The ALDH2 rs671 polymorphism affects post-stroke epilepsy susceptibility and plasma 4-HNE levels

Characteristics of Stroke-related Seizures and their Predictive Factors: A Tertiary Care Center Experience

BACKGROUND AND PURPOSE

Various risk factors have been described in the literature that increase the risk of seizures associated with stroke. This study was aimed to determine the occurrence rate of poststroke seizures (PSSs) and the associated risk factors in Arab population.

MATERIALS AND METHODS

Study included all stroke patients aged >18 years with a minimum follow-up of 24 months following stroke to identify seizure occurrence. Patient's hospital records for all admissions and clinic visits were reviewed. Seizures were classified into early PSS if they occur within 1 week of stroke, and late PSS if they occur after 1 week of stroke.

RESULTS

Out of 594 patients, 380 were males. Seizure occurrence was higher in anterior circulation infarctions (94.8%, P < 0.05), cortical location (80.5%, P < 0.05), large artery atherosclerosis (63.8%, P < 0.05), lower activated partial thromboplastin time (APTT) (P = 0.0007), patients with ischemic heart disease (IHD) (P = 0.01), and those who underwent craniotomy (P = 0.001). Nonhigh-density lipoprotein cholesterol was inversely related to PSS (P = 0.01). Higher stroke severity (89%) and confusion (67%) at the time of presentation were independently related to PSS.

CONCLUSIONS

Eighty-two (13.8%) patients had PSS. Greater stroke severity at presentation with altered sensorium was independent risk factors for the development of PSS. Patients with underlying IHD, lower APTT, and undergoing neurosurgical intervention require vigilant monitoring for PSS.

Causal relations between ischemic stroke and epilepsy: A bidirectional Mendelian randomization study

Background

Although previous studies have reported a bidirectional relationship between ischemic stroke (IS) and epilepsy, the existence of a causal nexus and its directionality remains a topic of controversy.

Methods

The single nucleotide polymorphisms (SNPs) associated with IS were extracted from the Genome-Wide Association Study (GWAS) database. Pooled genetic data encompassing all epilepsy cases, as well as generalized and focal epilepsy subtypes, were acquired from the International League Against Epilepsy's GWAS study. In this study, the primary analysis approach utilized the inverse variance weighting (IVW) method as the main analytical technique. To enhance the robustness of the findings against potential pleiotropy, additional sensitivity analyses were conducted.

Results

In the forward analysis, the IVW method demonstrated that IS was associated with an increased risk of all epilepsy (odds ratio (OR) = 1.127, 95 % confidence interval (CI) = 1.038-1.224, P = 0.004) and generalized epilepsy (IVW: OR = 1.340, 95 % CI = 1.162-1.546, P = 5.70 × 10-5). There was no substantial causal relationship observed between IS and focal epilepsy (P > 0.05). Furthermore, generalized epilepsy, focal epilepsy, and all epilepsy did not show a causal relationship with IS.

Conclusion

This Mendelian randomization (MR) analysis demonstrates that IS increases the risk of developing epilepsy, especially generalized epilepsy. Conversely, no clear causal association was found between epilepsy and the onset of stroke. Therefore, the possible mechanisms of the effect of epilepsy on the pathogenesis of IS still need to be further investigated.

Nimbidiol protects from renal injury by alleviating redox imbalance in diabetic mice

Introduction

Chronic hyperglycemia-induced oxidative stress plays a crucial role in the development of diabetic nephropathy (DN). Moreover, adverse extracellular matrix (ECM) accumulation elevates renal resistive index leading to progressive worsening of the pathology in DN. Nimbidiol is an alpha-glucosidase inhibitor, isolated from the medicinal plant, 'neem' (Azadirachta indica) and reported as a promising anti-diabetic compound. Previously, a myriad of studies demonstrated an anti-oxidative property of a broad-spectrum neem-extracts in various diseases including diabetes. Our recent study has shown that Nimbidiol protects diabetic mice from fibrotic renal dysfunction in part by mitigating adverse ECM accumulation. However, the precise mechanism remains poorly understood.

Methods

The present study aimed to investigate whether Nimbidiol ameliorates renal injury by reducing oxidative stress in type-1 diabetes. To test the hypothesis, wild-type (C57BL/6J) and diabetic Akita (C57BL/6-Ins2Akita/J) mice aged 10-14 weeks were used to treat with saline or Nimbidiol (400 μg kg-1 day-1) for 8 weeks.

Results

Diabetic mice showed elevated blood pressure, increased renal resistive index, and decreased renal vasculature compared to wild-type control. In diabetic kidney, reactive oxygen species and the expression levels of 4HNE, p22phox, Nox4, and ROMO1 were increased while GSH: GSSG, and the expression levels of SOD-1, SOD-2, and catalase were decreased. Further, eNOS, ACE2, Sirt1 and IL-10 were found to be downregulated while iNOS and IL-17 were upregulated in diabetic kidney. The changes were accompanied by elevated expression of the renal injury markers viz., lipocalin-2 and KIM-1 in diabetic kidney. Moreover, an upregulation of p-NF-κB and a downregulation of IkBα were observed in diabetic kidney compared to the control. Nimbidiol ameliorated these pathological changes in diabetic mice.

Conclusion

Altogether, the data of our study suggest that oxidative stress largely contributes to the diabetic renal injury, and Nimbidiol mitigates redox imbalance and thereby protects kidney in part by inhibiting NF-κB signaling pathway in type-1 diabetes.

The Progress of Poststroke Seizures

A stroke is one of the most common fatal diseases of the nervous system, and the number of strokes per year has increased substantially in recent years. Epilepsy is a poststroke complication that greatly affects the prognosis of patients and reduces their quality of survival. Effective avoidance of causative factors can reduce the risk of a poststroke seizure. However, while many studies have been devoted to elucidating the pathogenesis of poststroke seizures, the literature lacks a comprehensive understanding of the pathogenic mechanism. This article briefly presents the current definition, risk factors, pathogenesis, and prognosis of poststroke seizures based on reported studies and literature reviews, aiming to enrich the available knowledge of this disease.

Role of the glymphatic system and perivascular spaces as a potential biomarker for post-stroke epilepsy

Stroke is one of the most common causes of acquired epilepsy, which can also result in disability and increased mortality rates particularly in elderly patients. No preventive treatment for post-stroke epilepsy is currently available. Development of such treatments has been greatly limited by the lack of biomarkers to reliably identify high-risk patients. The glymphatic system, including perivascular spaces (PVS), is the brain's waste clearance system, and enlargement or asymmetry of PVS (ePVS) is hypothesized to play a significant role in the pathogenesis of several neurological conditions. In this article, we discuss potential mechanisms for the role of perivascular spaces in the development of post-stroke epilepsy. Using advanced MR-imaging techniques, it has been shown that there is asymmetry and impairment of glymphatic function in the setting of ischemic stroke. Furthermore, studies have described a dysfunction of PVS in patients with different focal and generalized epilepsy syndromes. It is thought that inflammatory processes involving PVS and the blood-brain barrier, impairment of waste clearance, and sustained hypertension affecting the glymphatic system during a seizure may play a crucial role in epileptogenesis post-stroke. We hypothesize that impairment of the glymphatic system and asymmetry and dynamics of ePVS in the course of a stroke contribute to the development of PSE. Automated ePVS detection in stroke patients might thus assist in the identification of high-risk patients for post-stroke epilepsy trials. PLAIN LANGUAGE SUMMARY: Stroke often leads to epilepsy and is one of the main causes of epilepsy in elderly patients, with no preventative treatment available. The brain's waste removal system, called the glymphatic system which consists of perivascular spaces, may be involved. Enlargement or asymmetry of perivascular spaces could play a role in this and can be visualised with advanced brain imaging after a stroke. Detecting enlarged perivascular spaces in stroke patients could help identify those at risk for post-stroke epilepsy.

The added value of risk assessment and subsequent targeted treatment for epileptic seizures after stroke: An early-HTA analysis

INTRODUCTION

The development of post-stroke epilepsy (PSE) is related to a worse clinical outcome in stroke patients. Adding a biomarker to the clinical diagnostic process for the prediction of PSE may help to establish targeted and personalized treatment for high-risk patients, which could lead to improved patient outcomes. We assessed the added value of a risk assessment and subsequent targeted treatment by conducting an early Health Technology Assessment.

