Topiramate in the catastrophic epilepsies of childhood

Treatment of infantile spasms: why do we know so little?

INTRODUCTION

Infantile spasm (IS) is an epileptic syndrome with typical onset within the first 2 years of life. This condition might be caused by several etiologies. IS is associated with pathological neuronal networks; however, definite hypotheses on neurobiological processes are awaited.

AREAS COVERED

Changes in NMDA and GABA_B receptors and increase of Ca²⁺ conductance are some of the possible pathophysiological mechanisms. Animal models can help, but most have only some features of IS. Outcome is strongly affected by etiology and the timing of treatment, which relies still on ACTH, oral steroids, and vigabatrin. No significant differences in terms of efficacy have been documented, though a combination of ACTH and vigabatrin seems to be associated with better long-term outcomes. Despite the increasing knowledge about the etiology and pathophysiology of IS, in the last years, no new treatment approaches have been recognized to be able to modify the neurobiological process underlying IS. Precision medicine has far to come in IS.

EXPERT OPINION

Recently, no new therapeutic options for IS have emerged, probably due to the lack of reliable animal models and to the extreme variability in etiologies. Consequently, the outlook for patients and families is poor and early recognition and intervention remain research priorities.

Early-Life Epilepsies and the Emerging Role of Genetic Testing

IMPORTANCE

Early-life epilepsies are often a consequence of numerous neurodevelopmental disorders, most of which are proving to have genetic origins. The role of genetic testing in the initial evaluation of these epilepsies is not established.

OBJECTIVE

To provide a contemporary account of the patterns of use and diagnostic yield of genetic testing for early-life epilepsies.

DESIGN, SETTING, AND PARTICIPANTS

In this prospective cohort, children with newly diagnosed epilepsy with an onset at less than 3 years of age were recruited from March 1, 2012, to April 30, 2015, from 17 US pediatric hospitals and followed up for 1 year. Of 795 families approached, 775 agreed to participate. Clinical diagnosis of the etiology of epilepsy were characterized based on information available before genetic testing was performed. Added contributions of cytogenetic and gene sequencing investigations were determined.

EXPOSURES

Genetic diagnostic testing.

MAIN OUTCOMES AND MEASURES

Laboratory-confirmed pathogenic variant.

RESULTS

Of the 775 patients in the study (367 girls and 408 boys; median age of onset, 7.5 months [interquartile range, 4.2-16.5 months]), 95 (12.3%) had acquired brain injuries. Of the remaining 680 patients, 327 (48.1%) underwent various forms of genetic testing, which identified pathogenic variants in 132 of 327 children (40.4%; 95% CI, 37%-44%): 26 of 59 (44.1%) with karyotyping, 32 of 188 (17.0%) with microarrays, 31 of 114 (27.2%) with epilepsy panels, 11 of 33 (33.3%) with whole exomes, 4 of 20 (20.0%) with mitochondrial panels, and 28 of 94 (29.8%) with other tests. Forty-four variants were identified before initial epilepsy presentation. Apart from dysmorphic syndromes, pathogenic yields were highest for children with tuberous sclerosis complex (9 of 11 [81.8%]), metabolic diseases (11 of 14 [78.6%]), and brain malformations (20 of 61 [32.8%]). A total of 180 of 446 children (40.4%), whose etiology would have remained unknown without genetic testing, underwent some testing. Pathogenic variants were identified in 48 of 180 children (26.7%; 95% CI, 18%-34%). Diagnostic yields were greater than 15% regardless of delay, spasms, and young age. Yields were greater for epilepsy panels (28 of 96 [29.2%]; P < .001) and whole exomes (5 of 18 [27.8%]; P = .02) than for chromosomal microarray (8 of 101 [7.9%]).

CONCLUSIONS AND RELEVANCE

Genetic investigations, particularly broad sequencing methods, have high diagnostic yields in newly diagnosed early-life epilepsies regardless of key clinical features. Thorough genetic investigation emphasizing sequencing tests should be incorporated into the initial evaluation of newly presenting early-life epilepsies and not just reserved for those with severe presentations and poor outcomes.

Topiramate in childhood epileptic encephalopathy with continuous spike-waves during sleep: A retrospective study of 21 cases

OBJECTIVE

Encephalopathy with continuous spike-wave during sleep (CSWS) is a particularly difficult-to-treat childhood epileptic syndrome. This study sought to present the EEG improvement and clinical efficacy of topiramate (TPM), a broad spectrum antiepileptic drug (AED), in a series of 21 children with CSWS encephalopathy.

METHODS

We retrospectively reviewed the EEG results and clinical data of children with CSWS followed-up in our institution and treated with TPM. Sleep EEGs were performed 0-3 months prior to TPM introduction and then at 3 and 12 months. The exclusion criteria were (1) introduction of another AED and (2) withdrawal of a potentially aggravating AED during the first 3 months of treatment. In addition to spike index (SI), the severity of EEG abnormalities was rated using an original scale that also considered the spatial extent of interictal epileptiform discharges.

