Are Newer AEDs Better Than the Classic Ones in the Treatment of Status Epilepticus?

Preliminary study on the mechanism of SAHA in the treatment of refractory epilepsy induced by GABRG2(F343L) mutation

Mutations in the γ-amino butyric acid type A (GABAA) receptor γ2 subunit gene, GABRG2, have been associated with refractory epilepsy. Increasing evidence indicates that suberoylanilide hydroxamic acid (SAHA), a broad-spectrum histone acetyltransferases (HDACs) inhibitor, can inhibit seizure onset. However, the mechanisms involved remains unknown. The present study aimed to explore the anti-epileptic effect and underlying mechanisms of SAHA in the treatment of refractory epilepsy induced by GABRG2 mutation. In the zebrafish line expressing human mutant GABRG2(F343L), Tg(hGABRG2F343L), SAHA was found to reduce seizure onset, swimming activity, and neuronal activity. In both Tg(hGABRG2F343L) zebrafish and HEK293T cells transfected with GABAA receptor subunits, SAHA could improve the pan-acetylation level and reduce the expression of HDAC1/10. The decreased expressions of GABAA receptor subunits could be rescued by SAHA treatment both in vivo and in vitro, which might be the result of increased gene transcription and protein trafficking. The up-regulated acetylation of histone H3 and H4 as well as Bip expression might be involved in the process. Taken together, our data proved that both histone and non-histone acetylation might contribute to the anti-epileptic effect of SAHA in refractory epilepsy caused by GABRG2(F343L) mutation, demonstrating SAHA as a promising therapeutic agent for refractory epilepsy.

Clinical outcomes and treatments effectiveness in status epilepticus resolved by antiepileptic drugs: A five-year observational study

Objective

To evaluate clinical outcomes and treatment effectiveness of status epilepticus finally resolved by nonbenzodiazepine antiepileptic drugs (AEDs).

Methods

All consecutive SE episodes observed from September 1, 2013, to September 1, 2018, and resolved by AEDs were considered. Diagnosis and classification of SE followed the 2015 ILAE proposal. Nonconvulsive status (NCSE) diagnosis was confirmed according to the Salzburg EEG criteria. The modified Rankin Scale and deaths at 30 days from onset were used to evaluate outcomes.

Results

A total of 277 status episodes (mean age 71 years; 61% female) were treated and resolved by antiepileptic drugs after 382 treatment trials. 68% of the SE resolved after AED use as first/second treatment line, while subsequent trials with AEDs gave an additional 32% resolution. A return to baseline conditions was observed in 48% of the patients, while overall mortality was 19% without significant changes across the study years. Mortality was higher in NCSE than in convulsive SE (22.5% vs 12.9%; P < .05), while mortality did not differ in SE episodes resolved by a first/second AED trial (17.2%) versus SE resolved by successive treatment trials (18.9%). The resolution rate of intravenous AEDs was 82% for valproate, 77% for lacosamide, 71% for phenytoin, and 62% for levetiracetam. No significant differences were found in head-to-head comparison, but for the valproate-levetiracetam one that was related to NCSE episodes in which valproate resulted to be effective in 86% of the trials while levetiracetam in 62% (P < .002).

Significance

A high short-term mortality, stable over time, was observed in SE despite resolution of seizures, especially in SE with nonconvulsive semiology. Comparative AED efficacy showed no significant differences except for higher resolution rate for valproate versus levetiracetam in NCSE.

Newer Antiepileptic Drugs for Status Epilepticus in Adults: What's the Evidence?

Status epilepticus (SE) is one of the most frequent neurological emergencies. Despite this, understanding of its pathophysiology and evidence regarding its management is limited. Rapid, effective, and well-tolerated treatment to achieve seizure cessation is advocated to prevent brain damage or potentially lethal outcomes. The last two decades have witnessed an exponential increase in the number of available antiepileptic drugs (AEDs). These compounds, especially lacosamide and levetiracetam, in view of their intravenous formulation, have been increasingly prescribed in SE. These and other newer AEDs present a promising profile in terms of tolerability, with few centrally depressive effects, favorable pharmacokinetic properties, and fewer drug interactions than classical AEDs; conversely, they are more expensive. There is still no clear evidence to suggest a specific beneficial impact of newer AEDs on SE outcome, preventing any strong recommendation regarding their prescription in SE. Further comparative studies are urgently required to clarify their place and optimal use in the armamentarium of SE treatment.

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Zusammenfassung. Der Status epilepticus, vor allem der konvulsive tonisch-klonische (Grand mal) Status epilepticus, ist ein Notfall, der zu einer sofortigen Behandlung führen muss. Die frühe Behandlung ist effektiver als der spätere Beginn, ebenso wie der Einsatz standardisierter Therapieprotokolle. Nach der Gabe von Benzodiazepinen muss die Aufdosierung eines Antikonvulsivums (Levetiracetam, Valproat oder Phenytoin) erfolgen, um das Wiederauftreten von Anfällen zu verhindern. Beim refraktären Status epilepticus werden die Anästhetika Propofol oder Midazolam (oder Thiopental) vorzugsweise unter EEG-Ableitung mit einem Burst-Suppressions-Muster eingesetzt. Neben der raschen Therapie sollte die Diagnostik nach der Ursache des Status epilepticus nicht vergessen werden. Insbesondere bei Persistenz sollte immer auch die Überprüfung der Diagnose erfolgen, um das Vorliegen eines Pseudostatus nicht-epileptischer Anfälle nicht zu übersehen.