METHODS

Interviews were conducted with four relevant stakeholders in the field of PSE to obtain a realistic view of the current healthcare and their opinions on the potential value of a PSE risk assessment and subsequent targeted treatment. The consequences on quality of life and costs of current care of a hypothetical care pathway with perfect risk assessment were modeled based on information from a literature review and the input from the stakeholders. Subsequently, the maximum added value (the headroom) was calculated. Sensitivity analyses were performed to test the robustness of this result to variation in assumed input parameters, i.e. the accuracy of the risk assessment, the efficacy of anti-seizure medication (ASM), and the probability of patients expected to develop PSE.

RESULTS

All stakeholders considered the addition of a predictive biomarker for the risk assessment of PSE to be of value. The headroom amounted to €12,983. The sensitivity analyses demonstrated that the headroom remained beneficial when varying the accuracy of the risk assessment, the ASM efficacy, and the number of patients expected to develop PSE.

DISCUSSION

We showed that a risk assessment for PSE development is potentially valuable. This work demonstrates that it is worthwhile to undertake clinical studies to evaluate biomarkers for the prediction of patients at high risk for PSE and to assess the value of targeted prophylactic treatment.

Post-Stroke Neuropsychiatric Complications: Types, Pathogenesis, and Therapeutic Intervention

Almost all stroke survivors suffer physical disabilities and neuropsychiatric disturbances, which can be briefly divided into post-stroke neurological diseases and post-stroke psychiatric disorders. The former type mainly includes post-stroke pain, post-stroke epilepsy, and post-stroke dementia while the latter one includes post-stroke depression, post-stroke anxiety, post-stroke apathy and post-stroke fatigue. Multiple risk factors are related to these post-stroke neuropsychiatric complications, such as age, gender, lifestyle, stroke type, medication, lesion location, and comorbidities. Recent studies have revealed several critical mechanisms underlying these complications, namely inflammatory response, dysregulation of the hypothalamic pituitary adrenal axis, cholinergic dysfunction, reduced level of 5-hydroxytryptamine, glutamate-mediated excitotoxicity and mitochondrial dysfunction. Moreover, clinical efforts have successfully given birth to many practical pharmaceutic strategies, such as anti-inflammatory medications, acetylcholinesterase inhibitors, and selective serotonin reuptake inhibitors, as well as diverse rehabilitative modalities to help patients physically and mentally. However, the efficacy of these interventions is still under debate. Further investigations into these post-stroke neuropsychiatric complications, from both basic and clinical perspectives, are urgent for the development of effective treatment strategies.

Polygenic Risk of Epilepsy and Post-Stroke Epilepsy

Background and Aims

Epilepsy is highly heritable, with numerous known genetic risk loci. However, the genetic predisposition's role in post-acute brain injury epilepsy remains understudied. This study assesses whether a higher genetic predisposition to epilepsy raises post-stroke or Transient Ischemic Attack (TIA) survivor's risk of Post-Stroke Epilepsy (PSE).

Methods

We conducted a three-stage genetic analysis. First, we identified independent epilepsy-associated ( p <5x10 -8 ) genetic variants from public data. Second, we estimated PSE-specific variant weights in stroke/TIA survivors from the UK Biobank. Third, we tested for an association between a polygenic risk score (PRS) and PSE risk in stroke/TIA survivors from the All of Us Research Program. Primary analysis included all ancestries, while a secondary analysis was restricted to European ancestry only. A sensitivity analysis excluded TIA survivors. Association testing was conducted via multivariable logistic regression, adjusting for age, sex, and genetic ancestry.

Results

Among 19,708 UK Biobank participants with stroke/TIA, 805 (4.1%) developed PSE. Likewise, among 12,251 All of Us participants with stroke/TIA, 394 (3.2%) developed PSE. After establishing PSE-specific weights for 39 epilepsy-linked genetic variants in the UK Biobank, the resultant PRS was associated with elevated odds of PSE development in All of Us (OR:1.16[1.02-1.32]). A similar result was obtained when restricting to participants of European ancestry (OR:1.23[1.02-1.49]) and when excluding participants with a TIA history (OR:1.18[1.02-1.38]).

Conclusions

Our findings suggest that akin to other forms of epilepsy, genetic predisposition plays an essential role in PSE. Because the PSE data were sparse, our results should be interpreted cautiously.

Preventing development of post-stroke hyperexcitability by optogenetic or pharmacological stimulation of cortical excitatory activity

Stroke is the most common cause of acquired epilepsy, but treatment for preventing the development of post-stroke epilepsy is still unavailable. Since stroke results in neuronal damage and death as well as initial loss of activity in the affected brain region, homeostatic plasticity may be trigged and contribute to an increase in network hyperexcitability that underlies epileptogenesis. Correspondingly, enhancing brain activity may inhibit hyperexcitability from enhanced homeostatic plasticity and prevent post-stroke epileptogenesis. To test these hypotheses, we first used in vivo two-photon and mesoscopic imaging of activity of cortical pyramidal neurons in Thy1-GCaMP6 transgenic mice to determine longitudinal changes in excitatory activity after a photothrombotic ischemic stroke. At 3-days post-stroke, there was a significant loss of neuronal activity in the peri-injury area as indicated by reductions in the frequency of calcium spikes and percentage of active neurons, which recovered to baseline level at day 7, supporting a homeostatic activity regulation of the surviving neurons in the peri-injury area. We further used optogenetic stimulation to specifically stimulate activity of pyramidal neurons in the peri-injury area of Thy-1 channelrhodopsin transgenic mice from day 5 to day 15 after stroke. Using pentylenetetrazole test to evaluate seizure susceptibility, we showed that stroke mice are more susceptible to Racine stage V seizures (time latency 54.3 ± 12.9 min) compared to sham mice (107.1 ± 13.6 min), but optogenetic stimulation reversed the increase in seizure susceptibility (114.0 ± 9.2 min) in mice with stroke. Similarly, administration of D-cycloserine, a partial N-methyl-d-aspartate (NMDA) receptor agonist that can mildly enhance neuronal activity without causing post-stroke seizure, from day 5 to day 15 after a stroke significantly reversed the increase in seizure susceptibility. The treatment also resulted in an increased survival of glutamic acid decarboxylase 67 (GAD67) positive interneurons and a reduced activation of glial fibrillary acidic protein (GFAP) positive reactive astrocytes. Thus, this study supports the involvement of homeostatic activity regulation in the development of post-stroke hyperexcitability and potential application of activity enhancement as a novel strategy to prevent post-stroke late-onset seizure and epilepsy through regulating cortical homeostatic plasticity.

Identifying the Molecular Drivers of Pathogenic Aldehyde Dehydrogenase Missense Mutations in Cancer and Non-Cancer Diseases

Human aldehyde dehydrogenases (ALDHs) comprising 19 isoenzymes play a vital role on both endogenous and exogenous aldehyde metabolism. This NAD(P)-dependent catalytic process relies on the intact structural and functional activity of the cofactor binding, substrate interaction, and the oligomerization of ALDHs. Disruptions on the activity of ALDHs, however, could result in the accumulation of cytotoxic aldehydes, which have been linked with a wide range of diseases, including both cancers as well as neurological and developmental disorders. In our previous works, we have successfully characterised the structure-function relationships of the missense variants of other proteins. We, therefore, applied a similar analysis pipeline to identify potential molecular drivers of pathogenic ALDH missense mutations. Variants data were first carefully curated and labelled as cancer-risk, non-cancer diseases, and benign. We then leveraged various computational biophysical methods to describe the changes caused by missense mutations, informing a bias of detrimental mutations with destabilising effects. Cooperating with these insights, several machine learning approaches were further utilised to investigate the combination of features, revealing the necessity of the conservation of ALDHs. Our work aims to provide important biological perspectives on pathogenic consequences of missense mutations of ALDHs, which could be invaluable resources in the development of cancer treatment.

Clinical Biomarkers and Prediction Models for Poststroke Epilepsy: Have We Settled the Scores Yet?

