Hyperhomocysteinemia in epileptic patients on new antiepileptic drugs

Antiseizure medications and their differing effects on cardiovascular risk

This review discusses the differing effects of enzyme-inducing and non-inducing antiseizure medications on cardiovascular risk and their implications for the management strategies of epilepsy patients. Traditional risk markers, including low density lipoprotein, high density lipoprotein and triglycerides, can be altered by both enzyme induction and inhibition. Other markers of vascular risk, including c-reactive protein, non-high-density lipoprotein and homocysteine, are affected by antiseizure medications, although adults and children may have different responses. The overall atherosclerotic risk picture is more complex due to indirect effects such as neuroendocrine function and the metabolic syndrome. Large scale data shows an evolving understanding of cardiovascular risk. Long term risks of enzyme inducing antiseizure medications and valproic acid are apparent when studies examine medications individually. Finally, effects of antiseizure medications on cardiac rhythm and possibly autonomic control are discussed with respect to their clinical relevance to the practicing clinician.

Co-Occurring Methylenetetrahydrofolate Reductase (MTHFR) rs1801133 and rs1801131 Genotypes as Associative Genetic Modifiers of Clinical Severity in Rett Syndrome

AIM

Remethylation disorders such as 5,10-methylenetetrahydrofolate reductase (MTHFR) deficiency reduce the remethylation of homocysteine to methionine. The resulting hyperhomocysteinemia can lead to serious neurological consequences and multisystem toxicity. The role of MTHFR genotypes has not been investigated in patients with Rett Syndrome (RTT). In this study, we sought to assess the impact of co-occurring MTHFR genotypes on symptom profiles in RTT.

METHOD

Using pharmacogenomic (PGx) testing, the MTHFR genetic polymorphisms rs1801133 (c.665C>T mutation) and rs1801131 (c.1286A>C mutation) were determined in 65 patients (18.7 years ± 12.1 [mean ± standard deviation]) with RTT as part of routine clinical care within the Centre for Interventional Paediatric Psychopharmacology (CIPP) Rett Centre, a National and Specialist Child and Adolescent Mental Health Service (CAMHS) in the UK. The clinical severity of patients was assessed using the RTT-anchored Clinical Global Impression Scale (RTT-CGI).

RESULTS

The clinical severity symptom distribution varied between the homozygous and heterozygous MTHFR rs1801133 and rs1801131 genotypes. Those with the homozygous genotype had a narrower spread of severity scores across several domains (language and communication, ambulation, hand-use and eye contact clinical domains). Patients with the homozygous genotype had statistically significantly greater CGI-Severity scores than individuals with a non-homozygous MTHFR genotype (Z = -2.44, p = 0.015). When comparing the ratings of moderately impaired (4), markedly impaired (5), severely impaired (6) and extremely impaired (7), individuals with the homozygous MTHFR genotype were more impaired than those with the non-homozygous MTHFR genotype (Z = -2.06, p = 0.039). There was no statistically significant difference in the number of prescribed anti-epileptic drugs between the genotypes.

CONCLUSIONS

Our findings show that in those with a pathogenic RTT genetic variant, co-occurring homozygotic MTHFR rs1801133 and rs1801131 polymorphisms may act as associative genetic modifiers of clinical severity in a subset of patients. Profiling of rs1801133 and rs1801131 in RTT may therefore be useful, especially for high-risk patients who may be at the most risk from symptom deterioration.

Maternal hyperhomocysteinemia increases seizures susceptibility of neonatal rats

AIMS

Neonatal seizures are severe pathologies which may result in long-term neurological consequences. High plasma concentrations of homocysteine - hyperhomocysteinemia (hHCy) - are associated with epilepsy. In the present study, we evaluated susceptibility to seizure of neonatal rats with prenatal hHCy.

MAIN METHODS

Prenatal hHCy was induced by feeding females with a high-methionine diet. Experiments were performed on pups during the first three postnatal weeks. Flurothyl-induced epileptic behavior was assessed according to Racine's scale. Epileptiform activity in the hippocampus was recorded using electrophysiological methods. The balance of excitation/inhibition, functional GABAergic inhibition and GABA reversal potential in hippocampal neurons were analyzed.

KEY FINDINGS

Rats with hHCy developed more severe stages of behavioral patterns during flurothyl-induced epilepsy with shorter latency. Electrophysiological recordings demonstrated higher background neuronal activity in rats with hHCy. Seizure-like events triggered by flurothyl (in vivo) or 4-aminopyridine (in vitro) showed shorter latency, higher power and amplitude. An increased glutamate/GABA synaptic ratio was shown in the pyramidal neurons of rats with hHCy and more slices demonstrated excitation by isoguvacine, a selective GABA(A) receptor agonist, during the first and second postnatal weeks. The GABA driving force and the reversal potential of GABA(A) currents were more positive during the second postnatal week for hHCy rats.

SIGNIFICANCE

The higher susceptibility to seizures in rats with prenatal hHCy due to a shift in the balance of excitation/inhibition toward excitation may underlie the clinical evidence about the association of hHCy with an increased risk of epilepsy.

Topiramate treatment during the peripubertal period does not alter aortic endothelial function in female Wistar rats

AIMS

This study aimed to evaluate the short- and long-term adverse effects of blood pressure (BP), vascular endothelial function, and estrogen receptor (ERα and ERβ) modulation on endothelial function in female Wistar rats treated with topiramate (TPM), an antiepileptic drug, during the peripubertal period.

MATERIALS AND METHODS

Female Wistar rats were treated with TPM (41 mg/kg) or water (CTR group) by gavage from postnatal day (PND) 28 to 50 (peripubertal phase). At the end of the treatment, the TPM and CTR rats were divided into two groups and evaluated after 24 h or from PND 85 (adulthood). The rats were evaluated for: thoracic aorta reactivity to phenylephrine (Phenyl), acetylcholine (ACh), and sodium nitroprusside (SNP); aortic ring reactivity after ERα and ERβ antagonism; and BP.

KEY FINDINGS

It was observed that vascular response to Phenyl, ACh, and SNP was similar between TPM and CTR rats in the short- and long-term evaluations. In addition, the ER antagonism did not interfere with aortic contraction or relaxation in either TPM or CTR.

SIGNIFICANCE

Taken together, the results show that TPM treatment during the peripubertal period does not alter aortic endothelial function and its estrogen modulation via classic ER in female Wistar rats, suggesting that TPM treatment in this period is safe for the vascular system.

Case report: Young-onset large vessel ischemic stroke due to hyperhomocysteinemia associated with the C677T polymorphism on 5,10-methylenetetrahydrofolate reductase and multi-vitamin deficiency

Hyperhomocysteinemia is an important risk factor for cerebral infarction. Herein, we report on a 30-year-old man previously diagnosed with epilepsy who presented with right hemiplegia and total aphasia. Magnetic resonance imaging showed a fronto-temporal ischemic lesion due to occlusion of the left middle cerebral artery. Clinical testing and imaging demonstrated that he had hyperhomocysteinemia induced by multiple factors including the C677T polymorphism on 5.10-methylenetetrahydrofolate reductase (MTHFR), and multiple vitamin deficiencies. The C677T polymorphism on MTHFR is closely related to hyperhomocysteinemia and folate deficiency in epileptic patients who are taking multiple anti-convulsants. Given hyperhomocysteinemia can independently cause stroke at a young age, physicians should periodically examine plasma homocysteine and serum folic acid levels in epileptic patients who are on long-term regimens of multiple anti-epileptic drugs.

Assessment of asymmetric dimethylarginine and homocysteine in epileptic children receiving antiepileptic drugs

BACKGROUND

Epilepsy is a neurological disease that requires long-term antiepileptic drugs (AEDs). The old generation of AEDs may affect serum homocysteine and asymmetric dimethylarginine (ADMA) and disturb lipid levels. The aim of the study was to evaluate serum ADMA, homocysteine, lipid profile, and carotid intima-media thickness (CIMT) in epileptic children.

