A Comparative Study on Intranasal Versus Intravenous Lorazepam in the Management of Acute Seizure in Children

Introduction: The acute seizure in childhood is a medical emergency which is usually managed by benzodiazepines used as a first line of therapy. There are no strict guidelines of using intranasal lorazepam in India. Many paediatricians use it in an emergency situation as it is inexpensive, easy to administer and even treatment can be started at home. Very few studies are available to compare efficacy and safety of intravenous lorazepam with intranasal lorazepam in childhood seizure, though both routes have comparable pharmacokinetic profile. Intravenous lorazepam (0.1 mg/kg) is already recommended as a first-line treatment of acute childhood seizures in India. There are very few studies regarding the usefulness of intranasal lorazepam. With this background, we compared intranasal lorazepam with the more widely accepted intravenous lorazepam for control of acute seizure. Aim: To compare effectiveness and safety of intranasal and intravenous lorazepam in acute seizure in children aged 5-12 years. Materials and methods: This is an analytical observational cross-sectional study involving patients with acute seizure who received lorazepam via either the intravenous or intranasal route. Formulation and dosage of lorazepam were the same in both routes. Results: Distributions of patient groups according to sex, age, and weight were statistically not significant (p=0.42, p=0.391, and p=0.605, respectively). Time to control seizure within 10 min and persistent cessation of seizure activity were similar in both groups. Safety parameters showed no differences statistically. Conclusions: Though intravenous lorazepam is recommended as first-line treatment, intranasal lorazepam may be a good alternative choice in a convulsing child.

Effect of Ellagic Acid on Seizure Threshold in Two Acute Seizure Tests in Mice

Ellagic acid (EA) is a natural dietary polyphenol that has many beneficial properties, including anti-inflammatory, antioxidant, antiviral, antibacterial, and neuroprotective effects. Studies have revealed that EA may modulate seizure activity in chemically induced animal models of seizures. Therefore, the aim of the present study was to investigate the effect of EA on the seizure threshold in two acute seizure tests in male mice, i.e., in the intravenous (i.v.) pentylenetetrazole (PTZ) seizure test and in the maximal electroshock seizure threshold (MEST) test. The obtained results showed that EA (100 mg/kg) significantly elevated the threshold for both the first myoclonic twitch and generalized clonic seizure in the i.v. PTZ seizure test. At the highest dose tested (200 mg/kg), EA increased the threshold for tonic hindlimb extension in the MEST test. EA did not produce any significant changes in motor coordination (assessed in the chimney test) or muscular strength (investigated in the grip-strength test). The plasma and total brain concentration-time profiles of EA after intraperitoneal and oral administration were also determined. Although further studies are necessary to confirm the anticonvulsant activity of EA, our findings suggest that it may modulate seizure susceptibility in animal models.

Distinct regulation of tonic GABAergic inhibition by NMDA receptor subtypes

Tonic inhibition mediated by extrasynaptic gamma-aminobutyric acid type A receptors (GABAARs) play important roles in the regulation of various brain functions. However, the regulatory mechanisms for tonic inhibition remain largely unknown. Here we report distinct actions of GluN2A- and GluN2B-containing subtypes of NMDA receptors (NMDARs) on tonic inhibition in hippocampal neurons. Mechanistically, GluN2A- and GluN2B-containing NMDARs play differential roles in alpha5-GABAAR internalization. Additionally, GluN2A-, but not GluN2B-, containing receptors are required for the homeostatic potentiation of tonic inhibition. In an acute seizure model induced by kainic acid, tonic inhibition is decreased during acute seizures, while it is increased 24 h later, and these alterations are dependent on the distinct GluN2-containing NMDARs. Collectively, these data reveal a critical link between NMDARs and extrasynaptic GABAARs in both physiological and pathological conditions.