In an era of time-dependent reperfusion and recanalization therapy for stroke leading to improved survival, there is a growing population at risk of poststroke epilepsy (PSE). Accumulating evidence suggests a multidirectional interaction among stroke, PSE, and dementia in stroke survivors. There is no evidence to justify prophylactic antiseizure medication (ASM) to reduce these morbidities. Although several predictive molecular biomarkers and scoring models have been proposed, they remain inadequately validated for stratifying risk and indicating who will benefit from prophylactic ASM. Studies leveraging advances in genetics, metabolomics, electrophysiology, imaging, and artificial intelligence (AI) may help to discover noninvasive molecular biomarkers and easy-to-score models. These discoveries should improve our understanding of epileptogenesis in PSE and identify new pharmacologic targets. Besides, accurately identifying high-risk patients and timely initiating prophylactic ASM therapy has the potential to disrupt the feed-forward multidirectional interaction among stroke, PSE, and dementia.

Epilepsy in Cerebrovascular Diseases: A Narrative Review

BACKGROUND

Epilepsy is a common comorbidity of cerebrovascular disease and an increasing socioeconomic burden.

OBJECTIVE

We aimed to provide an updated comprehensive review on the state of the art about seizures and epilepsy in stroke, cerebral haemorrhage, and leukoaraiosis.

METHODS

We selected English-written articles on epilepsy, stroke, and small vessel disease up until December 2021. We reported the most recent data about epidemiology, pathophysiology, prognosis, and management for each disease.

RESULTS

The main predictors for both ES and PSE are the severity and extent of stroke, the presence of cortical involvement and hemorrhagic transformation, while PSE is also predicted by younger age at stroke onset. Few data exist on physiopathology and seizure semiology, and no randomized controlled trial has been performed to standardize the therapeutic approach to post-stroke epilepsy.

CONCLUSION

Some aspects of ES and PSE have been well explored, particularly epidemiology and risk factors. On the contrary, few data exist on physiopathology, and existing evidence is mainly based on studies on animal models. Little is also known about seizure semiology, which may also be difficult to interpret by non-epileptologists. Moreover, the therapeutic approach needs standardization as regards indications and the choice of specific ASMs. Future research may help to better elucidate these aspects.

Blood and CSF biomarkers for post-stroke epilepsy: a systematic review

Post-stroke epilepsy is a common complication of ischemic stroke which adversely affects the prognosis of patients. Clinical and radiological parameters cannot adequately predict the risk. Therefore, the discovery of biomarkers is imperatively needed for predicting post-stroke epilepsy. We conducted a systematic review of diagnostic and prognostic biomarkers for post-stroke epilepsy through a comprehensive literature search in different databases. All articles that met our inclusion criteria were assessed for quality using the modified Quality Assessment of Diagnostic Accuracy Studies questionnaire. Eight eligible studies were included in this systematic review. Out of 22 assessed biomarkers, nine biomarkers showed significant association with post-stroke epilepsy. The T allele of CD40 (cluster of differentiation 40) −1C/T polymorphism, the CC genotype of TRPM6 (transient receptor potential cation channel subfamily M member 6) rs2274924, the allele polymorphism of MAD2 (mitochondrial aldehyde dehydrogenase 2), the mRNA level of interleukin-6 (IL-6), the plasma level of endostatin, and the mRNA expression of IL-1β show a positive correlation with post-stroke epilepsy; while S100 calcium-binding protein B, heat shock 70 kDa protein-8 and neuropeptide Y are inversely associated with post-stroke epilepsy. As a small number of patients were recruited, further studies are needed to confirm their potential use for predicting post-stroke epilepsy.

Poststroke Seizure and Epilepsy: A Review of Incidence, Risk Factors, Diagnosis, Pathophysiology, and Pharmacological Therapies

Stroke is the most common cause of epilepsy and ultimately leads to a decrease in the quality of life of those affected. Ischemic and hemorrhagic strokes can both lead to poststroke epilepsy (PSE). Significant risk factors for PSE include age < 65age less than 65 years, stroke severity measured by the National Institutes of Health Stroke Scale (NIHSS), cortical involvement, and genetic factors such as TRPM6 polymorphism. The diagnosis of PSE is made by using imaging modalities, blood biomarkers, and prognostic criteria. Electroencephalography (EEG) is currently the gold standard to diagnose PSE, while new combinations of modalities are being tested to increase diagnostic specificity. This literature review uncovers a newly found mechanism for the pathology of poststroke epilepsy. The pathogenesis of early-onset and late-onset is characterized by sequelae of neuronal cellular hypoxia and disruption of the blood-brain barrier, respectively. Interleukin-6 is responsible for increasing the activity of glial cells, causing gliosis and hyperexcitability of neurons. Epinephrine, high-mobility group protein B1, downregulation of CD32, and upregulation of HLA-DR impact the pathology of poststroke epilepsy by inhibiting the normal neuronal immune response. Decreased levels of neuropeptide Y, a neurotransmitter, act through multiple unique mechanisms, such as inhibiting intracellular Ca²⁺ accumulation and acting as an anti-inflammatory, also implemented in the worsening progression of poststroke epilepsy. Additionally, CA1 hippocampal resonant neurons that increase theta oscillation are associated with poststroke epilepsy. Hypertensive small vessel disease may also have an implication in the temporal lobe epilepsy by causing occult microinfarctions. Furthermore, this review highlights the potential use of statins as primary prophylaxis against PSE, with multiple studies demonstrating a reduction in incidence using statins alone, statins in combination with antiepileptic drugs (AEDs), and statins with aspirin. The evidence strongly suggests that the second generation AEDs are a superior treatment method for PSE. Data from numerous studies demonstrate their relative lack of significant drug interactions, increased tolerability, and potential superiority in maintaining seizure-free status.

Seizures and epilepsy in patients with ischaemic stroke

BACKGROUND

With the increased efficacy of stroke treatments, diagnosis and specific treatment needs of patients with post-stroke seizures (PSS) and post-stroke epilepsy have become increasingly important. PSS can complicate the diagnosis of a stroke and the treatment of stroke patients, and can worsen post-stroke morbidity. This narrative review considers current treatment guidelines, the specifics of antiseizure treatment in stroke patients as well as the state-of-the-art in clinical and imaging research of post-stroke epilepsy. Treatment of PSS needs to consider indications for antiseizure medication treatment as well as individual clinical and social factors. Furthermore, potential interactions between stroke and antiseizure treatments must be carefully considered. The relationship between acute recanalizing stroke therapy (intravenous thrombolysis and mechanical thrombectomy) and the emergence of PSS is currently the subject of an intensive discussion. In the subacute and chronic post-stroke phases, important specific interactions between necessary antiseizure and stroke treatments (anticoagulation, cardiac medication) need to be considered. Among all forms of prevention, primary prevention is currently the most intensively researched. This includes specifically the repurposing of drugs that were not originally developed for antiseizure properties, such as statins. PSS are presently the subject of extensive basic clinical research. Of specific interest are the role of post-stroke excitotoxicity and blood-brain barrier disruption for the emergence of PSS in the acute symptomatic as well as late (> 1 week after the stroke) periods. Current magnetic resonance imaging research focussing on glutamate excitotoxicity as well as diffusion-based estimation of blood-brain barrier integrity aim to elucidate the pathophysiology of seizures after stroke and the principles of epileptogenesis in structural epilepsy in general. These approaches may also reveal new imaging-based biomarkers for prediction of PSS and post-stroke epilepsy.

CONCLUSION

PSS require the performance of individual risk assessments, accounting for the potential effectiveness and side effects of antiseizure therapy. The use of intravenous thrombolysis and mechanical thrombectomy is not associated with an increased risk of PSS. Advances in stroke imaging may reveal biomarkers for PSS.

Prospective study: Aldehyde dehydrogenase 2 gene is associated with cardio-cerebrovascular complications in type 2 diabetes patients

AIMS/INTRODUCTION

Most studies have shown that aldehyde dehydrogenase 2 (ALDH2) mutations were associated with cardio-cerebrovascular complications of diabetes based on cross-sectional investigations, but few studies based on cohorts were carried out. The aim of this study was to explore the correlation between the ALDH2 gene and the occurrence of and death from cardio-cerebrovascular complications in type 2 diabetes patients through a prospective cohort study.