METHODS

This study was implemented on 159 epileptic children who were subdivided into 3 subgroups, with 53 receiving sodium valproate, 53 receiving levetiracetam, and 53 receiving polytherapy, for over 6 months and 53 healthy children.

RESULTS

Low-density lipoprotein, triglycerides, and cholesterol levels were increased in epileptic children (p < 0.001), which were higher in those receiving multidrug followed by a valproate receiver. While high-density lipoprotein was lower in those receiving multidrug more than those receiving valproate. ADMA and homocysteine levels increased in epileptic patients than in controls (p < 0.001). Higher ADMA was also observed in the multidrug receiver (5.78 ± 0.62), followed by the levetiracetam group (5.56 ± 0.61). Homocysteine levels were significantly higher in multidrug and valproate-treated children than those treated with levetiracetam. CIMT was significantly higher in multidrug and valproate-treated patients (p < 0.001).

CONCLUSIONS

Long-term use of AEDs, especially old-generation polytherapy, can elevate lipid profiles, homocysteine, ADMA levels, and carotid intima-media thickness compared to the minimal effect of new AEDs.

IMPACT

The long-term use of antiepileptic drugs, especially old-generation polytherapy, can increase lipid profiles, homocysteine levels, ADMA, and carotid intima thickness compared to the minimal effect of new antiepileptic generation. A routine follow-up of these markers and a lifestyle modification are recommended to avoid cerebrovascular events as much as possible.

Influence of Different Antiseizure Medications on Vascular Risk Factors in Children with Epilepsy

Many studies have proposed that plasma homocysteine levels are increased as a side effect with the prolonged use of antiseizure medications. This is associated with an increase in carotid intima media thickness; hence, it increases the threat of atherosclerosis at a young age. We aimed to assess serum levels of homocysteine in epileptic children on long-standing antiseizure medications and its association with increased occurrence of cardiovascular disease. The study included 60 epileptic children aged between 2 and 15 years old who visited our pediatric neurology outpatient clinic and 25 apparently healthy children served as a control group. All included children were subjected to careful history taking, clinical examination, anthropometric measures, laboratory investigations including serum homocysteine levels and lipid profile, along with radiological assessment involving carotid intima media thickness and carotid stiffness. Results demonstrated a significant increase in the serum levels of homocysteine, carotid intima media thickness, and carotid stiffness in children on monotherapy of old generation antiseizure medications and polytherapy than that in children on monotherapy of new generation antiseizure medications and control children. Epileptic children on old generation and polytherapy antiseizure medications have an increased risk for cardiovascular diseases and need follow up for early intervention when needed.

Late-Onset Focal Epilepsy: Electroclinical Features and Prognostic Role of Leukoaraiosis

The aim of this study was to describe the electroclinical and prognostic characteristics, and to investigate the role of leukoaraiosis in outpatients with new-onset elderly focal epilepsy aged ≥60 years, referred to a tertiary epilepsy center between 2005 and December 31, 2020. Among the 720 patients who were referred to the center, we retrospectively selected 162 consecutive outpatients, with a first referral for recent-onset focal epilepsy of unknown cause (UC) or structural cause (SC), and collected a clinical and standard-Electroencephalogram (S-EEG), 24-h ambulatory EEG (A-EEG), and neuroimaging data. We also analyzed the seizure prognosis after titration of the first antiseizure medication (ASM). One hundred and four UC and 58 SC patients, followed up for 5.8 ± 5.3 years (mean ± SD), were included. Compared with the SC group, the patients with UC showed a predominance of focal seizures with impaired awareness (51.9% of cases) and focal to bilateral tonic-clonic seizures during sleep (25%); conversely, the SC group, more frequently, had focal to bilateral tonic-clonic seizures during wakefulness (39.6%) and focal aware seizures (25.8%) (p < 0.0001). Oral or gestural automatisms were prevalent in UC epilepsy (20.2 vs. 6.9% in the SC group, p = 0.04). In UC compared to patients with SC, interictal epileptiform discharges showed a preferential temporal lobe localization (p = 0.0007), low expression on S-EEG, and marked activation during deep Non-Rapid Eye Movement (NREM) sleep (p = 0.003). An overall good treatment response was found in the whole sample, with a probability of seizure freedom of 68.9% for 1 year. The cumulative probability of seizure freedom was significantly higher in the UC compared with the SC group (p < 0.0001). The prognosis was worsened by leukoaraiosis (p = 0.012). In the late-onset focal epilepsy of unknown cause, electroclinical findings suggest a temporal lobe origin of the seizures. This group showed a better prognosis compared with the patients with structural epilepsy. Leukoaraiosis, per se, negatively impacted on seizure prognosis.

Is There a Relation between 677C>T Polymorphism in the MTHFR Gene and the Susceptibility to Epilepsy in Young Patients? A Meta-Analysis

Background: Numerous data show a role for genetic polymorphisms in the development of epilepsy. Previously, the TT genotype of the MTHFR 677C>T polymorphism was found to be associated with a decreased leucocyte DNA methylation status. Polymorphisms in the MTHFR gene could modify the pharmacodynamics of many drugs. This meta-analysis aimed to assess the relationship between MTHFR 677C>T polymorphism and susceptibility to epilepsy in young patients. Methods: Available databases (PubMed, Embase, Google Scholar, SciELO, and Medline) were searched using specific keywords. Eight studies, published between 1999 and 2019, with 1678 young patients with epilepsy and 1784 controls, met the inclusion criteria. Apart from the total groups, additional analyses in age subgroups (i.e., young adults and children) were conducted. Statistical analyses were conducted using the RevMan 5.4 and MedCalc software. The pooled odds ratio (OR) was estimated with a random- or fixed-effects model depending on the heterogeneity. Analyses were performed for five genetic models, i.e., dominant (CT + TT vs. CC), recessive (TT vs. CC + CT), additive (TT vs. CC), heterozygous (CT vs. CC), and allelic (T vs. C). The publication bias was assessed with the use of Egger's and Begg's tests. Results: Both the MTHFR TT genotype (in the additive model) and the T allele (in the allelic model) significantly increased the risk of epilepsy when the total groups were compared (OR = 1.44, p = 0.002, and OR = 1.183, p = 0.001, respectively). The sensitivity analysis for these models indicated the stability of the results. Similarly, significant results were obtained among young adults for all the genetic models (dominant model: OR = 1.28, p = 0.002; recessive model: OR = 1.48, p = 0.003; additive model: OR = 1.63, p < 0.001; heterozygous model: OR = 1.21, p = 0.028; and allelic model: OR = 1.256, p < 0.001). Those results were also stable and reliable. In the group of children, no relation between 677C>T polymorphism and epilepsy was observed; however, the analysis was based only on three studies, and one study also comprised young adults. No publication bias was demonstrated. Conclusions: The meta-analysis revealed that the carrier state for the T allele as well as the TT genotype of the MTHFR 677C>T polymorphism increases the risk of epilepsy in young adults but not in children.

Vitamin B status and association with antiseizure medication in pregnant women with epilepsy

OBJECTIVE

Antiseizure medication (ASM) use interacts with vitamin B status in nonpregnant epilepsy populations. We aimed to examine the association between ASM and vitamin B status in pregnant women with epilepsy.

METHODS

We performed a cross-sectional study of pregnancies in women with epilepsy enrolled in the Norwegian Mother, Father and Child Cohort Study from 1999 to 2008. Data on ASM and vitamin supplement use were collected from questionnaires. We analyzed maternal plasma concentrations of ASM and metabolites of folate, including unmetabolized folic acid (UMFA), riboflavin (vitamin B2), pyridoxine (vitamin B6), and niacin (vitamin B3) during gestational weeks 17-19.

