Should antiepileptic drugs be withdrawn in seizure-free patients?

Treating epilepsy across its different stages

Epilepsy is a chronic condition requiring long-term treatment with drugs that have intrinsic limitations. Antiepileptic drugs (AEDs) are effective in suppressing seizures but do not alter the disease process. They have a suboptimal tolerability profile and can be teratogenic. Second-generation compounds may be better tolerated but no more effective than traditional AEDs. In this light, as drug therapy is purely symptomatic, acute symptomatic seizures (i.e. seizures occurring in close temporal relationship with acute CNS insults) may require treatment only until recovery or stabilization of the injury. Treatment of the first unprovoked seizure may be considered in patients with abnormal EEG and imaging findings and in those in whom the relapse has severe social, emotional and personal implications. In these cases and in patients with epilepsy (i.e. repeated unprovoked seizures), drugs for partial seizures supported by class I regulatory trials or pragmatic trials are oxcarbazepine in children, carbamazepine or lamotrigine in adults, and lamotrigine or gabapentin in the elderly. Pragmatic trials support use of valproate for generalized seizures, except for women of childbearing age for whom the drug should be tailored to the individual patient. The lowest maintenance dose should be chosen, based on the efficacy and tolerability of the assigned drug. If the first monotherapy fails, the safety profile of a drug is important when opting for another monotherapy or for an add-on therapy. The epilepsy syndrome and the social, psychological and emotional profile of the patient all contribute to the individualization of treatment discontinuation after long-term seizure remission.

[Fear of having the antiepileptic drug withdrawn]

INTRODUCTION

The decision to withdraw antiepileptic drugs is based mostly on a balanced view of the overall risk of seizure relapse and factors most likely to affect that risk. The aim of this study was to find out the patient and family's attitudes towards the fear of having antiepileptic drug withdrawn, after three years of seizure control.

MATERIAL AND METHODS

This research was carried out at the Institute for Child and Youth Health care of Vojvodina in Novi Sad. During the study, which lasted from 2003 to 2008, a face-to-face interview about fear of having the antiepileptic therapy withdrawn was done within the adolescent patient examination. The study population included 150 adolescent patients and 265 of their parents.

RESULTS

In general, the adolescent patients were ready to accept a significantly higher risk of having recurrences after the antiepileptic drug withdrawal (p < 0.05) than their parents. None of their parents was ready to accept the risk 50% higher than the one in the general population.

CONCLUSION

It is important to take into consideration the fear of both adolescent patients and their parents of having recurrences of epileptic seizures before opting for the antiepileptic drug withdrawal.

Panayiotopoulos syndrome: a clinical, EEG, and neuropsychological study of 93 consecutive patients

PURPOSE

To explore the clinical, electroencephalography (EEG), neuropsychological features, and prognosis of Panayiotopoulos syndrome (PS).

METHODS

Of 1,794 children aged between 1 and 14 years referred for the first afebrile focal seizure, between January 1992 and December 2004, 93 (5.2%) had PS according to clinical criteria.

RESULTS

Age at onset ranged from 1.1 to 8.6 years, and was earlier in children with more than one seizure. Autonomic seizures followed a stereotypical onset and progression. Emesis, pallor, or flushing was almost always among the first symptoms that usually culminated in vomiting (77.4% of patients). More than half (55%) of seizures were longer than 30 min but these did not appear to affect remission and number of seizures. Interictal EEG showed great variability, with 79.5% of patients showing spikes of variable localizations and evolution over time; 16.1% had background abnormalities only, and 5.4% had consistently normal EEG studies. Onsets in five ictal EEGs were posterior or anterior-left or right. On neuropsychological testing, IQ and subtests of Wechsler Intelligence Scale for Children-Revised (WISC-R) were within normal limits, although some minor statistically significant differences were found in arithmetic, comprehension, and picture arrangement in comparison with controls. Cumulative probability of recurrence was 57.6%, 45.6%, 35.1%, and 11.7% at 6, 12, 24, and 36 months, respectively, after the first seizure. Thirty-four (58.6%) of 59 patients treated with antiepileptic drugs continued having seizures before ultimate remission.

DISCUSSION

PS is a uniform childhood susceptibility to autonomic seizures that is related to early age of development and with excellent prognosis with regard to seizure remission and neuropsychological development.

Stopping antiepileptic drugs: when and why?