MATERIALS AND METHODS

According to a community-based and disease-based prospective cohort study design, a baseline cohort of 10,339 persons with type 2 diabetes was established in 2016, and the occurrence of and death from cardio-cerebrovascular complications were followed up until December 2018. A total of 2,500 diabetes patients without cardio-cerebrovascular complications were randomly selected from the baseline cohort to detect the rs671 polymorphism of the ALDH2 gene. Cox regression analysis was carried out on the effect of different ALDH2 rs671 single-nucleotide polymorphisms on the risk and survival time of cardio-cerebrovascular complications among diabetes patients.

RESULTS

There were 215 cardio-cerebrovascular complications, including 10 deaths, that occurred in the 2,500 diabetes patients during the follow-up period. Cox regression analysis showed that rs671 GA/AA genotype, sex (male), poor control of high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, blood pressure and glycated were risk factors, whereas drinking alcohol was a protective factor for cardio-cerebrovascular complications (P < 0.05). After adjusting for age and sex, the risk of the rs671 GA/AA genotype was 1.314-fold (95% confidence interval 1.000-1.727) that of the GG genotype.

CONCLUSION

The G-A mutation of ALDH2 rs671 is a risk factor for the occurrence of and death from cardio-cerebrovascular complications in type 2 diabetes patients. Further studies with larger cohorts and longer follow up will be necessary to reveal a consensus.

The Aldehyde Dehydrogenase ALDH2*2 Allele, Associated with Alcohol Drinking Behavior, Dates Back to Prehistoric Times

Human alcohol-consumption behavior is partly genetically encoded. The alcohol consumption of 987 residents in Keelung, Taiwan, was evaluated by using the Alcohol Use Disorder Identification Test (AUDIT). We assessed ~750,000 genomic variants of 71 residents who drank hazardously (AUDIT score ≥ 8) and 126 residents who did not drink in their daily lives (AUDIT score = 0), using high-density single nucleotide polymorphism (SNP) arrays. The rs671 G > A manifests the highest significance of the association with drinking behavior (Fisher’s exact P = 8.75 × 10⁻⁹). It is a pleiotropic, non-synonymous variant in the aldehyde dehydrogenase 2 (ALDH2) gene. The minor allele “A”, commonly known as ALDH2*2, is associated with non-drinkers. Intriguingly, identity-by-descent haplotypes encompassing genomic regions with a median length of 1.6 (0.6–2.0) million nucleotide bases were found in all study participants with either heterozygous or homozygous ALDH2*2 (n = 81 and 13, respectively). We also analyzed a public-domain dataset with genome-wide genotypes of 2000 participants in Guangzhou, a coastal city in Southern China. Among them, 175 participants have homozygous ALDH2*2 genotype, and again, long ALDH2*2-carrying haplotypes were found in all 175 participants without exceptions. The median length of the ALDH2*2-carrying haplotype is 1.7 (0.5–2.8) million nucleotide bases. The haplotype lengths in the Keelung and Guangzhou cohorts combined indicate that the origin of the ALDH2*2 allele dates back to 7935 (7014–9381) years ago. In conclusion, the rs671 G > A is the leading genomic variant associated with the long-term drinking behavior among residents of Keelung, Taiwan. The ALDH2*2 allele has been in Asian populations since prehistoric times.

Pediatric Ischemic Stroke and Epilepsy: A Nationwide Cohort Study

Background and Purpose

The risk of epilepsy after stroke has not been thoroughly explored in pediatric ischemic stroke. We examined the risk of epilepsy in children with ischemic stroke as well as in their first-degree relatives.

Methods

In Swedish National Registers, we identified 1220 children <18 years with pediatric ischemic stroke diagnosed 1969 to 2016, alive 7 days after stroke and with no prior epilepsy. We used 12 155 age- and sex-matched individuals as comparators. All first-degree relatives to index individuals and comparators were also identified. The risk of epilepsy was estimated in children with ischemic stroke and in their first-degree relatives using Cox proportional hazard regression model.

Results

Through this nationwide population-based study, 219 (18.0%) children with ischemic stroke and 91 (0.7%) comparators were diagnosed with epilepsy during follow-up corresponding to a 27.8-fold increased risk of future epilepsy (95% CI, 21.5–36.0). The risk of epilepsy was still elevated after 20 years (hazard ratio [HR], 7.9 [95% CI, 3.3–19.0]), although the highest HR was seen in the first 6 months (HR, 119.4 [95% CI, 48.0–297.4]). The overall incidence rate of epilepsy was 27.0 per 100 000 person-years (95% CI, 21.1–32.8) after ischemic stroke diagnosed ≤day 28 after birth (perinatal) and 11.6 per 100 000 person-years (95% CI, 9.6–13.5) after ischemic stroke diagnosed ≥day 29 after birth (childhood). Siblings and parents, but not offspring, to children with ischemic stroke were at increased risk of epilepsy (siblings: HR, 1.64 [95% CI, 1.08–2.48] and parents: HR, 1.41 [95% CI, 1.01–1.98]).

Conclusions

The risk of epilepsy after ischemic stroke in children is increased, especially after perinatal ischemic stroke. The risk of epilepsy was highest during the first 6 months but remained elevated even 20 years after stroke which should be taken into account in future planning for children affected by stroke.

Current advances on mechanisms and treatment of post-stroke seizures

Cerebrovascular diseases are among the most common causes of seizures in adults, especially in the elderly. With the increased incidence of stroke, the population with post-stroke seizures has grown, leading to the increased awareness of this disorder in the society. The most common seizure type after stroke is the focal seizure with or without evolution into bilateral convulsive seizures. Post-stroke seizures impair the quality of life, as well as the physical and mental health of those patients. Currently, the pathological and physical processes of post-stroke seizures are not quite clear yet. In this review, we summarize current advances in the pathogenesis, risk factors, and therapeutic targets of post-stroke seizures.

Synergistic Effects of Aldehyde Dehydrogenase 2 Polymorphisms and Alcohol Consumption on Cognitive Impairment after Ischemic Stroke in Han Chinese

Aldehyde dehydrogenase 2 (ALDH2) polymorphisms are related to both stroke risk and alcohol consumption. However, the influence of ALDH2 polymorphisms and alcohol consumption on cognitive impairment after ischemic stroke remains unknown, as do the possible mechanisms. We enrolled 180 Han Chinese ischemic stroke patients from four community health centers in Bengbu, China. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA), and two different MoCA cutoff scores were used to define cognitive impairment in ischemic stroke patients. The ALDH2 genotypes were determined using polymerase chain reaction and direct sequencing. To assess the associations of ALDH2 polymorphisms and alcohol consumption with cognitive impairment after ischemic stroke, we performed binary logistic regression analysis with odds ratios. We revealed that individuals with the ALDH2 wild-type genotype were more likely to have high MoCA scores than those with the mutant and heterozygous types (p = 0.034). In addition, using two MoCA cutoff scores, the percentage of moderate to excessive alcohol consumption in the cognitive impairment group was higher than that in the nonimpairment group (p = 0.001). The levels of 4-hydroxy-2-nonenal (p = 0.001) and swallowing function (p = 0.001) were also higher in the cognitive impairment group than in the nonimpairment group. Moreover, after adjusting for other potential risk factors, ALDH2 polymorphisms and alcohol consumption had a significant synergistic effect on cognitive impairment (p = 0.022). Specifically, the ALDH2∗2 mutant allele and higher alcohol consumption were associated with cognitive impairment and swallowing ability after ischemic stroke. Targeting ALDH2 may be a useful biomarker for cognitive rehabilitation following ischemic stroke.

Advances in the Development of Biomarkers for Poststroke Epilepsy

Stroke is the main cause of acquired epilepsy in elderly people. Poststroke epilepsy (PSE) not only affects functional recovery after stroke but also brings considerable social consequences. While some factors such as cortical involvement, hemorrhagic transformation, and stroke severity are associated with increased seizure risk, so far that remains controversial. In recent years, there are an increasing number of studies on potential biomarkers of PSE as tools for diagnosing and predicting epileptic seizures. Biomarkers such as interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), glutamate, and S100 calcium-binding protein B (S100B) in blood are associated with the occurrence of PSE. This review is aimed at summarizing the progress on potential biomarkers of PSE.

