Tobacco smoking, epilepsy, and seizures

Exploring the Smoking-Epilepsy Nexus: a systematic review and meta-analysis of observational studies : Smoking and epilepsy

BACKGROUND

Epilepsy, characterized by recurrent unprovoked seizures, poses significant challenges to affected individuals globally. While several established risk factors for epilepsy exist, the association with cigarette smoking remains debated. This study aims to conduct systematic review and meta-analysis to elucidate the potential association between smoking and the likelihood of epilepsy.

METHODS

The search was performed on March 31st, 2023, using the Medline, Embase, Web of Science, Scopus, and ScienceDirect. We included cohort, cross-sectional, and case-control studies in our meta-analysis, conducting subgroup analyses based on smoking history, sex, and epilepsy type to yield specific insights.

RESULTS

We identified 2550 studies, of which 17 studies were finally included in this study. The pooled odds ratio of epilepsy was 1.14 (0.96-1.36) in smokers compared to non-smokers. In current smokers compared to non-smokers, the odds ratio was 1.46 (1.13-1.89), while, in former smokers compared to non-smokers, the odds ratio was 1.14 (0.83-1.56).

CONCLUSIONS

While the overall association between smoking and epilepsy did not reach statistical significance, a notable association was found among current smokers. The study emphasizes the importance of smoking cessation as a potential preventive measure against epilepsy, especially given the proconvulsive effects of nicotine. Future research should address limitations and explore specific clinical scenarios to enhance our understanding of the complex relationship between cigarette use and epilepsy.

SYSTEMATIC REVIEW REGISTRATION

CRD42022342510.

Causal relationship between addictive behaviors and epilepsy risk: A mendelian randomization study

BACKGROUND

Previous studies have reported inconsistent results regarding the potential relationships between addictive behaviors and the risk of epilepsy.

OBJECTIVE

To assess whether genetically predicted addictive behaviors are causally associated with the risk of epilepsy outcomes.

METHODS

The causation between five addictive behaviors (including cigarettes per day, alcoholic drinks per week, tea intake, coffee intake, and lifetime cannabis use) and epilepsy was evaluated by using a two-sample Mendelian Randomization (MR) analysis. The inverse-variance weighted (IVW) method was used as the primary outcome. The other MR analysis methods (MR Egger, weighted median, simulation extrapolation corrected MR-Egger, and Mendelian Randomization Pleiotropy Residual Sum and Outlier (MR-PRESSO)) were performed to complement IVW. In addition, the robustness of the MR analysis results was assessed by leave-one-out analysis.

RESULTS

The IVW analysis method indicated an approximately 20% increased risk of epilepsy per standard deviation increase in lifetime cannabis use (odds ratio [OR], 1.20; 95% confidence interval [CI]), 1.02-1.42, P = 0.028). However, there is no causal association between the other four addictive behaviors and the risk of epilepsy (cigarettes per day: OR, 1.04; 95% CI, 0.92-1.18, P = 0.53; alcoholic drinks per week: OR, 1.31; 95% CI, 0.93-1.84, P = 0.13; tea intake: OR, 1.15; 95% CI, 0.84-1.56, P = 0.39; coffee intake: OR, 0.86; 95% CI, 0.59-1.23, P = 0.41). The other MR analysis methods and further leave-one-out sensitivity analysis suggested the results were robust.

CONCLUSION

This MR study indicated a potential genetically predicted causal association between lifetime cannabis use and higher risk of epilepsy. As for the other four addictive behaviors, no evidence of a causal relationship with the risk of epilepsy was found in this study.

Nicotine modifies cocaine responding in a concurrent self-administration model

BACKGROUND

Preclinical models of cocaine use disorder (CUD) have not yielded any FDA-approved pharmacotherapies, potentially due to a focus on cocaine use in isolation, which may not fully translate to real-world drug taking patterns. Cocaine and nicotine are commonly used together, and clinical research suggests that nicotine may increase the potency and reinforcing strength of cocaine. In this study, we sought to determine whether and how the addition of nicotine would alter ongoing intravenous cocaine self-administration and motivation to take cocaine in rats.

METHODS

Male Sprague-Dawley rats self-administered cocaine alone on a long access, Fixed Ratio one (FR1) schedule, and then switched to a combination of cocaine and nicotine. Finally, rats responded on a Progressive Ratio (PR) schedule for several doses of cocaine alone and in combination with a single dose of nicotine.