RESULTS

21 patients were included (18 males, 4-14y, three symptomatic cases). At 3 months, sleep EEG was improved in 14 and normalized in four (TPM doses: 2-5.5 mg/kg/day). Among these 18 patients, 16 manifested cognitive or behavioural improvement. In a subgroup of seven patients with frequent seizures, five became seizure-free and one had over 75% decrease in seizure frequency. At the one-year follow-up, 20 children were still on TPM and 10 exhibited persistent EEG improvement without any other AED being introduced, most of them with clinical benefits.

CONCLUSION

TPM can decrease EEG abnormalities in epileptic encephalopathy with CSWS, achieving clinical improvement in the majority of patients. However, relapse may occur in the long-term in nearly half of cases. Otherwise, TPM has proven particularly useful in reducing seizure frequency in refractory cases.

Effects of ethyl loflazepate on refractory epilepsy in children

We evaluated the safety and efficacy of ethyl loflazepate in children with epilepsy. The study group comprised 21 outpatients (4 by generalized, 17 by localization-related) aged between 9 months and 17 years. Ethyl loflazepate was administered at a dose of 0.015 mg/kg/day twice daily. The final mean dose was 1.35 mg/day. The mean number of prior antiepileptic drugs was 5.7. The entire treatment period was more than 24 months after ethyl loflazepate administration. Six children (28.6%) became seizure-free for the entire study 6 months after administration, 11 (52.4%) had a seizure reduction of more than 50% for over entire 24 months. The mean number of co-medications was 2.4. Adverse events occurred in only 1 patient. Responders, defined as reduction of ≥50% in seizure frequency, included 2/2 of patients with West syndrome and 15/17 (88.2%) with localization-related epilepsy. Ethyl loflazepate represents an important addition to the treatments available for refractory epilepsies in children.

A new generation of anticonvulsants for the treatment of epilepsy in children

Over the past 12 years, a number of new anticonvulsant drugs have been introduced for the treatment of childhood epilepsy. The present article reviews these new agents and provides the considerations one should use in selecting an antiepileptic drug for use in children. While in some cases the newer antiepileptic drugs have a more favourable pharmacokinetic and toxicity profile than the older drugs, there appears to be no objective evidence that any currently available antiepileptic drug is superior in terms of therapeutic efficacy.

Rational treatment options with AEDs and ketogenic diet in Landau-Kleffner syndrome: still waiting after all these years

Antiepileptic drugs (AEDs) remain a first treatment approach in Landau-Kleffner syndrome (LKS) and related syndromes. In the current literature, only class IV evidence is available. Inclusion criteria and outcome parameters are ill-defined. Most commonly, valproate, ethosuximide, and/or benzodiazepines are used. More recent case series show that sulthiame and especially levetiracetam can be considered as effective drugs. Smaller studies also point to the ketogenic diet as a valuable treatment option in LKS.

Topiramate as a new antiepileptic drug in epileptic children in Iran

OBJECTIVE

It is known that current antiepileptic drugs cannot control seizures in 20-30% of patients. The aim of this study was to evaluate the efficacy and safety of topiramate (TPM) as add-on therapy in intractable epileptic children in Iran.

METHODS

As a quasi- experimental (before and after) study, 42 iranian children aged 1-15 years, 28 boys and 14 girls with refractory seizures seeking treatment were recruited to be subjects of this study.

RESULTS

Type of seizures of those 42 epileptic children were as follows: L.G.S (n=14), idiopathic epilepsy (n=8), symptomatic epilepsy (n=16) and progressive myoclonic epilepsy (n=4). At the end of three months of treatment in which topiramate was used concomitantly with previous AED, 17% became seizure free, 26% had more than 50% reduction of seizure frequency and 5% of them had increasing seizures. Therefore, the drug is statistically significant in seizures reduction. The efficacy of the drug was statistically significant in idiopathic and symptomatic epilepsy. The author's did not notice any serious side effects such as: hematologic abnormality, hepatotoxicity and nephrotoxicity.

CONCLUSION

This study supports efficacy and safety of TPM in controlling of intractable epilepsy in children and indicates the drug should be considered as an add-on therapy in the management of refractory epileptic syndromes.

New generation anticonvulsants for the treatment of epilepsy in children

In the last 12 years, 10 new anticonvulsants have been approved by the U.S. Food and Drug Administration and, as a result, the treatment options for children and adults with epilepsy have been expanded considerably. These new generation antiepileptic drugs offer equal efficacy with improved tolerability, pharmacokinetic properties, and side effect profiles compared with the traditional drugs. With many new medications available, the clinician treating children with epilepsy must be well versed in the application of these drugs to their patient population. This manuscript will review the indications, mechanism of action, pharmacokinetics, adverse effects, and dosing of the new generation of anticonvulsant medications.