Seizures and Epilepsy After Stroke: Epidemiology, Biomarkers and Management

Stroke is the leading cause of seizures and epilepsy in older adults. Patients who have larger and more severe strokes involving the cortex, are younger, and have acute symptomatic seizures and intracerebral haemorrhage are at highest risk of developing post-stroke epilepsy. Prognostic models, including the SeLECT and CAVE scores, help gauge the risk of epileptogenesis. Early electroencephalogram and blood-based biomarkers can provide information additional to the clinical risk factors of post-stroke epilepsy. The management of acute versus remote symptomatic seizures after stroke is markedly different. The choice of an ideal antiseizure medication should not only rely on efficacy but also consider adverse effects, altered pharmacodynamics in older adults, and the influence on the underlying vascular co-morbidity. Drug-drug interactions, particularly those between antiseizure medications and anticoagulants or antiplatelets, also influence treatment decisions. In this review, we describe the epidemiology, risk factors, biomarkers, and management of seizures after an ischaemic or haemorrhagic stroke. We discuss the special considerations required for the treatment of post-stroke epilepsy due to the age, co-morbidities, co-medication, and vulnerability of stroke survivors.

Multifactorial Predictors of Late Epileptic Seizures Related to Stroke: Evaluation of the Current Possibilities of Stratification Based on Existing Prognostic Models-A Comprehensive Review

Background: Epilepsy associated with strokes is a significant clinical and public health problem and has a negative impact on prognosis and clinical outcome. A late epileptic seizure occurring seven days after stroke is actually equated with poststroke epilepsy due to the high risk of recurrence. Predictive models evaluated in the acute phase of stroke would allow for the stratification and early selection of patients at higher risk of developing late seizures. Methods: The most relevant papers in this field were reviewed to establish multifactorial predictors of late seizures and attempt to standardize and unify them into a common prognostic model. Results: Clinical and radiological factors have become the most valuable and reproducible predictors in many reports, while data on electroencephalographic, genetic, and blood biomarkers were limited. The existing prognostic models, CAVE and SeLECT, based on relevant, readily available, and routinely assessed predictors, should be validated and improved in multicenter studies for widespread use in stroke units. Conclusions: Due to contradictory reports, a common and reliable model covering all factors is currently not available. Further research might refine forecasting models by incorporating advanced radiological neuroimaging or quantitative electroencephalographic analysis.

Genetic Contributions to Acquired Epilepsies

Whether genetic factors contribute to acquired epilepsies has long been controversial. Supporters observe that, among individuals exposed to seemingly the same brain insult, only a minority develops unprovoked seizures. Yet, only in relatively recent years have studies started to build a case for genetic contributions. Here, we appraise this emerging evidence, by providing a critical review of studies published in the field.

Activation of TGR5 with INT-777 attenuates oxidative stress and neuronal apoptosis via cAMP/PKCε/ALDH2 pathway after subarachnoid hemorrhage in rats

BACKGROUND

Oxidative stress and neuronal apoptosis play important roles in the pathogenesis of early brain injury (EBI) after subarachnoid hemorrhage (SAH). The activation of TGR5, a novel membrane-bound bile acid receptor, possesses anti-oxidative stress and anti-apoptotic effects in hepatobiliary disease and kidney disease. The present study aimed to explore the neuroprotective effect of TGR5 activation against EBI after SAH and the potential underlying mechanisms.

METHODS

The endovascular perforation model of SAH was performed on 199 Sprague Dawley rats to investigate the beneficial effects of TGR5 activation after SAH. INT-777, a specific synthetic TGR5 agonist, was administered intranasally at 1 h after SAH induction. TGR5 CRISPR and ALDH2 CRISPR were administered intracerebroventricularly at 48 h before SAH to illuminate potential mechanisms. The SAH grade, short-term and long-term neurobehavioral tests, TUNEL staining, Fluoro-Jade C staining, Nissl staining, immunofluorescence staining, and western blots were performed at 24 h after SAH.

RESULTS

The expressions of endogenous TGR5 and ALDH2 gradually increased and peaked at 24 h after SAH. TGR5 was expressed primarily in neurons, as well as in astrocytes and microglia. The activation of TGR5 with INT-777 significantly improved the short-term and long-term neurological deficits, accompanied by reduced the oxidative stress and neuronal apoptosis at 24 h after SAH. Moreover, INT-777 treatment significantly increased the expressions of TGR5, cAMP, phosphorylated PKCε, ALDH2, HO-1, and Bcl-2, while downregulated the expressions of 4-HNE, Bax, and Cleaved Caspase-3. TGR5 CRISPR and ALDH2 CRISPR abolished the neuroprotective effects of TGR5 activation after SAH.

CONCLUSIONS

In summary, the activation of TGR5 with INT-777 attenuated oxidative stress and neuronal apoptosis via the cAMP/PKCε/ALDH2 signaling pathway after SAH in rats. Furthermore, TGR5 may serve as a novel therapeutic target to ameliorate EBI after SAH.

Family history increases the risk of late seizures after stroke

OBJECTIVE

To assess the association between a family history of epilepsy and risk of late poststroke seizures (LPS).

METHODS

This register-based cohort study was based on adult patients from the Swedish Stroke Register (Riksstroke) with stroke from 2001 to 2012 and no prior epilepsy. LPS (>7 days after stroke) and epilepsy were ascertained in cases and in their first-degree biological relatives by cross-referencing Riksstroke, the Multi-Generation Register, and the National Patient Register.

RESULTS

Of 86,550 patients with stroke, a family history of epilepsy was detected in 7,433 (8.6%), and LPS (>7 days after stroke) occurred in 7,307 (8.4%). The survival-adjusted risk of LPS was higher in patients with compared to those without a family history of epilepsy: 6.8% (95% confidence interval [CI] 6.2%-7.4%) vs 5.9% (95% CI 5.7%-6.1%) at 2 years and 9.5% (95% CI 8.7%-10.3%) vs 8.2% (95% CI 8.0%-8.4%) at 5 years. In a Cox model adjusted for age, sex, and stroke type, the hazard ratio (HR) for LPS in patients with stroke with ≥1 relative with epilepsy was 1.18 (95% CI 1.09-1.28). The increased HR remained significant with adjustments for stroke severity and in multiple sensitivity analyses. A higher risk for patients with stroke with >1 relative with epilepsy was also seen but was not significant in all Cox models.

CONCLUSIONS

Although stroke characteristics remain the most important risk factors for LPS, having a first-degree relative with epilepsy also increases the risk in a multivariate analysis. The findings highlight the need for family history assessment in patients with stroke and the need for future studies on genetic vulnerability and environmental factors that may aid in the identification of at-risk individuals.

An animal model of genetic predisposition to develop acquired epileptogenesis: The FAST and SLOW rats

Epidemiological data and gene association studies suggest a genetic predisposition to developing epilepsy after an acquired brain insult, such as traumatic brain injury. An improved understanding of genetic determinants of vulnerability is imperative for early disease diagnosis and prognosis prediction, with flow-on benefits for the development of targeted antiepileptogenic treatments as well as optimal clinical trial design. In the laboratory, one approach to investigate why some individuals are more vulnerable to acquired epilepsy than others is to examine unique rodent models exhibiting either vulnerability or resistance to epileptogenesis. This review focuses on the most well-characterized of these models, the FAST (seizure-prone) and SLOW (seizure-resistant) rat strains, which were derived by selective breeding for differential amygdala electrical kindling rates. We describe how these strains differ in their seizure profiles, neuroanatomy, and neurobehavioral phenotypes, both at baseline and after a brain insult, with this knowledge proving fruitful to identify common pathological abnormalities associated with seizure susceptibility and psychiatric comorbidities. It is important to note that accruing data on strain differences in multiple biological processes provides insight into why some individuals may be more vulnerable to epileptogenesis, although future studies are evidently needed to identify the precise molecular and genetic risk factors. Together, the FAST and SLOW rat strains, and other similar experimental models, are invaluable neurobiological tools to investigate the effect of genetic background on acquired epilepsy risk, as well as the poorly understood relationship between epilepsy development and associated comorbidities.

