Discontinuation of medications after successful epilepsy surgery in children

Do we have to continue antiseizure medications post surgery in long-term epilepsy associated tumors (LEATs)?

OBJECTIVE

To identify the rate of successful antiseizure medication (ASM) withdrawal after resective surgery in patients with long-term epilepsy-associated tumors (LEATs).

METHODS

A retrospective analysis (from our prospectively archived data) on the post-operative ASM profile of 123 consecutive patients who completed a minimum of 2 years after resection of LEATs for ASM-resistant epilepsy. A comparison between recurred and non-recurred groups in terms of seizure recurrence was used to identify the potential predictors of seizure recurrence whose attributes were further analyzed using univariate and multiple logistic regression analysis. Kaplan-Meier survival curves were used to study the probability of ASM freedom following surgery.

RESULTS

We attempted ASM withdrawal in 102 (82.9 %) patients. Forty-eight (47.1 %) had seizure recurrence while reducing ASM, of which 22 (21.6 %) continued to have seizures even after ASM optimisation. On univariate analysis, presence of pre-operative secondary generalized seizure(s) was the only factor associated with seizure recurrence. At a mean follow-up of 6.1 years, 72 (58.5 %) patients were seizure-free and aura-free at terminal follow-up (53 patients were off any ASM). The cumulative probability of achieving complete ASM-free status was 29 % at fourth year, 42 % at sixth year, 55 % at eighth year, and 59 % at 10th year after surgery.

CONCLUSIONS

Following resective surgery for LEATs, ASM(s) could be successfully discontinued in half of the patients. About one-third of the patients may have recurrent seizures on follow-up. Presence of secondary generalized seizure(s) prior to surgery predicts seizure recurrence, whereas MRI defined completeness of resection will not. This information will help in rationalising decisions on ASM management post-resection.

Early antiseizure medication withdrawal and risk of seizure recurrence in children after epilepsy surgery: A retrospective study

OBJECTIVE

The timing of antiseizure medication (ASM) withdrawal in children after epilepsy surgery remains controversial and lacks recognized standards. Given the various negative effects of ASM on development in children, this study aimed to evaluate the safety and feasibility of early ASM withdrawal after epileptic resection surgery.

METHODS

We retrospectively assessed the seizure outcomes and ASM profiles of children who had undergone epileptic resection surgery between August 2015 and August 2020 and attempted ASM reduction in the early postoperative phase. Tapering the dose of ASM was attempted when children were seizure-free with no interictal epileptiform discharges (IEDs) on electroencephalogram (EEG) for at least 6 months postoperatively.

RESULTS

This study included 145 children with a median follow-up duration of 40 months. Early ASM tapering was attempted postoperatively in 99 (68.3 %) children. Postoperative ASM discontinuation was attempted in 87 (60.0 %) children. Nine (9.1 %) children experienced seizure recurrence during the ASM reduction stage, and 10 (11.5 %) experienced recurrence after ASM discontinuation. Incomplete resection (P = 0.003) and postoperative seizures before ASM tapering (P = 0.003) were independent predictors of seizure recurrence during and after early ASM withdrawal.

SIGNIFICANCE

ASM withdrawal is viable and safe to be initiated in children who are seizure-free postoperatively and have no IEDs on the scalp EEG for at least 6 months. Children with incomplete resection and postoperative seizures before ASM withdrawal are at a higher risk of seizure recurrence and may need to continue ASM for a longer period.

Outcome after conservative or surgical treatment for new-onset epilepsy in children with cerebral cavernous malformation

OBJECTIVE

This study aimed to investigate and compare the outcome of conservatively or surgically treated children with cerebral cavernous malformation (CCM) and new-onset CCM-related epilepsy (CRE) during a 5-year period.

METHODS

In this observational monocentric cohort study, data were collected ambispectivley. Our database was screened for CCM patients treated between 2003 and 2020. Patients ≤18 years of age with complete magnetic resonance imaging dataset, clinical baseline characteristics, and diagnosis of new-onset CRE were included. Definite seizure control was classified as International League Against Epilepsy class <2. Functional outcome was assessed using the modified Rankin Scale score. CRE patients were separated into two groups according to their treatment modality. Seizure control, intake of antiseizure medication, and functional outcomes were assessed. Systematic literature research was performed to identify other cases of new-onset CRE in children and to compare the collected data with published data.

