Alzheimer Disease and Epilepsy: A Mendelian Randomization Study

Comparing levetiracetam and zonisamide effects on rivastigmine anti-Alzheimer's activity in aluminum chloride-induced Alzheimer's-like disease in rats: Impact on α7 nicotinic acetylcholine receptors and amyloid β

BACKGROUND AND AIM

Alzheimer's disease (AD) is the most progressive form of neurodegenerative disease, which severely impairs cognitive function. The leading class of drugs used to treat AD is acetylcholinesterase inhibitors (AChE-Is) as Rivastigmine (RIVA), partially ameliorate its cognitive symptoms. Since epilepsy is a common comorbidity with AD, we explored the potential that new the antiepileptic drugs; Levetiracetam (LEV) and Zonisamide (ZNS) may possess an additional therapeutic benefit to RIVA in AlCl3-induced AD rat model.

MATERIALS AND METHODS

AlCl3 was used to provoke AD in rats which were then supplemented with treatment drugs for 2 weeks. Treated groups were: Control, AlCl3, RIVA, LEV, RIVA + LEV, ZNS and RIVA + ZNS. Then, the behavioral tests; passive avoidance (PA), Morris water maze (MWM) and novel object recognition (NOR) were conducted to assess cognitive behavior and memory. The Hippocampal Aβ assembly was thoroughly examined by histopathology and ELISA. α7 Nicotinic ACh receptors' (α7nAChRs) expression was assessed immunohistochemically and by real-time quantitative polymerase chain reaction (qPCR). Caspase 3 expression was also assessed by real-time qPCR in hippocampal tissues.

RESULTS

AlCl3 administration impaired memory and cognitive functions in rats, augmented hippocampal Aβ deposition, with subsequent neurodegeneration and α7nAChRs down-regulation. LEV, but not ZNS, administration significantly mitigated AlCl3-induced cognitive impairment probably through suppression of amyloid β (Aβ) deposition, enhancement of neurogenesis and α7nAChRs expression. When combined to RIVA, ZNS treatment negatively affected cognition possibly through its impact on hippocampal Aβ and subsequent neuronal damage.

CONCLUSION

Although our results indicated that neither LEV nor ZNS provided any extra benefit to cognitive enhancements in AD rats receiving rivastigmine, LEV demonstrated positive effects individually while ZNS had negative effects when combined with RIVA. As a result, this study suggests the use of LEV rather than ZNS for managing epilepsy in patients with AD given that Alzheimer's and epilepsy can coexist.

Transcriptomic analyses of human brains with Alzheimer's disease identified dysregulated epilepsy-causing genes

BACKGROUND & OBJECTIVE

Alzheimer's Disease (AD) patients at multiple stages of disease progression have a high prevalence of seizures. However, whether AD and epilepsy share pathophysiological changes remains poorly defined. In this study, we leveraged high-throughput transcriptomic data from sporadic AD cases at different stages of cognitive impairment across multiple independent cohorts and brain regions to examine the role of epilepsy-causing genes.

METHODS

Epilepsy-causing genes were manually curated, and their expression levels were analyzed across bulk transcriptomic data from three AD cohorts and three brain regions. RNA-seq data from sporadic AD and control cases from the Knight ADRC, MSBB, and ROSMAP cohorts were processed and analyzed under the same analytical pipeline. An integrative clustering approach employing machine learning and multi-omics data was employed to identify molecularly defined profiles with different cognitive scores.

RESULTS

We found several epilepsy-associated genes/pathways significantly dysregulated in a group of AD patients with more severe cognitive impairment. We observed 15 genes consistently downregulated across the three cohorts, including sodium and potassium channels genes, suggesting that these genes play fundamental roles in cognitive function or AD progression. Notably, we found 25 of these genes dysregulated in earlier stages of AD and become worse with AD progression.

CONCLUSION

Our findings revealed that epilepsy-causing genes showed changes in the early and late stages of AD progression, suggesting that they might be playing a role in AD progression. We can not establish directionality or cause-effect with our findings. However, changes in the epilepsy-causing genes might underlie the presence of seizures in AD patients, which might be present before or concurrently with the initial stages of AD.

Association between mental disorders and trigeminal neuralgia: a cohort study and Mendelian randomization analysis

BACKGROUND

Clinical observational evidence suggests a close association between Trigeminal Neuralgia (TN) and Mental disorders (MDs). However, the causal relationship between the two remains unclear. This study aims to observe and analyse the associations between depression, anxiety, insomnia, and TN through clinical research. It also employs Mendelian randomization (MR) analysis to verify the potential genetic correlation between TN and various mental disorders. offering new insights for the diagnosis, prevention, and intervention strategies for TN.

METHODS

In the cohort study section, clinical data were collected from 154 patients with TN, all of whom were excluded from preoperative use of psychotropic drugs such as carbamazepine. The PHQ-9, GAD-7, and ISI scales were used to assess preoperative symptoms of depression, anxiety, and insomnia. Multivariable linear regression models were used to identify factors associated with questionnaire scores, with model performance evaluated by adjusted R², AIC, BIC, and p-values. Patients with significant positive symptoms preoperatively were followed up one-year after surgery, and non-parametric tests were employed to examine changes in mental disorder symptoms after pain relief. In MR analysis section, the main MR analysis methods include Inverse Variance Weighted (IVW), MR Egger, Weighted Median, Simple Mode, and Weighted Mode. The Benjamini-Hochberg (BH) method was used to adjust the p -values ​​and control the false discovery rate (FDR). Subsequent sensitivity analyses involved Cochran's Q test, MR-Egger regression intercept, MR-pleiotropy residual sum and outlier test (MR-PRESSO).

RESULTS

Multiple linear regression analyses revealed that longer disease duration and greater involvement of trigeminal branches were consistently associated with higher PHQ-9, GAD-7, and ISI scores, while demographic factors and baseline BNI scores showed no significant predictive value. MR analysis indicated that autism (OR = 0.697, 95% CI [0.494-0.982], P = 0.039), schizophrenia (OR = 0.910, 95% CI [0.831-0.997], P = 0.042), and ADHD combined with OCD (OR = 0.175, 95% CI [0.044-0.693], P = 0.013) reduced the risk of TN. Conversely, bipolar disorder (OR = 1.249, 95% CI [1.016-1.535], P = 0.034), depression (OR = 2.375, 95% CI [1.043-5.409], P = 0.039), anxiety (OR = 1.174, 95% CI [1.008-1.368], P = 0.039), and insomnia (OR = 2.036, 95% CI [1.074-3.861], P = 0.029)increased the risk of TN. TN also elevated the risk of anxiety (OR = 1.43, 95% CI [1.04-1.96], P = 0.034), depression (OR = 1.00305, 95% CI [1.00036-1.00549], P = 0.013), and insomnia (OR = 1.00918, 95% CI [1.00236-1.01605], P = 0.008).

CONCLUSIONS

Longer disease duration and broader trigeminal nerve involvement were independently associated with increased severity of depressive, anxiety, and insomnia symptoms, highlighting the importance of early clinical intervention in patients with TN. And results of MR analysis provide evidence supporting a causal relationship between MDs and TN. In contrast to the traditional view that pain causes mood changes such as anxiety and depression, a variety of MDs such as anxiety, depression, and insomnia also alter the risk of developing TN.

