Predictors for relapse after antiepileptic drug withdrawal in seizure-free patients with epilepsy

A meta-analysis of the relationship between abnormal pretreatment EEG and epilepsy recurrence

BACKGROUND

Researchers have studied the risk factors for epilepsy recurrence among patients who withdraw from antiseizure medication (ASM). These studies aimed to determine the optimal time for ASM withdrawal. EEG findings are one of the risk factors that has been studied. However, it remains unclear whether abnormal pretreatment EEG findings are a risk factor for recurrence after ASM withdrawal. We performed this meta-analysis to clarify this issue.

METHODS

We retrieved literature from the PubMed and Embase databases, and used the NewcastleOttawa Scale to evaluate the methodological quality of the included studies. RevMan 5.3 software was used to analyse the data.

RESULTS

In total,710 articles were retrieved from the databases. Ultimately, after screening, 11 articles involving 1686 patients with epilepsy were included. Compared with that for a normal EEG, the odds ratio (OR) for an abnormal EEG was 1.10 (P=0.50), with an I2 value of 32% (P=0.15). Subgroup analysis revealed that the children-to-adolescents subgroup had an OR of 1.21 (P=0.27), and the children-to-adults subgroup had an OR of 0.64 (P=0.14) for an abnormal EEG. A separate subgroup analysis revealed that the focal epilepsy subgroup had an OR of 1.30 (P=0.37), and the generalized epilepsy and focal epilepsy subgroup had an OR of 1.07 (P=0.67) for an abnormal EEG.

CONCLUSIONS

The risk of epilepsy recurrence is not related to pretreatment EEG findings, regardless of age or epilepsy classification. The associations of pre- and posttreatment EEG alterations with epilepsy recurrence are controversial. Due to the limitations of our article, further research is needed.

The pharmacological treatment of epilepsy in adults

The pharmacological treatment of epilepsy entails several critical decisions that need to be based on an individual careful risk-benefit analysis. These include when to initiate treatment and with which antiseizure medication (ASM). With more than 25 ASMs on the market, physicians have opportunities to tailor the treatment to individual patients´ needs. ASM selection is primarily based on the patient's type of epilepsy and spectrum of ASM efficacy, but several other factors must be considered. These include age, sex, comorbidities, and concomitant medications to mention the most important. Individual susceptibility to adverse drug effects, ease of use, costs, and personal preferences should also be taken into account. Once an ASM has been selected, the next step is to decide on an individual target maintenance dose and a titration scheme to reach this dose. When the clinical circumstances permit, a slow titration is generally preferred since it is associated with improved tolerability. The maintenance dose is adjusted based on the clinical response aiming at the lowest effective dose. Therapeutic drug monitoring can be of value in efforts to establish the optimal dose. If the first monotherapy fails to control seizures without significant adverse effects, the next step will be to gradually switch to an alternative monotherapy, or sometimes to add another ASM. If an add-on is considered, combining ASMs with different modes of action is usually recommended. Misdiagnosis of epilepsy, non-adherence and suboptimal dosing are frequent causes of treatment failure and should be excluded before a patient is regarded as drug-resistant. Other treatment modalities, including epilepsy surgery, neuromodulation, and dietary therapies, should be considered for truly drug-resistant patients. After some years of seizure freedom, the question of ASM withdrawal often arises. Although successful in many, withdrawal is also associated with risks and the decision needs to be based on careful risk-benefit analysis.