RESULTS

Thirty-nine pediatric CRE patients were analyzed. A total of 18 (46.1%) patients were conservatively treated, while 21 (53.8%) underwent surgical CCM removal. While the functional outcome was similar in both groups at the last follow-up, definite seizure control was better in the surgical group (77.8%) than in the conservative group (25.0%) both after 5-years of follow-up (p = 0.038), and at last follow-up with 85.7% versus 50% respectively (p = 0.035). We found substantially higher rates of discontinuation of antiseizure medication at the last available follow-up in patients undergoing surgical resection (p = 0.009). The systematic literature review identified 4 studies with a total of 30 additional children with early onset CRE.

CONCLUSION

Surgical treatment of pediatric patients with new-onset CRE had higher rates of complete seizure control and early discontinuation of antiseizure medication than conservative treatment. Neurological outcomes of patients managed surgically or conservatively were comparable. These results encourage early surgical management of children with CRE even in the absence of pharmacoresistant epilepsy, but randomized control trials are urgently needed for further decision-making.

Epilepsy surgery for low-grade epilepsy-associated neuroepithelial tumor of temporal lobe: a single-institution experience of 61 patients

Background

Low-grade epilepsy-associated neuroepithelial tumor (LEAT) is highly responsive to surgery in general. The appropriate surgical strategy remains controversial in temporal LEAT. The aim of this study is to analyze the surgical seizure outcome of temporal LEAT, focusing on the aspects of surgical strategy.

Methods

Sixty-one patients from a single epilepsy center with temporal LEAT underwent surgery. The surgical strategy was according to the multidisciplinary presurgical evaluation. Electrocorticogram (ECoG)-assisted resection was utilized. Surgical extent including lesionectomy and extended resection was described in detail. Seizure outcome was classified as satisfactory (Engel class I) and unsatisfactory (Engel classes II–IV).

Results

After a median follow-up of 36.0 (30.0) months, 83.6% of patients achieved satisfactory outcome, including 72.1% with Engel class Ia. There was 39.3% (24/61) of patients with antiepileptic drug (AED) withdrawal. Use of ECoG (χ2 = 0.000, P > 0.1), preresection spike (χ2 = 0.000, P = 0.763), or spike residue (P = 0.545) was not correlated with the seizure outcome. For lateral temporal LEAT, outcome from lesionectomy was comparable to extended resection (χ2 = 0.499, P > 0.1). For mesial temporal LEAT, 94.7% (18/19) of patients who underwent additional hippocampectomy were satisfactory, whereas only 25% (1/4) of patients who underwent lesionectomy were satisfactory (P = 0.009).

Conclusion

Surgical treatment was highly effective for temporal LEAT. ECoG may not influence the seizure outcome. For lateral temporal LEAT, lesionectomy with or without cortectomy was sufficient in most patients. For mesial temporal LEAT, extended resection was recommended.

Antiseizure Medication Withdrawal Following Epilepsy Surgery

As pediatric epilepsy surgery cases increase in number and complexity, there remains a paucity of data regarding how, when, and in whom to discontinue antiseizure medications postoperatively. The "TimeToStop" data has been influential to clinical practice, revealing that while early discontinuation of antiseizure medications may reveal surgical failures earlier, it does not ultimately lead to a change in long-term seizure outcomes. The authors of other studies have also shown cognitive improvements in children for whom medications were discontinued postoperatively. Survey results over the last 2 decades have shown that clinicians have started to discontinue antiseizure medications earlier. This is an individualized decision with numerous factors to consider. Further research is needed to explore the optimal timing of medication discontinuation in this heterogeneous population of children undergoing epilepsy surgery.