Exploring biomarkers of neurodegeneration in epilepsy: Critical insights

The advent of biofluid biomarkers for neurodegenerative disorders has precipitated a surge in recent evidence regarding their role in epilepsy. In this literature review, we examine the diagnostic, prognostic, and therapeutic potential of several biomarkers, including amyloid-beta (Aβ) protein, total (t-tau), phosphorylated tau (p-tau) protein, alpha-synuclein, neurofilament light chain (NfL), glial fibrillary acidic protein (GFAP), and others in epilepsy. Recent studies highlight mid-life Aβ levels as a risk factor for late-onset epilepsy. Several studies also show that amyloid pathology correlates with cognitive impairment in people with epilepsy (PWE). T-tau and p-tau levels in CSF and serum show diagnostic potential, particularly for temporal lobe epilepsy (TLE). Tau may also have significant prognostic utility in cognition of PWE and status epilepticus. Despite promising findings, larger prospective studies are needed to validate these biomarkers for routine clinical use in older PWE. Mouse models demonstrate tau's association with increased seizure susceptibility and mortality and the association of tau reduction with reduced seizure severity. This further highlights the need to investigate tau-targeting therapies in future studies in older PWE. Recent small-scale retrospective studies link NfL's role in cognitive impairment and status epilepticus, suggest a prognostic role of alpha-synuclein in certain epilepsies, and propose emerging diagnostic and prognostic roles of other biomarkers in epilepsy, including GFAP, cytoskeletal proteins, and S100B. However, larger longitudinal studies are needed to confirm these findings. We propose integrating some of these biomarkers into clinical practice for selected older adults with epilepsy. This integration could improve diagnostic accuracy, prognosticate outcomes, and identify therapeutic targets that may improve seizure control and mitigate the progression of cognitive decline in PWE.

Epilepsy and Alzheimer disease: New insights and perspectives

Numerous epidemiological and pathophysiological arguments suggest a bidirectional link between late-onset epilepsy and Alzheimer's disease. However, the temporal and causal relationship between the pathophysiological processes underlying these two conditions remains unclear. It is likely that these connections are complex, requiring consideration of various scenarios of causality and reciprocity. In the absence of targeted therapies that effectively address the progression of both diseases, specific measures can be taken to improve patient care. These include screening for cognitive disorders in patients with late-onset epilepsy, detecting subclinical EEG activity in patients with Alzheimer's disease, and identifying and managing cardiovascular risk factors in both populations. Looking ahead, it is evident that global population aging and the potential demographic surge in these two patient groups will necessitate greater efforts to raise awareness and enhance the training of physicians and healthcare professionals in the emerging field of "epileptogeriatrics".

Longitudinal excitation-inhibition balance altered by sex and APOE-ε4

Neuronal hyperexcitation affects memory and neural processing across the Alzheimer's disease (AD) cognitive continuum. Levetiracetam, an antiepileptic, shows promise in improving cognitive impairment by restoring the neural excitation/inhibition balance in AD patients. We previously identified a hyper-excitable phenotype in cognitively unimpaired female APOE-ε4 carriers relative to male counterparts cross-sectionally. This sex difference lacks longitudinal validation; however, clarifying the vulnerability of female ε4-carriers could better inform antiepileptic treatment efficacy. Here, we investigated this sex-by-ε4 interaction using a longitudinal design. We used resting-state fMRI and diffusion tensor imaging collected longitudinally from 106 participants who were cognitively unimpaired for at least one scan event but may have been assessed to have clinical dementia ratings corresponding to early mild cognitive impairment over time. By including scan events where participants transitioned to mild cognitive impairment, we modeled the trajectory of the whole-brain excitation-inhibition ratio throughout the preclinical cognitively healthy continuum and extended to early impairment. A linear mixed model revealed a significant three-way interaction among sex, ε4-status, and time, with female ε4-carriers showing a significant hyper-excitable trajectory. These findings suggest a possible pathway for preventative therapy targeting preclinical hyperexcitation in female ε4-carriers.

Metformin Improves Spatial Memory and Reduces Seizure Severity in a Rat Model of Epilepsy and Alzheimer's Disease comorbidity via PI3K/Akt Signaling Pathway

Emerging evidence suggests a bidirectional relationship between Alzheimer's disease (AD) and epilepsy. In our previous studies, we identified a partial AD-like phenotype associated with central insulin resistance in the Wistar audiogenic rat (WAR), a genetic model of epilepsy. We also found that intracerebroventricular administration of streptozotocin, a compound used to model diabetes and AD, exacerbates seizure susceptibility. Given the role of insulin signaling in both AD and epilepsy, we hypothesized that metformin (MET), an anti-diabetic drug known for enhancing insulin sensitivity, could be a potential therapeutic agent for both conditions. Our objective was to investigate MET's effects on brain insulin signaling, seizure activity, and AD-like pathology in WARs. Adult male WARs received oral MET (250 mg/kg) for 21 days. Audiogenic seizures were assessed using the Categorized Severity Index and Racine's scale. Spatial memory was tested with the Morris water maze (MWM), followed by Western blot analysis of hippocampal proteins. MET significantly reduced seizure severity and improved MWM performance. Although MET did not affect insulin receptor levels or activation, it increased phosphoinositide 3-kinase (PI3K), activated Akt, and increased glycogen synthase kinase-3α/β (GSK-3α/β) levels. MET also decreased amyloid β precursor protein (AβPP) levels but did not affect Tau phosphorylation. These results suggest that chronic MET treatment alleviates behaviors related to both AD and epilepsy in WARs and modulates insulin signaling independently of insulin receptor activation. Our findings highlight MET's potential as a therapeutic agent for managing comorbid AD and epilepsy, warranting further investigation into its mechanisms of action.

Effects of Klotho in epilepsy: An umbrella review of observational and mendelian randomization studies

BACKGROUND

Klotho is a geroprotective protein which has been recognized for its anti-aging properties. Pre-clinical evidence suggested that boosting Klotho might hold therapeutic potential in ageing and disease. Epilepsy is a neurological disorder characterized by its recurrent seizures. The complex interplay between Klotho and epilepsy has not been elucidated. The main objective was to investigate the role of Klotho in epilepsy with combination of observational and mendelian randomization (MR) studies.

METHODS

The observational data set comprised 13,766 adults who were aged 20-80 years from the National Health and Nutrition Examination Survey (NHANES) between 2007 and 2016. We used weighted multivariable-adjusted logistic regression models to examine the association between Klotho and epilepsy. We also applied MR to discern if a causal link is present between Klotho and epilepsy.

RESULTS

In NHANES study, the incidence of epilepsy tended to decline with an increase of Klotho levels after covariate adjustments. Klotho was identified to have causal effects on epilepsy. MR analyses revealed that higher transformed Klotho (by rank-based inverse normal transformation) levels were correlated with a higher likelihood of developing generalized epilepsy, lesion-negative focal epilepsy, and focal epilepsy, indicating that higher Klotho concentrations were associated with reduced risks of epilepsy. The sensitivity analyses upheld these consistent relationships.

CONCLUSIONS

Our research, encompassing comprehensive NHANSE analysis and MR methods, revealed that an increase in Klotho levels was associated with a reduced risk of epilepsy, suggesting that increasing or restoring Klotho might play a protective role and offer new anti-aging therapeutic potential in epilepsy.

