effective therapeutic interventions.     

Kaplan-Meier analysis on seizure outcome after epilepsy surgery: do gender and race influence it?

OBJECTIVE: To evaluate seizure outcome following epilepsy surgery for patients with temporal lobe epilepsy and evaluate is gender and race/ethnicity influence it. METHODS: Data were obtained from the discharge database of the University of Alabama at Birmingham, Epilepsy Center, between 1985 and 2001. The sample consisted of all patients with a primary diagnosis of medically intractable temporal lobe epilepsy (TLE) who underwent anterior temporal lobectomy. Seizure recurrence was tabulated at 7 days, 2 months, 6 months, 1, 2, 3, 4, 5, and 6 years following surgery. Logistic regression analysis was used to model the presence of seizure recurrence after anterior temporal lobectomy for all patients. Kaplan-Meier analysis was done to obtain estimates and 95% CIs of seizure freedom from baseline. Baseline variables--age at surgery, age at seizure onset, sex, side of resection, immediate postoperative seizures, and pathology results--were assessed as potential predictors of each outcome by comparing the survival curves within each variable with a log rank test. RESULTS: Three hundred sixty-eight patients underwent surgical treatment for TLE, mean age of 30.2 years. Thirty-five patients were African American, 43% were men. Immediate postoperative seizures were seen in 23 patients, while seizure recurrence occurred in 27.3% patients within a year after surgery, and in 33.6% within 6 years. Logistic regression results showed no differences between African Americans and whites, between males and females. The occurrence of immediate postoperative seizures was a strong predictor of late seizure recurrence only at 1 year after surgery. CONCLUSIONS: The occurrence of seizures in the immediate postoperative period is a strong predictor of later seizure recurrence. Sex and race/ethnicity do not appear to be predictors of long-term outcome following surgery for temporal lobe epilepsy.     

Genomic microdeletions associated with epilepsy: not a contraindication to resective surgery

Purpose: Several recent reports of genomic microdeletions in epilepsy will generate further research; discovery of more microdeletions and other important classes of variants may follow. Detection of such genetic abnormalities in patients being evaluated for surgical treatment might raise concern that a genetic defect, possibly widely expressed in the brain, will affect surgical outcome. Methods: A reevaluation was undertaken of clinical presurgical data, histopathology of surgical specimen, and postsurgical outcome in patients with mesial temporal lobe epilepsy (MTLE) who have had surgical treatment for their drug‐resistant seizures, and who have been found to have particular genomic microdeletions. Key Findings: Three thousand eight hundred twelve patients with epilepsy were genotyped and had a genome‐wide screen to identify copy number variation. Ten patients with MTLE, who had resective epilepsy surgery, were found to have 16p13.11 microdeletions or other microdeletions >1 Mb. On histopathology, eight had classical hippocampal sclerosis (HS), one had nonspecific findings, and one had a hamartoma. Median postsurgical follow‐up time was 48 months (range 10–156 months). All patients with HS were seizure‐free after surgery, International League Against Epilepsy (ILAE) outcome class 1, at last follow‐up; the patient with nonspecific pathology had recurrence of infrequent seizures after 7 years of seizure freedom. The patient with a hamartoma never became seizure‐free. Significance: Large microdeletions can be found in patients with “typical” MTLE. In this small series, patients with MTLE who meet criteria for resective surgery and harbor large microdeletions, at least those we have detected, can have a good postsurgical outcome. Our findings add to the spectrum of causal heterogeneity of MTLE + HS.     

Surgery for drug‐resistant tuberous sclerosis complex‐associated epilepsy: who,when, and what