Risk factors of recurrence after drug withdrawal in children with epilepsy

This study aimed to evaluate the risk factors for recurrence in pediatric patients with epilepsy following normal antiseizure medication (ASM) treatment and drug withdrawal. We retrospectively analyzed 80 pediatric patients who received treatment at the Qilu Hospital of Shandong University between January 2009 and December 2019 after at least 2 years of seizure-free and normal electroencephalography (EEG) before the regular drug reduction. Patients were followed-up for at least 2 years and divided into the recurrence and nonrecurrence groups based on whether relapse occurred. Clinical information was gathered, and the risk variables for recurrence were statistically analyzed. Post 2 years of drug withdrawal, 19 patients showed relapses. The recurrence rate was 23.75%, and the mean time of recurrence was 11.09 ± 7.57 months, where 7 (36.8%) were women and 12 (63.2%) were men. In all, 41 pediatric patients were followed-up until the 3rd year, of which 2 (4.9%) patients experienced a relapse. Among the remaining 39 patients without relapse, 24 were followed-up until the 4th year, and no recurrence occurred. After being monitored for >4 years, 13 patients experienced no recurrence. The differences in the history of febrile seizures, combined use of ≥2 ASMs, and EEG abnormalities after drug withdrawal between the two groups were statistically significant (p < 0.05). Multivariate binary logistic regression analysis revealed that these factors are independent risk factors for recurrence after drug withdrawal in children with epilepsy: history of febrile seizures (OR = 4.322, 95% CI: 1.262-14.804), combined ASM use (OR = 4.783, 95% CI: 1.409-16.238), and EEG abnormalities after drug withdrawal (OR = 4.688, 95% CI: 1.154-19.050). In summary, our results suggest that the probability of seizure recurrence following drug cessation may be greatly increased by a history of febrile seizures, concomitant use of ≥2 ASMs, and EEG abnormalities after drug cessation. The majority of recurrences occurred in the first 2 years following drug discontinuation, whereas the rate of recurrence was minimal thereafter.

Risk of seizure relapse and long-term outcomes after discontinuation of antiseizure medication in children with epilepsy

OBJECTIVES

The aims of this study were to evaluate the demographic and clinical characteristics of children with epilepsy who discontinued their antiseizure medication (ASM), to determine potential predictors of seizure relapse, to calculate the rate of seizure relapse, and to detect long-term seizure outcomes.

METHODS

A total of 269 seizure-free children with epilepsy who were decided to discontinue their ASM and were followed up for at least 18 months after ASM withdrawal were retrospectively evaluated.

RESULTS

The enrolled children had been followed up for a median of 46 months (range 18-126 months; IQR: 29-61) after ASM withdrawal and 90 (33.5%) of their seizures relapsed. The median time to seizure relapse was 8 months (range 0.23-117 months; IQR: 2-25). Seizure relapse occurred in 16.7% of the 90 children at 1 month, 45.6% at 6 months, 62.2% at 1 year, 74.4% at 2 years, and 94.4% at 5 years. Univariate logistic regression analyses revealed six predictors significantly related to relapse: age at first seizure, age at diagnosis of epilepsy, intellectual disability, EEG findings after ASM withdrawal, ASM tapering time, and number of seizures on ASM. In multivariate logistic regression analyses, age at first seizure, intellectual disability, and ASM tapering time were not significantly associated anymore. The other three remained independently predictive. Pharmacological control of seizures with monotherapy was restored in 93.3% of the children with seizure relapse.

CONCLUSION

This study evaluated potential predictors of seizure relapse, some of which have rarely been evaluated in previous studies. Adolescent age at diagnosis, abnormal EEG findings after ASM withdrawal, and high number of seizures on ASM were associated with a higher risk of seizure relapse. Abnormal MRI findings such as malformations of cortical development and hydrocephalus may be potential biomarkers for the risk of seizure relapse.

Comparison of Long-Term Outcomes of Monotherapy and Polytherapy in Seizure-Free Patients With Epilepsy Following Antiseizure Medication Withdrawal

Objective: The objectives of this study were to compare the risk and timing of seizure relapse in seizure-free patients with epilepsy following the withdrawal of monotherapy or polytherapy and to identify relevant influencing factors.

Methods: Patients who had achieved at least a 2-year seizure remission and started the withdrawal of antiseizure medication (ASM) were enrolled in this study. All patients were followed for at least 3 years or until seizure relapse. According to the number of ASMs at the time of withdrawalwas about twice than that, patients were divided into two groups: monotherapy group and polytherapy group. The Cox proportional hazards model was used to compare the recurrence risk of the two groups. Univariate analysis and multiple logistic regression analysis were used to analyze potential confounding variables between patients treated with monotherapy and polytherapy.