Insulin signaling disruption exacerbates memory impairment and seizure susceptibility in an epilepsy model with Alzheimer's disease-like pathology

Alzheimer's disease (AD) and epilepsy exhibit a complex bidirectional relationship. Curiously, diabetes as a comorbidity increases the risk of epilepsy among AD patients. Recently, we reported that the Wistar audiogenic rat (WAR) strain, a genetic model of epilepsy, displays a partial AD-like phenotype, including brain insulin resistance. We also assessed seizure susceptibility in an AD model created through intracerebroventricular injections of streptozotocin (icv-STZ), which induces AD features via brain insulin resistance. Our goal was to explore how disrupted brain insulin signaling influences AD-like features and seizure susceptibility in the WAR strain. Adult male WARs received a single intracerebroventricular injection of streptozotocin (icv-STZ) (1.5 mg/kg) or vehicle (saline). Two weeks post-injection, spatial memory was assessed using the Barnes Maze (BM) test. Three weeks later, the rats underwent an audiogenic kindling (AuK) protocol (20 acoustic stimuli, 2 per day) to evaluate seizure frequency and severity. Seizures were analyzed using the Categorized Severity Index and Racine's scale and Western blot analysis was performed on hippocampal tissue. Our findings revealed that icv-STZ significantly worsened memory performance, increased seizure frequency, and reduced seizure onset relative to vehicle. Furthermore, icv-STZ decreased Akt activation and increased Glycogen Synthase Kinase-3 (GSK3) phosphorylation, indicating disrupted insulin signaling. Notably, icv-STZ decreased tau phosphorylation without altering amyloid β precursor protein (AβPP) levels. In conclusion, a low-dose icv-STZ injection exacerbates memory deficits and seizure susceptibility in the WAR strain by disturbing downstream proteins involved in insulin signaling. This highlights the implications of brain insulin resistance in both AD and epilepsy.

Exploring the mechanism of action of Phyllanthus emblica in the treatment of epilepsy based on network pharmacology and molecular docking

This study explores the mechanism of Phyllanthus emblica in treating epilepsy (EP) through network pharmacology and molecular docking. The Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform identified the chemical composition of P emblica, Swiss ADME screened active components, and Swiss Target Prediction predicted targets. EP-related targets were identified using Gene Cards, OMIM, Drug Bank, TTD, and DisGeNET, and Venny 2.1.0 was used to find intersecting targets. Protein-protein interaction network analysis was conducted with STRING and Cytoscape. Chem 3D and Pymol were used for structural optimization and molecular docking was performed with AutoDock Tools 1.5.7 and Vina. Fifty-three active components and 126 intersecting targets were identified. Gene Ontology analysis revealed 3416 biological processes, 287 cellular components, and 457 molecular functions. Kyoto Encyclopedia of Genes and Genomes pathways showed neuroactive ligand-receptor interactions, nitrogen metabolism, and serotonergic synapses as key pathways. Molecular docking indicated strong binding energies between P emblica core components and targets, especially 2-ethylhexyl ester with MAPK3, luteolin with SRC, and kaempferol with MAPK1. This study explores the therapeutic potential of P emblica in treating EP through network pharmacology and molecular docking. A total of 53 active components were identified, with key compounds like 2-ethylhexyl ester, phyllanthin, luteolin, and kaempferol targeting critical proteins such as SRC, AKT1, APP, MAPK3, and MAPK1. These targets are involved in pathways related to synaptic transmission, oxidative stress, and inflammation, indicating potential neuroprotective and anti-inflammatory effects. Gene Ontology analysis highlighted the regulation of synaptic activity, while Kyoto Encyclopedia of Genes and Genomes pathway analysis emphasized pathways like neuroactive ligand-receptor interactions and serotonergic synapses. Molecular docking demonstrated strong binding affinities between active components and core targets, supporting the effectiveness of P emblica in modulating neuronal excitability and reducing neuroinflammation. These findings provide a theoretical basis for its clinical application in EP management.

Associations between post-traumatic stress disorder and neurological disorders: A genetic correlation and Mendelian randomization study

BACKGROUND

Observational studies have reported a close relationship between post-traumatic stress disorder (PTSD) and neurological disorders, but the existence of a causal link remains uncertain. The aim of this study is to investigate these relationships and potential mediators via Mendelian randomization (MR) analysis.

METHODS

We sourced pooled data for genome-wide association study (GWAS) of PTSD (n = 1,222,882) from the psychiatric genomics consortium. Summary-level data for eight neurological traits were derived from large-scale GWASs. Genetic correlations were computed using linkage disequilibrium (LD) score regression. The inverse variance weighted (IVW) method served as the primary analysis method for MR. We employed a range of sensitivity analysis methods to ensure result robustness. A two-step approach was utilized to ascertain the effects and proportions of mediations.

RESULTS

We identified significant genetic associations between PTSD and any dementia, cognitive performance, multiple sclerosis, and migraine. MR analysis revealed a significant association between PTSD and an increased risk of migraine (P = 0.02). This was substantiated by the results of several sensitivity analyses. Notably, the robust association between PTSD and migraine persisted even after adjustment for major depressive disorder and anxiety. Mediation analysis revealed that both alcohol intake frequency and insomnia partially mediated the association between PTSD and migraine.

LIMITATIONS

Participants in the MR analysis were of European descent, and verification in other ethnicities was not possible due to data limitations.

CONCLUSION

Our findings indicate a close association between PTSD and migraine. Alcohol intake frequency and insomnia serve as intermediate factors, partially explaining the relationship between PTSD and migraine.

Transcriptomic analyses of human brains with Alzheimer's disease identified dysregulated epilepsy-causing genes

Background & Objective

Alzheimer's Disease (AD) patients at multiple stages of disease progression have a high prevalence of seizures. However, whether AD and epilepsy share pathophysiological changes remains poorly defined. In this study, we leveraged high-throughput transcriptomic data from sporadic AD cases at different stages of cognitive impairment across multiple independent cohorts and brain regions to examine the role of epilepsy-causing genes.

Methods

Epilepsy-causing genes were manually curated, and their expression levels were analyzed across bulk transcriptomic data from three AD cohorts and three brain regions. RNA-seq data from sporadic AD and control cases from the Knight ADRC, MSBB, and ROSMAP cohorts were processed and analyzed under the same analytical pipeline. An integrative clustering approach employing machine learning and multi-omics data was employed to identify molecularly defined profiles with different cognitive scores.

Results

We found several epilepsy-associated genes/pathways significantly dysregulated in a group of AD patients with more severe cognitive impairment. We observed 15 genes consistently downregulated across the three cohorts, including sodium and potassium channels, suggesting that these genes play fundamental roles in cognitive function or AD progression. Notably, we found 25 of these genes dysregulated in earlier stages of AD and become worse with AD progression.

Conclusion

Our findings showed that epilepsy-causing genes showed changes in the early and late stages of AD progression, suggesting that they might be playing a role in AD progression. We can not establish directionality or cause-effect with our findings. However, changes in the epilepsy-causing genes might underlie the presence of seizures in AD patients, which might be present before or concurrently with the initial stages of AD.