RESULTS

We included 227 singleton pregnancies exposed to ASM with available plasma samples (median maternal age 29 years, range 18 to 41 years). From the preconception period to gestational week 20, any supplement of folic acid was reported in 208 of pregnancies (94%), riboflavin in 72 (33%), pyridoxine in 77 (35%), and niacin in 45 (20%). High ASM concentrations correlated with high concentrations of UMFA and inactive folate metabolites, and with low concentrations of riboflavin and metabolically active pyridoxine. There was no association between ASM and niacin status.

SIGNIFICANCE

ASM concentrations during pregnancy were associated with vitamin B status in pregnant women with epilepsy. Additional studies are needed to determine the clinical impact of these findings, and to define the optimal vitamin doses that should be recommended to improve pregnancy outcomes.

Epilepsy, antiepileptic drugs, and the risk of major cardiovascular events

OBJECTIVE

This study was undertaken to determine whether epilepsy and antiepileptic drugs (including enzyme-inducing and non-enzyme-inducing drugs) are associated with major cardiovascular events using population-level, routinely collected data.

METHODS

Using anonymized, routinely collected, health care data in Wales, UK, we performed a retrospective matched cohort study (2003-2017) of adults with epilepsy prescribed an antiepileptic drug. Controls were matched with replacement on age, gender, deprivation quintile, and year of entry into the study. Participants were followed to the end of the study for the occurrence of a major cardiovascular event, and survival models were constructed to compare the time to a major cardiovascular event (cardiac arrest, myocardial infarction, stroke, ischemic heart disease, clinically significant arrhythmia, thromboembolism, onset of heart failure, or a cardiovascular death) for individuals in the case group versus the control group.

RESULTS

There were 10 241 cases (mean age = 49.6 years, 52.2% male, mean follow-up = 6.1 years) matched to 35 145 controls. A total of 3180 (31.1%) cases received enzyme-inducing antiepileptic drugs, and 7061 (68.9%) received non-enzyme-inducing antiepileptic drugs. Cases had an increased risk of experiencing a major cardiovascular event compared to controls (adjusted hazard ratio = 1.58, 95% confidence interval [CI] = 1.51-1.63, p < .001). There was no notable difference in major cardiovascular events between those treated with enzyme-inducing antiepileptic drugs and those treated with non-enzyme-inducing antiepileptic drugs (adjusted hazard ratio = .95, 95% CI = .86-1.05, p = .300).

SIGNIFICANCE

Individuals with epilepsy prescribed antiepileptic drugs are at an increased risk of major cardiovascular events compared with population controls. Being prescribed an enzyme-inducing antiepileptic drug is not associated with a greater risk of a major cardiovascular event compared to treatment with other antiepileptic drugs. Our data emphasize the importance of cardiovascular risk management in the clinical care of people with epilepsy.

Genetic Polymorphisms in Enzymes Involved in One-Carbon Metabolism and Anti-epileptic Drug Monotherapy on Homocysteine Metabolism in Patients With Epilepsy

Aims: To investigate the effects of single nucleotide polymorphisms (SNPs) in genes of one-carbon metabolism (OCM) related enzymes and anti-epileptic drug (AED) monotherapy on homocysteine (Hcy) metabolism in patients with epilepsy, and to further explore specific SNPs that may increase patients' susceptibility to the effects of AEDs on the Hcy imbalance.

Method: This case-control study analyzed 279 patients with epilepsy, including patients receiving monotherapy with valproate (VPA) (n = 53), oxcarbazepine (OXC) (n = 71), lamotrigine (LTG) (n = 55), or levetiracetam (LEV) (n = 35) and patients who had not taken any AEDs (controls, n = 65) for at least 6 months. Serum levels of vitamin B12 (vit B12), folate (FA) and Hcy were measured, and 23 SNPs in 13 genes of OCM-related enzymes were genotyped in all patients.

Results: Methylenetetrahydrofolate reductase (MTHFR) rs1801133 was associated with elevated serum Hcy levels in patients with epilepsy (P < 0.001), and patients presenting the TT genotype exhibited higher serum Hcy levels than patients with the CC (P < 0.001) or CT (P < 0.001) genotype. A subsequent multiple linear regression analysis showed that AED monotherapy with VPA (vs. control: P = 0.023) or OXC (vs. control: P = 0.041), and genotypes of MTHFR rs1801133 TT (vs. CC: P < 0.001; vs. CT: P < 0.001), transcobalamin 2 (TCN2) rs1801198 CC (vs. GC: P = 0.039) and folate receptor 1 (FOLR1) rs2071010 AA (vs. GA: P = 0.031) were independent risk factors for higher Hcy levels. In the subgroup analysis of patients taking OXC, we found that patients with genotypes of MTHFR rs1801133 TT (vs. CC: P = 0.001; vs. CT: P < 0.001) and TCN2 rs1801198 CC (vs. GC: P = 0.021; vs. GG: P = 0.018) exhibited higher serum Hcy levels.

Conclusions: VPA, OXC, and genotypes of MTHFR rs1801133 TT, TCN2 rs1801198 CC, and FOLR1 rs2071010 AA are all independent risk factors for elevated Hcy levels in patients with epilepsy. Moreover, genotypes of MTHFR rs1801133 TT and TCN2 rs1801198 CC may increase patients' susceptibility to the effect of OXC on disrupting Hcy homeostasis.

Management of antiepileptic drug-induced nutrition-related adverse effects

Although antiepileptic drugs (AEDs) are mainstay of the treatment of epilepsy, they are associated with significant adverse effects. The present study reviews the adverse effects of AEDs on some of the nutrition-related issues, including bone health, body weight, glucose and lipid metabolism, vitamin homeostasis, antioxidant defense system, and pregnancy. This paper also provides some nutritional recommendations for people with epilepsy. Patients with epilepsy should be regularly evaluated with regard to their nutrition status and any possible nutritional problems. Daily intake of adequate amounts of all nutrients from various sources should be encouraged, especially for vulnerable groups such as children, adolescents, elderly, and pregnant women. When necessary, preventative or therapeutic supplementation with appropriate micronutrients could be helpful. Graphical abstract.

Synaptic remodeling and reduced expression of the transcription factors, HES1 and HES5, in the cortex neurons of cognitively impaired hyperhomocysteinemic mice

Hyperhomocysteinemia (HHcy) is associated with cognitive impairment and neurodegenerative diseases. The synaptic ultrastructure and the expression of hairy enhancer of split (HES) genes are involved in cognitive impairment induced by HHcy, but their precise role remains unclear. The present study aimed to measure synaptic remodeling and the expression of HES1 and HES5 in the cortex neurons of mice with HHcy to clarify their role in cognitive impairment. Mild HHcy was induced in ApoE^-/- mice receiving a high-methionine diet. The correct response percentage, latency, and distance traveled in the mice with HHcy decreased compared with those of non-HHcy control mice (P < 0.05). There was no difference in the neuronal counts and the mean optical density of Nissl bodies in the frontal cortex of HHcy and non-HHcy mice. Increased apoptosis rates and numbers of autophagosomes were observed in the HHcy mice by TUNEL staining and electron microscopy, respectively, compared to those in the control group (P < 0.05). There was a significant increase in the area of postsynaptic density and size variation of synaptic vesicles in the HHcy group compared to that in the control (P < 0.05). Decreased expression of HES1 and HES5 was observed by western blotting and immunostaining in the HHcy group compared to that in the control (P < 0.05). Collectively, these results suggest that increased autophagy, apoptosis, synaptic remodeling, and downregulation of hes1 and hes5 are involved in the cognitive impairment induced by hyperhomocysteinemia.