Results: A total of 188 patients (119 males and 69 females) were included. The average prescribed daily dose of most ASMs at the time of withdrawal was moderate or low (30–50% defined daily dose). The recurrence of most patients (89.2%) occurred within the first 3 years after withdrawal. The recurrence risk in patients treated with polytherapy at the time of withdrawal was about twice than that of the monotherapy group [p = 0.001, hazard ratio (HR) = 2.152, 95% confidence interval (CI) = 1.350–3.428]. Multivariate analysis showed that patients treated with polytherapy were significantly older at seizure onset [p = 0.024, odd ratio (OR) = 1.027, 95% CI = 1.004–1.052] and had a significantly longer duration of epilepsy before treatment (p = 0.004, OR = 1.009, 95% CI = 1.003–1.015) compared to patients in the monotherapy group. In addition, a history of perinatal injury was found to be an independent risk factor of seizure relapse in patients with ASM withdrawal.

Conclusion: The average prescribed daily dose of most ASMs at the time of withdrawal was moderate or low. Patients who received polytherapy at the time of withdrawal, particularly those with later seizure onset age and longer epilepsy duration before treatment, had a higher recurrence risk after ASMs withdrawal compared to patients treated with monotherapy.

Risk of seizure recurrence from antiepileptic drug withdrawal among seizure-free patients for more than two years

OBJECTIVE

The aim of this study was to determine the outcome of antiepileptic drug (AED) withdrawal in patients who were seizure-free for more than two years.

METHODS

Patients with epilepsy who were seizure-free for at least two years and decided to stop AED therapy gradually were followed up every two months for seizure relapse. The inclusion criteria were as follows: (1) diagnosis of epilepsy, defined as the following conditions: ① at least two unprovoked (or reflex) seizures occurring >24 h apart; ② one unprovoked (or reflex) seizure and a probability of further seizures similar to the general recurrence risk (at least 60%) after two unprovoked seizures, occurring over the next 10 years; ③ diagnosis of an epilepsy syndrome; (2) patients remained seizure-free for at least 24 consecutive months during AED therapy; and (3) patients expressed a desire to discontinue AED therapy gradually and agreed to return for regular follow-ups. The time to a seizure relapse and predictive factors were analyzed by survival methods, including sex; age at seizure onset; number of episodes; seizure-free period before AED withdrawal; duration of follow-up after AED withdrawal; AED tapering off period (taper period); results from brain magnetic resonance (MRI); electroencephalogram (EEG) after drug withdrawal; EEG before drug withdrawal; seizure type (classified as generalized, partial, or multiple types based on history); and the number of AEDs administered for long-term seizure control. A log-rank test was used for univariate analysis, and a Cox proportional hazard model was used for multivariate analysis.

RESULTS

We selected 94 patients (58 men, 36 women). The relapse ratio was 29.8%. Univariate analysis and multivariate Cox regression analysis indicated that withdrawal times and multiple AEDs, as well as the seizure-free period before withdrawal and abnormal EEG after drug withdrawal were significantly correlated with seizure recurrence and were significant independent predictive factors, with a hazard ratio of 0.839 and 3.971, 0.957, and 3.684, respectively.

SIGNIFICANCE

The relapse rate in our study was similar to commonly reported overall rates for epilepsy. Distinguishing variables, such as withdrawal times, multiple AEDs, seizure-free period before withdrawal, and abnormal EEG after drug withdrawal, need to be considered when choosing to withdraw from AEDs. Therefore, our recommendation is that after two years of seizure-free survival, patients could consider withdrawal unless they have hippocampal sclerosis (HS).