RESULTS

Under long access conditions, rats co-self-administering cocaine and nicotine responded less and with decreased response rates than for cocaine alone and did not escalate responding. However, under PR conditions that test motivation to take drugs, the dose response curve for the combination was shifted upwards relative to cocaine alone.

CONCLUSIONS

Together, these results suggest that nicotine may enhance the reinforcing strength of cocaine, increasing PR responding for cocaine across the dose response curve.

How do smoking, vaping, and nicotine affect people with epilepsy and seizures? A scoping review protocol

BACKGROUND

Epilepsy is a prevalent disease that requires personalized care to control seizures, reduce side effects, and ameliorate the burden of comorbidities. Smoking is a major cause of preventable death and disease. There is evidence that patients with epilepsy smoke at high rates and that smoking may increase seizure frequency. However, there is a lack systematically synthesized evidence on the interactions between epilepsy and seizures and smoking, tobacco use, vaping, and smoking cessation.

METHODS AND ANALYSIS

This scoping review protocol guided by the Joanna Briggs Institute Manual for Evidence Synthesis and the PRISMA Extension for Scoping Reviews will investigate what is known about the interactions between smoking and epilepsy. This review will include the population of persons with all types of epilepsy or seizures and examine an inclusive list of concepts including tobacco use, vaping, nicotine replacement, and smoking cessation. The MEDLINE, Embase, APA Psycinfo, CINAHL, Cochrane, Scopus, and Web of Science databases will be searched. Following systematic screening of records, data will be charted, synthesized, and summarized for presentation and publication.

ETHICS AND DISSEMINATION

No ethical approval is required for this literature-based study. The results of this scoping review will be submitted for publication in a peer-reviewed journal. This synthesis will be informative to clinicians and direct further research that may improve health outcomes for people with epilepsy.

REGISTRATION

This protocol is registered with the Open Science Framework (DOI: https://doi.org/10.17605/OSF.IO/D3ZK8).

Big Five personality predict epilepsy diagnosis in 7 years

Objective

Recently, there is growing interest in investigating how personality traits could predict a subsequent diagnosis of various diseases. Regarding epilepsy, there is only preliminary evidence based on cross-sectional studies linking personality traits to epilepsy, hence, emphasizing the need for longitudinal studies. The aim of the current study is to assess if the Big Five personality traits can predict the risk of an epilepsy diagnosis.

Methods

The current study analyzed data from 17,789 participants who participated in Understanding Society: the UK Household Longitudinal Study (UKHLS) at Wave 3 (collected between 2011 and 2012) and Wave 10 (collected between 2018 and 2019). The mean age was 47.01 (SD = 16.31) years and were 42.62% male. Two binary logistic regressions were used by including age, monthly income, highest educational qualification, legal marital status, residence, and standardized personality traits scores at Wave 3 as predictors for a clinical diagnosis of epilepsy at Wave 10 for males and females, respectively.

Results

There were 175 participants (0.98%) with epilepsy and 17,614 participants (99.02%) without epilepsy at Wave 10. Results of the binary regression analyses revealed that Neuroticism is positively related to the risk of an epilepsy diagnosis in males (OR = 1.32, p = 0.04, 95% CI [1.01, 1.71]) but not in females 7  years after Wave 3 at Wave 10. However, other personality traits including Agreeableness, Openness, Conscientiousness, and Extraversion were not significant predictors of epilepsy diagnosis.

Conclusion

These findings suggested that personality traits might enhance our understanding of psychophysiological associations in epilepsy. Neuroticism might be a relevant factor that should be taken into account in epilepsy education and treatment. Moreover, sex differences must be taken into account.

