Comparative analysis of background EEG activity in juvenile myoclonic epilepsy during valproic acid treatment: a standardized, low-resolution, brain electromagnetic tomography (sLORETA) study

Abstract

Background By definition, the background EEG is normal in juvenile myoclonic epilepsy (JME) patients and not accompanied by other developmental and cognitive problems. However, some recent studies using quantitative EEG (qEEG) reported abnormal changes in the background activity. QEEG investigation in patients undergoing anticonvulsant treatment might be a useful approach to explore the electrophysiology and anticonvulsant effects in JME. Methods We investigated background EEG activity changes in patients undergoing valproic acid (VPA) treatment using qEEG analysis in a distributed source model. In 17 children with JME, non-parametric statistical analysis using standardized low-resolution brain electromagnetic tomography was performed to compare the current density distribution of four frequency bands (delta, theta, alpha, and beta) between untreated and treated conditions. Results VPA reduced background EEG activity in the low-frequency (delta-theta) bands across the frontal, parieto-occipital, and limbic lobes (threshold log-F-ratio = ±1.414, p < 0.05; threshold log-F-ratio= ±1.465, p < 0.01). In the delta band, comparative analysis revealed significant current density differences in the occipital, parietal, and limbic lobes. In the theta band, the analysis revealed significant differences in the frontal, occipital, and limbic lobes. The maximal difference was found in the delta band in the cuneus of the left occipital lobe (log-F-ratio = −1.840) and the theta band in the medial frontal gyrus of the left frontal lobe (log-F-ratio = −1.610). Conclusions This study demonstrated the anticonvulsant effects on the neural networks involved in JME. In addition, these findings suggested the focal features and the possibility of functional deficits in patients with JME.

Acute effect of antiseizure drugs on background oscillations inScn1aA1783VDravet syndrome mouse model

“…VA had a variable impact on spike frequency, reducing the frequency by over 50% in 57% of the tested mice, with a smaller effect in 28% of the mice, and increased spike frequency in one mouse (Figure 2B-C). Focusing on quantitative analyses of background activity, VA reduced the total power spectral density (PSD) in all the tested DS mice (Figure 2D-F), in agreement with previous reports in humans 14,15 . When inspecting the relative power of each frequency band, we observed an increase in the contribution of the beta band (Figure 2G).…”

“…The effect of ASMs on background EEG activity was studied before, but not in Dravet. VA was shown to reduce the power of background EEG in patients with idiopathic generalized epilepsy, and juvenile myoclonic epilepsy 14,15 , and CLB caused spectral changes in rabbits 16 and kindled rats 17 .…”

Acute effect of antiseizure drugs on background oscillations in Scn1aA1783V Dravet syndrome mouse model

“…VA had a variable impact on spike frequency, reducing the frequency by over 50% in 57% of the tested mice, with a smaller effect in 28% of the mice, and increased spike frequency in one mouse ( Figures 2B, C ). Focusing on quantitative analyses of background activity, VA reduced the total power spectral density (PSD) in all the tested DS mice ( Figures 2D–F ), in agreement with previous reports in humans ( Clemens et al, 2006 ; Moon et al, 2022 ). When inspecting the relative power of each frequency band, we observed an increase in the contribution of the beta band ( Figure 2G ).…”

“…The effect of ASMs on background EEG activity was studied before, but not in Dravet. VA was shown to reduce the power of background EEG in patients with idiopathic generalized epilepsy, and juvenile myoclonic epilepsy ( Clemens et al, 2006 ; Moon et al, 2022 ), and CLB caused spectral changes in rabbits ( Gerhards, 1978 ) and kindled rats ( Harris et al, 1988 ). Here, utilizing DS mice ( Scn1a A1783V/WT ) we show that acute administration of Dravet-recommended drugs, VA, CLB, a combination of CLB + STP, or STP alone, was associated with a reduction in the frequency of interictal spikes in most of the tested mice, along with a significant increase in relative beta band contribution to the total power.…”

Distributed source localization of epileptiform discharges in juvenile myoclonic epilepsy: Standardized low-resolution brain electromagnetic tomography (sLORETA) Study

“…Furthermore, we recently published another study that investigated background EEG changes before and after anticonvulsant treatments in JME. [ 32 ] In that study, focal features of EEG were observed by the source localization method, but various cortical regions including the frontal, parietal, occipital, and limbic lobes were also involved. The results were consistent with this study, suggesting that JME is distinct from focal epilepsies.…”