Analysis of the short-term outcomes and risk factors of seizure relapse in patients with gliomas after antiepileptic drugs withdrawal

OBJECTIVE

The optimal timing for glioma patients to stop taking antiepileptic drugs (AEDs) and the risk factors of seizure relapse have not been determined. Here, we explored the short-term outcomes and risk factors of seizure relapse in glioma patients after withdrawal of AEDs.

METHODS

91 patients with gliomas who had no seizures at least 2 years after surgery were enrolled in the study. The patients were followed up for 1 year or until the relapse of seizure after AEDs withdrawal. The risk factors of seizure relapse were analyzed by univariate and multivariate analysis. The optimal discrimination point was determined by plotting a receiver operating characteristic (ROC) curve to explore the relationship between the number of risk factors and seizure relapse.

RESULTS

28 patients (30.8%) relapsed during the follow-up period while 63 patients (69.2%) remained seizure-free. Of the 28 relapsed patients, 20 (71.4%) relapsed within the first 6 months after the AEDs withdrawal. Multivariate analyses revealed that subtotal resection (p = 0.026), IDH1 mutation (p = 0.019), and combined use of AEDs (p = 0.037) were independent risk factors for seizure relapse in glioma patients. ROC curve based on the seizure relapse showed that the sensitivity was 0.821 and 1-specificity was 0.238, corresponding to 1.5 independent risk factors for each patient.

CONCLUSION

To obtain a favorable outcome for glioma patients with preoperative seizures, only patients with less than two independent risk factors for seizure relapse should consider discontinuing AEDs.

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.

Patients' attitude toward AED withdrawal: A survey among individuals who had been seizure-free for over 2 years

OBJECTIVE

The study aimed to evaluate the attitudes of seizure-free patients toward the antiepileptic drug (AED) withdrawal and to highlight the factors that affect their perspectives.

METHODS

The study participants were recruited among the individuals attending the epilepsy outpatient clinic of a university hospital in Skopje between January 2018 and April 2019. Patients with epilepsy who had been seizure-free for at least 2 years on stable monotherapy were included.

RESULTS

Among the 90 participants, 43 were female, and the mean age was 36.3 years. The mean duration of active epilepsy before remission was 7.9 years, and the length of the seizure-free period at the time of evaluation was 2-20 years. Forty-four percent of participants aimed to taper their antiseizure medications because of concerns about the potential long-term side effects and teratogenicity, the burden of taking medication daily, stigma, as well as the impression of no longer having a chronic disease after withdrawal. The majority of them preferred slow versus rapid withdrawal. On the other side, 55% of patients choose to continue AED treatment, mainly feeling well-adjusted to it and being concern about possible seizure recurrence after withdrawal and subsequent loss of driving license or even their jobs. Previous unsuccessful attempts to discontinue AED together with previously uncontrolled seizures were additional motives against withdrawal. The patients' views toward stopping or withholding AED were significantly associated with their gender and marital status (male patients as well as single ones favored medication withdrawal). Patients' age to some extent, though not significantly, affected their viewpoints (younger participants tended to question the further necessity of AEDs and were more concerned about the potential adverse consequences). No other demographic or epilepsy-related data considerably predisposed the decisions.

CONCLUSIONS

More than half of the patients with epilepsy preferred to continue their AED after 2 years of seizure freedom. Male gender, being single, and somewhat younger age were associated preferences to withdraw AED.

Risk factors for recurrence after drug withdrawal in childhood epilepsy

BACKGROUND

Several studies have been conducted to determine the risk of recurrence after withdrawal of antiepileptic drugs (AEDs) in recent years. There is no consensus concerning the circumstances affecting discontinuation of AEDs. This study was designed to determine the recurrence rate of epilepsy after withdrawal of AEDs and the risk factors related with recurrence.

METHODS

Children with epilepsy onset between 1 month and 16 years of age who were followed up at least 3 years after AED treatment withdrawal were enrolled. Patients were classified into groups according to defined risk factors for recurrence.