Levetiracetam inhibits THP-1 monocyte chemotaxis and adhesion via the synaptic vesicle 2A

Long-term therapy with older antiepileptic drugs (AEDs), but not levetiracetam (LEV), may increase the risk of atherosclerosis (AS), suggesting that LEV may have a potential anti-AS effect. The synaptic vesicle 2A (SV2A) is known to the specific binding site of LEV. Numerous studies have documented that SV2A is a membrane protein specifically expressed in nervous system. Interestingly, our previous research showed that SV2A also existed in human CD8+ T lymphocytes. Therefore, we hypothesized that LEV was associated with decreased risk of AS by regulating monocytes chemotaxis and adhesion. We showed that SV2A protein were detected in THP-1 human monocytic leukemia cells. LEV (300 μM) inhibited the chemotaxis and adhesion of THP-1 cells after transfection with plasmids expressing SV2AWT, but not SV2AR383Q which was a known functional mutation site of human SV2A. Furthermore, RT-PCR and western blot analysis demonstrated that LEV (300 μM) decreased the expression level of chemokine-related receptors (CX3CL1, CCR1, CCR2, and CCR5),and reduced levels of phosphorylated AKT (p-AKT) in THP-1 cells with SV2AWT expressing plasmids. Taken together, these findings indicated that LEV has an inhibitory effect on THP-1 monocyte adhesion and chemotaxis, suggesting that SV2A may serve as a novel therapeutic target to prevent AS.

Concentrations of the Selected Biomarkers of Endothelial Dysfunction in Response to Antiepileptic Drugs: A Literature Review

Epilepsy is a disease arising from morphological and metabolic changes in the brain. Approximately 60% of patients with seizures can be controlled with 1 antiepileptic drug (AED), while in others, polytherapy is required. The AED treatment affects a number of biochemical processes in the body, including increasing the risk of cardiovascular diseases (CVDs). It is indicated that the duration of AED therapy with some AEDs significantly accelerates the process of atherosclerosis. Most of AEDs increase levels of homocysteine (HCys) as well as may affect concentrations of new, nonclassical risk factors for atherosclerosis, that is, asymmetric dimethylarginine (ADMA) and homoarginine (hArg). Because of the role of these parameters in the pathogenesis of CVD, knowledge of HCys, ADMA, and hArg concentrations in patients with epilepsia treated with AED, both pediatric and adult, appears to be of significant importance.

Elevated Plasma Homocysteine Levels in Anti-N-methyl-D-aspartate Receptor Encephalitis

Objective: Homocysteine (Hcy) levels have been investigated in many diseases, such as neurodegenerative and autoimmune diseases. However, changes in Hcy levels in anti-N-Methyl-D-aspartate receptor (anti-NMDAR) encephalitis have not been investigated thus far.

Methods: Case data were collected from 45 patients with anti-NMDAR encephalitis and 179 age- and sex-matched healthy controls (HCs). Clinical characteristics, Hcy levels, C reactive protein (CRP) levels, and cerebrospinal fluid (CSF) parameters were determined. Association of Hcy and clinical parameters were evaluated in these patients. Among these 45 patients, 15 had a follow-up evaluation at 3 months after treatment.

Results: Hcy levels (p < 0.001) and CRP levels (p = 0.005) from the patients with anti-NMDAR encephalitis were significantly higher than those from HCs. Hcy levels from male patients were significantly lower than those from male HCs (p < 0.001). Comparing anti-NMDAR encephalitis patients after treatment with before treatment, the former has significantly higher Hcy levels (p = 0.004), CRP levels (p = 0.041) and mRS scores (p = 0.002). Furthermore, a significant negative correlation between the changes in Hcy levels and the changes in mRS scores (r = −0.534, p = 0.040) was observed.

Conclusion: Elevated plasma homocysteine occurs in anti-NMDAR encephalitis, and seems associated with male sex.

A novel approach in the management of hyperhomocysteinemia

Hyperhomocysteinemia (Hhcy) is a biochemical alteration with plasma levels of homocysteine higher than 15 µmol/L, associated with atherosclerosis, and with vascular thrombosis by disrupting endothelial cells. Homocysteine is a sulfur-containing amino acid derived from methionine which is an essential amino acid. Excess homocysteine produced in the body is expelled out by liver and kidney from the systemic circulation. Hhcy is caused by the excess deficiencies of the vitamins like pyridoxine (B6), folic acid (B9), or cyanocobalamin (B12). High protein consumers are usually at risk for hyperhomocysteinemia because of low plasma B12 levels. It is approximated that mild Hhcy occurs in 5-7% of the general population and 40% in patients with vascular disease. Patients with heart failure, impaired renal function, and diabetes should be screened since the prevalence of Hhcy in these patients appears to be quite high. In this article, we hypothesise that citicoline is a novel drug for the management of Hhcy. Furthermore, the side effects of citicoline are also minimal and self-limiting. If this strategy is validated, citicoline will be the cost-effective way to be administered for Hhcy. Many evidences are available which suggest that ignoring homocysteine levels in patients with the vascular disease would be unwise. Thus, there is an urgent need for health care providers to develop effective preventions and interventions program (folic acid, Vitamin B6 and Vitamin B12 supplementation as well as lifestyle change) to reduce this disorder.

Vitamin B12 and Folate Status in Patients with Epilepsy Under Levetiracetam Monotherapy

Background:

Antiepileptic drugs (AEDs) may lead to an increase in the plasma concentration of homocysteine. There is limited information, especially from Iran, regarding the risk in patients who are treated with levetiracetam as a new type of AED. The aim of the present study was to investigate the effect of levetiracetam on plasma homocysteine, vitamin B12, and folate levels in adult patients with epilepsy.

Methods:

We conducted a case-control study and enrolled adult patients with epilepsy who had received monotherapy with levetiracetam for at least 6 months at some time prior to the study. homocysteine serum, vitamin B12, and folate were measured, and folate and vitamin B12 intake was determined by the food frequency questionnaire (FFQ).

Results:

Thirty-three patients on levetiracetam and 35 control subjects aged between 18 and 60 years were enrolled. No statistically significant differences in the means of the serum markers of vitamin B12, FA, and homocysteine levels were found between the two groups. In the first model, i.e., the crude model, no significant differences were observed in the serum concentrations of homocysteine, vitamin B12, and folate. In the second model, education was considered, and body mass index and folate intake was controlled with no significant difference being observed in the mean homocysteine serum level.

Conclusions:

Treatment with levetiracetam in patients with epilepsy has no effect on the serum levels concentrations of homocysteine, vitamin B12, and folate. This medication is suggested for patients who use AEDs on a long-term basis and at high dosages.

Synthesis, Characterization and Anticonvulsant Activity of Novel Fused 1,2,4-Triazolo-1,3,4-Thiadiazoles

A novel category of 1,2,4-triazolo-1,3,4-thiadiazoles were ready by the utilization of 3-amino-4-hydroxybenzoate as the beginning material. Spectral information results were used for the establishing of prepared compounds. Compounds were screened anticonvulsant activity for obtaining better results by MES test and scPTZ methods. The rotarod method was used for neurotoxicity analysis. Majority of the compounds displayed distinguished anticonvulsant impact practically identical to standard drugs (phenytoin and carbamazepine) with slight neurotoxicity.

Short-Term and Long-Term Effects of Levetiracetam Monotherapy on Homocysteine Metabolism in Children with Epilepsy: A Prospective Study

Background and Purpose

Long-term treatment with some older antiepileptic drugs may lead to hyperhomocysteinemia. Levetiracetam (LEV) is a newer broad-spectrum antiepileptic agent whose effects on homocysteine concentrations remain unclear. The purpose of this study was to prospectively determine the short-term and long-term effects of LEV monotherapy on homocysteine metabolism in children with epilepsy.

