Reduction of seizures with low-dose clonazepam in children with epilepsy

Efficacy of intravenous clonazepam for paediatric convulsive status epilepticus

AIM

To compare the efficacy of intravenous clonazepam (CLZ) for the initial management of convulsive status epilepticus (CSE) in children as a function of the first-line in-hospital dose used.

METHOD

This monocentric retrospective study included children who received a first dose of CLZ for CSE at Montpellier University Hospital, France, between January 2016 and June 2019. Data from medical records (clinical, treatment, course) were collected and compared as a function of the first CLZ dose used.

RESULTS

Among the 310 children treated for CSE, 105 received at least one CLZ dose (median age 3 years; quartile 1-quartile 3 [Q1-Q3] = 1 years 2 months-6 years 6 months). Among these 105 patients, 24 (22%) received a dose less than 0.03 mg/kg (low dose) and 69 (65%) received a dose of at least 0.03 mg/kg (high dose). Seizure cessation rate was not different between the low- and high-dose groups (62.5% vs 76%; odds ratio 0.53, 95% confidence interval [CI] 0.19-1.44, p = 0.29). The administration of a second dose of CLZ was more frequent in the low- than the high-dose group (37.5% vs 16%; odds ratio 3.2, 95% CI 1.1-9.1, p = 0.04).

INTERPRETATION

Our study did not find any difference in seizure termination rate as a function of CLZ dose in children with CSE. However, a second CLZ dose was more frequently needed in the group receiving low (less than 0.03 mg/kg) CLZ.

Antiepileptic Drug Selection According to Seizure Type in Adult Patients with Epilepsy

Epilepsy is a common neurological disorder that is mainly treated using antiepileptic drugs. Several antiepileptic drugs such as phenobarbital, phenytoin, primidone, and ethosuximide were developed in the early 20th century. More than 10 types of antiepileptic drugs have been developed since the 1990s, and there are now more than 20 antiepileptic drugs in active clinical use. The choice of antiepileptic drugs is based on the clinical features of the seizure types, electroencephalogram findings, epileptic syndrome, and drug stability. Currently there are 19 antiepileptic drugs approved by the Korean Food and Drug Administration, 18 of which (with the exclusion of brivaracetam) are covered by the National Health Insurance Service in Korea. We reviewed the selection of antiepileptic drugs according to the classification of epileptic seizures.

The role of ARID1B, a BAF chromatin remodeling complex subunit, in neural development and behavior

Haploinsufficiency of the chromatin remodeling factor ARID1B leads to autism spectrum disorder and intellectual disability. Several independent research groups, including our own, recently examined the effects of heterozygous deletion of Arid1b in mice and reported severe behavioral abnormalities reminiscent of autism spectrum disorders and intellectual disability as well as marked changes in gene expression and decreased body size. Arid1b heterozygous mice also display significant cortical excitatory/inhibitory imbalance due to altered GABAergic neuron numbers and impaired inhibitory synaptic transmission. Abnormal epigenetic modifications, including histone acetylation and methylation, are additionally associated with Arid1b haploinsufficiency in the brain. Treating adult Arid1b mutant mice with a positive GABA allosteric modulator, however, rescues multiple behavioral abnormalities, such as cognitive and social impairments, as well as elevated anxiety. While treating Arid1b haploinsufficient mice with recombinant mouse growth hormone successfully increases body size, it has no effect on aberrant behavior. Here we summarize the recent findings regarding the role of ARID1B in brain development and behavior and discuss the utility of the Arid1b heterozygous mouse model in neurodevelopmental and psychiatric research. We also discuss some of the opportunities and potential challenges in developing translational applications for humans and possible avenues for further research into the mechanisms of ARID1B pathology in the brain.

Arid1b haploinsufficiency disrupts cortical interneuron development and mouse behavior

Haploinsufficiency of the AT-rich interactive domain 1B (ARID1B) gene causes autism spectrum disorder (ASD) and intellectual disability, however, the neurobiological basis for this is unknown. Here, we generated Arid1b knockout mice and examined heterozygotes to model human patients. Arid1b heterozygous mice showed a decreased number of cortical GABAergic interneurons and reduced proliferation of interneuron progenitors in the ganglionic eminence. Arid1b haploinsufficiency also led to an imbalance between excitatory and inhibitory synapses in the cerebral cortex. Furthermore, we found that Arid1b haploinsufficiency suppressed histone H3 lysine 9 acetylation (H3K9Ac) overall, and in particular reduced H3K9Ac of the Pvalb promoter, resulting in decreased transcription. Arid1b heterozygous mice exhibited abnormal cognitive and social behavior, which was rescued by treatment with a positive allosteric GABA_A receptor modulator. Our results demonstrate a critical role for the Arid1b gene in interneuron development and behavior, and provide insight into the pathogenesis of ASD and intellectual disability.

Development of a rapid RP–HPLC method for the determination of clonazepam in human plasma

A rapid and sensitive high-performance liquid chromatography method with UV detection was developed for the determination of clonazepam in human plasma using 3-methylclonazepam, as internal standard. A one-step extraction of both compounds was performed with a mixture of hexane/ethyl acetate (90:10, v/v). The HPLC analysis was carried out on a Nova Pak((R)) C(18) reversed-phase column with a mobile phase of acetonitrile-0.01 M sodium acetate adjusted to pH 7 with dilute acetic acid (40:60, v/v). A linear response was observed over the concentration range 5-100 ng/mL. Intra- and inter-day assay precision and accuracy fulfilled the international requirements. The lower limit of quantification was 5 ng/mL without interference of endogenous components. For analytical purpose, the stability of clonazepam in bidistilled water and plasma has been studied. A rapid degradation was noticed when clonazepam was stored in bidistilled water at the daylight following a first-order kinetic rate with a 87 min half life whereas no significant degradation was observed in plasma. This method was applied to measure plasma concentrations of clonazepam either in patients receiving therapeutic doses or in poisoning cases.