RESULTS

A total of 284 patients, 137 (48.2%) girls and 147 (51.8%) boys were included, and seizures recurred after withdrawal in 51 patients (18%). Thirty-three (64.7%) patients had recurrence in the first year after withdrawal. The recurrence risk was calculated based on the electro-clinical syndromes classification; the recurrence risk was the highest in the juvenile myoclonic/absence group and lowest in the benign infantile seizure group. No recurrence was observed in the infantile spasm group. Data evaluated by multivariable analysis showed that having the structural-metabolic and unknown epilepsy and <3 years seizure free period before withdrawal of AEDs were the main risk factors for recurrence after AED withdrawal in our study.

CONCLUSION

We suggest a seizure-free period of at least 3 years under AED medication and we must be cautious in patients with structural-metabolic and unknown epilepsy before AED withdrawal.

Correlation between EEG during AED withdrawal and epilepsy recurrence: a meta-analysis

To assess the risk of epilepsy recurrence after withdrawal from antiepileptic drugs (AEDs), researchers extensively studied recurrence-related risk factors, including electroencephalogram (EEG) during AED withdrawal. The relationship between EEG and epilepsy recurrence is controversial. We used meta-analysis to determine the correlation between EEG during AED withdrawal and epilepsy recurrence. A total of seven studies met the criteria for inclusion. The Newcastle-Ottawa Scale was used to conduct the research quality evaluation. Seven hundred three patients were included in meta-analysis. Patients with abnormal EEGs during withdrawal had a higher recurrence rate than patients with normal EEGs. Abnormal EEGs during withdrawal were a risk factor for recurrence.

Antiepileptic drug withdrawal in juvenile myoclonic epilepsy

OBJECTIVES

Withdrawal of antiepileptic drugs (AEDs) has been discouraged in juvenile myoclonic epilepsy (JME). However, impulsivity as a consequence of executive dysfunction in JME may influence treatment adherence. The aim of the present study was to assess how common withdrawal of AEDs is in a large and representative JME group.

MATERIALS AND METHODS

Patients with genetic generalized epilepsy (GGE) were identified through a retrospective search of medical records at Drammen Hospital, Norway, and invited to a clinical interview. Information related to AED withdrawal was analyzed in those classified as JME.

RESULTS

A total of 132 patients with GGE were interviewed (87 JME). Thirty-five patients with JME (40%) discontinued AEDs, of which 74% did so without consulting a doctor. The rate of self-withdrawal was significantly higher in JME than in other types of GGE. Having a parent with psychosocial difficulties was significantly over-represented in the JME self-withdrawal group. Twelve of those who discontinued AEDs (34%) were free from generalized tonic-clonic seizures (GTCS) and without antiepileptic drugs >1 year. All but one of them withdrew AEDs without consulting a doctor. Age at first motor seizure was significantly higher in those with a favorable outcome of AED withdrawal.

CONCLUSIONS

Self-withdrawal of AEDs is common in JME, especially in those with troublesome conditions at home. However, about 1/3 may remain free from GTCS without AEDs. The findings indicate a need for a stronger follow-up with appropriate information about the prognosis of the disorder.

Long-term outcome of seizure-free patients and risk factors of relapse following antiepileptic drug withdrawal

OBJECTIVE

This study aimed to investigate the long-term outcome in seizure-free patients and to explore the risk factors of seizure relapse following antiepileptic drug (AED) withdrawal.

METHODS

This study included 161 patients who had been seizure-free for at least 2 years. These patients were monitored over a follow-up period of at least 3 years or until seizure relapse after AED withdrawal. Patients were grouped into a seizure-free group and a relapse group. Risk factors of seizure relapse were analyzed.

RESULTS

During the follow-up period, 72 patients (44.7%) relapsed while 89 patients (55.3%) did not. The average time of relapse was 19.12 ± 27.17 months after the initiation of AED withdrawal, and majority of cases occurred within the first 24 months of AED withdrawal (73.6%). Univariate analysis showed that the likelihood of relapse was higher in patients with uncontrolled seizures beyond the first 6 months of AED therapy initiation, patients with a history of perinatal injury, patients with multiple seizure types, and patients who had been treated with a combination of AEDs. Multiple logistic regression analysis revealed that uncontrolled seizures beyond the first 6 months of AED treatment and a history of perinatal injury were independent risk factors of seizure relapse.