Nicotinic acetylcholine receptors and epilepsy

Despite recent advances in understanding the causes of epilepsy, especially the genetic, comprehending the biological mechanisms that lead to the epileptic phenotype remains difficult. A paradigmatic case is constituted by the epilepsies caused by altered neuronal nicotinic acetylcholine receptors (nAChRs), which exert complex physiological functions in mature as well as developing brain. The ascending cholinergic projections exert potent control of forebrain excitability, and wide evidence implicates nAChR dysregulation as both cause and effect of epileptiform activity. First, tonic-clonic seizures are triggered by administration of high doses of nicotinic agonists, whereas non-convulsive doses have kindling effects. Second, sleep-related epilepsy can be caused by mutations on genes encoding nAChR subunits widely expressed in the forebrain (CHRNA4, CHRNB2, CHRNA2). Third, in animal models of acquired epilepsy, complex time-dependent alterations in cholinergic innervation are observed following repeated seizures. Heteromeric nAChRs are central players in epileptogenesis. Evidence is wide for autosomal dominant sleep-related hypermotor epilepsy (ADSHE). Studies of ADSHE-linked nAChR subunits in expression systems suggest that the epileptogenic process is promoted by overactive receptors. Investigation in animal models of ADSHE indicates that expression of mutant nAChRs can lead to lifelong hyperexcitability by altering i) the function of GABAergic populations in the mature neocortex and thalamus, ii) synaptic architecture during synaptogenesis. Understanding the balance of the epileptogenic effects in adult and developing networks is essential to plan rational therapy at different ages. Combining this knowledge with a deeper understanding of the functional and pharmacological properties of individual mutations will advance precision and personalized medicine in nAChR-dependent epilepsy.

A Single-center Analysis of Three Japanese Patients with Mahjong-related Seizures

Mahjong is one of the most popular Chinese tile games played in Japan. Mahjong-related seizures (MRS) are rare praxis-induced seizures. We identified three patients with MRS from February 2000 to February 2021. All cases were men, with a middle-age onset, generalized convulsive seizures, and lack of non-provoked, myoclonic, and absence seizures. All patients had no or non-specific neuroimaging or electroencephalogram abnormalities. They did not have features linked to idiopathic generalized epilepsy. All patients were seizure-free after behavioral adjustments, although one patient required anti-seizure medication and avoided long duration games. These changes may help other patients with MRS continue playing Mahjong.

Reduced paraoxonase 1 activities may explain the comorbidities between temporal lobe epilepsy and depression, anxiety and psychosis

BACKGROUND

Temporal lobe epilepsy (TLE) is the most common focal epilepsy subtype in adults and is frequently accompanied by depression, anxiety and psychosis. Aberrations in total paraoxonase 1 (PON1) status may occur in TLE and these psychiatric conditions.

AIM

To examine PON1 status, namely Q192R PON1 genotypes and PON1 enzymatic activities, in TLE.

METHODS

We recruited 40 normal controls and 104 TLE patients, 27 without comorbidities and 77 with comorbidities including mood disorders (n = 25), anxiety disorders (n = 27) and psychosis (n = 25).

RESULTS

Four-(chloromethyl)phenyl acetate hydrolysis (CMPAase) and arylesterase activities were significantly lower in TLE and mesial temporal sclerosis (MTS) with and without psychiatric comorbidities than those in normal controls. The areas under the receiver operating characteristic curve of CMPAase were 0.893 (0.037) for TLE and 0.895 (± 0.037) for MTS. Partial least squares path analysis showed that there were specific indirect effects of PON1 genotype on TLE severity (P < 0.0001) and psychopathology (P < 0.0001), which were both mediated by lowered CMPAase activity, while arylesterase activity was not significant. The severity of TLE was significantly associated with psychopathology scores. Furthermore, PON1 CMPAase activity was inversely associated with Mini Mental State Examination score.

CONCLUSION

The severity of TLE and comorbidities are to a large extent explained by reduced PON1 enzyme activities and by effects of the Q192R genotype, which are mediated by reduced CMPAase activity. Total PON1 status plays a key role in the pathophysiology of TLE, MTS and psychiatric comorbidities by increasing the risk of oxidative toxicity. PON1 enzyme activities are new drug targets in TLE to treat seizure frequency and psychiatric comorbidities.

Ethnomedicine and neuropsychopharmacology in Mesoamerica

ETHNOPHARMACOLOGICAL RELEVANCE

The burden of disease caused by mental and neurological disorders is increasing globally, to a disproportionate degree in Latin America. In contrast to the many psychoactive plants with a use history in Mesoamerican cultures, the translation to the wider population of knowledge around numerous botanicals used contemporarily by indigenous Mesoamerican societies to treat psychological and neurological disorders did not receive the same attention.

MATERIAL AND METHODS

We used the previously published Mesoamerican Medicinal Plant Database to extract species and associated botanical drugs used as treatments for illnesses associated with the nervous system by Mesoamerican cultures in Belize, Guatemala, and Mexico. With the critical use of published pharmacological literature, the cross-culturally most salient genera are systematically reviewed.