Objective: Tuberous sclerosis complex (TSC) is a multisystem genetic disorder associated with refractory early‐onset epilepsy. Current evidence supports surgery as the intervention most likely to achieve long‐term seizure freedom, but no specific guidelines are available on TSC pre‐surgical workup. This critical review assesses which TSC patients are suitable for surgical treatment, when pre‐surgical evaluation should start, and what degree of surgical resection is optimal for postsurgical outcome. Methods: We searched for publications from 2000 to 2020 in Pubmed and Embase using the terms “tuberous sclerosis,” “epilepsy,” and “epilepsy surgery”. To evaluate postsurgical seizure outcome, we selected only studies with at least one year of follow‐up. Results: Overall, we collected data on 1,026 patients from 34 studies. Age at surgery ranged from one month to 54 years. Mean age at surgery was 8.41 years. Of the diagnostic non‐invasive pre‐surgical tools, MRI and video‐EEG were considered most appropriate. Promising data for epileptogenic tuber detection is provided from invasive SEEG studies. Data on surgery and related outcome were available for 769 patients. Seizure freedom was seen in 64.4% of patients who underwent tuberectomy, 68.9% treated with lobectomy and 65.1% with multilobar resection. The most effective surgical approach was lobectomy, even though more recently tuberectomy associated with the resection of the perituberal area seems to be the best approach to reach seizure freedom. Published postsurgical seizure freedom rates in patients with TSC were between 65% and 75%, but reduced to 48%‐57% over longer follow‐up periods. Early surgery might positively affect neurodevelopmental trajectory in some patients, even though data on cognitive outcome are still to be confirmed with longitudinal studies. Significance: Considering the strong correlation between epilepsy duration and neurocognitive outcome, all patients with TSC ought to be referred early to a dedicated epilepsy centre for individually tailored pre‐surgical evaluation by a multi‐disciplinary epilepsy surgery team.     

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.     

A population‐based study of long‐term outcome of epilepsy in childhood with a focal or hemispheric lesion on neuroimaging

Purpose: To evaluate long‐term seizure outcome in children with epilepsy and a focal or hemispheric neuroimaging abnormality. Methods: All children (<18 years and residing in Olmsted County, Minnesota) with new‐onset epilepsy diagnosed between 1980 and 2004 and a single focal lesion on neuroimaging were identified by review of the Rochester Epidemiologic Project database. Outcomes were divided into three categories: (1) seizure freedom for 1 or more years at last follow‐up, (2) ongoing seizures but not medically intractable epilepsy, and (3) medically intractable epilepsy or undergoing epilepsy surgery. We also evaluated the proportion who achieved seizure control without surgical intervention and whether lesion type predicted intractability. Key Findings: Of the 359 children with newly diagnosed epilepsy, 37 (10%) had a focal or hemispheric lesion on neuroimaging. Median age of diagnosis was 89 months (25th percentile 26 months, 75th percentile 142 months) and at follow‐up was 137 months (25th percentile 95 months, 75th percentile 211 months). Eighty‐three percent of children with malformations of cortical development, 67% with mesial temporal sclerosis, 33% with encephalomalacia, and 50% with vascular malformations had intractable epilepsy at follow‐up or underwent resective surgery for medically intractable epilepsy. Among the different etiologies, presence of encephalomalacia predicted the lowest likelihood of medical intractability or undergoing surgery (p < 0.01). At final follow‐up, 24 (65%) of our entire cohort was seizure free. Following surgery, seizure freedom was achieved in 80% with mesial temporal sclerosis, 67% with encephalomalacia, 67% with vascular malformation, and 50% with malformations of cortical development. There was no statistically significant difference between the different etiologies on neuroimaging and seizure freedom after surgery. Twelve children (32%) achieved seizure freedom with medical management alone. Significance: Focal lesions on neuroimaging confer a high risk of medical intractability among children with new‐onset epilepsy. However, 32% of this cohort achieved seizure remission with medical management alone, including 58% with encephalomalacia and 33% with mesial temporal sclerosis.     

Treatment outcome in patients with mesial temporal sclerosis.

The long-term prognosis of pharmacological therapy in patients with mesial temporal sclerosis (MTS) is generally considered poor. On the contrary, successful surgical therapy is frequently reported. We performed a retrospective case record survey of patients with MTS in a comprehensive epilepsy center between 1993 and 1999 in order to develop treatment strategies. The time period allowed access to high-resolution qualitative magnetic resonance imaging (MRI) and a minimum of 1-year outcome assessment. Eighty-three patients with intractable partial epilepsy with MRI and electroencephalograph (EEG) abnormalities and seizure semiology consistent with temporal lobe epilepsy were identified. Thirty-six patients were treated pharmacologically and surgically and 47 patients received only pharmacotherapy. The number of patients who became seizure free was in total 37 (45%); in the surgical group 26 and in the non-surgical group 11. The proportions of seizure-free patients in each group were 72% (surgical) and 23% (non-surgical). Clinical factors such as age, gender, lesion side, previous medical history, duration of illness, seizure frequency and IQ did not correlate to prognosis. A good seizure outcome was associated with early age of seizure onset, low number of previously used antiepileptic drugs (AEDs) and surgical treatment. There is a better long-term outcome in patients with MTS receiving surgical therapy in comparison with medical therapy.     