CONCLUSION

In the majority of cases, epilepsy relapse occurred within the first two years after the initiation of AED withdrawal. The independent risk factors of seizure relapse were uncontrolled seizures beyond the first 6 months of AED therapy and cases with a history of perinatal injury.

Prognostic analysis of patients with epilepsy according to time of relapse after withdrawal of antiepileptic drugs following four seizure-free years

OBJECTIVE

We performed a retrospective, prognostic analysis of a cohort of patients with epilepsy according to time of relapse after four seizure-free years.

METHODS

Planned withdrawal of antiepileptic drugs (AEDs) and at least 3 years of follow-up after AED discontinuation were performed. The following two groups were assessed: (1) an early relapse (ER) group of patients who experienced recurrence during AED withdrawal and (2) a late relapse (LR) group of patients who experienced recurrence after completion of the AED discontinuation process. After dichotomization, the relapse rate, prognostic factors, and their impacts for each group were compared with those of a group of patients who continued to be seizure-free after AED withdrawal (SF group) using multiple logistic regression analysis. The AED intake mode was also analyzed.

RESULTS

Two hundred seventeen (64.6%) of the 336 total patients experienced relapse. One hundred thirty-nine patients (41.4%) and 78 patients (23.2%) were included in the LR and ER groups, respectively. Symptom duration >120 months showed the strongest negative prognostic impact as demonstrated by the 4.7-fold higher risk of recurrence in the ER group compared with the SF group. Additional factors with a negative prognostic impact included an age at epilepsy onset of ≤20 years and the presence of localization-related epilepsy. No reliable predictor between the SF and LR groups was revealed. After exclusion of the SF group, post hoc analysis according to age at epilepsy onset and symptom duration showed that the above-mentioned negative prognostic factors significantly affected the relapse patterns of the LR and ER groups.

SIGNIFICANCE

The results suggest that longer symptom duration, which could be associated with intrinsic reactivation of epilepsy, is the strongest negative prognostic factor for relapse. Relapse after AED withdrawal in prolonged follow-up of seizure-free patients is one aspect of the natural history of epilepsy.

Can electroencephalograms provide guidance for the withdrawal of antiepileptic drugs: A meta-analysis

OBJECTIVE

The discontinuation of antiepileptic drugs (AEDs) is an important treatment decision for epilepsy patients who have been seizure-free for 2years or longer. Some patients experience seizures relapse after AED withdrawal. The prognostic value of electroencephalograms (EEGs) for seizure relapse following AED withdrawal is controversial. To our knowledge, this is the first meta-analysis to address whether EEG data can be used to guide the discontinuation of AEDs.

METHOD

We performed a meta-analysis of cohort studies that reported original EEG data from before AED withdrawal and recurrence after AED-withdrawal. The quality of each study was assessed using the Newcastle-Ottawa Scale.

RESULTS

Fifteen studies including a total of 2349 participants were included in this meta-analysis. This meta-analysis of 15 studies demonstrates that an abnormal electroencephalogram was a predictor of the risk of relapse. Additionally, paroxysmal, slowing, spike and wave activities on electroencephalograms were associated with increased risk of relapse.

CONCLUSION

We reveal that abnormal EEG records, particularly paroxysmal abnormalities, before AED withdrawal predicted a high risk of relapse. Slowing and spike and wave activities also exhibited moderate predictive values.

SIGNIFICANCE

Our findings suggest that, EEGs might be an important prognostic tool for antiepileptic drug reduction.

Risk of seizure relapse after antiepileptic drug withdrawal in adult patients with focal epilepsy

OBJECTIVE

The objective of this study was to estimate the risk of a seizure relapse and the high-risk period of recurrence after antiepileptic drug (AED) withdrawal and to determine the predictive factors for a seizure relapse in adult patients with focal epilepsy who were seizure-free for more than 2years.