Ambulatory EEG Usefulness in Epilepsy Management

SUMMARY

Long-term video-EEG monitoring has been the gold standard for diagnosis of epileptic and nonepileptic events. Medication changes, safety, and a lack of recording EEG in one's habitual environment may interfere with diagnostic representation and subsequently affect management. Some spells defy standard EEG because of ultradian and circadian times of occurrence, manifest nocturnal expression of epileptiform activity, and require classification for clarifying diagnostic input to identify optimal treatment. Some patients may be unaware of seizures, have frequent events, or subclinical seizures that require quantification before optimal management. The influence on antiseizure drug management and clinical drug research can be enlightened by long-term outpatient ambulatory EEG monitoring. With recent governmental shifts to focus on mobile health, ambulatory EEG monitoring has grown beyond diagnostic capabilities to target the dynamic effects of medical and nonmedical treatment for patients with epilepsy in their natural environment. Furthermore, newer applications in ambulatory monitoring include additional physiologic parameters (e.g., sleep, detection of myogenic signals, etc.) and extend treatment relevance to patients beyond seizure reduction alone addressing comorbid conditions. It is with this focus in mind that we direct our discussion on the present and future aspects of using ambulatory EEG monitoring in the treatment of patients with epilepsy.

Prediction of the recurrence risk in patients with epilepsy after the withdrawal of antiepileptic drugs

Many seizure-free patients who consider withdrawing from antiepileptic drugs (AEDs) hope to discontinue treatment to avoid adverse effects. However, withdrawal has certain risks that are difficult to predict. In this study, we performed a literature review, summarized the causes of significant variability in the risk of postwithdrawal recurrent seizures, and reviewed study data on the age at onset, cause, types of seizures, epilepsy syndrome, magnetic resonance imaging (MRI) abnormalities, epilepsy surgery, and withdrawal outcomes of patients with epilepsy. Many factors are associated with recurrent seizures after AED withdrawal. For patients who are seizure-free after treatment, the role of an electroencephalogram (EEG) alone in ensuring safe withdrawal is limited. A series of prediction models for the postwithdrawal recurrence risk have incorporated various potentially important factors in a comprehensive analysis. We focused on the populations of studies investigating five risk prediction models and analyzed the predictive variables and recommended applications of each model, aiming to provide a reference for personalized withdrawal for patients with epilepsy in clinical practice.

The Concept of Drug-Resistant Epileptogenic Zone

Resective surgery is the most effective way to treat drug-resistant epilepsy. Despite extensive pre-surgical evaluation, only 30–70% patients would become seizure-free after surgery. New approaches and strategies are needed to improve the outcome of epilepsy surgery. It is commonly observed in clinical practice that antiepileptic drugs (AEDs) could maintain seizure freedom in a large proportion of patients after surgery, who were uncontrolled before the operation. In some patients cessation of AEDs leads to seizure recurrence which, in most cases, can be controlled by resuming AEDs. These observations suggest that the surgery has converted the epilepsy from drug-resistant to drug-responsive, implying that the operation has removed the brain tissue accounting for pharmacoresistance, rather than the pathological substrate of epilepsy (at least not completely). Based on these observations, it is hypothesized that there is a drug-resistant epileptogenic zone (DREZ) which overlaps with the epileptogenic zone (EZ), and has both epileptogenic and drug-resistant properties. DREZ is necessary and sufficient to cause drug-resistant epilepsy, and its remove would render the epilepsy drug-responsive. Testing the hypothesis requires the development of new methods to define the DREZ, which may be used to guide surgical planning when the epileptogenic zone cannot be completely excised. This concept can also help understand the mechanisms of drug-resistant epilepsy, leading to new therapeutic strategies.

Antiepileptic Drug Withdrawal after Surgery in Children with Focal Cortical Dysplasia: Seizure Recurrence and Its Predictors

Background and Purpose

This study investigated the seizure recurrence rate and potential predictors of seizure recurrence following antiepileptic drug (AED) withdrawal after resective epilepsy surgery in children with focal cortical dysplasia (FCD).

Methods

We retrospectively analyzed the records of 70 children and adolescents with FCD types I, II, and IIIa who underwent resective epilepsy surgery between 2004 and 2015 and were followed for at least 2 years after surgery.