Methods

The study population consisted of 32 children [18 females, 14 males; age 5.94±4.10 years (mean±SD), age range 1–15 years] who received LEV monotherapy for new-onset epilepsy. Serum folate, serum vitamin B₁₂, and plasma total homocysteine (p-tHcy) were measured before and at 2 months (n=32), 6 months (n=25), and 12 months (n=18) of LEV monotherapy.

Results

p-tHcy was significantly decreased at 2 months of treatment (p=0.031). Furthermore, analysis of covariance showed statistically significant decreases in p-tHcy at 2 months (p=0.013) and 6 months (p=0.015) of LEV treatment after controlling for age, sex, body mass index, and LEV dose. There were no significant alterations in the other parameters during the study. The drug doses were 18.1±7.1, 20.1±9.2, and 21.2±11.8 mg/kg at 2, 6, and 12 months of LEV treatment, respectively.

Conclusions

In contrast with older antiepileptic drugs, long-term LEV monotherapy in children with epilepsy does not cause adverse alterations on homocysteine metabolism. Larger prospective studies are needed to definitively clarify whether LEV may be considered a safer alternative drug for preventing antiepileptic-drug-induced cardiovascular complications in adult life.

Medicines associated with folate-homocysteine-methionine pathway disruption

Folate is vital for cell development and growth. It is involved in one-carbon transfer reactions essential for the synthesis of purines and pyrimidines. It also acts in conjunction with cobalamin (vitamin B₁₂) as a fundamental cofactor in the remethylation cycle that converts homocysteine to methionine. A deficiency in folate or vitamin B₁₂ can lead to elevated homocysteine level, which has been identified as an independent risk factor in several health-related conditions. Adequate folate levels are essential in women of childbearing age and in pregnant women, and folate deficiency is associated with several congenital malformations. Low folate levels can be caused by dietary deficiencies, a genetic predisposition or treatment with medicines that affect folate concentration. Women who are pregnant or of child-bearing age commonly use medicines, so it is important to identify the basic biochemical mechanisms by which medicines interfere with the folate-homocysteine-methionine pathway. This review focuses on prescription medicines associated with folate disruption. It also summarizes their undesirable/toxic effects. Recommendations regarding folate supplementation during medical therapy are also reviewed.

Bidirectional relations among common psychiatric and neurologic comorbidities and epilepsy: Do they have an impact on the course of the seizure disorder?

The treatment of epilepsy is not limited to the achievement of a seizure‐free state. It must also incorporate the management of common psychiatric and neurologic comorbidities, affecting on average between 30 and 50% of patients with epilepsy, which have a significant impact on their lives at various levels, including quality of life and the prognosis of the seizure disorder. Mood and anxiety disorders are the most frequent psychiatric comorbidities, whereas stroke and migraine are among the more common neurologic comorbidities, migraine among the younger patients and stroke among the older patients. Not only do these psychiatric and neurologic comorbidities each have a bidirectional relation with epilepsy, but primary mood disorders have a bidirectional relation with these 2 neurologic disorders. Furthermore, depression and migraine have been each associated with a more severe epilepsy course, whereas depression has been associated with a more severe course of stroke and migraines. The purpose of this article is to review the clinical implications of the complex relations among epilepsy and these 3 comorbid disorders, and to identify any clinical and/or experimental evidence that may suggest that having more than one of these comorbid disorders may increase the risk of and course of epilepsy.

Reversal of homocysteine-induced neurotoxicity in rat hippocampal neurons by astaxanthin: evidences for mitochondrial dysfunction and signaling crosstalk

Elevated plasma level of homocysteine (Hcy) represents an independent risk for neurological diseases, and induction of oxidative damage is considered as one of the most important pathomechanisms. Astaxanthin (ATX) exhibits strong antioxidant activity in kinds of experimental models. However, the potential of ATX against Hcy-induced neurotoxicity has not been well explored yet. Herein, the neuroprotective effect of ATX against Hcy-induced neurotoxicity in rat hippocampal neurons was examined, and the underlying mechanism was evaluated. The results showed that ATX pre-treatment completely reversed Hcy-induced neurotoxicity through inhibiting cell apoptosis in rat primary hippocampal neurons. The mechanical investigation revealed that ATX effectively blocked Hcy-induced mitochondrial dysfunction by regulating Bcl-2 family and opening of mitochondrial permeability transition pore (MPTP). ATX pre-treatment also attenuated Hcy-induced oxidative damage via inhibiting the release of intracellular reactive oxide species (ROS) and superoxide anion through regulating MPTP opening. Moreover, normalization of MAPKs and PI3K/AKT pathways also contributed to ATX-mediated protective effects. Taken together, these results above suggested that ATX has the potential to reverse Hcy-induced neurotoxicity and apoptosis by inhibiting mitochondrial dysfunction, ROS-mediated oxidative damage and regulation of MAKPs and AKT pathways, which validated the strategy of using ATX could be a highly effective way in combating Hcy-mediated neurological disorders.

Verbal abilities in children of mothers with epilepsy: Association to maternal folate status

Objective

To examine the effect of maternal folic acid supplementation and maternal plasma folate and antiepileptic drug (AED) concentrations on language delay in AED-exposed children of mothers with epilepsy.

Methods

Children of mothers with and without epilepsy enrolled from 1999 to 2008 in the Norwegian Mother and Child Cohort study were included. Information on medical history, AED use, and folic acid supplementation during pregnancy was collected from parent-completed questionnaires. Maternal plasma folate and maternal plasma and umbilical cord AED concentrations were measured in blood samples from gestational weeks 17 to 19 and immediately after birth, respectively. Language development at 18 and 36 months was evaluated by the Ages and Stages Questionnaires.

Results

A total of 335 AED-exposed children of mothers with epilepsy and 104,222 children of mothers without epilepsy were surveyed. For those with no maternal periconceptional folic acid supplementation, the fully adjusted odds ratio (OR) for language delay in AED-exposed children compared to the controls at 18 months was 3.9 (95% confidence interval [CI] 1.9–7.8, p < 0.001) and at 36 months was 4.7 (95% CI 2.0–10.6, p < 0.001). When folic supplementation was used, the corresponding ORs for language delay were 1.7 (95% CI 1.2–2.6, p = 0.01) and 1.7 (95% CI 0.9–3.2, p = 0.13), respectively. The positive effect of folic acid supplement use on language delay in AED-exposed children was significant only when supplement was used in the period from 4 weeks before the pregnancy and until the end of the first trimester.

Conclusion

Folic acid use early in pregnancy may have a preventive effect on language delay associated with in utero AED exposure.

Effects of Antiepileptic Drugs on the Carotid Artery Intima-Media Thickness in Epileptic Patients

BACKGROUND AND PURPOSE

It has been reported that taking antiepileptic drugs (AEDs) may increase the risk of atherosclerosis. We performed a meta-analysis to evaluate the carotid artery intima-media thickness (CA-IMT) as a surrogate factor for atherosclerosis in epileptic patients.

METHODS

We searched NCBI (PubMed), ISI Web of Knowledge, EMBASE, and the Cochrane Library databases for studies of the association between AEDs and CA-IMT in epileptic patients. A random-effects meta-analysis was used to pool results across studies.

RESULTS

Fifteen studies involving 1,775 epileptic patients were included in the analysis. The overall CA-IMT was significantly larger among users of AEDs [mean difference (MD)=0.09 mm, 95% confidence interval (CI)=0.06-0.12 mm). When stratified by age, the MD was similar in adult patients (MD=0.09 mm, 95% CI=0.06-0.13 mm), but no significant difference was observed in children (MD=0.03 mm, 95% CI=0.00-0.07 mm). Regarding specific AEDs, monotherapy with carbamazepine (CBZ) or valproic acid (VPA) was associated with a larger CA-IMT, while phenytoin monotherapy was not and the result for lamotrigine was inconclusive.