Relationship between ALDH2 genotype and in-stent restenosis in Chinese Han patients after percutaneous coronary intervention

BACKGROUND

It is well known that the genotype of ALDH2 is associated with coronary artery disease (CAD), and in-stent restenosis (ISR) is a primary complication of percutaneous coronary intervention (PCI), a primary recommended treatment for CAD. The aim of this study was to identify the relationship between aldehyde dehydrogenase 2 (ALDH2) genotype and in-stent restenosis (ISR).

METHODS

This study recruited 531 patients who were undergoing PCI at two Chinese hospitals from 2015 to 2017 and 183 were diagnosed with ISR after PCI during the one-year follow-up period. We used polymerase chain restriction fragment length polymorphism (PCR-RFLP) and sequencing to determine ALDH2 polymorphisms.

RESULTS

Among all 531 patients (mean age = 59.4 ± 9.8; 65.9% male), 68.7% carried the wild-type genotype, 28.4% were heterozygous for the mutation, and 2.8% were homozygous for the mutation. Multiple logistical regression analyses indicated no correlation between ALDH2 genotype and the occurrence of restenosis after PCI (OR = 1.448, 95% CI: 0.965-2.168, p = 0.073), though a significant association was observed for patients with diabetes (OR = 4.053, 95% CI: 1.668-10.449, p = 0.003).

CONCLUSION

In this study, we found that carrying an ALDH2*2 allele had no notable relationship with ISR one year after PCI but that it did have a significant association with complications in diabetic patients. Further studies with larger sample sizes will be necessary to reveal a consensus.

[Activation of aldehyde dehydrogenase 2 alleviates H 2O 2-induced injury in cardiomyocytes]

OBJECTIVE

To investigate the changes of aldehyde dehydrogenase 2 (ALDH2) expression in H ₂O ₂inducedcardiomyocytes oxidative stress injury.

METHODS

Cultured H9C2 cardiomyocytes were exposed to H ₂O ₂-inducedoxidative stress and the effects of the ALDH2 agonist Alda-1 and ALDH2 inhibitor Daidzin were tested on the stress level ofthe exposed cells. MTT colorimetric assay was used to assess the cell viability after the treatments. The oxidative stress level inthe myocardial cells was detected using DHE fluorescence staining, and the activity and protein level of ALDH2 were detectedwith spectrophotometry and Western blotting.

RESULTS

Compared with normal control cells, Alda-1 treatment did notsignificantly affect the cell viability, oxidative stress level, or ALDH2 activity and protein level. H ₂O ₂ exposure significantlylowered the cell activity and ALDH2 activity and protein expression and increased the oxidative stress level; Alda-1 treatmentobvious antagonized the effects of H ₂O ₂. Blocking ALDH2 with Daidzin produced similar effects to H ₂O ₂ exposure on theviability, oxidative stress level, and ALDH2 activity and expression in the myocardial cells.

CONCLUSIONS

H ₂O ₂ exposure lowersthe activity and reduces the protein expression of ALDH2 in cardiomyocyte H9C2 cells, and activation of ALDH2 can alleviateH ₂O ₂-induced oxidative stress in the cells.

Increased risk of post-stroke epilepsy in Chinese patients with a TRPM6 polymorphism

OBJECTIVES

We attempted to determine whether a functional polymorphism of TRPM6 (rs2274924) is associated with susceptibility to epilepsy following ischemic stroke, and to further explore the effect of this polymorphism on serum levels of Mg²⁺ in post-stroke patients.

METHODS

We carried out a case-control study on 378 post-stroke epilepsy patients and 420 controls (stroke patients without secondary epilepsy). We used DNA sequencing to determine the genotypes of the TRPM6 rs2274924 polymorphism, and used the ion selective electrode method to measure serum levels of Mg²⁺.

RESULTS

The distribution of the CC genotype and the frequency of the C allele were significantly higher in the post-stroke epilepsy patients than in the controls (P < 0.01). With regard to the post-stroke epilepsy patients, the serum levels of Mg²⁺ decreased significantly in the TRPM6 rs2274924 C allele carriers compared to the rs2274924 T allele carriers.

CONCLUSION

The TRPM6 rs2274924 polymorphism may be associated with susceptibility to epilepsy following stroke, and the C allele may be associated with increased risk of post-stroke epilepsy. The TRPM6 rs2274924 polymorphism may also influence serum levels of Mg²⁺ in post-stroke epilepsy patients.

Poststroke epilepsy: current perspectives on diagnosis and treatment

Seizures and epilepsy are quite a common outcome of arterial ischemic stroke (AIS) both in pediatric and adult patients, with distinctly higher occurrence in children. These poststroke consequences affect patients' lives, often causing disability. Poststroke seizure (PSS) may also increase mortality in patients with AIS. Early PSS (EPSS) occurring up to 7 days after AIS, late PSS (LPSS) occurring up to 2 years after the onset of AIS, as well as poststroke epilepsy (PSE) can be distinguished. However, the exact definition and cutoff point for PSE should be determined. A wide range of risk factors for seizures and epilepsy after AIS are still being detected and analyzed. More accurate knowledge on risk factors for PSS and PSE as well as possible prediction of epileptic seizures after the onset of AIS may have an impact on improving the prevention and treatment of PSE. The aim of the present review was to discuss current perspectives on diagnosis and treatment of PSS and PSE, both in adult and paediatric patients.

Stroke-related epilepsy

Stroke is the cause of about 10% of all epilepsy and 55% of newly diagnosed seizures among the elderly. Although recent advances in acute stroke therapy have improved longevity, there has been a consequent rise in the prevalence of stroke-related epilepsy (STRE). Many clinical studies make a distinction between early (within 7 days of onset of stroke) and late (beyond 7 days of onset of stroke) seizures based on presumed pathophysiological differences. Although early seizures are thought to be the consequence of local metabolic disturbances without altered neuronal networks, late seizures are thought to occur when the brain has acquired a predisposition for seizures. Overall, STRE has a good prognosis, being well controlled by antiepileptic drugs. However, up to 25% of cases become drug resistant. STRE can also result in increased morbidity, longer hospitalization, greater disability at discharge and greater resource utilization. Additional controlled trials are needed to explore the primary and secondary prevention of STRE as well as to provide high-quality evidence on efficacy and tolerability of antiepileptic drugs to guide treatment of STRE. Robust pre-clinical and clinical prediction models of STRE are also needed to develop treatments to prevent the transformation of infarcted tissue into an epileptic focus.

Association between Physical Exercise and Biomarkers of Oxidative Stress among Middle-Aged and Elderly Community Residents with Essential Hypertension in China

This study aimed to investigate the role of different types and frequencies of physical exercise in biomarkers of oxidative stress among middle-aged and elderly community residents with essential hypertension in China. A community-based cross-sectional survey was undertaken in 7 subdistricts. Individuals, 45-79 years old, with essential hypertension (n = 402) and without cardiovascular disease (n = 1047) were included. Superoxide dismutase (SOD) activities and plasma levels of malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE) were determined. Multilevel linear regression was used to estimate the associations between various types of physical exercise and oxidative stress biomarker levels. Participants engaged in high frequency walking/square dancing or taiji/yoga demonstrated decreased systolic blood pressure in both groups; however, diastolic blood pressure decreased only among individuals with hypertension participating in walking/square dancing. In individuals with hypertension, MDA levels decreased in those participating in walking/square dancing, SOD activity increased in those participating in walking/square dancing, and 4-HNE levels decreased in those involved in taiji/yoga. In individuals without cardiovascular disease, MDA levels decreased in those involved in walking/square dancing or taiji/yoga, SOD activity increased in those performing walking/square dancing, and 4-HNE levels decreased in those involved in taiji/yoga. Oxidative stress marker levels also improved in those involved in walking/square dancing or taiji/yoga groups as the exercise frequency increased. Thus, frequent participation in walking/square dancing or taiji/yoga effectively decreases hypertension-related oxidative stress biomarker levels.