After a patient has initiated an antiepileptic drug (AED) and achieved a sustained period of seizure freedom, the bias towards continuing therapy indefinitely can be substantial. Studies show that the rate of seizure recurrence after AED withdrawal is about two to three times the rate in patients who continue AEDs, but there are many benefits to AED withdrawal that should be evaluated on an individualized basis. AED discontinuation may be considered in patients whose seizures have been completely controlled for a prolonged period, typically 1 to 2 years for children and 2 to 5 years for adults. For children, symptomatic epilepsy, adolescent onset, and a longer time to achieve seizure control are associated with a worse prognosis. In adults, factors such as a longer duration of epilepsy, an abnormal neurologic examination, an abnormal EEG, and certain epilepsy syndromes are known to increase the risk of recurrence. Even in patients with a favorable prognosis, however, the risk of relapse can be as high as 20% to 25%. Before withdrawing AEDs, patients should be counseled about their individual risk for relapse and the potential implications of a recurrent seizure, particularly for safety and driving.

A systematic review of antiepileptic drug initiation and withdrawal

BACKGROUND

The proper clinical context to initiate or discontinue antiepileptic drug (AED) treatment has been extensively studied over the past 40 years. Differences in study design and methodology have led to reports of seizure recurrence rates of 7% to 96% in drug initiation trials and seizure relapse rates of 12% to 67% in drug withdrawal trials. A number of different historical and clinical factors have been cited in various studies as altering seizure risk. Our objective was to review the data from large, well-conducted, prospective studies.

REVIEW SUMMARY

We performed an electronic search of 3 medical and scientific databases for articles on initiating or withdrawing antiepileptic medication. Our review focused primarily on articles meeting specific inclusion and exclusion criteria. We discuss the risk of seizure recurrence after a first seizure and the factors associated with an elevated risk of recurrence. The risks of treatment, including life-threatening idiosyncratic reactions and dose-related physical and cognitive side effects are reviewed. We also summarize the data on the seizure relapse risk after drug discontinuation and the factors associated with an increased relapse risk. Benefits of successful AED withdrawal are highlighted. The special considerations of treatment initiation and withdrawal in the pediatric population are explored. We propose general guidelines to assist the clinician in evaluating the risk/benefit ratio of initiating and withdrawing antiepileptic drugs.

CONCLUSION

Drug initiation after a first seizure decreases early seizure recurrence, but does not affect the long-term prognosis of developing epilepsy. Medication withdrawal after a period of seizure remission increases the risk of relapse, but the benefits of successful AED discontinuation may be substantial. In the end, the decision of whether to initiate treatment after a single seizure and whether to withdraw AED therapy in patients enjoying a prolonged period of seizure freedom should be made on an individual case basis, which balances the risk of seizure relapse and subsequent disability against the likely impact of medication-related physical, cognitive, and psychologic adverse effects.

To stop or not to stop the AED?

Consequences of Antiepileptic Drug Withdrawal: A Randomized, Double-Blind Study (Akershus Study). Lossius MI, Hessen E, Mowinckel P, Stavem K, Erikssen J, Gulbrandsen P, Gjerstad L. Epilepsia 2008;49:455–463. OBJECTIVE: Despite side effects associated with the use of antiepileptic drugs (AEDs), withdrawal of AEDs remains controversial, even after prolonged seizure freedom. The main objective of this study was to assess the effects of AED withdrawal on cognitive functions, seizure relapse, health-related quality of life (HRQOL), and EEG results. Additionally, potential predictors for freedom from seizures after AED withdrawal were studied. METHODS: Patients, seizure-free for more than 2 years on AED monotherapy, were recruited for a controlled, prospective, randomized, double-blinded withdrawal study lasting for 12 months, or until seizure relapse. Patients were randomized to AED withdrawal (n = 79) and nonwithdrawal (n = 81) groups. The examination program included clinical neurological examinations, neuropsychological testing, EEG-recordings, cerebral MRI, and assessments of HRQOL. Follow-up data on seizure relapse were also collected beyond the 12-month study period (median 47 months). RESULTS: Seizure relapse at 12 months occurred in 15% of the withdrawal group and 7% of the nonwithdrawal group (RR 2.46; 95% CI: 0.85–7.08; p = 0.095). After withdrawal, seizure relapse rates were 27% after a median of 41 months off medication. A normal result to all 15 neuropsychological tests increased significantly from 11% to 28% postwithdrawal. We found no significant effects of withdrawal on quality of life and EEG. Predictors for remaining seizure-free after AED-withdrawal over 1 year were normal neurological examination and use of carbamazepine prior to withdrawal. CONCLUSION: Seizure-free epilepsy patients on AED monotherapy who taper their medication may improve neuropsychological performance with a relative risk of seizure relapse of 2.46, compared to those continuing therapy.