Causal role of peripheral immune cells in epilepsy: A large-scale genetic correlation study

BACKGROUND

While an increasing number of researchers have focused on the correlation between the immune system and epilepsy, the precise causal role of immune cells in epilepsy continues to elude scientific understanding. The aim of the study was to examine the causal relationship between peripheral immune phenotypes and epilepsy.

METHODS

Mendelian randomization (MR) analysis and linkage disequilibrium score regression (LDSC) were utilized to determine the causal relationship between 731 immune cell traits and various types of epilepsy in this study.

RESULTS

LDSC revealed that 80 immunophenotypes showed genetic correlation with epilepsy, including 58 immunophenotypes associated with a single type of epilepsy (72.5 %),14 immunophenotypes associated with two types of epilepsy (17.5 %),7 immunophenotypes with 3 types of epilepsy (8.75 %) and 1 immunophenotype with 5 types of epilepsy (1.25 %). Although none of the types of epilepsy had a statistically significant effect on immunophenotypes, it is noteworthy that the MR revealed the protective effects of five immunophenotypes on epilepsy: CD45RA+CD8br AC (OR:0.86, 95 %CI:0.80-0.93), FSC-A on myeloid DC (OR:0.95, 95 %CI:0.91-0.98）, CM CD8br AC (OR:0.69, 95 %CI:0.59--0.82), CD33 on CD66b++ Myeloid cell (OR:0.88, 95 %CI:0.83-0.93) and CD127 on CD28- CD8br (OR:0.97, 95 %CI:0.95-0.98). Additionally, harmful effects were observed for two immunophenotypes on epilepsy:CD4 Treg %CD4 (OR:1.04, 95 %CI:1.02-1.06) and SSC-A on plasmacytoid DC (OR:1.01, 95 %CI:1.00-1.02).

CONCLUSION

Our research has demonstrated the causal connections between immune cells and epilepsy, potentially providing valuable insights for future clinical studies.

Amyloid deposition in adults with drug-resistant temporal lobe epilepsy

OBJECTIVE

Pathological amyloid-β (Aβ) accumulation and hyperphosphorylated tau proteins have been described in resected temporal lobe specimens of epilepsy patients. We aimed to determine cerebrospinal fluid (CSF) Aβ1-42 and p181-tau levels and cerebral Aβ deposits on positron emission tomography (Aβ PET) and correlate these findings with cognitive performance in adults with drug-resistant temporal lobe epilepsy (TLE).

METHODS

In this cross-sectional study, we enrolled individuals with drug-resistant TLE who were 25-55 years old. Each participant underwent 18F-flutemetamol PET, determination of CSF Aβ1-42, p181-tau, and total tau, and a comprehensive neuropsychological assessment. We evaluated normalized standard uptake value ratios (SUVRs) for different brain regions on Aβ PET.

RESULTS

Thirty patients (mean age = 41.9 ± SD 8.1 years, 57% men) were included. The median disease duration was 9.5 (interquartile range = 4-24) years. Twenty-six patients (87%) had a clinically significant cognitive impairment on neuropsychological evaluation, 18 (69%) of the amnesic type. On Aβ PET, high uptake was observed in both mesial temporal regions (ipsilateral: SUVR z-score = .90, 95% confidence interval [CI] = .60-1.20; contralateral: SUVR z-score = .92, 95% CI = .57-1.27; p < .001), which was higher when compared to SUVR z-scores in all the remaining regions (p < .001) and in the ipsilateral anterior cingulate (SUVR z-score = .27, 95% CI = .04-.49, p = .020). No significant deposition was observed in other regions. Seven patients (23%) had low Aβ1-42 levels, and two (7%) had elevated p181-tau levels in CSF. Higher p181-tau levels correlated with poorer verbal fluency (R = -.427, p = .044).

SIGNIFICANCE

Our findings reveal a considerable Aβ deposition in mesial temporal regions and ipsilateral anterior cingulate among adults with drug-resistant TLE. Additionally, abnormal CSF Aβ1-42 levels were observed in a significant proportion of patients, and p181-tau levels were associated with verbal fluency. These results suggest that markers of neuronal damage can be observed in adults with TLE, warranting further investigation.

A Mutual Nexus Between Epilepsy and α-Synuclein: A Puzzle Pathway

Alpha-synuclein (α-Syn) is a specific neuronal protein that regulates neurotransmitter release and trafficking of synaptic vesicles. Exosome-associated α-Syn which is specific to the central nervous system (CNS) is involved in the pathogenesis of epilepsy. Therefore, this review aimed to elucidate the possible link between α-Syn and epilepsy, and how it affects the pathophysiology of epilepsy. A neurodegenerative protein such as α-Syn is implicated in the pathogenesis of epilepsy. Evidence from preclinical and clinical studies revealed that upregulation of α-Syn induces progressive neuronal dysfunctions through induction of oxidative stress, neuroinflammation, and inhibition of autophagy in a vicious cycle with subsequent development of severe epilepsy. In addition, accumulation of α-Syn in epilepsy could be secondary to the different cellular alterations including oxidative stress, neuroinflammation, reduction of brain-derived neurotrophic factor (BDNF) and progranulin (PGN), and failure of the autophagy pathway. However, the mechanism of α-Syn-induced-epileptogenesis is not well elucidated. Therefore, α-Syn could be a secondary consequence of epilepsy. Preclinical and clinical studies are warranted to confirm this causal relationship.

Causal effect of air pollution on the risk of brain health and potential mediation by gut microbiota

OBJECTIVE

Epidemiologic investigations have examined the correlation between air pollution and neurologic disorders and neuroanatomic structures. Increasing evidence underscores the profound influence of the gut microbiota on brain health. However, the existing evidence is equivocal, and a causal link remains uncertain. This study aimed: to determine if there is a causal connection between four key air pollutants, and 42 neurologic diseases, and 1325 distinct brain structures; and to explore the potential role of the gut microbiota in mediating these associations.

METHODS

Univariable Mendelian randomization (UVMR) and multivariable Mendelian randomization (MVMR) models were deployed to estimate the causal impact of air pollutants (including particulate matter [PM] with aerodynamic diameters <2.5 μm [PM2.5], and <10 μm [PM10]; PM2.5 absorbance; and nitrogen oxides [NOx]) on brain health through various Mendelian randomization methodologies. Lastly, the mediating role of the gut microbiome in the connections between the identified pollutants and neurologic diseases and brain structures was systematically examined.

RESULTS

The potential causal associations of PM2.5, PM2.5 absorbance, PM10, and exposure to NOx, with the risks of intracerebral hemorrhage, hippocampal perivascular spaces, large artery strokes, generalized epilepsy with tonic-clonic seizures, Alzheimer's disease, multiple sclerosis, anorexia nervosa, post-traumatic stress disorder (PTSD), and 420 brain structures, were investigated by UVMR analysis. Following adjustment for air pollutants by MVMR analysis, the genetic correlations between PM10 exposure and PTSD and multiple sclerosis remained significant and robust. Importantly, we observed that phylum Lentisphaerae may mediate the association between PM10 and multiple sclerosis. Additionally, PM2.5 absorbance with a greater risk of reduced thickness in the left anterior transverse temporal gyrus of Heschl and a decreased area in the right sulcus intermedius primus of Jensen, mediated by genus Senegalimassilia and genus Lachnospiraceae UCG010, respectively. Finally, we provided evidence that Clostridium innocuum and genus Ruminococcus2 may partly mediate the causal effect of NOx on altered thickness in the left transverse temporal cortex and area in the right sulcus intermedius primus of Jensen, respectively.