METHODS

Using the Wenzhou Epilepsy Follow-Up Registry Database, 200 adult patients with focal epilepsy were recruited, who were undergoing follow-up, met the inclusion criteria of this study, were seizure-free for more than 2years, began withdrawing between June 2003 and June 2014, and were followed up prospectively for at least 1year or until a seizure relapse. The risk of recurrence and the time to seizure relapse were analyzed by the Kaplan-Meier method, and the predictive factors were identified by the Cox proportional hazard regression model.

RESULT

A total of 99 patients had an unprovoked relapse during the follow-up period. The relapse rate was 49.5%, and each year, the recurrence probability of 12, 24, 36, 48, 60, 72, and 84months after AED withdrawal was 24.0%, 20.4%, 8.3%, 2.7%, 4.6%, 0.97%, and 0.98%, respectively. The two independent risk factors for recurrence after withdrawal in adult patients with focal epilepsy were a longer duration of active epilepsy and a shorter seizure-free period before withdrawal.

CONCLUSION

The high-risk period of a seizure relapse in adult patients with focal epilepsy is the first 2years after withdrawal, and beyond 5years after withdrawal, seizures rarely relapse (relapse rate<1%). A seizure-free period for less than 4years before withdrawal is a predictive factor of risk for seizure recurrence after AED withdrawal in adult patients with focal epilepsy.

The withdrawal of antiepileptic drugs in patients with low-grade and anaplastic glioma

INTRODUCTION

The withdrawal of antiepileptic drugs (AEDs) in World Health Organization (WHO) grade II-III glioma patients with epilepsy is controversial, as the presence of a symptomatic lesion is often related to an increased risk of seizure relapse. However, some glioma patients may achieve long-term seizure freedom after antitumor treatment, raising questions about the necessity to continue AEDs, particularly when patients experience serious drug side effects. Areas covered: In this review, we show the evidence in the literature from 1990-2016 for AED withdrawal in glioma patients. We put this issue into the context of risk factors for developing seizures in glioma, adverse effects of AEDs, seizure outcome after antitumor treatment, and outcome after AED withdrawal in patients with non-brain tumor related epilepsy. Expert commentary: There is currently scarce evidence of the feasibility of AED withdrawal in glioma patients. AED withdrawal could be considered in patients with grade II-III glioma with a favorable prognosis, who have achieved stable disease and long-term seizure freedom. The potential benefits of AED withdrawal need to be carefully weighed against the presumed risk of seizure recurrence in a shared decision-making process by both the clinical physician and the patient.

Anticonvulsant and behavioral effects observed in mice following treatment with an ester derivative of ferulic acid: Isopentyl ferulate

The objective of this study was to evaluate the potential anticonvulsant effect of isopentyl ferulate, a new ester derived from ferulic acid in mice (Mus musculus) subjected to two models of induced seizures. According to the results obtained, the IF at doses of 25, 50 and 75 mg/kg (i.p.) showed protective effect against induced seizures by pilocarpine (400 mg/kg, i.p.) and pentylenetetrazole (70 mg/kg, i.p.). In the two animal models of seizures, the pretreatment of the IF (25, 50 and 75 mg/kg) with flumazenil blocked the anticonvulsant effect, suggesting that the mechanism of action of this ester derived of ferulic acid may be related to activity in the benzodiazepine-binding site of the GABAA receptor (γ-aminobutyric acid, type A). In addition to the anticonvulsant effect, behavioral changes as neurotoxicity indication were assessed by using the rota rod and open field tests. The results obtained showed that the IF (25, 50 and 75 mg/kg) does not induce significant changes in locomotor activity and motor coordination when compared with the control group, unlike the results presented by diazepam. Thus, these results demonstrate a new pharmacological knowledge of IF with potential application against epileptic seizures. However, further studies are needed to elucidate other neurobiological mechanisms underlying epilepsy.

