Treating myoclonic epilepsy in children: state-of-the-art

Pharmacological Management of the Genetic Generalised Epilepsies in Adolescents and Adults

Common genetic generalised epilepsy syndromes encountered by clinicians include childhood and juvenile absence epilepsies, juvenile myoclonic epilepsy and generalised tonic-clonic seizures on awakening. Treatment of these syndromes involves largely the use of broad-spectrum antiseizure drugs. Those effective for the generalised epilepsies include sodium valproate, phenobarbital, ethosuximide, clobazam, clonazepam, lamotrigine, levetiracetam, topiramate, zonisamide and, more recently, perampanel and brivaracetam. Results from the few rigorous studies comparing outcomes with drugs for genetic generalised epilepsies show valproate to be the most effective. The majority of patients with genetic generalised epilepsy syndromes will become seizure free on antiseizure monotherapy; those for whom control proves elusive may benefit from combination regimens. Early counselling regarding management may assist the patient to come to terms with their diagnosis and improve long-term outcomes. Treatment can be lifelong in some individuals, although others may remain seizure free without medication. Choice of antiseizure medication depends on the efficacy for specific seizure types, as well as tolerability. For patients prescribed comedication, drug interactions should be considered. In particular, for young women taking oral hormonal contraceptives, ≥ 200 mg/day of topiramate can decrease the circulating concentration of ethinylestradiol and ≥ 12 mg/day of perampanel can induce levonorgestrel metabolism. The use of valproate in women of childbearing potential is limited by associated teratogenic and neurodevelopmental effects in offspring. Given that valproate is often the antiseizure drug of choice for genetic generalised epilepsies, this creates a dilemma for patients and clinicians. Decision making can be aided by comprehensive assessment and discussion of treatment options. Psychiatric comorbidities are common in adolescents and adults with genetic generalised epilepsies. These worsen the prognosis, both in terms of seizure control and quality of life. Attendant lifestyle issues can impact significantly on the individual and society. Frontal lobe dysfunction, which can present in patients with juvenile myoclonic epilepsy, can adversely affect the long-term outlook, regardless of the nature of seizure control. Ongoing management requires consideration of psychosocial and behavioural factors that can complicate diagnosis and treatment. An assured supportive attitude by the neurologist can be an important contributor to a positive outcome. The mechanisms underlying genetic generalised epilepsies, including genetic abnormalities, are unclear at present. As the pathophysiology is unravelled, this may lead to the development of novel therapies and improved outcomes for patients with these syndromes.

Treatment of Juvenile Myoclonic Epilepsy in Patients of Child-Bearing Potential

Juvenile myoclonic epilepsy (JME) is both a frequent and a very characteristic epileptic syndrome with female preponderance. Treatment of JME in women of childbearing potential must consider multiple factors such as desire for pregnancy, use of contraception, seizure control and previously used antiepileptic drugs (AEDs). Approximately 85% of cases are well controlled with valproate, which remains the reference AED in JME but is nowadays considered unsafe for the expecting mother and her fetus. The prescription of valproate is now severely restricted in women of childbearing potential but may still be considered, at the lowest possible dose and when pregnancies can be reliably planned, with temporary alternatives to valproate prescribed before fertilization. Alternatives have emerged, especially lamotrigine and levetiracetam, but also topiramate, zonisamide, and recently perampanel, but none of these AEDs can be considered fully safe in the context of pregnancy. In special settings, benzodiazepines and barbiturates may be useful. In some cases, combination therapy, especially lamotrigine and levetiracetam, may be useful or even required. However, lamotrigine may have the potential to aggravate JME, with promyoclonic effects. Carbamazepine, oxcarbazepine and phenytoin must be avoided. Valproate, levetiracetam, zonisamide, topiramate if the daily dose is ≤ 200 mg and perampanel if the daily dose is ≤ 10 mg do not affect combined hormonal contraception. Lamotrigine ≥ 300 mg/day has been shown to decrease levonorgestrel levels by 20% but does not compromise combined hormonal contraception. Patients with JME taking oral contraceptive should be counselled on the fact that the estrogenic component can reduce concentrations of lamotrigine by over 50%, putting patients at risk of increased seizures. Pregnancy is a therapeutic challenge, and the risk/benefit ratio for the mother and fetus must be considered when choosing the appropriate drug. Lamotrigine (< 325 mg daily in the European Registry of Antiepileptic Drugs in Pregnancy) and levetiracetam seem to be comparatively safer in pregnancy than other AEDs, especially topiramate and valproate. Plasma concentration of lamotrigine and levetiracetam decreases significantly during pregnancy, and dosage adjustments may be necessary. With persisting generalized tonic-clonic seizures, the combination of lamotrigine and levetiracetam offer the chance of seizure control and lesser risks of major congenital malformations. The risk of malformation increases when valproate or topiramate are included in the drug combination. In one study, the relative risk of autism and autism spectrum disorders (ASD) in children born to women with epilepsy (WWE) treated with valproate were, respectively, 5.2 for autism and 2.9 for ASD versus 2.12 for autism and 1.6 for ASD in WWE not treated with valproate. More studies are needed to assess the risk of autism with AEDs other than valproate. The current knowledge is that the risk appears to be double that in the general population. In patients with JME, valproate remains an essential and life-changing agent. The consequences of a lifetime of poorly controlled epilepsy need to be balanced against the teratogenic risks of valproate during limited times in a woman's life. The management of JME in WWE should include lifestyle interventions, with avoidance of sleep deprivation, and planned pregnancy.

