Methylation of BDNF and SLC6A4 Gene Promoters in Brazilian Patients With Temporal Lobe Epilepsy Presenting or Not Psychiatric Comorbidities

Psychosis of Epilepsy: An Update on Clinical Classification and Mechanism

Epilepsy is a prevalent chronic neurological disorder that can significantly impact patients' lives. The incidence and risk of psychosis in individuals with epilepsy are notably higher than in the general population, adversely affecting both the management and rehabilitation of epilepsy and further diminishing patients' quality of life. This review provides an overview of the classification and clinical features of psychosis of epilepsy, with the aim of offering insights and references for the clinical diagnosis and treatment of various types of psychosis of epilepsy. Additionally, we examine the potential pathophysiological mechanisms underlying the psychosis of epilepsy from three perspectives: neuroimaging, neurobiology, and genetics. The alterations in brain structure and function, neurotransmitters, neuroinflammatory mediators, and genetic factors discussed in this review may offer insights into the onset and progression of psychotic symptoms in epilepsy patients and are anticipated to inform the identification of novel therapeutic targets in the future.

Psychosis and schizophrenia among patients with epilepsy: A systematic review and meta-analysis

BACKGROUND

Prior research has indicated an association between epilepsy and psychosis. This review aimed to estimate the global prevalence rate of psychosis and schizophrenia in epilepsy and assess the odds of psychosis and schizophrenia among patients with epilepsy (PWE).

METHOD

A comprehensive literature search was carried out utilizing relevant keywords in PubMed/MEDLINE and Scopus, covering from January 1, 1990, to November 18, 2023. The meta-analysis was performed using R software employing a random-effect model to establish the overall prevalence and odds ratio (OR), with 95 % confidence intervals (95 % CI), of psychosis and schizophrenia in epilepsy.

RESULT

Eighty-one studies encompassing 970,497 PWE met the inclusion criteria. The meta-analysis revealed that the overall prevalence of psychosis and schizophrenia among PWE was 7.8 % (95 % CI: 6.3-9.2 %, I2 = 100 %) and 3 % (95 % CI: 1.7-4.3 %, I2 = 95 %), respectively. Moreover, epilepsy was associated with a threefold rise in the odds of psychosis (OR = 3.41, 95 % CI: 2.3-5.08, p-value < 0.01, I2 = 99 %, p-heterogeneity < 0.01). Furthermore, epilepsy was found to be significantly correlated with a fivefold increased odds of schizophrenia (OR = 5.22, 95 % CI: 2.99-9.11, p-value < 0.01, I2 = 94 %, p-heterogeneity < 0.01) CONCLUSION: Epilepsy can increase the risk of developing psychosis and schizophrenia. Additional longitudinal research is warranted to elucidate the influence of epilepsy and its treatments on the risk of psychosis and schizophrenia, and also a comprehensive suite of confounding adjustments will be requisite.

The Possible Role of Brain-derived Neurotrophic Factor in Epilepsy

Epilepsy is a neurological disease characterized by repeated seizures. Despite of that the brain-derived neurotrophic factor (BDNF) is implicated in the pathogenesis of epileptogenesis and epilepsy, BDNF may have a neuroprotective effect against epilepsy. Thus, the goal of the present review was to highlight the protective and detrimental roles of BDNF in epilepsy. In this review, we also try to find the relation of BDNF with other signaling pathways and cellular processes including autophagy, mTOR pathway, progranulin (PGN), and α-Synuclein (α-Syn) which negatively and positively regulate BDNF/tyrosine kinase receptor B (TrkB) signaling pathway. Therefore, the assessment of BDNF levels in epilepsy should be related to other neuronal signaling pathways and types of epilepsy in both preclinical and clinical studies. In conclusion, there is a strong controversy concerning the potential role of BDNF in epilepsy. Therefore, preclinical, molecular, and clinical studies are warranted in this regard.

Circulating cell-free DNA methylation mirrors alterations in cerebral patterns in epilepsy

BACKGROUND

DNA methylation profiling of circulating cell-free DNA (cfDNA) has rapidly become a promising strategy for biomarker identification and development. The cell-type-specific nature of DNA methylation patterns and the direct relationship between cfDNA and apoptosis can potentially be used non-invasively to predict local alterations. In addition, direct detection of altered DNA methylation patterns performs well as a biomarker. In a previous study, we demonstrated marked DNA methylation alterations in brain tissue from patients with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS).

RESULTS

We performed DNA methylation profiling in cfDNA isolated from the serum of MTLE patients and healthy controls using BeadChip arrays followed by systematic bioinformatic analysis including deconvolution analysis and integration with DNase accessibility data sets. Differential cfDNA methylation analysis showed an overrepresentation of gene ontology terms and transcription factors related to central nervous system function and regulation. Deconvolution analysis of the DNA methylation data sets ruled out the possibility that the observed differences were due to changes in the proportional contribution of cortical neurons in cfDNA. Moreover, we found no overrepresentation of neuron- or glia-specific patterns in the described cfDNA methylation patterns. However, the MTLE-HS cfDNA methylation patterns featured a significant overrepresentation of the epileptic DNA methylation alterations previously observed in the hippocampus.

CONCLUSIONS

Our results support the use of cfDNA methylation profiling as a rational approach to seeking non-invasive and reproducible epilepsy biomarkers.