Results

We attempted AED withdrawal in 40 patients. The median time of starting the AED reduction was 10.8 months after surgery. Of these 40 patients, 14 patients (35%) experienced seizure recurrence during AED reduction or after AED withdrawal. Half of the 14 patients who experienced recurrence regained seizure freedom after AED reintroduction and optimization. Compared with their preoperative status, the AED dose or number was decreased in 57.1% of patients, and remained unchanged in 14.3% after surgery. A multivariate analysis found that incomplete resection (p=0.004) and epileptic discharges on the postoperative EEG (p=0.025) were important predictors of seizure recurrence after AED withdrawal. Over the mean follow-up duration of 4.5 years after surgery, 34 patients (48.6% of the entire cohort) were seizure-free with and without AEDs.

Conclusions

Children with incomplete resection and epileptic discharges on postoperative EEG are at a high risk of seizure recurrence after drug withdrawal. Complete resection of FCD may lead to a favorable surgical outcome and successful AED withdrawal after surgery.

"Time is Brain"-How early should surgery be done in drug-resistant TLE?

OBJECTIVES

To explore the effect of duration of epilepsy and delay in surgery on seizure outcome in patients operated for drug-resistant temporal lobe epilepsy (TLE).

MATERIALS & METHODS

A total of 664 consecutive patients who underwent anterior temporal lobectomy (ATL) for TLE from 1995 to 2008 formed the study cohort. We divided them into two, one as seizure-free with or without antiepileptic drugs after ATL as "good outcome" (Engel class I a) and seizures of any type, any time after surgery as "poor outcome." The probability of seizure freedom/seizure recurrence based on the duration of epilepsy was compared using Kaplan-Meier curves, univariate Cox regression survival analysis, and multivariate Cox proportional hazards regression model.

RESULTS

A total of 136 children and 528 adults underwent ATL during this period. Mean duration of epilepsy pre-ATL was 17.1 + 9.4 years. At mean follow-up of 8.5 years, 331 patients (49.8%) had good outcome and 333 (50.2%) had poor outcome. The hazard of seizure recurrence linearly increased with duration of epilepsy pre-ATL, from 1.5 (duration of epilepsy, 5-10 years) to 1.9 (duration of epilepsy, 10-15 years) to 2 (duration of epilepsy over 15 years). In addition, encephalitis as antecedent, bilateral mesial temporal sclerosis in MRI, normal histopathology, and spikes in postoperative EEG at 3 months and 1 year predicted poor seizure outcome.

CONCLUSIONS

"Epilepsy duration" independently predicted both short- and long-term seizure outcome after surgery in TLE. "Lost years" translate into poor seizure outcome after ATL. Therefore, all cases of drug-resistant TLE should be referred to a surgical center at the earliest.

Uncertainties from a worldwide survey on antiepileptic drug withdrawal after seizure remission

Background

We sought to determine differences in practice for discontinuation of antiepileptic drugs (AEDs) after seizure remission and stimulate the planning and conduction of withdrawal trials.

Methods

We utilized a worldwide electronic survey that included questions about AED discontinuation for 3 paradigmatic cases in remission: (1) focal epilepsy of unknown etiology, (2) temporal lobe epilepsy after surgery, and (3) juvenile myoclonic epilepsy. We analyzed 466 complete questionnaires from 53 countries, including the United States. Statistical analysis included χ² and multivariate logistic regression.

Results

Case 1: responders in practice for <10 years were less likely to taper AEDs: odds ratio (OR) (95% confidence interval [CI]) 0.52 (0.32-0.85), p = 0.02. The likelihood of stopping AEDs was higher among doctors treating children: OR (95% CI): 11.41 (2.51-40.13), p = 0.002. Doctors treating children were also more likely to stop after 2 years or less of remission: OR (95% CI): 6.91 (2.62-19.31), p = 0.002, and the same was observed for US physicians: OR (95% CI): 1.61 (1.01-2.57), p = 0.0049. Case 2: responders treating children were more likely to taper after 1 year or less of postoperative remission, with the goal of discontinuing all medications: OR (95% CI): 1.91 (1.09-3.12), p = 0.015, and so were US-based responders: OR (95% CI): 1.73 (1.21-2.41), p = 0.003. Case 3: epileptologists were less likely to withdraw the medication: OR (95% CI): 0.56 (0.39-0.82), p = 0.003, and so were those in practice for 10 or more years: OR (95% CI): 0.54 (0.31-0.95), p = 0.025.