CONCLUSION

This study established a genetic connection between air pollution and brain health, implicating the gut microbiota as a potential mediator in the relationship between air pollution, neurologic disorders, and altered brain structures.

Deregulation of Melatonin Receptors and Differential Modulation of After-Hyperpolarization and Ih Currents Using Melatonin Treatment Due to Amyloid-β-Induced Neurotoxicity in the Hippocampus

Treatment with melatonin is routinely prescribed for its potent antioxidant and cognitive-promoting effects, nevertheless, it has yet to find neuromodulatory effects in normal and disease conditions. Therefore, to investigate its neuromodulatory mechanisms, melatonin was systemically administered over 10 consecutive days to both intracortical normal saline- and amyloid-β 1-42 (Aβ) peptide-injected rats. At the behavioral level, treatment with melatonin was associated with reduced efficacy in restoring Aβ-induced deficit in passive-avoidance memory. Whole-cell patch-clamp recordings from CA1 pyramidal neurons revealed that melatonin treatment reduced spontaneous and evoked intrinsic excitability in control rats while exerting a reduction of spontaneous, but not evoked activity, in the Aβ-injected group. Interestingly, treatment with melatonin enhances after-hyperpolarization in control, but not Aβ-injected rats. In contrast, our voltage-clamp study showed that Ih current is significantly enhanced by Aβ injection, and this effect is further strengthened by treatment with melatonin in Aβ-injected rats. Finally, we discovered that the transcription of melatonin receptors 1 (MT1) and 2 (MT2) is significantly upregulated in the hippocampi of Aβ-injected rats. Collectively, our study demonstrates that systemic treatment with melatonin has differential neuromodulation on CA1 neuronal excitability, at least in part, via differential effects on after-hyperpolarization and Ih currents due to Aβ-induced neurotoxicity.

Calsyntenin-1 expression and function in brain tissue of lithium-pilocarpine rat seizure models

To present the expression of calsyntenin-1 (Clstn1) in the brain and investigate the potential mechanism of Clstn1 in lithium-pilocarpine rat seizure models. Thirty-five male SD adult rats were induced to have seizures by intraperitoneal injection of lithium chloride pilocarpine. Rats exhibiting spontaneous seizures were divided into the epilepsy (EP) group (n = 15), whereas those without seizures were divided into the control group (n = 14). Evaluate the expression of Clstn1 in the temporal lobe of two groups using Western blotting, immunohistochemistry, and immunofluorescence. Additionally, 55 male SD rats were subjected to status epilepticus (SE) using the same induction method. Rats experiencing seizures exceeding Racine's level 4 (n = 48) were randomly divided into three groups: SE, SE + control lentivirus (lentiviral vector expressing green fluorescent protein [LV-GFP]), and SE + Clstn1-targeted RNA interference lentivirus (LV-Clstn1-RNAi). The LV-GFP group served as a control for the lentiviral vector, whereas the LV-Clstn1-RNAi group received a lentivirus designed to silence Clstn1 expression. These lentiviral treatments were administered via hippocampal stereotactic injection 2 days after SE induction. Seven days after SE, Western blot analysis was performed to evaluate the expression of Clstn1 in the hippocampus and temporal lobe. Meanwhile, we observed the latency of spontaneous seizures and the frequency of spontaneous seizures within 8 weeks among the three groups. The expression of Clstn1 in the cortex and hippocampus of the EP group was significantly increased compared to the control group (p < .05). Immunohistochemistry and immunofluorescence showed that Clstn1 was widely distributed in the cerebral cortex and hippocampus of rats, and colocalization analysis revealed that it was mainly co expressed with neurons in the cytoplasm. Compared with the SE group (11.80 ± 2.17 days) and the SE + GFP group (12.40 ± 1.67 days), there was a statistically significant difference (p < .05) in the latency period of spontaneous seizures (15.14 ± 2.41 days) in the SE + Clstn1 + RNAi group rats. Compared with the SE group (4.60 ± 1.67 times) and the SE + GFP group (4.80 ± 2.05 times), the SE + Clstn1 + RNAi group (2.0 ± .89 times) showed a significant reduction in the frequency of spontaneous seizures within 2 weeks of chronic phase in rats (p < .05). Elevated Clstn1 expression in EP group suggests its role in EP onset. Targeting Clstn1 may be a potential therapeutic approach for EP management.

LncRNA ILF3-AS1 mediates oxidative stress and inflammation through miR-504-3p/HMGB1 axis in a cellular model of temporal lobe epilepsy

BACKGROUND

Temporal lobe epilepsy (TLE), a prevalent neurological disorder, is associated with hippocampal oxidative stress and inflammation. A recent study reveals that the long noncoding RNA ILF3 divergent transcript (ILF3-AS1) level is elevated in the hippocampus of TLE patients; however, the functional roles of ILF3-AS1 in TLE and underlying mechanisms deserve further investigation. Hence, this study aimed to elucidate whether ILF3-AS1 is involved in the pathogenesis of TLE by regulating oxidative stress and inflammation and to explore its underlying mechanism in vitro.

METHODS

Human hippocampal neurons were subjected to a magnesium-free (Mg2+-free) solution to establish an in vitro model of TLE. The potential binding sites between ILF3-AS1 and miRNA were predicted by TargetScan/Starbase and confirmed by dual luciferase reporter assay. Cell viability and damage were assessed by cell counting kit-8 and lactate dehydrogenase assay kits, respectively. Levels of reactive oxygen species, malondialdehyde, and superoxide dismutase were determined by commercial kits. Levels of Interleukin-6 (IL-6), IL-1β, and tumor necrosis factor-alpha were quantified by enzyme-linked immunosorbent assay. The expressions of gene and protein were determined by quantitative real-time polymerase chain reaction and Western blot analysis.

RESULTS

In Mg2+-free-treated hippocampal neurons, both ILF3-AS1 and HMGB1 were highly up-regulated, whereas miR-504-3p was down-regulated. ILF3-AS1 knockdown ameliorated Mg2+-free-induced cellular damage, oxidative stress, and inflammatory response. Bioinformatics analysis revealed that miR-504-3p was a target of ILF3-AS1 and was negatively regulated by ILF3-AS1. MiR-504-3p inhibitor blocked the protection of ILF3-AS1 knockdown against Mg2+-free-induced neuronal injury. Further analysis presented that ILF3-AS1 regulated HMGB1 expression by sponging miR-504-3p. Moreover, HMGB1 overexpression reversed the protective functions of ILF3-AS1 knockdown.

CONCLUSION

Our findings indicate that ILF3-AS1 contributes to Mg2+-free-induced hippocampal neuron injuries, oxidative stress, and inflammation by targeting the miR-504-3p/HMGB1 axis. These results provide a novel mechanistic understanding of ILF3-AS1 in TLE and suggest potential therapeutic targets for the treatment of epilepsy.