Update on pharmacotherapy of myoclonic seizures

INTRODUCTION

Myoclonic seizures are brief, involuntary muscular jerks arising from the central nervous system that can occur in different epilepsy syndromes, including idiopathic generalized epilepsies or the most severe group of epileptic encephalopathies. Valproate is commonly the first choice alone or in combination with some benzodiazepines or levetiracetam. However, more treatment options exist today as there is emerging evidence to support the efficacy of some newer antiepileptic drugs. In addition, of major importance remains avoidance of medications (e.g., carbamazepine, phenytoin) that may aggravate myoclonic seizures. This is an updated review on the available therapeutic options for treatment of myoclonic seizures. Areas covered: Key efficacy, tolerability and efficacy data are showed for different antiepileptic drugs with antimyoclonic effect, alone and/or in combination. Expert opinion: Pharmacological treatment of myoclonic seizures is based on clinical experience with little evidence from randomized clinical trials. Valproate, levetiracetam, and some benzodiazepines, are widely used. There is still insufficient evidence for the use of other antiseizure drugs, such as topiramate or zonisamide as monotherapy. Better understanding of pathophysiologic mechanisms of myoclonic epilepsies could yield great improvement in the treatment and quality of life of patients.

Pharmacological outcomes in juvenile myoclonic epilepsy: Support for sodium valproate

PURPOSE

Juvenile myoclonic epilepsy (JME) is one of the most frequently diagnosed of the idiopathic generalised epilepsy syndromes, but long term outcome data still remain sparse.

METHODS

A retrospective audit was undertaken in 186 patients (male: n=78; female: n=108) diagnosed with JME at the Epilepsy Unit at the Western Infirmary in Glasgow, Scotland between July 1981 and July 2012. Median age at treatment start was 16 years (range 13-44), with median follow-up of 14 years (range 2-32).

RESULTS

Overall, 171 patients (92%) achieved remission with antiepileptic drug (AED) treatment (median 9.5 years; range 1-31). After discontinuing treatment in 28 patients, only 11 remained seizure-free off medication. Fifteen patients (8%) continued to have seizures despite having tried up to 8 AED regimens: (5 male, 10 female), 7 of whom had psychiatric comorbidities. AEDs most commonly prescribed included sodium valproate (VPA; n=142), lamotrigine (LTG; n=66) and levetiracetam (LEV; n=22). More male patients than female attained remission with their first or second AED schedule (88% versus 56%). More male patients (44%) received VPA than female (31%) overall. Fewer male patients than female received LTG (26% versus 74%) and LEV (22% versus 78%). Of the monotherapies, remission was achieved using VPA (n=74; 52%), LTG (n=21; 32%) and LEV (n=12, 55%). A total of 76 (25%) of AED schedules resulted in intolerable side-effects, including 29 with VPA, 12 with LTG and 4 with LEV.

CONCLUSION

Overall, JME showed a high rate of seizure freedom with AED treatment. VPA appeared to be the most effective AED. Women tended to have a worse outcome than men, since they were increasingly less likely to receive VPA. Patients with psychiatric comorbidities also had a poorer prognosis.

Third International Congress on Epilepsy, Brain, and Mind: Part 2

Epilepsy is both a disease of the brain and the mind. Here, we present the second of two papers with extended summaries of selected presentations of the Third International Congress on Epilepsy, Brain and Mind (April 3-5, 2014; Brno, Czech Republic). Humanistic, biologic, and therapeutic aspects of epilepsy, particularly those related to the mind, were discussed. The extended summaries provide current overviews of epilepsy, cognitive impairment, and treatment, including brain functional connectivity and functional organization; juvenile myoclonic epilepsy; cognitive problems in newly diagnosed epilepsy; SUDEP including studies on prevention and involvement of the serotoninergic system; aggression and antiepileptic drugs; body, mind, and brain, including pain, orientation, the "self-location", Gourmand syndrome, and obesity; euphoria, obsessions, and compulsions; and circumstantiality and psychiatric comorbidities.

Metabolic and endocrine effects of valproic acid chronic treatment

Treatment of epileptic patients with valproic acid (VPA) may be associated with substantial weight changes that may increase morbidity and impair adherence to the treatment regimen. VPA-induced weight gain seems to be associated with many metabolic disturbances; the most frequent are hyperinsulinemia and insulin resistance, hyperleptinemia and leptin resistance. Patients who gain weight during VPA therapy can develop dyslipidemia and metabolic syndrome that are associated with long-term vascular complications such as hypertension and atherosclerosis. Moreover, an elevation in the levels of uric acid and homocysteine, together with oxidative stress, may contribute to atherosclerotic risk in patients under long-term therapy with VPA. The aim of this review is to discuss the metabolic and endocrine effects of VPA chronic treatment in patients with epilepsy.