Management of a first seizure. Special problems: adults and elderly

A first seizure out of a clear blue sky can be a major life-changing event. Careful history-taking and appropriate investigation together with a clear explanation provided to patient and family are an essential requirement. Although for most patients, pharmacotherapy can be withheld and events awaited, there are circumstances where introduction of antiepileptic drug (AED) therapy should be considered. Medical causes of seizures should also be sought and treated. In addition, a first seizure in HIV-positive patients and in those with underlying neurocysticercosis should usually provoke the introduction of AED therapy. Particular problems can occur in patients with a single episode of provoked status epilepticus, a first tonic-clonic seizure during pregnancy and, particularly, an unprovoked event in older and learning disabled people. Treatment following a first seizure should balance risk factors for recurrence with the informed opinion of the patients and their family.

Effects of levetiracetam on EEG abnormalities in juvenile myoclonic epilepsy

PURPOSE

A multicenter, prospective, long-term, open-label study to evaluate the effects of levetiracetam on electroencephalogram (EEG) abnormalities and photoparoxysmal response (PPR) of patients affected by juvenile myoclonic epilepsy (JME).

METHODS

Forty-eight patients with newly diagnosed JME (10) or resistant/intolerant (38) to previous antiepileptic drugs (AEDs) were enrolled. After an 8-week baseline period, levetiracetam was titrated in 2 weeks to 500 mg b.i.d. and then increased to up to 3,000 mg/day. Efficacy parameters were based on the comparison and analysis of EEG interictal abnormalities classified as spikes-and-waves, polyspikes-and-waves, and presence of PPR. Secondary end point was evaluation of EEG and PPR changes as predictive factors of 12-month seizure freedom.

RESULTS

Overall, mean dose of levetiracetam was 2,208 mg/day. Mean study period was 19.3 +/- 11.5 months (range 0.3-38). During the baseline period, interictal EEG abnormalities were detected in 44/48 patients (91.6%) and PPR was determined in 17/48 (35.4%) of patients. After levetiracetam treatment, 27/48 (56.2%) of patients compared to 4/48 (8.3%) in the baseline period (p < 0.0001) had a normal EEG. Thirteen of 17 (76.4%) (p < 0.0003) patients showed suppression of PPR. Cumulative probability of days with myoclonia (DWM) 12-month remission was significantly higher (p < 0.05) in patients with a normal (normalized) EEG after levetiracetam treatment compared to those with an unchanged EEG.

CONCLUSIONS

Levetiracetam appeared to be effective in decreasing epileptiform EEG abnormalities, and suppressing the PPR in JME patients. This effect, along with a good efficacy and tolerability profile in this population further supports a first-line role for levetiracetam in the treatment of JME.

Consequences of antiepileptic drug withdrawal: a randomized, double-blind study (Akershus Study)

OBJECTIVE

Despite side effects associated with the use of antiepileptic drugs (AEDs), withdrawal of AEDs remains controversial, even after prolonged seizure freedom. The main objective of this study was to assess the effects of AED withdrawal on cognitive functions, seizure relapse, health-related quality of life (HRQOL), and EEG results. Additionally, potential predictors for freedom from seizures after AED withdrawal were studied.

METHODS

Patients, seizure-free for more than 2 years on AED monotherapy, were recruited for a controlled, prospective, randomized, double-blinded withdrawal study lasting for 12 months, or until seizure relapse. Patients were randomized to AED withdrawal (n = 79) and nonwithdrawal (n = 81) groups. The examination program included clinical neurological examinations, neuropsychological testing, EEG-recordings, cerebral MRI, and assessments of HRQOL. Follow-up data on seizure relapse were also collected beyond the 12-month study period (median 47 months).