CONCLUSIONS

This study suggests that using AEDs is associated with the CA-IMT in patients with epilepsy, particularly for adult patients. In particular, CBZ and VPA may be related to a significant increase in CA-IMT.

Hyperhomocysteinaemia in children receiving phenytoin and carbamazepine monotherapy: a cross-sectional observational study

OBJECTIVE

Long-term therapy with phenytoin and carbamazepine is known to cause hyperhomocysteinaemia. We evaluated the prevalence of hyperhomocysteinaemia in North Indian children receiving phenytoin or carbamazepine monotherapy for >6 months duration and the effect of folic acid supplementation on plasma homocysteine.

METHODS

In this cross-sectional observational study we enrolled consecutive children aged 2-12 years with epilepsy who had received phenytoin or carbamazepine monotherapy for >6 months. Plasma total homocysteine, folic acid, vitamin B12 and antiepileptic drug concentrations were measured. Healthy age- and sex-matched controls were recruited. Children with homocysteine >10.4 µmol/L received folic acid supplementation for 1 month and homocysteine and folic acid concentrations were measured after 1 month follow-up.

RESULTS

A total of 112 children receiving antiepileptic monotherapy for >6 months were enrolled. Hyperhomocysteinaemia was present in 54 children (90%) receiving phenytoin, 45 children (90%) receiving carbamazepine therapy and 17 (34%) controls (p<0.05). Mean plasma homocysteine concentrations were significantly higher (18.9±10.2 vs 9.1±3 µmol/L) and serum folic acid concentrations (10.04±8.5 ng/ml vs 12.6±4.8 p<0.001) and vitamin B12 concentrations (365±155 pg/mL vs 474±332 pg/mL, p=0.02) were significantly lower in the study group compared with the control group. Duration of antiepileptic drug therapy correlated significantly with elevated homocysteine and reduced folic acid concentrations (p<0.05). Supplementation with folic acid for 1 month led to a reduction in plasma homocysteine concentrations in the study group (from 20.9±10.3 µmol/L to 14.2±8.2 µmol/L, p<0.05).

CONCLUSIONS

Phenytoin or carbamazepine monotherapy for >6 months duration is associated with hyperhomocysteinaemia in 90% of North Indian children. Elevated homocysteine concentrations were normalised in these children with folic acid supplementation.

Clinical Profile and Changes of Serum Lipid Levels in Epileptic Patients after Cerebral Infarction

BACKGROUND

Antiepileptic drugs (AEDs) may increase development of dyslipidemia and cerebrovascular disease (CVD). We examined the clinical profile and changes of serum lipid levels after AED monotherapy in patients with poststroke epilepsy (PSE) after cerebral infarction (CI).

SUBJECTS AND METHODS

Medical records were reviewed in consecutive 2144 CI patients. Monotherapy of valproate, carbamazepine (CBZ), phenytoin (PHT), zonisamide, levetiracetam, or lamotrigine was performed in PSE patients. Serum lipid levels were measured before and at 3 months after AED treatment.

RESULTS

The prevalence of PSE was 7.0% in CI patients. The TOAST etiology disclosed large-artery atherosclerosis in 68 patients (45%), cardioembolism in 63 patients (42%), and undetermined cause in 19 patients (13%). CVD risk profile showed obesity of 18 patients (12%), current smoker of 30 patients (20%), hypertension of 75 patients (50%), diabetes mellitus of 32 patients (21%), dyslipidemia of 15 patients (10%), and atrial fibrillation of 63 patients (42%). CBZ or PHT administration increased serum total cholesterol (TC) and low-density lipoprotein-cholesterol (LDL-C) levels significantly compared to baseline and AED-untreated controls. Those levels were not increased significantly in other AED and control groups. Serum high-density lipoprotein-cholesterol and triglyceride levels did not differ statistically in all groups.

CONCLUSIONS

The prevalence of post-CI epilepsy was 7.0%. The pathogenesis contributed to atherothrombosis and cardioembolism. CBZ or PHT administration increased serum TC and LDL-C significantly. Thus, we should pay more attention to serum lipid levels in patients receiving cytochrome P450 (CYP)-induced AEDs, and might considerer switching to non-CYP-induced AEDs in patients with unfavorable serum lipid changes.

Oxcarbazepine administration and the serum levels of homocysteine, vitamin B12 and folate in epileptic patients: A systematic review and meta-analysis

The objectives were to determine the influence of oxcarbazepine (OXC) monotherapy on the serum levels of total homocysteine (tHcy), vitamin B12 and folate in patient with epilepsy pooling together case-control or interventional studies. A comprehensive literature search was done through four databases including MEDLINE/PubMed, Scopus, Embase and Web of Science from January 2000 to February 2016. A random effects model (the DerSimonian-Laird estimator) was utilized to pool the effect sizes of the individual studies. The between-study variance was assessed using the Q2 test (significance level p<0.1) and quantified using the I² test (>50% indicated evidence of heterogeneity). Overall, six studies found eligible for inclusion. The meta-analysis for tHcy revealed that the serum level of tHcy was no significant difference between patient on OXC monotherapy and healthy people [mean difference (MD) 0.31; 95% CI -1.05, 1.67, p=0.653]. The meta-analysis for vitamin B12 [MD -46.51; 95% CI -113.63, 20.62, p=0.174] and folate [MD -0.48; 95% CI -1.06, 0.11, p=0.113] indicated that there was no significant difference between patients on OXC monotherapy and healthy people. In conclusion, the meta-analysis does not support the hypotheses that OXC monotherapy changes the serum levels of tHcy, vitamin B12 and folate.

Inhibition of glutamate receptors reduces the homocysteine-induced whole blood platelet aggregation but does not affect superoxide anion generation or platelet membrane fluidization

Homocysteine (Hcy) is an excitotoxic amino acid. It is potentially possible to prevent Hcy-induced toxicity, including haemostatic impairments, by antagonizing glutaminergic receptors. Using impedance aggregometry with arachidonate and collagen as platelet agonists, we tested whether the blockade of platelet NMDA (N-methyl-D-aspartate), AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) and kainate receptors with their inhibitors: MK-801 (dizocilpine hydrogen maleate, [5R,10S]-[+]-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine), CNQX (7-nitro-2,3-dioxo-1,4-dihydroquinoxaline-6-carbonitrile) and UBP-302 (2-{[3-[(2S)-2-amino-2-carboxyethyl]-2,6-dioxo-3,6-dihydropyrimidin 1(2H)-yl]methyl}benzoic acid) may hamper Hcy-dependent platelet aggregation. All the tested compounds significantly inhibited Hcy-augmented aggregation of blood platelets stimulated either with arachidonate or collagen. Hcy stimulated the generation of superoxide anion in whole blood samples in a concentration-dependent manner; however, this process appeared as independent on ionotropic glutamate receptors, as well as on NADPH oxidase and protein kinase C, and was not apparently associated with the extent of either arachidonate- or collagen-dependent platelet aggregation. Moreover, Hcy acted as a significant fluidizer of surface (more hydrophilic) and inner (more hydrophobic) regions of platelet membrane lipid bilayer, when used at the concentration range from 10 to 50 µmol/l. However, this effect was independent on the Hcy action through glutamate ionotropic receptors, since there was no effects of MK-801, CNQX or UBP-302 on Hcy-mediated membrane fluidization. In conclusion, Hcy-induced changes in whole blood platelet aggregation are mediated through the ionotopic excitotoxic receptors, although the detailed mechanisms underlying such interactions remain to be elucidated.

Comparative case-control study of homocysteine, vitamin B12, and folic acid levels in patients with epilepsy

INTRODUCTION

Increased blood homocysteine levels are a known cardiovascular risk factor. Epileptic patients on long-term treatment with antiepileptic drugs may present higher homocysteine levels and, consequently, a potential increase in cardiovascular risk.