Epilepsy and childhood psychiatric disorders: a two-sample bidirectional Mendelian randomization study

BACKGROUND

Observational studies have indicated that psychiatric disorders are the most common comorbidities in pediatric epilepsy. However, the existence and direction of a causal relationship between the two remains controversial. This study aims to investigate the association between common childhood psychiatric disorders and epilepsy using a two-sample, bidirectional Mendelian randomization (MR) approach.

METHODS

Genetic instruments were obtained from the most recent and largest genome-wide association studies (GWAS), including datasets for epilepsy (N_case = 29,994, N_control = 52,538), attention deficit hyperactivity disorder (ADHD) (N_case = 38,691, N_control = 186,843), autism spectrum disorder (ASD) (N_case = 18,381, N_control = 27,969), and Tourette syndrome (TS) (N_case = 4,819, N_control = 9488). MR analyses were conducted using the inverse variance weighted (IVW) method, weighted median method, and MR-Egger regression.

RESULTS

No reliable evidence was found to suggest a causal effect of ADHD, ASD, or TS on epilepsy, nor was there any reliable evidence indicating that epilepsy increases the risk of these three psychiatric disorders. These findings remained consistent across various sensitivity analyses.

CONCLUSION

Although observational studies have highlighted a high comorbidity rate between pediatric epilepsy and psychiatric disorders like ADHD and ASD, the MR analysis did not confirm a causal relationship between them. This suggests that previous studies might have been influenced by confounding biases or other biases, potentially overestimating the true relationship. A deeper understanding of the mechanisms underlying these comorbidities is crucial for refining the treatment of pediatric epilepsy.

Alzheimer's Disease and Epilepsy: Exploring Shared Pathways and Promising Biomarkers for Future Treatments

Background: Alzheimer's disease (AD) and epilepsy represent two complex neurological disorders with distinct clinical manifestations, yet recent research has highlighted their intricate interplay. This review examines the association between AD and epilepsy, with particular emphasis on late-onset epilepsy of unknown etiology, increasingly acknowledged as a prodrome of AD. It delves into epidemiology, pathogenic mechanisms, clinical features, diagnostic characteristics, treatment strategies, and emerging biomarkers to provide a comprehensive understanding of this relationship. Methods: A comprehensive literature search was conducted, identifying 128 relevant articles published between 2018 and 2024. Results: Findings underscore a bidirectional relationship between AD and epilepsy, indicating shared pathogenic pathways that extend beyond traditional amyloid-beta and Tau protein pathology. These pathways encompass neuroinflammation, synaptic dysfunction, structural and network alterations, as well as molecular mechanisms. Notably, epileptic activity in AD patients may exacerbate cognitive decline, necessitating prompt detection and treatment. Novel biomarkers, such as subclinical epileptiform activity detected via advanced electroencephalographic techniques, offer promise for early diagnosis and targeted interventions. Furthermore, emerging therapeutic approaches targeting shared pathogenic mechanisms hold potential for disease modification in both AD and epilepsy. Conclusions: This review highlights the importance of understanding the relationship between AD and epilepsy, providing insights into future research directions. Clinical data and diagnostic methods are also reviewed, enabling clinicians to implement more effective treatment strategies.

Potential causal association of diabetes mellitus and blood glucose related indexes with the onset of epilepsy: a two-sample Mendelian randomization study

Aim

Diabetes mellitus (DM) may promote the occurrence of epilepsy through mechanisms, such as inflammation, immune imbalance, and cerebrovascular injury, caused by metabolic abnormalities. However, evidence for the effects of DM and blood glucose (BG) on the risk of epilepsy is limited. Herein, this study used the Mendelian randomization (MR) method to investigate the potential causal associations of DM and BG-related indexes with epilepsy.

Methods

In this two-sample MR study, summary statistics data of the genome-wide association studies (GWASs) on exposures, including type 1 diabetes mellitus (T1DM), T2DM, fasting glucose, and glycated hemoglobin (HbAlc), were extracted from the MRC-Integrative Epidemiology Unit (MRC-IEU). The GWAS data on study outcomes, including epilepsy, focal epilepsy, and generalized epilepsy, were obtained from the FinnGen consortium. MR-Egger regression was used to examine horizontal pleiotropism of instrumental variables (IVs), and Cochran's Q statistics was used to quantify the heterogeneity. MR analysis methods including inverse variance weighted (IVW) tests, weighted median, and MR-Egger were utilized to investigate the causal associations between DM and BG-related indexes with epilepsy. The evaluation indexes were odds ratios (ORs) and 95% confidence intervals (CIs). Reverse causal association analyses were also performed. In addition, IVW-radial and leave-one-out tests were utilized for sensitivity analyses.

Results

IVW estimates suggested that T1DM has potential causal associations with epilepsy (OR = 1.057, 95% CI: 1.031-1.084) and generalized epilepsy (OR = 1.066, 95% CI: 1.018-1.116). No significant reverse causal associations of T1DM with epilepsy or generalized epilepsy were found (all P > 0.05). In addition, sensitivity analysis results identified no outlier, indicating that the associations of T1DM with epilepsy and generalized epilepsy were relatively robust.

Conclusion

Patients with T1DM had a potential risk of developing epilepsy, and prompt treatment of DM and dynamic monitoring may be beneficial to prevent epilepsy in this high-risk population. However, the causal associations of DM and BG with epilepsy may warrant further verification.

Genetically identified mediators associated with increased risk of stroke and cardiovascular disease in individuals with autism spectrum disorder

Growing evidence suggested that individuals with autism spectrum disorder (ASD) associated with stroke and cardiovascular disease (CVD). However, the causal association between ASD and the risk of stroke and CVD remains unclear. To validate this, we performed two-sample Mendelian randomization (MR) and two-step mediation MR analyses, using relevant genetic variants sourced from the largest genome-wide association studies (GWASs). Two-sample MR evidence indicated causal relationships between ASD and any stroke (OR = 1.1184, 95% CI: 1.0302-1.2142, P < 0.01), ischemic stroke (IS) (OR = 1.1157, 95% CI: 1.0237-1.2160, P = 0.01), large-artery atherosclerotic stroke (LAS) (OR = 1.2902, 95% CI: 1.0395-1.6013, P = 0.02), atrial fibrillation (AF) (OR = 1.0820, 95% CI: 1.0019-1.1684, P = 0.04), and heart failure (HF) (OR = 1.1018, 95% CI: 1.0007-1.2132, P = 0.05). Additionally, two-step mediation MR suggested that type 2 diabetes mellitus (T2DM) partially mediated this effect (OR = 1.14, 95%CI: 1.02-1.28, P = 0.03). The mediated proportion were 10.96% (95% CI: 0.58%-12.10%) for any stroke, 11.77% (95% CI: 10.58%-12.97%) for IS, 10.62% (95% CI: 8.04%-13.20%) for LAS, and 7.57% (95% CI: 6.79%-8.36%) for HF. However, no mediated effect was observed between ASD and AF risk. These findings have implications for the development of prevention strategies and interventions for stroke and CVD in patients with ASD.

Causal link between oxidative stress and epilepsy: A two-sample Mendelian randomization study

BACKGROUND

Although a growing body of research has indicated a strong link between oxidative stress and epilepsy, the exact nature of their interaction remains elusive. To elucidate this intricate relationship, we conducted a bidirectional Mendelian randomization (MR) analysis employing two independent datasets.