Clinical adult outcome 11–30 years after pediatric epilepsy surgery: Complications and other surgical adverse events,seizure control,and cure of epilepsy

Objective

Pediatric epilepsy surgery promises seizure freedom or even cure of epilepsy. We evaluated the long-term (≥10 years) adult clinical outcome including surgery-related adverse events and complications, which are generally underreported.

Methods

A monocentric, single-arm, questionnaire study in now adult patients who underwent epilepsy surgery during childhood. A novel ad hoc parental/patient questionnaire, which addressed diverse outcome domains was applied.

Results

From a total of 353 eligible patients, 203 could be contacted (3 patients died of causes unknown) and 101 (50%) returned appropriately filled-in surveys. No evidence for a survey-response bias was found. The rate of surgical complications according to the patient records was 9%. As regards the survey, half of the parents/patients reported surgical adverse events (expected and unexpected issues) and one-third reported permanent aversive sequels. Two-thirds of the patients were seizure-free during the last year before follow-up; 63% were Engel class 1A; favorable seizure outcomes (including auras only) were obtained in 73%; and 54% were seizure-free and off antiseizure medicine (ASM), that is, cured of epilepsy. In non–seizure-free patients, seizure relapse occurred at any time during the follow-up interval but 87% of those with a seizure-free first postoperative year were seizure-free at follow-up. One patient experienced a seizure relapse during the ASM withdrawal trial but became seizure-free again with ASMs. Eleven patients reported an increased number of ASMs as compared to the time before surgery. Earlier focal surgery did not affect the long-term clinical outcome.

Significance

Pediatric epilepsy surgery was capable of curing epilepsy in about one-half of the children and to significantly control seizures in about three-fourths. Long-term success of focal surgery did not depend on age at surgery or duration of epilepsy. Surgical adverse events including complications may be underreported and must be assessed more thoroughly.     

Presurgical seizure frequency and tumoral etiology predict the outcome after extratemporal epilepsy surgery

OBJECTIVE: To examine the predictive value of demographic data for the seizure outcome after extratemporal epilepsy surgery. METHODS: Eightyone patients who underwent resective extratemporal epilepsy surgery were retrospectively studied concerning (a) age at surgery, (b) onset of epilepsy, (c) duration of epilepsy, (d) number of seizures at the time of presurgical evaluation, (d) number of presurgically tested antiepileptic substances and (f) number of seizure types. The data were correlated to the postoperative seizure outcome after two years. RESULTS: 33 patients (40.7%) were seizure free two years after surgery. Univariate and multivariate analysis revealed that both tumor etiology and low presurgical seizure frequency were independently associated with seizure freedom after epilepsy surgery. The recurrence rate in patients with one or more seizures per day was more than two-fold if compared with patients with fewer seizures. The remaining demographic factors did not show a significant association with seizure outcome in our 81 patients. CONCLUSIONS: Fewer than daily seizures prior to surgery and a tumoral etiology independently increase the likelihood of remaining seizure free two years after extratemporal epilepsy surgery.     

Failed epilepsy surgery: is this the end?

Resective epilepsy surgery can lead to sustained seizure control in 70–80% of patients evaluated for epilepsy surgery, indicating that up to 30% of patients still have recurrent seizures after surgery. Definitions of failed epilepsy surgery vary amongst studies. This review focuses on seizure outcome predictors after reoperation, possible mechanisms of failure and best management for this difficult patient population.     

