Alterations in Cortical-Subcortical Metabolism in Temporal Lobe Epilepsy With Impaired Awareness Seizures

Anticonvulsant effect of glycitin in pentylenetetrazol induced male Wistar rat model by targeting oxidative stress and Nrf2/HO-1 signaling

Epilepsy, characterized by recurrent seizures, poses a significant health challenge globally. Despite the availability of anti-seizure medications, their adverse effects and inadequate efficacy in controlling seizures propel the exploration of alternative therapeutic measures. In hypothesis, glycitin is a phytoestrogenic compound found in soybeans and due to its estrogenic properties may have anti-epileptic and neuroprotective effects. This study investigates the potential anti-epileptic properties of glycitin in the context of pentylenetetrazol (PTZ) induced seizures in male Wistar rats. The rats were pretreated with varying doses of glycitin (5, 10, and 20 mg/kg) before PTZ (35 mg/kg) administration, and assessments included behavioral observations and histological evaluation via hematoxylin and eosin (H&E) staining. Additionally, oxidative stress markers, such as malondialdehyde (MDA), glutathione peroxidase (GPx), and superoxide dismutase (SOD) levels, were quantified to examine glycitin's impact on oxidative stress. Molecular analysis was conducted to assess the activation of the Nuclear factor erythroid 2-related factor (Nrf2)/Heme oxygenase 1 (HO-1) signaling pathway. Results indicated that glycitin pretreatment effectively mitigated PTZ-induced convulsive behaviors, supported by histological findings from H&E staining. Furthermore, glycitin administration led to significant alterations in MDA, GPx, and SOD levels, suggestive of its ability to modulate oxidative stress. Notably, glycitin treatment induced activation of the Nrf2/HO-1 signaling pathway. These findings underscore the potential of glycitin as an anticonvulsant agent, elucidating its mechanism of action through histological protection, modulation of oxidative stress markers, and activation of the Nrf2/HO-1 signaling pathway.

Inhibitory control deficits in patients with mesial temporal lobe epilepsy: an event-related potential analysis based on Go/NoGo task

Objective

Neuropsychiatric comorbidities are common among patients with mesial temporal lobe epilepsy (MTLE). One of these comorbidities, impulsivity, can significantly impact the quality of life and prognosis. However, there have been few studies of impulsivity in these patients, and the existing findings are inconsistent. The present study investigates impulsivity in MTLE patients from the perspective of inhibitory control and its underlying processes using event-related potentials (ERPs) initiated using a Go/NoGo task.

Methods

A total of 25 MTLE patients and 25 age-, gender-, and education-matched healthy controls (HCs) completed an unequal visual Go/NoGo task. Different waveforms as well as behavioral measures were analyzed between Go and NoGo conditions (N2d and P3d). Impulsivity was also assessed using self -rating scales, and clinical variables that may be related to ERPs were explored.

Results

Compared with HCs, MTLE patients exhibited significantly longer reaction time (RT) (p = 0.002) and lower P3d especially at the frontal electrode sites (p = 0.001). In the MTLE group, the seizure frequency (p = 0.045) and seizure types (p < 0.001) were correlated with the P3d amplitude. A self-rated impulsivity assessment revealed that MTLE patients had higher non-planning (p = 0.017) and total scores (p = 0.019) on the BIS-11 as well as higher DI (p = 0.010) and lower FI (p = 0.007) on the DII.

Conclusion

The findings demonstrate that the presence of inhibitory control deficits in patients with MTLE are characterized by deficits in the late stage of inhibition control, namely the motor inhibition stage. This study improves our understanding of impulsivity in MTLE patients and suggests that ERPs may constitute a sensitive means of detecting this trait.

Differences in whole-brain metabolism are associated with the expression of genes related to neurovascular unit integrity and synaptic plasticity in temporal lobe epilepsy

PURPOSE

Temporal lobe epilepsy (TLE) is a common, polygenic epilepsy syndrome that involves glucose hypometabolism in the epileptogenic zone. However, the transcriptional and cellular signatures underlying the metabolism in TLE remain unclear.

METHODS

In this retrospective study, 2-[18F]-fluoro-2-deoxy-D-glucose ([18F]FDG) positron emission tomography (PET) scans of TLE patients (n = 104) who underwent anterior temporal lobectomy were consecutively collected between 2016 and 2021. The transcriptional profiles of TLE risk genes across the brain were identified by the gene expression analyses from six TLE patients and twelve postmortem donors (six from the Allen Human Brain Atlas). Integrating the neuroimaging and transcriptomic data, we examined the relationship between the expression of TLE-associated genes and metabolic alterations in TLE. Furthermore, we performed functional enrichment analyses of the genes with higher weight in partial least squares regression using Metascape.

RESULTS

A total of 104 patients with TLE (mean age 29 ± 9 years, 50% male) and 30 healthy controls (HCs) (mean age 31 ± 6 years, 53% male) were enrolled. Compared to that of HCs, patients with TLE showed hypometabolism in the temporal lobes and adjacent structures but hypermetabolism in the thalamus and basal ganglia. The cortical map of inter-group differences in cerebral metabolism was spatially correlated with the expression of a weighted combination of genes enriched in ontology terms and pathways related to neurovascular unit (NVU) integrity and synaptic plasticity.

DISCUSSION

Our findings, combined with the analysis of neuroimaging and transcriptional data, suggest that genes related to NVU integrity and synaptic plasticity may drive alterations to brain metabolism that mediate the genetic risk of TLE.