METHODS

A two-sample MR analysis was performed using instrumental variables derived from genome-wide association study summary statistics of oxidative stress injury biomarkers (OSIB) and epilepsy. The OSIBs were selected from eight primary metabolic pathways associated with oxidative stress. Additionally, seven distinct epilepsy phenotypes were considered, which encompassed all epilepsy, generalized epilepsy, generalized tonic-clonic seizures, focal epilepsy, focal epilepsy with hippocampal sclerosis (focal HS), focal epilepsy with lesions other than HS (focal NHS), and lesion-negative focal epilepsy. Causal estimates were computed using the inverse-variance weighted method or the Wald ratio method, and the robustness of causality was assessed through sensitivity analyses.

RESULTS

For OSIB and epilepsy, 520 and 23 genetic variants, respectively, were selectively extracted as instrumental variants. Genetically predicted higher kynurenine level was associated with a decreased risk of focal epilepsy (odds ratio [OR] 1.950, 95% CI 1.373-2.528, p = .023) and focal NHS (OR 1.276, 95% CI 1.100-1.453, p = .006). For reverse analysis, there was a suggestive effect of focal NHS on urate (OR 1.19 × 1015, 95% CI 11.19 × 1015 to 1.19 × 1015, p = .0000746) and total bilirubin (Tb) (OR 4.98, 95% CI 3.423-6.543, p = .044). In addition, genetic predisposition to focal HS was associated with higher Tb levels (OR 9.83, 95% CI 7.77-11.888, p = .034).

CONCLUSION

This MR study provides compelling evidence of a robust association between oxidative stress and epilepsy, with a notable emphasis on a causal relationship between oxidative stress and focal epilepsy. Additional research is warranted to confirm the connection between oxidative stress and the risk of epilepsy and to unravel the underlying mechanisms.

Metabolome-Wide Mendelian Randomization Assessing the Causal Role of Serum and Cerebrospinal Metabolites in Traumatic Brain Injury

Previous studies have identified metabolites as biomarkers or potential therapeutic targets for traumatic brain injury (TBI). However, the causal association between them remains unknown. Therefore, we investigated the causal effect of serum metabolites and cerebrospinal fluid (CSF) metabolites on TBI susceptibility through Mendelian randomization (MR). Genetic variants related to metabolites and TBI were extracted from a corresponding genome-wide association study (GWAS). Causal effects were estimated through the inverse variance weighted approach, supplemented by a weighted median, weight mode, and the MR-Egger test. In addition, sensitivity analyses were further performed to evaluate the stability of the MR results, including the MR-Egger intercept, leave-one-out analysis, Cochrane's Q-test, and the MR-PRESSO global test. Metabolic pathway analysis was applied to uncover the underlying pathways of the significant metabolites in TBI. In blood metabolites, substances such as 4-acetaminophen sulfate and kynurenine showed positive links, whereas beta-hydroxyisovalerate and creatinine exhibited negative correlations. CSF metabolites such as N-formylanthranilic acid were positively related, while kynurenate showed negative associations. The metabolic pathway analysis highlighted the potential biological pathways involved in TBI. Of these 16 serum metabolites, 11 CSF metabolites and metabolic pathways may serve as useful circulating biomarkers in clinical screening and prevention, and may be candidate molecules for the exploration of mechanisms and drug targets.

Diabetes mellitus, glycemic traits, SGLT2 inhibition, and risk of pulmonary arterial hypertension: A Mendelian randomization study

This study aimed to investigate the causal role of diabetes mellitus (DM), glycemic traits, and sodium-glucose cotransporter 2 (SGLT2) inhibition in pulmonary arterial hypertension (PAH). Utilizing a two-sample two-step Mendelian randomization (MR) approach, we determined the causal influence of DM and glycemic traits (including insulin resistance, glycated hemoglobin, and fasting insulin and glucose) on the risk of PAH. Moreover, we examined the causal effects of SGLT2 inhibition on the risk of PAH. Genetic proxies for SGLT2 inhibition were identified as variants in the SLC5A2 gene that were associated with both levels of gene expression and hemoglobin A1c. Results showed that genetically inferred DM demonstrated a causal correlation with an increased risk of PAH, exhibiting an odds ratio (OR) of 1.432, with a 95% confidence interval (CI) of 1.040-1.973, and a p-value of 0.028. The multivariate MR analysis revealed comparable outcomes after potential confounders (OR = 1.469, 95%CI = 1.021-2.115, p = 0.038). Moreover, genetically predicted SGLT2 inhibition was causally linked to a reduced risk of PAH (OR = 1.681*10-7, 95%CI = 7.059*10-12-0.004, p = 0.002). Therefore, our study identified the suggestively causal effect of DM on the risk of PAH, and SGLT2 inhibition may be a potential therapeutic target in patients with PAH.

The Interplay Between Epilepsy and Alzheimer's Disease: A Pas De Deux

[Box: see text]

Latest advances in mechanisms of epileptic activity in Alzheimer's disease and dementia with Lewy Bodies

Alzheimer's disease (AD) and dementia with Lewy bodies (DLB) stand as the prevailing sources of neurodegenerative dementia, impacting over 55 million individuals across the globe. Patients with AD and DLB exhibit a higher prevalence of epileptic activity compared to those with other forms of dementia. Seizures can accompany AD and DLB in early stages, and the associated epileptic activity can contribute to cognitive symptoms and exacerbate cognitive decline. Aberrant neuronal activity in AD and DLB may be caused by several mechanisms that are not yet understood. Hyperexcitability could be a biomarker for early detection of AD or DLB before the onset of dementia. In this review, we compare and contrast mechanisms of network hyperexcitability in AD and DLB. We examine the contributions of genetic risk factors, Ca2+ dysregulation, glutamate, AMPA and NMDA receptors, mTOR, pathological amyloid beta, tau and α-synuclein, altered microglial and astrocytic activity, and impaired inhibitory interneuron function. By gaining a deeper understanding of the molecular mechanisms that cause neuronal hyperexcitability, we might uncover therapeutic approaches to effectively ease symptoms and slow down the advancement of AD and DLB.

The impact of brivaracetam on cognitive processes and anxiety in various experimental models

BACKGROUND

Memory deficits and anxiety symptoms are undesirable effects that occur in epilepsy patients. They may be associated with the pathophysiology of the disease but also with anticonvulsant therapy. Brivaracetam (BRV) is one of the newest antiseizure drugs. It acts as a ligand for synaptic vesicle glycoprotein 2A (SV2A), which may play a significant role in cognitive processes. Although BRV has a favorable safety profile, its central side effects remain unclear. Hence, this study aimed to evaluate the effect of BRV on various types of memory and anxiety in rats.

METHODS

BRV was given to adult male Wistar rats (n = 80) via gastric tube as a single dose (6 mg/kg or 20 mg/kg) or chronically (6 mg/kg). The effect of the drug on spatial memory was evaluated in the Morris water maze (MWM), fear-learning by passive avoidance (PA), and recognition memory with novel object recognition (NOR). The elevated plus maze (EPM) was used to assess anxiety-like behaviors.