MRI-guided laser interstitial thermal therapy for treatment of medically refractory non-lesional mesial temporal lobe epilepsy: Outcomes,complications, and current limitations: A review

There is a new focus on minimally invasive treatments for medically refractory mesial temporal lobe epilepsy (MTLE). MRI-guided laser interstitial thermal therapy (MRgLITT) is one such minimally invasive procedure, which utilizes MRI guidance and real-time feedback to ablate an epileptogenic focus. A total of 38 patients presenting exclusively with MTLE and no other lesions (including neoplasia), who underwent MRgLITT were reviewed. We evaluated a number of outcome measures, including seizure freedom, neuropsychological performance, complications, and other considerations. Eighteen (53%) had an Engel class I outcome, 10 patients had repeat procedures/operations, and 12 post-procedural complications occurred. Follow-up time ranged from 6 to 38.5 months. There was a decreased length of procedure time, hospitalization time, and analgesic requirement when compared to open surgery. In cases of well-localized MTLE this procedure may offer similar (albeit slightly lower) rates of seizure freedom versus traditional surgery. MRgLITT may be an alternative treatment option for high risk surgical patients and, more importantly, could increase referrals for surgery in patients with medically refractory MTLE. However, data is limited and long-term outcomes have not been evaluated. Further investigation is required to understand the potential of this minimally invasive technique for MTLE.     

Epilepsy surgery in tuberous sclerosis: a systematic review

PURPOSE: Tuberous sclerosis complex (TSC) is often associated with intractable epilepsy. Although epilepsy surgery has gained interest in recent years uncertainties exist about which patients are good surgical candidates. A systematic review of the available literature has been undertaken to assess the overall outcome of epilepsy surgery and identify risk factors of seizure recurrence. METHODS: We searched MEDLINE, Embase, and bibliographies of reviews and book chapters to identify articles published in English since 1960. Twenty-five articles, describing postoperative seizure outcome and type of surgery in 177 TSC patients, were included in this study. Seizure outcome was analyzed both as seizure freedom and good outcome, including patients with >90% seizure reduction. RESULTS: Seizure freedom was achieved in 101 patients (57%). Seizure frequency was improved by > 90% in 32 patients (18%). Moderate or severe intellectual disability (IQ < 70) (RR 1.8; 95% CI 1.2-2.8) and the presence of tonic seizures (RR 1.7; 95 % CI 1.2-2.4) were related to seizure recurrence. CONCLUSIONS: A relation between multiple seizures types with early onset, multiple cortical tubers and multifocal epileptogenicity, and poor outcome is not supported by this systematic analysis. Although there is considerable variation among studies reviewed here, the literature suggests that resective surgery may offer benefit in a selected population of TSC patients with drug-resistant epilepsy.     

Minimally invasive surgical approaches for temporal lobe epilepsy

Surgery can be a highly effective treatment for medically refractory temporal lobe epilepsy (TLE). The emergence of minimally invasive resective and nonresective treatment options has led to interest in epilepsy surgery among patients and providers. Nevertheless, not all procedures are appropriate for all patients, and it is critical to consider seizure outcomes with each of these approaches, as seizure freedom is the greatest predictor of patient quality of life. Standard anterior temporal lobectomy (ATL) remains the gold standard in the treatment of TLE, with seizure freedom resulting in 60–80% of patients. It is currently the only resective epilepsy surgery supported by randomized controlled trials and offers the best protection against lateral temporal seizure onset. Selective amygdalohippocampectomy techniques preserve the lateral cortex and temporal stem to varying degrees and can result in favorable rates of seizure freedom but the risk of recurrent seizures appears slightly greater than with ATL, and it is not clear whether neuropsychological outcomes are improved with selective approaches. Stereotactic radiosurgery presents an opportunity to avoid surgery altogether, with seizure outcomes now under investigation. Stereotactic laser thermo-ablation allows destruction of the mesial temporal structures with low complication rates and minimal recovery time, and outcomes are also under study. Finally, while neuromodulatory devices such as responsive neurostimulation, vagus nerve stimulation, and deep brain stimulation have a role in the treatment of certain patients, these remain palliative procedures for those who are not candidates for resection or ablation, as complete seizure freedom rates are low. Further development and investigation of both established and novel strategies for the surgical treatment of TLE will be critical moving forward, given the significant burden of this disease.     