RESULTS

From 2188 plant taxa contained in the database 1324 are used as treatments for illnesses associated with the nervous system. The ethnomedical data was critically confronted with the available biomedical literature for the 58 cross-culturally most salient genera. For a considerable proportion of the frequently used taxa, preclinical data are available, mostly validating ethnomedicinal uses.

CONCLUSION

This quantitative approach facilitates the prioritization of taxa for future pre-clinical, clinical and treatment outcome studies and gives patients, practitioners, and legislators a fundamental framework of evidence, on which to base decisions regarding phytomedicines.

Effects of Developmental Nicotine Exposure on Frontal Cortical GABA-to-Non-GABA Neuron Ratio and Novelty-Seeking Behavior

Cigarette smoking during pregnancy is a major public health concern, resulting in detrimental health effects in the mother and her offspring. The adverse behavioral consequences for children include increased risk for attention deficit hyperactivity disorder, working memory deficits, epilepsy, novelty-seeking, and risk-taking behaviors. Some of these behavioral conditions are consistent with an imbalance in frontal cortical excitatory (glutamate) and inhibitory (GABA) neurotransmitter signaling. We used a GAD67-GFP knock-in mouse model to examine if developmental nicotine exposure alters frontal cortical GABA neuron numbers, GABA-to-non-GABA neuron ratio and behavioral phenotypes. Female mice were exposed to nicotine (100 or 200 μg/mL) in drinking water beginning 3 weeks prior to breeding and until 3 weeks postpartum. Male and female offspring were examined beginning at 60 days of age. The nicotine exposure produced dose-dependent decreases in GABA-to-non-GABA neuron ratios in the prefrontal and medial prefrontal cortices without perturbing the intrinsic differences in cortical thickness and laminar distribution of GABA or non-GABA neurons between these regions. A significant increase in exploratory behavior and a shift toward "approach" in the approach-avoidance paradigm were also observed. Thus, developmental nicotine exposure shifts the cortical excitation-inhibition balance toward excitation and produces behavioral changes consistent with novelty-seeking behavior.

Modifiable risk factors for epilepsy: A two-sample Mendelian randomization study

INTRODUCTION

We conducted a two-sample Mendelian randomization study to determine the associations of modifiable risk factors with epilepsy.

METHODS

Fourteen potential risk factors for epilepsy were selected based on a systematic review of risk factors for epilepsy. Single-nucleotide polymorphisms associated with each exposure at the genome-wide significance threshold (p < 5×10^-8 ) were proposed as instrumental variables from corresponding genome-wide association studies. Summary-level data for epilepsy were obtained from the FinnGen consortium (4,588 cases and 144 780 noncases). Potential causal associations (p < .05) were attempted for replication using UK Biobank data (901 cases and 395 209 controls).

RESULTS

Among 14 potential risk factors, 4 showed significant associations with epilepsy in FinnGen. All associations were directionally similar in UK Biobank and associated with epilepsy at p ≤ .004 in meta-analyses of FinnGen and UK Biobank data. The odds ratios of epilepsy were 1.46 (95% CI, 1.18, 1.82) for one unit increase in log odds ratio of having depression, 1.44 (95% CI, 1.13, 1.85) for one standard deviation increase in serum ferritin, 1.12 (95% CI, 1.04, 1.21) for one standard deviation increase in transferrin saturation, and 1.25 (95% CI, 1.09, 1.43) for one standard deviation increase in the prevalence of smoking initiation. There were suggestive associations of serum iron and magnesium with epilepsy. No association was observed for insomnia, blood pressure, alcohol consumption, or serum vitamin B12, 25-hydroxyvitamin D and calcium levels.

CONCLUSION

This MR study identified several modifiable risk factors for adulthood epilepsy. Reducing prevalence of depression and smoking initiation should be considered as primary prevention strategies for epilepsy.

[Anesthesia for electroconvulsive therapy]

Electroconvulsive therapy (ECT) is an important component in the treatment of depression and schizophrenia in Germany. For this intervention patients undergo short-term general anesthesia and muscle relaxation. Before anesthesia can be carried out patients are subject to a comprehensive examination. For general anesthesia all established hypnotics can be used, but differences with respect to the success of the ECT have been described. Short-acting or reversible relaxants should be preferentially used. The risks of general anesthesia during ECT are estimated to be low but a transient hemodynamic instability of patients can occur. Treatment can be performed as an inpatient but also as an outpatient procedure.