MATERIAL AND METHODS

We conducted an observational case-control study to compare plasma levels of homocysteine, folic acid, and vitamin B₁₂.

RESULTS

Our study included a total of 88 subjects: 52 patients with epilepsy and 36 controls. Epileptic patients showed higher homocysteine levels (P=.084) and lower levels of folic acid (P<.05).

CONCLUSION

Homocysteine levels should be monitored in epileptic patients on long-term treatment with antiepileptic drugs. We suggest starting specific treatment in patients with high homocysteine levels.

Management of psychiatric and neurological comorbidities in epilepsy

The treatment of epileptic seizure disorders is not restricted to the achievement of seizure-freedom, but must also include the management of comorbid medical, neurological, psychiatric and cognitive comorbidities. Psychiatric and neurological comorbidities are relatively common and often co-exist in people with epilepsy (PWE). For example, depression and anxiety disorders are the most common psychiatric comorbidities in PWE, and they are particularly common in PWE who also have a neurological comorbidity, such as migraine, stroke, traumatic brain injury or dementia. Moreover, psychiatric and neurological comorbodities often have a more severe impact on the quality of life in patients with treatment-resistant focal epilepsy than do the actual seizures. Epilepsy and psychiatric and neurological comorbidities have a complex relationship, which has a direct bearing on the management of both seizures and the comorbidities: the comorbidities have to be factored into the selection of antiepileptic drugs, and the susceptibility to seizures has to be considered when choosing the drugs to treat comorbidities. The aim of this Review is to highlight the complex relationship between epilepsy and common psychiatric and neurological comorbidities, and provide an overview of how treatment strategies for epilepsy can positively and negatively affect these comorbidities and vice versa.

Severe Hyperhomocysteinemia Decreases Respiratory Enzyme and Na(+)-K(+) ATPase Activities, and Leads to Mitochondrial Alterations in Rat Amygdala

Severe hyperhomocysteinemia is caused by increased plasma levels of homocysteine (Hcy), a methionine derivative, and is associated with cerebral disorders. Creatine supplementation has emerged as an adjuvant to protect against neurodegenerative diseases, due to its potential antioxidant role. Here, we examined the effects of severe hyperhomocysteinemia on brain metabolism, and evaluated a possible neuroprotective role of creatine in hyperhomocysteinemia, by concomitant treatment with Hcy and creatine (50 mg/Kg body weight). Hyperhomocysteinemia was induced in young rats (6-day-old) by treatment with homocysteine (0.3-0.6 µmol/g body weight) for 23 days, and then the following parameters of rat amygdala were evaluated: (1) the activity of the respiratory chain complexes succinate dehydrogenase, complex II and cytochrome c oxidase; (2) mitochondrial mass and membrane potential; (3) the levels of necrosis and apoptosis; and (4) the activity and immunocontent of Na(+),K(+)-ATPase. Hcy treatment decreased the activities of succinate dehydrogenase and cytochrome c oxidase, but did not alter complex II activity. Hcy treatment also increased the number of cells with high mitochondrial mass, high mitochondrial membrane potential, and in late apoptosis. Importantly, creatine administration prevented some of the key effects of Hcy administration on the amygdala. We also observed a decrease in the activity and immunocontent of the α1 subunit of the Na(+),K(+)-ATPase in amygdala after Hcy- treatment. Our findings support the notion that Hcy modulates mitochondrial function and bioenergetics in the brain, as well as Na(+),K(+)-ATPase activity, and suggest that creatine might represent an effective adjuvant to protect against the effects of high Hcy plasma levels.

Current Research on Antiepileptic Compounds

Epilepsy affects about 1% of the world’s population. Due to the fact all antiepileptic drugs (AEDs) have some undesirable side effects and about 30% of epileptic patients are not seizure-free with the existing AEDs, there is still an urgent need for the development of more effective and safer AEDs. Based on our research work on antiepileptic compounds and other references in recent years, this review covers the reported work on antiepileptic compounds which are classified according to their structures. This review summarized 244 significant anticonvulsant compounds which are classified by functional groups according to the animal model data, although there are some limitations in the data. This review highlights the properties of new compounds endowed with promising antiepileptic properties, which may be proven to be more effective and selective, and possibly free of unwanted side effects. The reviewed compounds represent an interesting possibility to overcome refractory seizures and to reduce the percentage of patients with a poor response to drug therapy.

Effects of antiepileptic drug monotherapy on one-carbon metabolism and DNA methylation in patients with epilepsy

PURPOSE

The aim of this study was to compare the serum levels of one-carbon metabolism (OCM) nutrients (e.g., folate, homocysteine and vitamin B12) and peripheral blood DNA methylation in epileptic patients under treatment with antiepileptic drugs (AEDs) and in healthy controls.

METHODS

In this cross-sectional study, 60 patients with epilepsy who were receiving valproate (VPA) (n = 30) or lamotrigine (LTG) (n = 30) monotherapy were enrolled. Thirty age and sex matched healthy subjects served as the controls. Serum concentrations of OCM nutrients and peripheral blood DNA methylation status were measured.

RESULTS

Compared to the control group, the VPA group had higher serum levels of homocysteine (p<0.05). No difference in homocysteine concentration was observed in the LTG group. Patients receiving VPA or LTG had significantly lower serum folate levels in comparison with controls (p<0.001). The level of methylation of long interspersed nucleotide element-1 (LINE-1) in peripheral blood was not significantly different between the AED monotherapy group and healthy controls. A difference in the methylation levels of methylenetetrahydrofolate reductase (MTHFR) amplicon was observed between AED-treated patients with epilepsy and controls (p<0.01). A positive correlation between serum folate levels and peripheral blood MTHFR amplicon methylation status was also observed (r = 0.25, p = 0.023).

CONCLUSION

Our findings suggest that the effects of AED monotherapy on OCM may induce specific regions of DNA hypomethylation.

Stroke after adult-onset epilepsy: a population-based retrospective cohort study

BACKGROUND

Earlier studies indicate a higher risk of subsequent stroke in PWE aged ≥60. However, little is known of the incidence of subsequent stroke in people with epilepsy (PWE) aged 35 through 60. We determined the risk factors that increase the incidence of stroke following adult-onset epilepsy in a large statewide population over a 10-year period.

METHODS

South Carolina hospital discharge and emergency department (ED) data from 2000 to 2011 were used. The study was limited to persons aged ≥35years without prior stroke. Cases included patients diagnosed with epilepsy who were hospitalized or visited the ED. Controls were people with an isolated fracture of the lower extremity without any history of epilepsy or seizure disorders, presumed to approximate the health status of the general population. Epilepsy, fracture, stroke, and comorbid conditions were ascertained by diagnostic codes from health-care encounters. Only persons having stroke occurring ≥6months after the onset of epilepsy or after the first clinical encounter for controls were included. Cox proportional hazards modeling was performed to determine the risk of stroke.

RESULTS

There were 21,035 cases with epilepsy and 16,638 controls who met the inclusion criteria. Stroke incidence was 2.5 times higher following adult-onset epilepsy (6.3%) compared with controls (2.5%). After adjusting for comorbidities and other factors, cases with epilepsy showed a 60% higher risk of stroke (HR=1.6; 95% CI: 1.42-1.80) compared with controls. Nearly half of the strokes in cases with epilepsy occurred in those with first diagnosis between ages 35 and 55. Somatic comorbidities associated with increased risk of stroke were more prevalent in cases with epilepsy than controls yet similar in both groups with stroke. Risk of stroke increased with increasing age in both groups. However, the risk of stroke in cases with epilepsy increased faster and was similar to that in controls who were ≥10years older.

