Drug treatment of benign focal epilepsies of childhood

The natural history of seizures and neuropsychiatric symptoms in childhood epilepsy with centrotemporal spikes (CECTS)

OBJECTIVE

Childhood epilepsy with centrotemporal spikes (CECTS) (formally benign epilepsy with centrotemporal spikes, BECTS) is a common childhood epilepsy syndrome characterized by psychiatric, behavioral, and cognitive abnormalities and self-limited seizures. Although CECTS is one of the most well-characterized electroclinical epilepsy syndromes, the natural history of neuropsychiatric outcomes is poorly understood. We report the psychiatric, behavioral, and cognitive profiles over the course of disease from a large, prospectively-enrolled, longitudinal cohort of children with CECTS. We further characterize the detailed seizure course and test the relationship between several proposed risk factors and neuropsychiatric and seizure outcomes in these children.

METHODS

Patients diagnosed with CECTS were enrolled as part of a community-based study and followed from diagnosis through disease resolution (16.0 ± 3.1 years, N = 60). Twenty sibling controls were also recruited. We report the natural history of premorbid neuropsychiatric concerns, postmorbid neuropsychiatric diagnoses, long-term neuropsychological performance, seizure course, antiseizure medication (ASM) treatment response, and the relationship between duration seizure-free and remission. Age at onset and premorbid neuropsychiatric concerns were tested as predictors of seizure count, epilepsy duration, postmorbid neuropsychiatric diagnoses, and long-term neuropsychological performance. Antiseizure medication treatment duration, seizure count, and epilepsy duration were tested as predictors of postmorbid neuropsychiatric diagnoses and long-term neuropsychological performance.

RESULTS

Children with CECTS had a high incidence of ADD/ADHD symptoms (18.3%) or learning difficulties (21.7%) before diagnosis. New or persistent ADHD (20%), mood disorders (23.6%), learning difficulties (14.5%), and behavioral disorders (7.3%) were common after CECTS diagnosis. At 9-year follow-up, performance on formal neuropsychological testing was comparable to population statistics and sibling controls. More than two-thirds of treated children experienced at least one seizure during treatment. Most children (61.7%) had entered terminal resolution after 12 months seizure-free. Among all children, for each month seizure-free, there was a 6-7% increase in the probability of achieving terminal remission (p < 1e-10). The presence of a premorbid neurodevelopmental concern predicted a longer epilepsy duration (p = 0.02), higher seizure count (p = 0.02), and a postmorbid psychiatric or neurodevelopmental diagnosis (p = 0.002). None of the tested features predicted long-term neuropsychological performance.

SIGNIFICANCE

Children are at high risk of neuropsychiatric symptoms along the course of the disease in CECTS, however, long-term cognitive performance is favorable. The majority of children had a seizure while being treated with ASMs, suggesting that CECTS is not as pharmacoresponsive as assumed or that treatment approaches are not optimized. Among treated and untreated children, future seizure-risk can be estimated from duration seizure-free. The presence of a premorbid neuropsychiatric concern predicted a more severe disease course in CECTS.

Scalp recorded spike ripples predict seizure risk in childhood epilepsy better than spikes