How are results of EEG activation procedures associated with patient perception of seizure provocative factors? A single-center cross-sectional pilot study

PURPOSE

The purpose of this study was to examine the relationship between subjectively perceived seizure provocative factors or inhibitors and objectively recorded changes in epileptiform activity (EA) during EEG activation procedures.

MATERIAL AND METHODS

Consenting epilepsy patients (≥18 years old) were asked to complete a questionnaire by indicating whether items on a list provoke, inhibit or have no effect on their seizures. A scalp EEG was recorded afterwards to evaluate baseline epileptiform activity and its change (increase/decrease in frequency) during a set of activation procedures. These included hyperventilation, intermittent photic stimulation (IPS), eye-closing/eye-opening, tasks of reading aloud in a native and a foreign language, solving a Rubik's cube and crossing-out letters. We used correlation and multiple regression analysis to search for associations between the sum of self-reported provocative/inhibiting items and changes in EA.

RESULTS

Of the 90 patients recruited 75 (83.3%) indicated at least one seizure provocative factor. Sleep deprivation, emotional stress, negative emotions and alcohol use were most frequently selected as provoking seizures. Positive feelings, focused thinking, mental calculation and exercising were the most predominant seizure inhibitors. EEG data revealed a weak, but statistically significant correlation with the sum of items in distinct questionnaire groups (0.20 ≤ Spearman's ρ ≤ 0.39). Sensory stimuli (olfactory, gustatory, auditory and visual), cognitive phenomena (thoughts and feelings) and substance use were found to be significantly correlated with EEG results by being self-reported as both provoking and inhibiting seizures. A statistically significant relationship was also found between the increase in EA while reading aloud in a native language and the number of physiological states (sleep deprivation, stress etc.) indicated as provoking seizures (Spearman's ρ = 0.320, P = 0.005). A suitable stepwise multiple regression model was feasible for this finding (F(3, 71) = 7.396, P < 0.001, adjusted R squared = 0.206) with the additional inclusion of EA change during IPS and epilepsy type as explanatory variables.

CONCLUSION

Our pilot study indicates that there is a previously non-explored association between patients' self-perception of seizure provocative/inhibiting factors and objectively recorded changes in epileptiform activity during activation EEGs. Distinct EEG tests might be useful in activating ictogenic networks that are sensitive to indirect influence by hormonal, emotional or diurnally variable factors.

Expression profile of cytochrome P450s and effects of polycyclic aromatic hydrocarbons and antiepileptic drugs on CYP1 expression in MOG-G-CCM cells

AIMS

This study was performed to investigate the expression profile of cytochrome P450 (CYP) isoforms and effects of polycyclic aromatic hydrocarbons (PAHs) and antiepileptic drugs on CYP1 expression in human astrocytoma MOG-G-CCM cells.

MAIN METHODS

CYP1A1 and CYP1B1 expression were determined by quantitative real-time polymerase chain reaction, Western blotting, and immunocytochemistry.

KEY FINDINGS

MOG-G-CCM cells expressed various CYP isoforms. Among the CYP isoforms analyzed, CYP1B1 showed the highest expression level, followed by CYP1A1. Furthermore, CYP1B1 was localized in both the endoplasmic reticulum and mitochondria. 3-Methylcholanthrene (3-MC), benz[a]anthracene (B[a]A), benzo[a]pyrene (B[a]P), and valproic acid (VPA) increased the expression of CYP1B1 and CYP1A1. The potent aryl hydrocarbon receptor antagonist GNF351 significantly suppressed the 3-MC- and VPA-mediated upregulation of CYP1B1 and CYP1A1. In addition, VPA potentiated the induction of CYP1B1 and CYP1A1 by 3-MC, B[a]A, and B[a]P, although the augmentation of CYP1A1 was more remarkable than that of CYP1B1. In contrast, other antiepileptic drugs (carbamazepine, lamotrigine, levetiracetam, phenytoin) did not affect the 3-MC-mediated upregulation of CYP1B1 and CYP1A1. VPA is known to act as a histone deacetylase (HDAC) inhibitor. Therefore, the effects of trichostatin A, a representative HDAC inhibitor, on CYP1 induction by 3-MC were examined. Trichostatin A enhanced the 3-MC-mediated upregulation of CYP1A1 but not CYP1B1.

SIGNIFICANCE

These results partially indicated that VPA may augment the PAH-mediated induction of CYP1B1 and CYP1A1 through the activation of transcription by HDAC inhibition.