RESULTS

Seizure relapse at 12 months occurred in 15% of the withdrawal group and 7% of the nonwithdrawal group (RR 2.46; 95% CI: 0.85-7.08; p = 0.095). After withdrawal, seizure relapse rates were 27% after a median of 41 months off medication. A normal result to all 15 neuropsychological tests increased significantly from 11% to 28% postwithdrawal. We found no significant effects of withdrawal on quality of life and EEG. Predictors for remaining seizure-free after AED-withdrawal over 1 year were normal neurological examination and use of carbamazepine prior to withdrawal.

CONCLUSION

Seizure-free epilepsy patients on AED monotherapy who taper their medication may improve neuropsychological performance with a relative risk of seizure relapse of 2.46, compared to those continuing therapy.

Observations on juvenile myoclonic epilepsy amongst ethnic Bengalees in West Bengal—An Eastern Indian State

BACKGROUND

Juvenile myoclonic epilepsy (JME) is not too uncommonly encountered in Indian neurological practice. A number of reports from different parts of India have documented the clinical phenomenology and EEG characteristics of this genetically determined epileptic syndrome. However, no study has yet been reported from the Eastern part of India and none done so far in patients in a specific ethnic group. Furthermore therapy response and follow up data are not available in detail in the Indian studies.

OBJECTIVE

To study disease expression, EEG characteristics and therapy response of JME patients in ethnic Bengalees in West Bengal, an Eastern Indian State, in a clinic based study.

MATERIAL AND METHODS

200 patients with JME attending the Neurology Department of the Institute have been followed up for 5 years and different parameters of disease expression as outlined above have been studied.

RESULTS

Overall clinical disease expression has been found to be similar in this clinic based study in ethnic Bengalees as compared to other reports from India and elsewhere. About 16% of patients showed a relative resistance to Valproate therapy. Hundred percent of patients in whom therapy withdrawal was attempted, relapsed within<1-2 years. Amongst female patients (132), 16 developed features of polycystic ovarian syndrome while on Valproate therapy. In over half of them, the symptoms regressed after successful switch over from Valproate to Clobazam. 12/132 female patients became pregnant during follow up and while on Valproate; teratogenic effect was evident in only one such patient.

CONCLUSIONS

Phenotypic variations in disease expression including therapy response have been noted within a single ethnic group of patients attending the clinic and might account for genetic heterogeneity noted in molecular genetic studies. JME cannot really be called a very 'benign' epileptic syndrome; recurrence after therapy withdrawal almost invariably occurs.

Juvenile myoclonic epilepsy: epidemiology, pathophysiology, and management

Juvenile myoclonic epilepsy (JME) is a common epilepsy syndrome that begins most frequently in the early teenage years. It is officially classified as a type of idiopathic generalized epilepsy and is often under-recognized or misdiagnosed. This syndrome has a strong genetic component with multiple gene mutations being associated with the clinical presentation. Based upon genetic associations, there may be multiple pathophysiologic mechanisms for the disorder; the pathophysiology has not been clearly defined. A diagnosis of JME is made using the clinical history and EEG findings. Valproic acid is the primary antiepileptic drug (AED) used for JME, but some newer AEDs may be effective alternatives. Selection of an appropriate AED is essential to the proper management of JME, because of the possibility of exacerbation of seizures by some AEDs and the adverse effect profiles of effective drugs. It is important for clinicians to understand JME to correctly diagnose and manage patients with this syndrome.

Withdrawal of antiepileptic drugs in adult patients free of seizures for 4 years: a prospective study

We aimed to assess the relapse rate of epilepsy, prospectively attributable to antiepileptic drug (AED) withdrawal in seizure-free patients and to determine the risk factors for seizure recurrence. Seventy-nine patients with epilepsy who were seizure-free for at least 4 years were enrolled into the study. The AEDs were tapered by one-sixth every 2 months. The EEG and clinical examination were performed at the beginning; at each visit during discontinuation and 2, 6, 12, 24, and 36 months after the complete drug withdrawal. For each patient, records were obtained of the main demographic and clinical variables. A total of 49 patients completed the discontinuation programme. Twenty-eight patients (57%) relapsed while 21 of those (42.8%) did not suffer a relapse at the end of the study period. In patients discontinuing treatment, the probability of relapse was 21.4% during the tapering period (especially in the last months), 28.6% at 1 month, 14.3% at 3 months, 3.6% at 6 months, 7.1% at 12 months, 17.8% at 24 months, and 7.1% at 36 months. The age at onset of epilepsy and the duration of active disease were found to affect the risk of relapse. Although drug withdrawal could be considered in adult patients free of seizures for 4 years, the final decision should be tailored to the patient's clinical, emotional, and socio-cultural profile.