In the past decade, brief bursts of fast oscillations in the ripple range have been identified in the scalp EEG as a promising non-invasive biomarker for epilepsy. However, investigation and clinical application of this biomarker have been limited because standard approaches to identify these brief, low amplitude events are difficult, time consuming, and subjective. Recent studies have demonstrated that ripples co-occurring with epileptiform discharges ('spike ripple events') are easier to detect than ripples alone and have greater pathological significance. Here, we used objective techniques to quantify spike ripples and test whether this biomarker predicts seizure risk in childhood epilepsy. We evaluated spike ripples in scalp EEG recordings from a prospective cohort of children with a self-limited epilepsy syndrome, benign epilepsy with centrotemporal spikes, and healthy control children. We compared the rate of spike ripples between children with epilepsy and healthy controls, and between children with epilepsy during periods of active disease (active, within 1 year of seizure) and after a period of sustained seizure-freedom (seizure-free, >1 year without seizure), using semi-automated and automated detection techniques. Spike ripple rate was higher in subjects with active epilepsy compared to healthy controls (P = 0.0018) or subjects with epilepsy who were seizure-free ON or OFF medication (P = 0.0018). Among epilepsy subjects with spike ripples, each month seizure-free decreased the odds of a spike ripple by a factor of 0.66 [95% confidence interval (0.47, 0.91), P = 0.021]. Comparing the diagnostic accuracy of the presence of at least one spike ripple versus a classic spike event to identify group, we found comparable sensitivity and negative predictive value, but greater specificity and positive predictive value of spike ripples compared to spikes (P = 0.016 and P = 0.006, respectively). We found qualitatively consistent results using a fully automated spike ripple detector, including comparison with an automated spike detector. We conclude that scalp spike ripple events identify disease and track with seizure risk in this epilepsy population, using both semi-automated and fully automated detection methods, and that this biomarker outperforms analysis of spikes alone in categorizing seizure risk. These data provide evidence that spike ripples are a specific non-invasive biomarker for seizure risk in benign epilepsy with centrotemporal spikes and support future work to evaluate the utility of this biomarker to guide medication trials and tapers in these children and predict seizure risk in other at-risk populations.

Efficacy and safety of oxcarbazepine in the treatment of children with epilepsy: a meta-analysis of randomized controlled trials

BACKGROUND

To assess the efficacy and safety of oxcarbazepine (OXC) in the treatment of children with epilepsy.

METHODS

Randomized controlled trials (RCTs) published in PubMed, Embase, Web of Science, Cochrane Library, Scopus, SinoMed (Chinese BioMedical Literature Service System, China), and Chinese National Knowledge Infrastructure (China) database were systematically reviewed. Eligible studies were those that compared the efficacy and safety of OXC with other antiepileptic drugs in epilepsy. Risk ratio (RR) with 95% confidence intervals (95% CIs) was calculated using fixed-effects or random-effects model.

RESULTS

Eleven RCTs with a total of 1,241 patients met the inclusion criteria and were included in this meta-analysis. Compared with other antiepileptic drugs (sodium valproate, levetiracetam, phenytoin, and placebo), OXC was associated with similar seizure-free rate (RR =1.06, 95% CI: 0.94, 1.20; P=0.366) and percentage reduction from baseline in seizure frequency (for ≥75% reduction: RR =1.15, 95% CI: 0.88, 1.49; P=0.310; for 50%-75% reduction: RR =1.12, 95% CI: 0.90, 1.39; P=0.301; for <50% reduction: RR =0.79, 95% CI: 0.56, 1.12; P=0.179). Moreover, patients treated with OXC had a comparable incidence of adverse events compared with those treated with other antiepileptic drugs (RR =1.01, 95% CI: 0.92, 1.11; P=0.760).

CONCLUSION

OXC showed similar effects and safety as other antiepileptic drugs in the treatment of children with epilepsy. Further well-conducted, large-scale RCTs are needed to validate these findings.

Pediatric focal epilepsy syndromes

Benign epilepsy with centrotemporal spikes, early-onset childhood occipital epilepsy (Panayiotopoulos syndrome [PS]) and late-onset childhood occipital epilepsy (Gastaut type [LOCE-G]) are the principal pediatric focal epilepsy syndromes. They share major common characteristics: the appearance and resolution of electroclinical features are age related, there is a strong genetic predisposition, the clinical course is often mild with infrequent and easy to control seizures, interictal epileptiform activity is disproportionately abundant when compared with the clinical correlate, and tends to potentiate and generalize during sleep. In this review, we outline the relevant pathophysiology underlying this electroclinical spectrum. Then, the initial description of individual syndromes is followed by a summary of overlapping features and intermediate presentations that question the boundaries between these entities and provide the basis for the concept of a childhood seizure susceptibility syndrome. Additionally, we outline the main features of the related epileptic encephalopathies. An outlook on potential future lines of research completes this review.