Early versus late antiepileptic drug withdrawal for people with epilepsy in remission

BACKGROUND

Epilepsy is a chronic neurological disorder which affects millions of people around the world. Antiepileptic drugs (AED) are the main interventions used to prevent seizures and control epilepsy. Although effective in most cases, AEDs are related to long-term adverse effects, such as cognitive and behavioural alterations. Thus when epilepsy is in remission, it may be in the individual's best interest to discontinue medication. However, the optimal timing of AED discontinuation is still unknown.This is an updated version of the original Cochrane review published in Issue 3, 2001.

OBJECTIVES

(1) To quantify and compare risk of seizure recurrence, status epilepticus and mortality after early and late AED discontinuation in adult and pediatric epilepsy patients.(2) To assess which variables modify the risk of seizure recurrence.(3) To define a subpopulation in which early AED discontinuation is safe.

SEARCH METHODS

We searched the Cochrane Epilepsy Group Specialised Register (June 2014); CENTRAL (Issue 5, The Cochrane Library, May 2014); MEDLINE (1946 to June 2014); CINAHL (23 June 2014); Scopus (1823 to June 2014); ClinicalTrials.gov (23 June 2014); and WHO International Clinical Trials Registry Platform (23 June 2014). We also checked the reference lists of studies found through the electronic searches.

SELECTION CRITERIA

Randomised controlled trials that evaluate withdrawal of AEDs after varying periods of seizure remission in adults and children with epilepsy. Included studies compared an early AED discontinuation time (defined as a period of remission of seizures of less than two years) versus a late AED discontinuation time (defined as a period of remission of seizures of more than two years).

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed trial quality. Risk ratio (RR) with 95% confidence interval (CI) was calculated for each trial. Summary RRs and 95% CIs for dichotomous data were calculated using a fixed-effect model. A test of statistical heterogeneity was conducted for each pooled risk ratio calculation. Each included study underwent a 'Risk of bias' assessment, based on the Cochrane Handbook recommendations, and we examined the overall quality of information through the GRADE system, presented in two 'Summary of Findings' tables.

MAIN RESULTS

Five trials were included in this review, representing 924 randomised children with epilepsy, all under 16 years of age at randomisation, with a median follow-up of 5.6 years. No eligible trial evaluated adults or assessed mortality or status epilepticus as outcomes. The pooled risk ratio for seizure relapse after AED withdrawal was 1.34 (95% CI 1.13 to 1.59, P = 0.0007). Conforming to this estimate, the number needed to harm, that is expose an individual to a higher risk of seizure relapse because of early withdrawal of AED, is 8 (95% CI 5 to 20). Early discontinuation was associated with greater relapse rates in people with partial seizures with a pooled risk ratio of 1.51 (95% CI 0.97 to 2.35, P = 0.07). Absence type epilepsy showed a lower risk of relapse. Variables associated with higher risk of seizure relapse were abnormal EEG findings (pooled RR 1.44, 95% CI 1.13 to 1.83, P = 0.003), especially epileptiform activity (RR 2.58, 95% CI 2.03 to 3.28, P < 0.0001); epilepsy onset before 2 years or after 10 years of age; history of status epilepticus; intellectual disability (IQ < 70); and high seizure frequency before and during treatment. Gender and family history did not show any significant influence over seizure relapse. Overall, the included trials were classified as low or unclear risk of bias where methodological information was not reported and could not be provided by original study authors.

AUTHORS' CONCLUSIONS

There is evidence to support waiting for at least two seizure-free years before discontinuing AEDs in children, particularly if individuals have an abnormal EEG or partial seizures, or both. There is insufficient evidence to establish when to withdraw AEDs in children with generalised seizures. There is no evidence to guide the timing of withdrawal of AEDs in seizure-free adults. Further high-quality randomised controlled trials are needed, particularly recruiting adults and recruiting those with generalised seizure types, to identify the optimal timing of AED withdrawal and risk factors predictive of relapse.