Conclusions

We observed several differences in practice for AED withdrawal after seizure remission that highlight global uncertainty. Trials of AED discontinuation are needed to provide evidence-based guidance.

Does early postoperative drug regimen impact seizure control in patients undergoing temporal lobe resections?

OBJECTIVE

To evaluate the impact of postoperative antiepileptic drug (AED) load on seizure control in patients who underwent surgical treatment for pharmacoresistant mesiotemporal lobe epilepsy during the first two postoperative years.

PATIENTS AND METHODS

532 consecutive patients (48.7% males and 51.7% females) who underwent surgical treatment for mesiotemporal lobe epilepsy were retrospectively evaluated regarding effects of AED load on seizures control during the first 2 years following epilepsy surgery. We analyzed whether postoperative increases in postoperative AED load are associated with better seizure control in patients initially not seizure free, and if postoperative decreases in postoperative AED load would increase the risk for seizure persistence or recurrence. For statistical analyses, Fisher's exact and Wilcoxon test were applied.

RESULTS

68.9, 64.0 and 59.1% of patients were completely seizure free (Engel Ia) at 3, 12 and 24 months after surgery, respectively. Patients in whom daily drug doses were increased did not have a higher rate of seizure freedom at any of the three follow-up periods. Of 16 patients achieving secondary seizure control at 12 months after surgery, only one did so with an increase in drug load in contrast to 15 patients who experienced a running down of seizures independent of drug load increases. Decreases in drug load did not significantly increase the risk for seizure recurrence. Of postoperatively seizure free patients at 3 months after surgery in whom AED were consequently reduced, 85% remained completely seizure free at 1 year and 76% at 1 year after surgery, respectively, as opposed to 86% each when AED was not reduced (differences n.s.). Mean daily drug load was significantly lower in seizure free patients at 12 and 24 months compared to patients with ongoing seizures.

CONCLUSION

In this large patient cohort stratified to the epilepsy syndrome neither did a postoperative reduction in drug load significantly increase the risk for seizure relapse nor did increases in drug dosages lead to improved seizure control. Mean drug load was on average lower in seizure free- than non-seizure free patients at 12 and 24 months of follow-up. Secondary seizure control after initial postoperative seizures in > 90% of cases occurred as a running down, independent of an AED increase. Thus, the effect of the surgical intervention rather than the postoperative drug regimen was the key determinant for seizure control. This finding supports a curative role of temporal lobe surgery rather than an effect rendering the majority of patients' pharmacoresponsive with a critical role of the antiepileptic drug regime for seizure control.

Pediatric epilepsy surgery: could age be a predictor of outcomes?

OBJECTIVE Like adults, many children suffering from intractable seizures benefit from surgical therapy. Although various reports indicate that early intervention may avoid severe developmental consequences often associated with intractable epilepsy, surgery is still considered a last option for many children. In this retrospective study, the authors aimed to determine whether pediatric epilepsy surgery, in particular during the first years of life, relates to measurable benefits. METHODS Data from 78 patients (age range 5 months to 17 years) who underwent epilepsy surgery at the Geneva and Lausanne University Hospitals between 1997 and 2012 were reviewed retrospectively. Patients were dichotomized into 2 groups: infants (≤ 3 years of age, n = 19), and children/adolescents (4-17 years of age, n = 59). Compared with children/adolescents, infants more often had a diagnosis of dysplasia (37% vs 10%, respectively; p < 0.05, chi-square test). RESULTS The overall seizure-free rate was 76.9%, with 89.5% in infants and 72.9% in the children/adolescents group. Infants were 2.76 times as likely to achieve seizure-free status as children/adolescents. Postoperative antiepileptic medication was reduced in 67.9% of patients. Only 11.4% of the patients were taking more than 2 antiepileptic drugs after surgery, compared with 43% before surgery (p < 0.0001). The overall complication rate was 15.1% (6.4% transient hemiparesis), and no major complications or deaths occurred. CONCLUSIONS The data show a high seizure-free rate in children ≤ 3 years of age, despite a higher occurrence of dysplastic, potentially ill-defined lesions. Pediatric patients undergoing epilepsy surgery can expect a significant reduction in their need for medication. Given the excellent results in the infant group, prospective studies are warranted to determine whether age ≤ 3 years is a predictor for excellent surgical outcome.