Identification of susceptibility variants to benign childhood epilepsy with centro-temporal spikes (BECTS) in Chinese Han population

BACKGROUND

Benign Childhood Epilepsy with Centro-temporal Spikes (BECTS) is the most common form of idiopathic epilepsy in children, accounting for up to 23% of pediatric epilepsy. The pathogenesis of BECTS is unknown, but it is thought that genetic factors play a role in susceptibility to the disease.

METHODS

To investigate the role of common genetic variants in BECTS pathogenesis, a 2-stage genome-wide association study (GWAS) was performed in 1,800 Chinese Han BECTS patients, and 7,090 healthy controls. Genetic findings were used in a Mendelian Randomization study in the UK Biobank dataset to investigate the potential role of smoking in BECTS.

FINDINGS

Definitive evidence of a role for common-variant heritability was demonstrated, with heritability of BECTS of >10% observed even with conservative disease prevalence assumptions. Although no individual locus achieved genome-wide significance, twelve loci achieved suggestive evidence of association (5 × 10^-8<P<10^-5). Using combined genetic and brain tissue gene expression data analyzed by Summary-data-based Mendelian Randomization (SMR), causative association of BECTS was demonstrated with SNP rs1948 and the CHRNA5 t3603436 transcript (P_eqtl = 2·10 × 10^-12, P_smr = 7·9 × 10^-5). This finding indicates rs1948 is significantly associated with BECTS through effects on expression of CHRNA5 in brain tissue. The identification of novel loci suggests involvements of KALRN and the CHRNA5-A3-B4 cluster in BECTS. Using a generalized SMR approach we demonstrate that maternal smoking around birth is significantly associated with increased risk of BECTS (odds ratio = 3·90, P = 0·0099).

INTERPRETATION

This study shows that BECTS risk is at least partially heritable and due to common genetic variants. Additionally, we demonstrate that BECTS risk is substantially increased by maternal smoking around birth.

A Systematic Literature Review of E-Cigarette-Related Illness and Injury: Not Just for the Respirologist

Following the recent electronic cigarette (e-cigarette) illness outbreak, the current review aimed to collect all related clinical cases for study and analysis and provide a critical synopsis of the proposed injury mechanism. Adhering to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analysis) guidelines, e-cigarette-related clinical cases were identified via Google Scholar and PubMed databases. Additionally, references of published case reports and previous review papers were manually searched, revealing 159 publications presenting e-cigarette-related case reports and 19 reports by the Centers for Disease Control and Prevention. 238 individual cases were identified; 53% traumatic injuries due to e-cigarette explosion or self-combustion, 24% respiratory cases, and 12% poisonings. Additional cases pertained to oral, cardiovascular, immunologic, hematologic, allergic reactions, infant complications, and altered medication levels. Case reports were mainly published between 2016-2019 (78%). The oldest case, a lipoid pneumonia, was published in 2012. The current review showed that e-cigarette-related health effects extend beyond the acute lung injury syndrome, including traumatic, thermal injuries and acute intoxications. Physicians should be aware of the distinct clinical presentations and be trained to respond and treat effectively. Regulators and public health authorities should address the regulatory gap regarding electronic nicotine delivery systems (ENDS) and novel tobacco products.

Seizure recurrence risk in persons with epilepsy undergoing antiepileptic drug tapering

OBJECTIVES

Antiepileptic drug (AED) tapering in persons with epilepsy (PWE) after 2-3 years of seizure freedom is still debatable because of the risk of seizure recurrence. Tapering patterns have wide variability and could impact seizure recurrence; this study aimed to find out the correlation between them.

MATERIAL AND METHODS

This prospective, observational independent assessor study enrolled PWE undergoing AED tapering in a tertiary care hospital. Data collected included demography, seizure history, AED treatment, and investigational findings. Tapering pattern was assessed based on seizure-free period and AED dose before onset of tapering, dose reduction percentage and frequency, duration of tapering, and follow-up. These variables were compared among the PWE with seizure recurrence and no seizure recurrence.

RESULTS

Among 408 enrolled PWE, 181 were on AED monotherapy: levetiracetam (73), valproate (45), carbamazepine (44), phenytoin (16), and clobazam (3). With a minimum 19 (maximum 41 months) follow-up, seizure recurrence was reported in 119 (29.2%) PWE. The seizure recurrence was not significantly different in-between mono and polytherapy groups; however, among monotherapy groups seizure recurrence was significantly higher (P = .023) in valproate (35.5%) followed by levetiracetam (28.8%) group. Parameters having significant association with seizure recurrence were duration of epilepsy (P = .03), frequency of seizures before control (P = .002), history of previously failed tapering (P = .04), and history of smoking/alcoholic/tobacco intake (P = .003).