Levetiracetam Efficacy in Epileptic Syndromes with Continuous Spikes and Waves during Slow Sleep: Experience in 12 Cases

PURPOSE

To assess the add-on efficacy of levetiracetam on the EEG, behavior, and cognition of children with continuous spikes and waves during slow sleep (CSWS).

METHODS

Charts of children with behavioral and/or cognitive deterioration associated with CSWS who received levetiracetam at 50 mg/kg/day as add-on treatment were retrospectively reviewed. Awake and sleep EEG recordings and detailed neuropsychological and behavioral assessments were available at baseline and 2 months after levetiracetam initiation. In children showing clinical and/or electrophysiological improvement after 2 months, levetiracetam was continued with a new evaluation at 1 year.

RESULTS

Twelve patients were included (9 cryptogenic and 3 symptomatic cases). Seven patients (58.3%) showed improvement of EEG record. Among these seven patients, neuropsychological evaluation was improved in three, and in the other four patients, not testable because of severe cognitive impairment, behavior was improved. Two patients improved in neuropsychological evaluation despite the lack of EEG improvement. Eight patients (66.6%) continued levetiracetam treatment after 2 months. After 1 year, four patients were still on levetiracetam, two because sustained effect on EEG and behavior and the two others because improvement in neuropsychological testing despite unchanged EEG. Levetiracetam was discontinued in the other four patients because of neuropsychological or behavioral deterioration associated with CSWS pattern, between 9 and 11 months after treatment initiation.

CONCLUSIONS

This retrospective study suggests that levetiracetam has a positive effect on the EEG, the behavior, and the cognition of patients with epilepsy and CSWS. Additional studies are warranted in order to assess the place of this drug in these epileptic conditions.

Topiramate in long-term treatment of epilepsy in the intellectually disabled

BACKGROUND

To study the effectiveness of topiramate (TPM) in refractory epilepsy in patients who have intellectual disability (ID).

METHODS

A representative population sample of 57 patients with ID (age range 2-61, mean 32.8) was administered add-on TPM for drug-refractory epilepsy.

RESULTS

Seizure freedom for at least for 6 months was attained by 10 (17%), and seizure reduction of > or = 50% by further 26 (46%). Less than 50% decrease in seizure frequency was found in 16 (29%). TPM was more efficacious in localisation-related than in generalised epilepsies (81% vs. 50%, P=0.019). An at least 50% decrease in seizure frequency was achieved by patients with temporal lobe epilepsy in 100%, continuous spike-waves during sleep syndrome in 75%, Lennox-Gastaut syndrome in 52%, and those with infantile spasms in 25% of cases. As great decrease in seizure frequency was found in most patients with cortical dysplasia (83%), acquired encephalopathy with mesial temporal sclerosis (MTS) (75%), and genetic disease associated with MTS (66%). Adverse effects occurred in 10% including two (3%) with seizure aggravation and three (5%) necessitating discontinuation.

CONCLUSION

TPM is an effective antiepileptic drug which is of value in treating people with seizures that are resistant to other antiepileptic medication. As a broad-spectrum drug it may substitute for polypharmacy and, at the same time decrease adverse effects and costs of therapy.

Efficacy of levetiracetam in pharmacoresistant continuous spikes and waves during slow sleep

OBJECTIVE

To evaluate the efficacy of levetiracetam (LEV) in continuous spikes and waves during slow sleep (CSWS). Despite first description dates back to 1971, no agreement exists about CSWS treatment. The condition is rare and controlled clinical trials are very difficult to perform, so the reports about efficacy of different drugs are anecdotal.

PATIENTS AND METHODS

We introduced LEV in three children affected by symptomatic focal epilepsy and pharmacoresistant CSWS and evaluated clinical, neuropsychological and electroencephalographic outcome.

RESULTS

Two cases responded completely, one case showed only a mild reduction of spikes and waves during slow sleep.

CONCLUSION

Even if our report is anecdotal, LEV expands the spectrum of antiepileptic drugs that can be used for the treatment of CSWS. LEV efficacy should be confirmed in larger series.

Treatment Strategies for Myoclonic Seizures and Epilepsy Syndromes with Myoclonic Seizures

Despite the availability of numerous treatment options, the diagnosis and treatment of myoclonic seizures continue to be challenging. Based on clinical experience, valproate and benzodiazepines have historically been used to treat myoclonic seizures. However, many more treatment options exist today, and the clinician must match the appropriate treatment with the patient's epilepsy syndrome and its underlying etiology. Comorbidities and other medications must also be considered when making decisions regarding treatment. Rarely, some antiepileptic drugs may exacerbate myoclonic seizures. Most epileptic myoclonus can be treated pharmacologically, but some cases respond better to surgery, the ketogenic diet, or vagus nerve stimulation. Because myoclonic seizures can be difficult to treat, clinicians should be flexible in their approach and tailor therapy to each patient.