Seizure outcomes in children with epilepsy after resective brain surgery

PURPOSE

To assess the role of resective brain surgery in childhood epilepsy.

METHODOLOGY

We retrospectively analysed the seizure outcomes in 55 children with epilepsy who had resective brain surgery between 1997 and 2012, at our centre. The children were 1.5-18 years at the time of surgery; their seizure onset was between 0.2 andto 15 years of age. 48 had refractory epilepsy. One child died of tumour progression. Follow-up duration in the survivors ranged from 2 to -16 years (mean: 9).Presurgical evaluation included clinical profiles, non-invasive V-EEG monitoring, neuroimaging with MRIs in all; SPECT and PET in selected patients. 54 had intraoperative ECoG.

RESULTS

An Engel Class 1 outcome was seen in 78% of the cohort, with 67% being off all AEDs at the most recent follow-up. Children with tumours constituted the majority (56%), with 87% of this group showing a Class 1 outcome and 84% being off AEDs. Children with cortical dysplasia had a Class 1 outcome in 56%.

CONCLUSION

Resective brain surgery is an efficacious option in some children with epilepsy. We found ECoG useful to tailor the cortical resection and in our opinion ECoG contributed to the good seizure outcomes.

Improvement of language development after successful hemispherotomy

PURPOSE

To investigate language development after functional hemispherotomy and to evaluate prognostic factors for (un-)favourable outcomes.

METHODS

Children and adolescents who had vertical perithalamic hemispherotomy at the Medical University Wien (MUW) paediatric epilepsy centre were identified from a prospectively maintained database. Inclusion criteria were: complete clinical, neurophysiological and neuropsychological data, seizure freedom and a minimum follow-up of 12 months after surgery. The language quotients (LQ) prior to surgery and at last follow-up were calculated for each child. In addition, associations between pre- to post-surgical changes in LQ and the following variables were examined: age at epilepsy-onset, age at surgery and duration of epilepsy prior to surgery, aetiology, side of surgery, interictal EEG including sleep organization before and 12 months after surgery and antiepileptic-drug (AED) withdrawal state at last follow-up. Analyses were carried out in SPSS version 20.0 (SPSS Inc., Chicago, IL, USA). Nonparametric Wilcoxon and chi-square tests were applied, as required.

RESULTS

Data from 28 children (14 female) were analyzed. The median age at epilepsy surgery was 64.5 months. The median follow-up after surgery was 3.0 years (±2.6 years, range 12 months to 12 years). Significant gains in LQs at last follow-up were found in 31% of the children (p=0.008). Short disease duration prior to surgery, acquired pathology, lack of epileptiform EEG discharges in the contralateral hemisphere and/or normalization of EEG sleep patterns after surgery, and successful AED withdrawal were linked to favourable language outcomes.

CONCLUSION

Successful and early hemispherotomy results in improvement of language function in the intact hemisphere.

Prognostic Tests and Antiepileptic Drug Withdrawal After Epilepsy Surgery

Approximately one in three patients with a successful epilepsy surgery will have seizure recurrence following antiepileptic drugs (AED) withdrawal. The value of postoperative testing for predicting seizure relapse after AED tapering is not clear. The purpose of this study was to review the literature for evidence on the use of postoperative investigations before AED discontinuation after successful epilepsy surgery. We were unable to identify studies on the prognostic value of postoperative magnetic resonance imaging and AED blood levels. The literature review yielded seven studies on the predictive value of electroencephalography. Four studies found no association between interictal discharges (IED) and seizure relapse. These studies suffered from various limitations due to their retrospective design and generally small cohorts. Two of the three studies reporting a positive association were prospective and provided strong evidence of an increased risk of seizure recurrence with presence of postoperative IED in successfully operated patients undergoing AED withdrawal.