ALDH2 Protects Against Ischemic Stroke in Rats by Facilitating 4-HNE Clearance and AQP4 Down-Regulation

Aldehyde dehydrogenase 2 (ALDH2) is a new therapeutic target in the central nervous system. However, the association between ALDH2 and brain edema following ischemic stroke (IS) remains unclear. The present study was investigated to whether active ALDH2 can attenuate brain edema by using a rat model of IS, with the aim of clarifying the underlying mechanisms involved. Rats were administered the ALDH2 agonist Alda-1, vehicle or the ALDH2 inhibitor cyanamide (CYA) 15 min prior to a 1.5 h middle cerebral artery occlusion (MCAO) surgery. The effects of ALDH2 were subsequently investigated 24 h after reperfusion by evaluating neurological function, infarct sizes, brain edema volumes, 4-hydroxy-2-nonenal (4-HNE) levels, and aquaporin 4 (AQP4) protein expression. The results demonstrated that increasing ALDH2 activity significantly improved neurological deficits, reduced infarct sizes, and attenuated brain edema after MCAO. Alda-1 administration led to decreased 4-HNE levels and inhibited AQP4 protein expression in the peri-infarct section of the brain. Whereas, CYA administration increased 4-HNE levels, AQP4 expression, and simultaneously aggravated brain edema following MCAO. In conclusion, increasing ALDH2 activity can improve brain edema, infarct volumes, and reduce neurological impairment in a rat IS model. The therapeutic benefits of ALDH2 are related to 4-HNE clearance and AQP4 down-regulation.

Commonalities in epileptogenic processes from different acute brain insults: Do they translate?

The most common forms of acquired epilepsies arise following acute brain insults such as traumatic brain injury, stroke, or central nervous system infections. Treatment is effective for only 60%-70% of patients and remains symptomatic despite decades of effort to develop epilepsy prevention therapies. Recent preclinical efforts are focused on likely primary drivers of epileptogenesis, namely inflammation, neuron loss, plasticity, and circuit reorganization. This review suggests a path to identify neuronal and molecular targets for clinical testing of specific hypotheses about epileptogenesis and its prevention or modification. Acquired human epilepsies with different etiologies share some features with animal models. We identify these commonalities and discuss their relevance to the development of successful epilepsy prevention or disease modification strategies. Risk factors for developing epilepsy that appear common to multiple acute injury etiologies include intracranial bleeding, disruption of the blood-brain barrier, more severe injury, and early seizures within 1 week of injury. In diverse human epilepsies and animal models, seizures appear to propagate within a limbic or thalamocortical/corticocortical network. Common histopathologic features of epilepsy of diverse and mostly focal origin are microglial activation and astrogliosis, heterotopic neurons in the white matter, loss of neurons, and the presence of inflammatory cellular infiltrates. Astrocytes exhibit smaller K+ conductances and lose gap junction coupling in many animal models as well as in sclerotic hippocampi from temporal lobe epilepsy patients. There is increasing evidence that epilepsy can be prevented or aborted in preclinical animal models of acquired epilepsy by interfering with processes that appear common to multiple acute injury etiologies, for example, in post-status epilepticus models of focal epilepsy by transient treatment with a trkB/PLCγ1 inhibitor, isoflurane, or HMGB1 antibodies and by topical administration of adenosine, in the cortical fluid percussion injury model by focal cooling, and in the albumin posttraumatic epilepsy model by losartan. Preclinical studies further highlight the roles of mTOR1 pathways, JAK-STAT3, IL-1R/TLR4 signaling, and other inflammatory pathways in the genesis or modulation of epilepsy after brain injury. The wealth of commonalities, diversity of molecular targets identified preclinically, and likely multidimensional nature of epileptogenesis argue for a combinatorial strategy in prevention therapy. Going forward, the identification of impending epilepsy biomarkers to allow better patient selection, together with better alignment with multisite preclinical trials in animal models, should guide the clinical testing of new hypotheses for epileptogenesis and its prevention.

The Progress of Epilepsy after Stroke

BACKGROUND

Epilepsy is the second most common disease caused by multiple factors and characterized by an excessive discharge of certain neurons in the nervous system. Cerebrovascular disease, including stroke, is viewed as the most common cause of epilepsy in the elderly population, accounting for 30%-50% of the newly diagnosed cases of epilepsy cases in this age group.

METHODS

Data were collected from Web of Science, Medline, Pubmed, Scopus, through searching of these keywords: "Stroke" and "epilepsy".

RESULTS

Depending on the underlying cerebrovascular disease, 3%-30% of patients after stroke may develop post-stroke epilepsy (PSE), which has a negative effect on stroke prognosis and the quality of life.

CONCLUSION

In this review, we summarized new aspects emerging from research into PSE, including definition, epidemiology, risk factors, mechanism, accessory examination and treatment strategies for post-stroke epilepsy, which will enrich our knowledge of this disorder.

Enzymatic and non-enzymatic detoxification of 4-hydroxynonenal: Methodological aspects and biological consequences

4-Hydroxynonenal (HNE), an electrophilic end-product deriving from lipid peroxidation, undergoes a heterogeneous set of biotransformations including enzymatic and non-enzymatic reactions. The former mostly involve red-ox reactions on the HNE oxygenated functions (phase I metabolism) and GSH conjugations (phase II) while the latter are due to the HNE capacity to spontaneously condense with nucleophilic sites within endogenous molecules such as proteins, nucleic acids and phospholipids. The overall metabolic fate of HNE has recently attracted great interest not only because it clearly determines the HNE disposal, but especially because the generated metabolites and adducts are not inactive molecules (as initially believed) but show biological activities even more pronounced than those of the parent compound as exemplified by potent pro-inflammatory stimulus induced by GSH conjugates. Similarly, several studies revealed that the non-enzymatic reactions, initially considered as damaging processes randomly involving all endogenous nucleophilic reactants, are in fact quite selective in terms of both reactivity of the nucleophilic sites and stability of the generated adducts. Even though many formed adducts retain the expected toxic consequences, some adducts exhibit well-defined beneficial roles as documented by the protective effects of sublethal concentrations of HNE against toxic concentrations of HNE. Clearly, future investigations are required to gain a more detailed understanding of the metabolic fate of HNE as well as to identify novel targets involved in the biological activity of the HNE metabolites. These studies are and will be permitted by the continuous progress in the analytical methods for the identification and quantitation of novel HNE metabolites as well as for proteomic analyses able to offer a comprehensive picture of the HNE-induced adducted targets. On these grounds, the present review will focus on the major enzymatic and non-enzymatic HNE biotransformations discussing both the molecular mechanisms involved and the biological effects elicited. The review will also describe the most important analytical enhancements that have permitted the here discussed advancements in our understanding of the HNE metabolic fate and which will permit in a near future an even better knowledge of this enigmatic molecule.

Alcohol flushing is independently associated with lesser degree of carotid atherosclerosis in Japanese type 2 diabetic patients

Background

Type 2 diabetes mellitus is a well-known risk factor for atherosclerosis. Intima media thickness (IMT) of the carotid arteries has been widely used for assessing atherosclerotic changes representing cerebro-cardiovascular disease risk. Previous studies have associated the presence of inactive aldehyde dehydrogenase with progression of atherosclerosis and alcohol flushing. However, reports conflict on whether alcohol flushing could potentially modify the degree of atherosclerosis in type 2 diabetic patients.

Methods

We retrospectively assessed the relationships among alcohol flushing, IMT, and clinical characteristics in 123 consecutive Japanese type 2 diabetic patients. Alcohol flushing was assessed by standardized questionnaires.

Results

Patients with alcohol flushing had lower mean IMT [0.7 (0.65-0.80) vs. 0.8 (0.73-0.90) mm, p < 0.05], despite having higher triglycerides [132 (94-169) vs. 98 (70-139) mg/dL, p < 0.01] and lower high-density lipoprotein cholesterol [52 (44-60) vs. 59 (49-67) mg/dL, p < 0.05] concentration. Patients with alcohol flushing had lower frequency of alcohol intake (45 vs. 76%, p < 0.0001). Mean IMT was positively associated with age and low-density lipoprotein cholesterol concentration, and negatively with alcohol flushing according to stepwise multiple regression analysis. Alcohol flushing was also independently associated with mean IMT by multivariate analysis.