RESULTS

The impact of BRV on memory is dose-dependent and mainly high doses may alter retrieval memory and fear-learning. Sub-chronic administration also impaired retrieval and spatial memory in animals. Moreover, chronic BRV may increase anxiety levels in rats but did not affect recognition memory.

CONCLUSIONS

BRV may cause transient memory deficits as well as anxiety disturbances. However, the results are varied and depend on the type of memory, used dose, and duration of administration.

Association between migraine and mitochondria: A Mendelian randomization study

BACKGROUND AND OBJECTIVE

Mitochondria are important organelles functioning in metabolic processes, inflammatory response and neurological disorders. Migraines are chronic and paroxysmal neurological disorders characterized by recurrent episodes of severe headache and other neurological symptoms. We explored whether mitochondria may be genetically and/or causally associated with migraine.

METHODS

Summary-level statistics of mitochondrial DNA copy number (mtDNA-CN), 69 mitochondria related exposures and migraine with aura, migraine without aura, migraine with aura and triptan purchases, migraine with aura, drug-induced, migraine without aura and triptan purchases and migraine without aura, drug-induced, were collected from genome-wide association studies (GWAS). The analysis employed two-sample Mendelian randomization, utilizing various methods including MR-Egger, inverse-variance weighted (IVW), MR-PRESSO (MR-pleiotropy residual sum and outlier), maximum likelihood, and weighted median.

RESULTS

We observed a potential association with decreased levels of mtDNA-CN with the risk of migraine without aura (Odds ratio (OR) 1.517, 95% Confidence interval (CI) 1.072-2.147, p = 0.019). Besides, for every 1 unit in NAD-dependent protein deacylase sirtuin-5 (SIRT5), relative risk of migraine without aura increased by 16.4%. For every 1 unit increase in Phenylalanine-transfer RNA (tRNA) ligase, relative risk of migraine without aura increased by 13.5%. For every 1 unit increase in Apoptosis-inducing factor 1, relative risk of migraine without aura increased by 27.4%.

CONCLUSION

This study indicates fresh evidence of association between mtDNA-CN, mitochondrial related exposures and migraine especially migraine without aura. The findings may shed light on developing interventions targeting on the causal pathway from mitochondria to migraine.

Potential Causal Association between Depression and Oral Diseases: A Mendelian Randomization Study

BACKGROUND

Globally, oral diseases are common, pose an economic burden, and significantly decline the quality of life of affected individuals. Recently, researchers have substantially highlighted the effect of depression on oral disease incidence and development. In this study, we elucidated the correlation between depression and oral diseases.

METHODS

Using two-sample Mendelian randomization (MR), the association between depression and the risk of 17 oral diseases was evaluated. Three methods were used to perform MR analysis: the inverse variance-weighted, weighted median, and MR-Egger methods. Furthermore, Cochran's Q test, MR-Egger intercept test, MR Pleiotropy RESidual Sum and Outlier test, and leave-one-out analysis were performed to analyze sensitivity.

RESULTS

After implementing multiple test corrections, we observed that genetic susceptibility to depression was associated with an increased risk of mouth ulcers, toothache, loose teeth, bleeding gums, painful gums, chronic periodontitis, chronic tonsil and adenoid diseases, peritonsillar abscess, and excessive tooth attrition. However, a causal relationship between depression and other oral diseases was not observed. Sensitivity analysis confirmed the robustness of the results.

CONCLUSIONS

We confirmed the causal relationship between depression and several oral diseases, thereby providing a novel viewpoint on the prevention and treatment of oral diseases. Our findings suggest the integration of depression control into routine clinical care to enhance the effectiveness of oral disease treatment.

The bidirectional relationship between Alzheimer's disease (AD) and epilepsy: A Mendelian randomization study

BACKGROUND

There is a complex, bidirectional relationship between Alzheimer's disease (AD) and epilepsy. However, the causality of this association is unclear, as confounders play a role in this association.

METHODS

We conducted a Mendelian randomization (MR) study to clarify the causal relationship and direction of epilepsy on AD risk. We used publicly available summary statistics to obtain all genetic datasets for the MR analyses. AD and AD-by-proxy and late-onset AD (LOAD) cohorts were included in our study. The epilepsy cohort comprised all epilepsy, generalized epilepsy, focal epilepsy, and its subtypes, as well as some epilepsy syndromes. Next, we conducted validation using another AD cohort.

RESULTS

Two correlations between AD and epilepsy using the inverse variance-weighted (IVW) method are as follows: LOAD and focal epilepsy (ORIVW  = 1.079, pIVW  = .013), focal epilepsy-documented hippocampal sclerosis (HS) and AD (ORIVW  = 1.152, pIVW  = .017). The causal relationship between epilepsy-documented HS and AD has been validated (ORIVW  = 3.994, pIVW  = .027).

CONCLUSIONS

Our MR study provides evidence for a causal relationship between focal epilepsy-documented HS and AD.

Clinical, imaging, and biomarker evidence of amyloid- and tau-related neurodegeneration in late-onset epilepsy of unknown etiology

Accumulating evidence suggests amyloid and tau-related neurodegeneration may play a role in development of late-onset epilepsy of unknown etiology (LOEU). In this article, we review recent evidence that epilepsy may be an initial manifestation of an amyloidopathy or tauopathy that precedes development of Alzheimer's disease (AD). Patients with LOEU demonstrate an increased risk of cognitive decline, and patients with AD have increased prevalence of preceding epilepsy. Moreover, investigations of LOEU that use CSF biomarkers and imaging techniques have identified preclinical neurodegeneration with evidence of amyloid and tau deposition. Overall, findings to date suggest a relationship between acquired, non-lesional late-onset epilepsy and amyloid and tau-related neurodegeneration, which supports that preclinical or prodromal AD is a distinct etiology of late-onset epilepsy. We propose criteria for assessing elevated risk of developing dementia in patients with late-onset epilepsy utilizing clinical features, available imaging techniques, and biomarker measurements. Further research is needed to validate these criteria and assess optimal treatment strategies for patients with probable epileptic preclinical AD and epileptic prodromal AD.

Advances in amyloid-targeting monoclonal antibodies for Alzheimer's disease: clinical and public health issues

INTRODUCTION

Alzheimer's disease (AD) is a major global public health challenge. To date, no treatments have been shown to stop the underlying pathological processes. The cerebral accumulation of amyloid-beta (Ab) is still considered as the primum movens of AD and disease-modifying treatments targeting Ab are reaching - or have already reached - clinical practice.

AREAS COVERED

The authors explore the main advancements from Aβ-targeting monoclonal antibodies (mAbs) for the treatment of AD. From a public health perspective, they address ethically relevant issues such as the benevolence and non-maleficence principles. They report on the potential biological and clinical benefits of these drugs, discussing minimal clinically important differences (MCID) and other relevant outcomes. They examine the short- and long-term effects of amyloid-related imaging abnormalities (ARIA), and explore the differences between eligibility criteria in clinical trials, appropriate use recommendations, and prescribing information content. In doing so, they contextualize the discussion on the disagreements among different regulatory authorities.

EXPERT OPINION

Although anti-β-amyloid monoclonal antibodies may be effective in selected scenarios, non-negligible knowledge gaps and implementation limits persist. Overcoming these gaps can no longer be postponed if we are to ensure the principles of Quality of Care for patients with cognitive impairment who would be eligible for this class of drugs.