Reducing versus stopping antiepileptic medications after temporal lobe surgery

Objective

To study the safety of antiepileptic drug (AED) withdrawal after temporal lobe epilepsy (TLE) surgery.

Methods

We reviewed patients who underwent TLE surgery from 1995 to 2011, collecting data on doses, dates of AED initiation, reduction, and discontinuation. Predictors of seizure outcome were defined using Cox-proportional hazard modeling and adjusted for, while comparing longitudinal seizure-freedom in patients for whom AEDs were unchanged after resection as opposed to reduced or stopped.

Results

A total of 609 patients (86% adults) were analyzed. Follow-up ranged from 0.5 to 16.7 years. Most (64%) had hippocampal sclerosis. Overall, 229 patients had remained on their same baseline AEDs, while 380 patients stopped (127 cases) or reduced (253 cases) their AEDs. Mean timing of the earliest AED change was shorter in patients with recurrent seizures (1.04 years) compared to those seizure-free at last follow-up (1.44 years; P-value 0.03). Whether AEDs were withdrawn 12 or 24 months after surgery, there was a 10–25% higher risk of breakthrough seizures within the subsequent 2 years. However, 70% of patients with seizure recurrence after AED discontinuation reachieved remission, as opposed to 50% of those whose seizures recurred while reducing AEDs (P = 0.0001). Long-term remission rates were similar in both AED discontinuation and “unchanged” groups (82% remission for AEDs withdrawn after 1 year and 90% for AEDs withdrawn after 2 years), while only 65% of patients whose recurrences started during AED reduction achieved a 2-year remission by last follow-up.

Interpretation

AED withdrawal increases the short-term risk of breakthrough seizures after TLE surgery, and may alter the long-term disease course in some patients.

Pediatric epilepsy surgery: long-term 5-year seizure remission and medication use

BACKGROUND

It is unclear whether long-term seizure outcomes in children are similar to those in adult epilepsy surgery patients.

OBJECTIVE

To determine 5-year outcomes and antiepilepsy drug (AED) use in pediatric epilepsy surgery patients from a single institution.

METHODS

The cohort consisted of children younger than 18 years of age whose 5-year outcome data would have been available by 2010. Comparisons were made between patients with and without 5-year data (n = 338), patients with 5-year data for seizure outcome (n = 257), and seizure-free patients on and off AEDs (n = 137).

RESULTS

Five-year data were available from 76% of patients. More seizure-free patients with focal resections for hippocampal sclerosis and tumors lacked 5-year data compared with other cases. Of those with 5-year data, 53% were continuously seizure free, 18% had late seizure recurrence, 3% became seizure free after initial failure, and 25% were never seizure free. Patients were more likely to be continuously seizure free if their surgery was performed during the period 2001 to 2005 (68%) compared with surgery performed from 1996 to 2000 (61%), 1991 to 1995 (36%), and 1986 to 1990 (46%). More patients had 1 or fewer seizures per month in the late seizure recurrence (47%) compared with the not seizure-free group (20%). Four late deaths occurred in the not seizure-free group compared with 1 in the seizure-free group. Of patients who were continuously seizure free, 55% were not taking AEDs, and more cortical dysplasia patients (74%) had stopped taking AEDs compared with hemimegalencephaly patients (18%).

CONCLUSION

In children, 5-year outcomes improved over 20 years of clinical experience. Our results are similar to those of adult epilepsy surgery patients despite mostly extratemporal and hemispheric operations for diverse developmental etiologies.

Improved outcomes in pediatric epilepsy surgery: the UCLA experience, 1986-2008

OBJECTIVE

Epilepsy neurosurgery is a treatment option for children with refractory epilepsy. Our aim was to determine if outcomes improved over time.

METHODS

Pediatric epilepsy surgery patients operated in the first 11 years (1986-1997; pre-1997) were compared with the second 11 years (1998-2008; post-1997) for differences in presurgical and postsurgical variables.