CONCLUSION

Adult-onset epilepsy at age 35 and older warrants consideration for occult cerebrovascular disease as an etiology of the epilepsy, which may also increase the risk of subsequent stroke. Somatic comorbidities frequently associated with epilepsy include comorbid conditions that share the same underlying pathology with stroke (i.e., hypertension, hyperlipidemia, myocardial infarction, diabetes, and arteriosclerosis). This increased risk of stroke in patients with adult-onset epilepsy should dictate the evaluation and management of stroke risk factors to prevent stroke.

Hyperhomocysteinemia and neurologic disorders: a review

Homocysteine (Hcy) is a sulfur-containing amino acid that is generated during methionine metabolism. It has a physiologic role in DNA metabolism via methylation, a process governed by the presentation of folate, and vitamins B6 and B12. Physiologic Hcy levels are determined primarily by dietary intake and vitamin status. Elevated plasma levels of Hcy (eHcy) can be caused by deficiency of either vitamin B12 or folate, or a combination thereof. Certain genetic factors also cause eHcy, such as C667T substitution of the gene encoding methylenetetrahydrofolate reductase. eHcy has been observed in several medical conditions, such as cardiovascular disorders, atherosclerosis, myocardial infarction, stroke, minimal cognitive impairment, dementia, Parkinson's disease, multiple sclerosis, epilepsy, and eclampsia. There is evidence from laboratory and clinical studies that Hcy, and especially eHcy, exerts direct toxic effects on both the vascular and nervous systems. This article provides a review of the current literature on the possible roles of eHcy relevant to various neurologic disorders.

Risk factors of hyperammonemia in patients with epilepsy under valproic acid therapy

Hyperammonemia has been reported to be associated with patients who receive valproic acid (VPA) therapy. This study aimed to determine the risk factors for hyperammonemia in patients with epilepsy treated with VPA. One hundred and fifty-eight adult patients with epilepsy aged older than 17 years who received VPA therapy were enrolled into this study. Blood samples were taken during the interictal state and analyzed for the blood level of ammonia. Statistical analysis was conducted between different groups of patients. The results showed that the frequency of hyperammonemia associated with VPA therapy was 27.8% (ammonia level >93 µg/dL), and 5.1% of the patients had severe hyperammonemia (ammonia level >150 µg/dL). The blood ammonia level was significantly correlated with the dosage of VPA and the plasma concentration of VPA. An increase of 1 mg in the dosage of VPA increased the risk of hyperammonemia by 0.1%. In addition, combination treatment with liver enzyme inducing antiepileptic drugs (AEDs) and antipsychotic drugs increased the risk of hyperammonemia. In conclusion, the use of VPA in adult patients with epilepsy was associated with a dose-dependent increase in blood concentrations of ammonia. Combination treatment with liver enzyme-inducing AEDs and antipsychotic drugs increased the risk of VPA-induced hyperammonemia. Most of the patients with VPA-induced hyperammonemia were asymptomatic; however, if patients taking VPA present with symptoms such as nausea, fatigue, somnolence, ataxia, and consciousness disturbance, the blood ammonia level should be measured.

Increased homocysteine levels in valproate-treated patients with epilepsy: a meta-analysis

OBJECTIVE

To determine whether valproate (VPA) monotherapy influences homocysteine metabolism in patients with epilepsy.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

We searched all articles in English through PubMed, Web of Science and EMBASE published up to August 2013 concerning the homocysteine levels in VPA monotherapeutic patients with epilepsy.

PARTICIPANTS

VPA-treated patients with epilepsy (n=266) and matched healthy controls (n=489).

OUTCOME MEASURES

Heterogeneity between studies was assessed using I(2) statistics. Pooled standardised mean difference (SMD) and 95% CIs were calculated using a random effect model.

RESULTS

A total of eight eligible studies were enrolled in our meta-analysis. We compared the plasma levels of homocysteine in VPA-treated patients with epilepsy and healthy controls. There was significant heterogeneity in the estimates according to the I(2) test (I(2)=65.6%, p=0.005). Plasma homocysteine levels in VPA-treated patients with epilepsy were significantly higher than in healthy controls under a random effect model. (SMD, 0.62; 95% CI 0.32 to 0.92). Further subgroup analyses suggested that no significant differences were present when grouped by ethnicity and age, but the risk of heterogeneity in the West Asian group (I(2)=47.4%, p=0.107) was diminished when compared with that of the overall group (I(2)=65.6%, p=0.005).

CONCLUSIONS

Our meta-analysis indicates that VPA monotherapy is associated with the increase in plasma homocysteine levels in patients with epilepsy. Whether this association is influenced by ethnicity needs further research.

Association between methylenetetrahydrofolate reductase C677T polymorphism and epilepsy susceptibility: a meta-analysis

PURPOSE

Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism has been implicated as a potential risk factor for epilepsy. To date, many case-control studies have investigated the association between MTHFR C677T polymorphism and epilepsy susceptibility. However, those findings were inconsistent. The objective of this study is to evaluate the precise association between MTHFR C677T polymorphism and epilepsy.

METHODS

An electronic search of PubMed, EMBASE for papers on the MTHFR C677T polymorphism and epilepsy susceptibility was performed. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the association.

RESULTS

Ten case-control studies containing 1713 cases and 1867 controls regarding MTHFR C677T polymorphism were selected. A significant association between the MTHFR C677T polymorphism and epilepsy susceptibility was revealed in this meta-analysis (for T vs. C: OR=1.19, 95% CI=1.08-1.32; for TT+CT vs. CC: OR=1.20, 95% CI=1.05-1.38; for TT vs. CC: OR=1.48, 95% CI=1.20-1.83; for TT vs. CT+CC: OR=1.35, 95% CI=1.12-1.64). In subgroup analysis by ethnicity, the results also indicated the association between the MTHFR C677T polymorphism and epilepsy susceptibility within the Asian populations (for T vs. C: OR=1.55, 95% CI=1.15-2.07; for TT+CT vs. CC: OR=1.67, 95% CI=1.08-2.59; for TT vs. CC: OR=2.33, 95% CI=1.30-4.20; for TT vs. CT+CC: OR=1.89, 95% CI=1.12-3.18).

CONCLUSION

The results indicated that MTHFR C677T polymorphism was associated with an increased risk of epilepsy. However, further studies in various regions are needed to confirm the findings from this meta-analysis.

One-carbon metabolism and bipolar disorder

OBJECTIVE

Folate is one of the most widely used nutraceuticals for the treatment of mood disorders. In this article, we review folate metabolism, its relationship with bipolar disorder, and its therapeutic potential.

METHODS

We searched PubMed and the Cochrane Library for relevant articles up to and including the year 2012. Background information, proposed mechanisms of action, and results from clinical trials were reviewed.

RESULTS

Folate is an essential cofactor involved in methylation reactions, which are critical for monoamine synthesis and homocysteine regulation. Folate level is thought to be associated with mood disorders and limited response to antidepressants. Functional deficiency, due to a common genetic variant of the methylenetetrahydrofolate reductase (NAD(P)H) (MTHFR) gene, could also affect the presentation of bipolar disorder. Sodium valproate and lamotrigine, commonly used mood stabilizers for the treatment of bipolar disorder, can potentially interfere with folate and homocysteine metabolism. Previous studies consistently support the efficacy of folate in the treatment of depression; one study showed efficacy in the treatment of mania. Biologically active forms of folate formulations, which do not require biochemical conversion, could be beneficial in the treatment of bipolar disorder.

CONCLUSIONS

Folate augmentation could be effective for the treatment of bipolar disorder. A common genetic variant of the MTHFR gene might impact the treatment effect of folate augmentation. The biologically active form of folate could potentially correct mood stabilizer-associated functional folate deficiency, help normalize monoamine synthesis, and improve outcomes.