Seizure Recurrence and Risk Factors after Antiepilepsy Drug Withdrawal in Children with Brain Tumors

PURPOSE

To study seizure outcome after antiepilepsy drug (AED) withdrawal in brain tumor patients and to analyze risk factors for seizure recurrence.

METHODS

Brain tumor patients with seizures and at least one attempt at AED discontinuation were identified from the hospital database and neurology clinic records. After defining study variables, patient charts were abstracted for clinical and demographic data. Statistical analyses used log-rank tests and multivariable Cox proportional hazards models.

RESULTS

Sixty-two patients discontinued AEDs at a median time of 5.6 years from the first seizure (range, 1.2-19.6 years). Median time since AED withdrawal was 2.3 years (range, 0.4-15.1 years). Seizures recurred in 17 (27%) patients within a median time of 0.8 years (range, 0.06-7.7 years). Median seizure-free period before AED withdrawal was 1.3 years (range, 0.1-11 years). More than one tumor resection and whole-brain radiation treatment (WBRT) were associated with seizure recurrence, whereas posterior fossa tumor location was correlated with reduced seizure recurrence risk. At seizure recurrence, control was easily reestablished in 10 patients with AED reinstitution and after dose adjustment in five; two patients with poor drug compliance continue to have seizures. In 48 patients who had an EEG before AED withdrawal, spikes or slow waves did not correlate with seizure recurrence.

CONCLUSIONS

AED withdrawal can be successfully achieved in majority of carefully selected patients. WBRT and multiple tumor resections seem to be associated with an increased hazard for seizure recurrence.

Pharmacotherapy of Epileptic Seizures in Glioma Patients: Who, When, Why and How Long?

BACKGROUND

The risk for patients with primary brain tumors of experiencing an epileptic seizure at least once in the course of disease probably exceeds 50%, depending on tumor location and tumor type. Several aspects regarding the role of anticonvulsants in the treatment of brain tumor patients have remained controversial.

PATIENTS AND METHODS

We reviewed the seizure history in 107 patients undergoing a surgical procedure for glioma at our institution.

RESULTS

The overall seizure incidence was 68%. Pre-operative seizures did not predict the occurrence of post-operative seizures. After surgery, postoperative chemo- or radiotherapy and anticonvulsive therapy one third of patients was seizure-free whereas one third showed frequent seizures despite this treatment. Seizure frequency increased regardless of anticonvulsive treatment with progressive or recurrent tumor growth.

CONCLUSIONS

Based on a literature review and our institutional experience, we delineate some recommendations for the management of seizures in patients with brain tumors.

Uncontrolled epilepsy following discontinuation of antiepileptic drugs in seizure-free patients: a review of current clinical experience

PURPOSE

We reviewed the impact of planned discontinuation of antiepileptic drugs (AEDs) in seizure-free patients on seizure recurrence and the seizure outcome of reinstituted treatment.

METHODS

A literature review was performed yielding 14 clinical observations of seizure recurrence after discontinuation and its treatment outcome.

RESULTS

Seizure recurrence rate after AED discontinuation ranged between 12 and 66% (mean 34%, 95%CI: 27-43) in the 13 reviewed studies (no data in one study). Reinstitution of AEDs after recurrence was efficacious between 64-91% (mean of 14 studies, 80%, 95%CI: 75-85%) at follow-up. Mean follow-up ranged from 1-9 years. Seizure outcome of resumed treatment was not different for series in children and adolescents (84%, mean of 4 studies, 95%CI: 75-93) or in adults only (80%, mean of 9 studies, 95%CI: 74-86). Although seizure control was regained within approximately one year in half of the cases becoming seizure free, it took some patients as many as 5-12 years. In addition, in 19% (mean of 14 studies, 95%CI: 15-24%), resuming medication did not control the epilepsy as before, and chronic drug-resistant epilepsy with many seizures over as many as five years was seen in up to 23% of patients with a recurrence. Factors associated with poor treatment outcome of treating recurrences were symptomatic etiology, partial epilepsy and cognitive deficits.

CONCLUSIONS

These serious and substantial risks weigh against discontinuation of AEDs in seizure-free patients, except perhaps for selected patients with idiopathic epilepsy syndromes of childhood or patients with rare seizures.