RESULTS

Despite similarities in seizure frequency, age at seizure onset, and age at surgery, the post-1997 series had more lobar/focal and fewer multilobar resections, and more patients with tuberous sclerosis complex and fewer cases of nonspecific gliosis compared with the pre-1997 group. Fewer cases had intracranial EEG studies in the post-1997 (0.8%) compared with the pre-1997 group (9%). Compared with the pre-1997 group, the post-1997 series had more seizure-free patients at 0.5 (83%, +16%), 1 (81%, +18%), 2 (77%, +19%), and 5 (74%, +29%) years, and more seizure-free patients were on medications at 0.5 (97%, +6%), 1 (88%, +9%), and 2 (76%, +29%), but not 5 (64%, +8%) years after surgery. There were fewer complications and reoperations in the post-1997 series compared with the pre-1997 group. Logistic regression identified post-1997 series and less aggressive medication withdrawal as the main predictors of becoming seizure-free 2 years after surgery.

CONCLUSIONS

Improved technology and surgical procedures along with changes in clinical practice were likely factors linked with enhanced and sustained seizure-free outcomes in the post-1997 series. These findings support the general concept that clearer identification of lesions and complete resection are linked with better outcomes in pediatric epilepsy surgery patients.

Medication policy after epilepsy surgery

The postsurgical medication policy was reviewed for 109 children (age at surgery, 0-16 years) who had epilepsy surgery between 1991 and 2005. Intervals between surgery and both start (n = 84) and completion (n = 68) of withdrawal of antiepileptic drugs (AEDs) were calculated and analyzed in relation to demographic and epilepsy variables and to recurrent seizures. Postoperative seizure freedom was associated with completeness of surgical resection, defined as complete removal of the cortical region exhibiting ictal or interictal abnormalities on intracranial electroencephalography and lesion on magnetic resonance imaging (P = 0.008). Etiology seemed to be related, but numbers were too small for statistical analysis. In 24 children (22%), seizures recurred postoperatively, and in 19 of these 24 children the AEDs were never withdrawn. Two of the five children in whom seizures recurred after medication withdrawal regained seizure freedom. Mean interval from surgery to start of drug withdrawal was 1.71 years (n = 84), and 2.86 years (n = 68) from surgery to complete withdrawal. Seizure recurrence seemed not associated with withdrawal decisions. Timing of seizure relapse was identical in children still on AEDs and in those who stopped. Eight children with early discontinuation (0.6 years from surgery to start of withdrawal and 0.8 years to complete withdrawal) had no seizure recurrence. Long-term continuation of AEDs is probably not indicated in children with complete resection of the epileptogenic zone. The optimal timing needs to be further explored.

Drug withdrawal after successful epilepsy surgery: how safe is it?

Discontinuation of antiepileptic drugs (AEDs) is one reason patients undergo epilepsy surgery, but little is known about the risk of seizure recurrence. We describe a prospective pilot study of withdrawal performed at our epilepsy center. Sixty completely seizure-free patients were included between 1997 and 2003. AED withdrawal was proposed 1 year after surgery after a detailed discussion of the risks and benefits. On the basis of their decision on withdrawal, patients were stratified into two cohorts (withdrawal group, N=34; control group, N=26). Discontinuation was carried out in small tapering steps over 1 year with yearly follow-up visits. Withdrawal was stopped when seizures recurred or the patients objected to further discontinuation. Twenty-six of 34 (76.5%) persons in the withdrawal group and 16 of 26 (61.5%) persons in the control group were seizure free 5 years after surgery. In this study, AED discontinuation 1 year after successful epilepsy surgery was not associated with a risk of seizure recurrence higher than that of controls.

Debate: Should antiepileptic drugs be stopped after successful epilepsy surgery?

There is no consensus on whether or when to stop anticonvulsant drug treatment in patients after apparently successful epilepsy surgery. Although there are compelling reasons to consider antiepileptic drug (AED) discontinuation, there are relatively few data, and no class 1 data, to guide patient and physician decision-making on this topic. This debate lays out a conceptual framework for considering the issue of AED discontinuation, and reviews and critiques the available data. The goal is to provide physicians with the best available data, a context in which to consider it, and a full understanding of its limitations. This article also highlights an area that is ripe for further prospective study.