Cognitive outcome after epilepsy surgery in children

The ultimate goal of epilepsy surgery in young children is to stop seizures, interrupt the downhill course of the epileptic encephalopathy, and improve developmental capacities. Postoperative outcome after childhood epilepsy surgery should therefore not only be expressed in terms of seizure freedom, cognitive outcome is an equally important outcome measure. Insight in the mutually dependent variables that can determine pre and postoperative cognitive developmental abilities will improve prediction of outcome and presurgical counseling of parents. The purpose of this review is to discuss the literature regarding cognitive outcome and the predictors of postoperative cognitive functioning after epilepsy surgery in children, particularly those with “catastrophic” epilepsy. There are only few studies in which the relation between possible determinants and cognitive outcome or change was statistically tested in a multivariable manner. Duration of epilepsy, presurgical Developmental Quotient (DQ) or Intelligence Quotient (IQ), and postoperative seizure freedom were the only factors reported in different studies to be independently related to eventual cognitive outcome after epilepsy surgery. Underlying etiology, gender, age at surgery, presurgical DQ/IQ, postoperative seizure freedom, cessation of antiepileptic medication, and follow-up interval have all been described in different surgical cohorts to be independently related to a postoperative change of IQ or DQ scores. To appreciate how each of the pre-epileptic, presurgical, and postoperative variables may independently influence eventual cognitive outcome and postoperative cognitive improvement, we need multicenter studies with large homogenous surgical populations, using standardized tests and multivariable analyses.     

Seizure prognosis of patients with low-grade tumors

PurposeSeizures frequently impact the quality of life of patients with low grade tumors. Management is often based on best clinical judgment. We examined factors that correlate with seizure outcome to optimize seizure management.MethodsPatients with supratentorial low-grade tumors evaluated at a single institution were retrospectively reviewed. Using multiple regression analysis the patient characteristics and treatments were correlated with seizure outcome using Engel's classification.ResultsOf the 73 patients with low grade tumors and median follow up of 3.8 years (range 1–20 years), 54 (74%) patients had a seizure ever and 46 (63%) had at least one seizure before tumor surgery. The only factor significantly associated with pre-surgical seizures was tumor histology. Of the 54 patients with seizures ever, 25 (46.3%) had a class I outcome at last follow up. There was no difference in seizure outcome between grade II gliomas (astrocytoma grade II, oligodendroglioma grade II, mixed oligo-astrocytoma grade II) and other pathologies (pilocytic astrocytoma, ependymomas, DNET, gangliocytoma and ganglioglioma). Once seizures were established seizure prognosis was similar between different pathologies. Chemotherapy (p = 0.03) and radiation therapy (p = 0.02) had a positive effect on seizure outcome. No other parameter including significant tumor growth during the follow up period predicted seizure outcome. Only three patients developed new-onset seizures after tumor surgery that were non-perioperative. Anticonvulsant medication was tapered in 14 patients with seizures and 10 had no further seizures. Five patients underwent additional epilepsy surgery with a class I outcome in four. Two patients received a vagal nerve stimulator with >50% seizure reduction.DiscussionSeizures at presentation are the most important factor associated with continued seizures after tumor surgery. Pathology does not influence seizure outcome. Use of long term prophylactic anticonvulsants is unwarranted. Chemotherapy and radiation therapy have a favorable impact on seizure outcome. Additional epilepsy surgery is effective.     

Deciphering the surgical treatment gap for drug-resistant epilepsy (DRE): A literature review

Patients with drug-resistant epilepsy (DRE) rarely achieve seizure freedom with medical therapy alone. Despite being safe and effective for select patients with DRE, epilepsy surgery remains heavily underutilized. Multiple studies have indicated that the overall rates of surgery in patients with DRE have stagnated in recent years and may be decreasing, even when hospitalizations for epilepsy-related problems are on the rise. Ultimately, many patients with DRE who might otherwise benefit from surgery continue to have intractable seizures, lacking access to the full spectrum of available treatment options. In this article, we review the various factors accounting for the persistent underutilization of epilepsy surgery and uncover several key themes, including the persistent knowledge gap among physicians in identifying potential surgical candidates, lack of coordinated patient care, patient misconceptions of surgery, and socioeconomic disparities impeding access to care. Moreover, factors such as the cost and complexity of the preoperative evaluation, a lack of federal resource allocation for the research of surgical therapies for epilepsy, and difficulties recruiting patients to clinical trials all contribute to this multifaceted dilemma.