Conclusions

These findings suggest that alcohol flushing is independently associated with lesser degree of carotid atherosclerosis in Japanese type 2 diabetic patients.

Advances in the development of biomarkers for epilepsy

Over 50 million people worldwide have epilepsy. In nearly 30% of these cases, epilepsy remains unsatisfactorily controlled despite the availability of over 20 antiepileptic drugs. Moreover, no treatments exist to prevent the development of epilepsy in those at risk, despite an increasing understanding of the underlying molecular and cellular pathways. One of the major factors that have impeded rapid progress in these areas is the complex and multifactorial nature of epilepsy, and its heterogeneity. Therefore, the vision of developing targeted treatments for epilepsy relies upon the development of biomarkers that allow individually tailored treatment. Biomarkers for epilepsy typically fall into two broad categories: diagnostic biomarkers, which provide information on the clinical status of, and potentially the sensitivity to, specific treatments, and prognostic biomarkers, which allow prediction of future clinical features, such as the speed of progression, severity of epilepsy, development of comorbidities, or prediction of remission or cure. Prognostic biomarkers are of particular importance because they could be used to identify which patients will develop epilepsy and which might benefit from preventive treatments. Biomarker research faces several challenges; however, biomarkers could substantially improve the management of people with epilepsy and could lead to prevention in the right person at the right time, rather than just symptomatic treatment.

Post-stroke epilepsy

Post-stroke epilepsy (PSE) is a common complication after stroke, yet treatment options remain limited. While many physicians prescribe antiepileptic drugs (AED) for secondary prevention of PSE, it is unclear which treatments are most effective in the prevention of recurrence of symptoms, or whether such therapy is needed for primary prevention. This review discusses the current understanding of epidemiology, diagnoses, mechanisms, risk factors, and treatments of PSE.

Genetic polymorphisms in ALDH2 are associated with drug addiction in a Chinese Han population

We investigated the association between single nucleotide polymorphisms (SNPs) in ALDH2, which has been associated with alcohol dependence and several types of diseases, and the risk of drug addiction in a Chinese Han population. In a case-control study that included 692 cases and 700 healthy controls, eight SNPs in ALDH2 were selected and genotyped using the Sequenom MassARRAY platform. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using unconditional logistic regression after adjusting for age and gender. We determined that rs671 is significantly associated with a 1.551-fold increased drug addiction risk (95% CI = 1.263-1.903; p < 0.001). In the genetic model analysis, we found that rs671 is associated with an increased risk of drug addiction under additive, dominant and recessive models (p < 0.001), while rs886205, rs441 and rs4646778 displayed a decreased drug addiction risk under additive and recessive model, respectively (p < 0.05). SNP rs671 remained significant after Bonferroni correction (p<0.00125). Additionally, we observed that haplotype "GTCAC" was associated with increased drug addiction risk (OR = 1.668; 95% CI, 1.328-2.094, p < 0.001); in contrast, "ATCGC" was a protective haplotype for drug addiction risk (OR = 0.444; 95% CI, 0.281-0.704, p < 0.001). Our findings showed that ALDH2 polymorphisms are significantly associated with the risk of drug addiction in the Chinese Han population.

The Role of Mitochondrial Aldehyde Dehydrogenase 2 (ALDH2) in Neuropathology and Neurodegeneration

Aldehydes-induced toxicity has been implicated in many neurodegenerative diseases. Exposure to reactive aldehydes from (1) alcohol and food metabolism; (2) environmental pollutants, including car, factory exhausts, smog, pesticides, herbicides; (3) metabolism of neurotransmitters, amino acids and (4) lipid peroxidation of biological membrane from excessive ROS, all contribute to 'aldehydic load' that has been linked to the pathology of neurodegenerative diseases. In particular, the α, β-unsaturated aldehydes derived from lipid peroxidation, 4-hydroxynonenal (4-HNE), DOPAL (MAO product of dopamine), malondialdehyde, acrolein and acetaldehyde, all readily form chemical adductions with proteins, DNA and lipids, thus causing neurotoxicity. Mitochondrial aldehyde dehydrogenase 2 (ALDH 2) is a major aldehyde metabolizing enzyme that protects against deleterious aldehyde buildup in brain, a tissue that has a particularly high mitochondrial content. In this review, we highlight the deleterious effects of increased aldehydic load in the neuropathology of ischemic stroke, Alzheimer's disease and Parkinson's disease. We also discuss evidence for the association between ALDH2 deficiency, a common East Asianspecific mutation, and these neuropathologies. A novel class of small molecule aldehyde dehydrogenase activators (Aldas), represented by Alda-1, reduces neuronal cell death in models of ischemic stroke, Alzheimer's disease and Parkinson's disease. Together, these data suggest that reducing aldeydic load by enhancing the activity of aldehyde dehydrogenases, such as ALDH2, represents as a therapeutic strategy for neurodegenerative diseases.

[Fundamental Properties of Aldehyde Dehydrogenase 2 (ALDH2) and the Importance of the ALDH2 Polymorphism]

Human aldehyde dehydrogenase 2 (ALDH2) is a 56 kDa mitochondrial protein that forms homodimers through hydrogen bonding interactions between the Glu487 and Arg475 residues of two ALDH2 proteins. Two ALDH2 homodimers can interact to form an ALDH2 tetramer. ALDH2 is widely distributed throughout the organs of the body. In addition to its dehydrogenase activity, ALDH2 also exhibits esterase and reductase activities, with the main substrates for these three activities being aldehydes, 4-nitrophenyl acetate and nitroglycerin, respectively. ALDH2 can be readily inhibited by a wide variety of endogenous and exogenous chemicals, but the induction or activation of this enzyme remains unlikely. The polymorphism of ALDH2 to the corresponding ALDH2*2 variant results in a severe deficiency in ALDH2 activity, and this particular polymorphism is prevalent among people of Mongoloid descent. It seems reasonable to expect that people with the ALDH2*2 variant would be more vulnerable to stress and diseases because ALDH2 defends the human body against toxic aldehydes. However, it has been suggested that people with the ALDH2*2 variant are protected by alternative stress-defending systems. The ALDH2*2 variant has been reported to be associated with many different kinds of diseases, although the mechanisms underlying these associations have not yet been elucidated. ALDH2 polymorphism has a significant impact on human health; further studies are therefore required to determine the practical implications of this polymorphism in the fields of preventive and clinical medicine.

The causes of new-onset epilepsy and seizures in the elderly

With increasing age, the prevalence and incidence of epilepsy and seizures increases correspondingly. New-onset epilepsy in elderly people often has underlying etiology, including cerebrovascular diseases, primary neuron degenerative disorders, intracerebral tumors, and traumatic head injury. In addition, an acute symptomatic seizure cannot be called epilepsy, which manifests usually as a common symptom secondary to metabolic or toxicity factors in older people. In this review, we have mainly focused on the causes of new-onset epilepsy and seizures in elderly people. This knowledge will certainly help us to understand the reasons for high incidences of epilepsy and seizures in elderly people. We look forward to controlling epileptic seizures via the treatment of primary diseases in the future.

Development of epilepsy after ischaemic stroke

For about 30% of patients with epilepsy the cause is unknown. Even in patients with a known risk factor for epilepsy, such as ischaemic stroke, only a subpopulation of patients develops epilepsy. Factors that contribute to the risk for epileptogenesis in a given individual generally remain unknown. Studies in the past decade on epilepsy in patients with ischaemic stroke suggest that, in addition to the primary ischaemic injury, existing difficult-to-detect microscale changes in blood vessels and white matter present as epileptogenic pathologies. Injury severity, location and type of pathological changes, genetic factors, and pre-injury and post-injury exposure to non-genetic factors (ie, the exposome) can divide patients with ischaemic stroke into different endophenotypes with a variable risk for epileptogenesis. These data provide guidance for animal modelling of post-stroke epilepsy, and for laboratory experiments to explore with increased specificity the molecular 'mechanisms, biomarkers, and treatment targets of post-stroke epilepsy in different circumstances, with the aim of modifying epileptogenesis after ischaemic stroke in individual patients without compromising recovery.