Effect of ethosuximide (ETX) on neuropsychiatric comorbidities in absence seizures

Abstract

This study focused on the effects of the antiepileptic drug ethosuximide (ETX), at a dose of 200 mg/kg, on the psychiatric comorbidities in childhood absence epilepsy. The psychiatric comorbidity of interest was anxiety since ETX is said to exhibit antianxiety effects. Therefore, ETX was studied with respect to its anxiolytic or anxiogenic effects on three strains of rats: GAERS as the epileptic rats, NEC being the nonepileptic control and Wistar as a second control. The behaviour of rats reflects their anxiety levels, and thus, changes in behaviour were seen as an increase or decrease in anxiety. Rats were divided into two groups, vehicle and treatment group, and were administered with vehicle solution or ETX, accordingly. Each group was further divided into two groups: those undergoing hole-board (HB) test and those undergoing elevated plus-maze (EPM) test. During these tests, rats were recorded, and the video recordings were used to analyse the behavioural parameters of each test. The data obtained was used to carry out two-way ANOVA and Sidak’s post hoc test for multiple comparisons. These statistical tests determined the significance of the behavioural changes observed, following the administration of ETX or vehicle. They also showed whether ETX had varying anxiolytic effects on the different strains. The results showed that the anxiolytic effects of ETX were more prominent in GAERS, being epileptic, than in any of the other non-epileptic strains. The research conducted is part of an ongoing effort to find better treatments for childhood absence epilepsy and the accompanying psychiatric comorbidities.