Idiopathic focal epilepsies

In this chapter we include a series of epilepsies with onset in pediatric age characterized by focal seizures, idiopathic etiology, normal psychomotor development, and a benign course related to the spontaneous remission of seizures without sequelae. These entities are age-dependent and seizures tend to disappear spontaneously. For these reasons often the drug treatment is not necessary. On the basis of genetic assessment idiopathic focal epilepsies can be divided into two groups: nonautosomal dominant and autosomal dominant. In the group of nonautosomal entities we include benign epilepsy with centro-temporal spikes, Panayiotopoulos syndrome, idiopathic childhood occipital epilepsy described by Gastaut, and benign idiopathic midline spikes epilepsy. Seizures are rare, sometimes prolonged, as autonomic status in Panayiotopoulos syndrome. A common feature is the presence of peculiar EEG interictal paroxysmal abnormalities. In the group with an autosomal dominant mode of inheritance we include benign familial infantile seizures and benign familial neonatal-infantile seizures. These entities are characterized by partial seizures in cluster, self-limited in a brief period during the first months of life. There are no typical interictal EEG abnormalities. In some families a mutation in SCN2A, the gene coding for the 2α subunit of the voltage-gated sodium channel, has been described.

Electrical status epilepticus in sleep: clinical presentation and pathophysiology

Electrical status epilepticus in sleep involves an electroencephalographic pattern where interictal epileptiform activity is potentiated in the transition from wakefulness to sleep. Near-continuous spikes and waves that occupy a significant proportion of nonrapid eye movement sleep appear as a result of sleep-potentiated epileptiform activity. This electroencephalographic pattern appears in different electroclinical syndromes that present three common characteristics with different degrees of severity: seizures, sleep-potentiated epileptiform activity, and neuropsychologic regression. Continuous spikes and waves during sleep comprise the severest epileptic encephalopathy in the electroclinical spectrum. Landau-Kleffner syndrome presents with intermediate severity. Some "benign" pediatric focal epileptic syndromes represent the mildest end of this continuum. Based on published data, we provide a framework for clinical and electrical events. The underlying mechanisms leading to sleep potentiation of epileptiform activity in electrical status epilepticus in sleep are incompletely understood. A genetic basis or acquired early developmental insult may disrupt the normal maturation of neuronal networks. These factors may dynamically alter normal processes of brain development, leading to an age-related pattern of electroclinical expression of electrical status epilepticus in sleep.

Benign epilepsy in children

The diagnosis of benign epilepsy syndrome should meet the following criteria: age-related and self-limited; good response to medication; and no obvious neurological sequelae after seizure. However, the current concept of benign epilepsy syndrome has been challenged because of the advancements in genetic studies, neuroimaging, and molecular techniques. Many studies have revealed that the prevalence of behavioral problems and learning difficulties as well as subtle cognitive deficits is higher among patients with benign epilepsy, compared with the normal population. Here, we review updated results of these studies to show the latest and broad comprehensive knowledge of benign epilepsy in children.

Treatment of benign focal epilepsies in children: when and how should be treated?

Benign focal epilepsies represent almost one-fourth of all childhood epilepsies and are a frequent occurrence in clinical practice. They include benign infantile seizures (BIS), Panayiotopoulos syndrome (PS), and benign childhood epilepsy with centrotemporal spikes (BCECTS) in this order of the onset age. Because the prognosis is always excellent in patients with benign focal epilepsies, we must consider the risks and benefits of chronic antiepileptic drug (AED) administration. AED treatment is usually not recommended for the patients with a first attack, but should be considered for those with a second or third attack. A choice of AED has been based on the expert opinion. Carbamazepine (CBZ) is recommended for both acute and chronic treatment of seizure clusters in patients with BIS. Valproic acid (VPA), CBZ or clobazam (CLB) appears to be a first option of AED for patients with PS. A common first choice for BCECTS is CBZ in the USA and Japan, and VPA in the EU. The treatment period should be as short as possible without waiting for EEG normalization, possibly within 2 years after the initiation of AED. We must remember that some patients with BCECTS may have an "atypical evolution". In conclusion, when and how to treat this benign condition should be determined in an individual manner based on the length and frequency of seizures, circadian rhythm of the attacks, interictal EEG findings, cognitive and behavioral functions in daily life and the attitude of the parents toward seizure recurrences and AED side effects.

Neuropsychological deficits in childhood epilepsy syndromes

Seizure disorders are relatively common in childhood, and the International League Against Epilepsy (ILAE) provides a hierarchical classification system to define seizure types. At the final level of classification, specific epilepsy syndromes are defined that represent a complex of signs and symptoms unique to an epilepsy condition. The present review discusses the issues related to several of these epilepsy syndromes in childhood, including those classified as generalized idiopathic epilepsies (e.g., childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy), focal epilepsies (benign rolandic epilepsy, occipital epilepsy, temporal lobe epilepsy, frontal lobe epilepsy) and the "epileptic encephalopathies," including Dravet's Syndrome, West Syndrome, Lennox-Gastaut Syndrome, Myoclonic Astatic Epilepsy, and Landau-Kleffner Syndrome. For each syndrome, the epidemiology, clinical manifestations, treatments, and neuropsychological findings are discussed.

Neuropsychological deficits in childhood epilepsy syndromes

Seizure disorders are relatively common in childhood, and the International League Against Epilepsy (ILAE) provides a hierarchical classification system to define seizure types. At the final level of classification, specific epilepsy syndromes are defined that represent a complex of signs and symptoms unique to an epilepsy condition. The present review discusses the issues related to several of these epilepsy syndromes in childhood, including those classified as generalized idiopathic epilepsies (e.g., childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy), focal epilepsies (benign rolandic epilepsy, occipital epilepsy, temporal lobe epilepsy, frontal lobe epilepsy) and the "epileptic encephalopathies," including Dravet's Syndrome, West Syndrome, Lennox-Gastaut Syndrome, Myoclonic Astatic Epilepsy, and Landau-Kleffner Syndrome. For each syndrome, the epidemiology, clinical manifestations, treatments, and neuropsychological findings are discussed.

Levetiracetam or oxcarbazepine as monotherapy in newly diagnosed benign epilepsy of childhood with centrotemporal spikes (BECTS): an open-label, parallel group trial

To evaluate the efficacy and tolerability of levetiracetam or oxcarbazepine as monotherapy in children with newly diagnosed benign epilepsy with centrotemporal spikes (BECTS). Twenty-one children (11 males, 10 females), aged between 5 and 13 years (mean 10.5 years), and 18 (10 M, 8 F), aged between 3.3 and 14 years (mean 8.4 years), were randomised to receive monotherapy with levetiracetam or oxcarbazepine, respectively. LEV was titrated up to 20-30 mg/kg/once or twice a day, and OXC up to 20-35 mg/kg once or twice a day. Thirty-nine consecutive children (21 males, 18 females), aged between 3.3 and 14 years (mean 10.7 years), were recruited into the study. Twenty-one were randomised on LEV (11 male, 10 female; mean age 10.5 years), and 18 on OXC (10 male, 8 female; mean age 8.4 years). After a mean follow-up period of 18.5 months (range 12-24 months), 19 out of 21 patients (90.5%) on levetiracetam, and 13 out of 18 (72,22%) on oxcarbazepine did not have further seizures. Mean serum level of LEV was 4.1 microg/ml (range 1.3-9.0), and of OXC was 15.2 microg/ml (range 4.2-27.5). Adverse side effects on LEV were reported in 3 children (14.3%), represented by mild and transient decreased appetite (2) and cephalalgia (1). They were reported on OXC in 2/18 (11.1%), including headache (1), and sedation (1). These preliminary data from an open, parallel group study suggest that levetiracetam and oxcarbazepine may be potentially effective and well tolerated drugs for children with BECTS who require treatment.

Levetiracetam for benign epilepsy of childhood with centrotemporal spikes-three cases

Benign epilepsy with centrotemporal spikes (BECTS), also known as benign rolandic epilepsy (BRE) of childhood represents 15% of all childhood epilepsies [Handbook of Epilepsy Treatment (2000)]. A majority of these patients do no require treatment; however, in those cases where treatment is justified, the most efficacious medication with a benign safety profile should be selected. We present three clinical cases of otherwise healthy children with BECTS who were treated only with levetiracetam. All three of these children remain seizure-free and are experiencing no reported side effects.