CONCLUSIONS

There is a wide variation in AEDs tapering pattern and seizure recurrence risk can be minimized by considering the risk factors like history of smoking/alcoholic/tobacco, longer duration of epilepsy, frequency of seizures before control, and previously failed tapering.

In utero beta-2-adrenergic agonists exposure and risk of epilepsy: A Danish nationwide population-based cohort study

PURPOSE

To examine the association between maternal use of beta-2-adrenergic agonists (β2AAs) and the risk of epilepsy in offspring.

METHODS

A nationwide retrospective cohort study was performed based on Danish registries. Children of mothers who used β2AAs during pregnancy were allocated to the exposed group and other children to the unexposed group. The outcome was a diagnosis of epilepsy. Cox regression was performed to estimate the hazard ratios (HRs) of epilepsy after adjusting for parental and children factors. To evaluate confounding by indication, we extended the exposure time window from 2 years before pregnancy and stratified the analyses by maternal asthma, in particular analyses by trimesters.

RESULTS

The exposed children had a 1.24-fold risk of epilepsy (HR = 1.24, 95% confidence interval [CI]: 1.12, 1.38). Compared with no prenatal exposure from 2 years before pregnancy through delivery, the HR was 1.11 (95% CI: 1.01, 1.22) in children of mothers with β2AAs use only before pregnancy, 1.28 (95% CI: 1.09, 1.50) only during pregnancy, and 1.23 (95% CI: 1.07, 1.41) both before and during pregnancy. The increased risk was only observed in children of mothers with β2AAs use in the first (HR = 1.33, 95% CI: 1.01, 1.75) or second trimesters (HR = 1.35, 95% CI: 1.05, 1.74), but not the third trimester.

CONCLUSIONS

In utero exposure to β2AAs, particularly in the first or second trimesters, may be associated with an increased risk of epilepsy. It may partly be due to the indication of β2AAs use, but a direct effect of β2AAs cannot be ruled out.

Successful treatment of reflex epilepsy with praxis induction by stimulus avoidance only

PURPOSE

Reflex epilepsy is a type of epilepsy with seizures that are consistently triggered by a specific stimulus. Zipai is a Chinese ancient card game which has been popular in Southern China for hundreds of years. We sought to report and characterize clinical features of patients with reflex epilepsy evoked by playing Zipai.

METHODS

We collected and analyzed clinical data of patients with Zipai-induced epilepsy. Patients were regarded as having Zipai-induced epilepsy if they suffered at least two seizure attack during the course of playing Zipai. Prolonged electroencephalography (EEG) and brain magnetic resonance imaging (MRI) were applied to all patients. All patients were advised to avoid watching and playing Zipai games in daily life, instead of using antiepileptic drugs. The seizure outcome was assessed during outpatient visits and by telephone contact.

RESULTS

Five patients were included in this study. No spontaneous seizures occurred in all five patients. No patients had experienced myoclonic and coexistent absences with generalized tonic-clonic seizures (GTCS). All patients had normal MRI and prolonged EEG findings. All patients were advised to avoid the Zipai game, and became seizure-free without medication during the follow-up period (mean 5.4 years, range 3.5-7 years).

CONCLUSION

Zipai-induced epilepsy may be an unreported subtype form of reflex epilepsy with praxis induction. Nonpharmacological conservative treatment plays a significant role in the treatment of reflex epilepsy.

Epigenetic mechanisms associated with addiction-related behavioural effects of nicotine and/or cocaine: implication of the endocannabinoid system

The addictive use of nicotine (NC) and cocaine (COC) continues to be a major public health problem, and their combined use has been reported, particularly during adolescence. In neural plasticity, commonly induced by NC and COC, as well as behavioural plasticity related to the use of these two drugs, the involvement of epigenetic mechanisms, in which the reversible regulation of gene expression occurs independently of the DNA sequence, has recently been reported. Furthermore, on the basis of intense interactions with the target neurotransmitter systems, the endocannabinoid (ECB) system has been considered pivotal for eliciting the effects of NC or COC. The combined use of marijuana with NC and/or COC has also been reported. This article presents the addiction-related behavioural effects of NC and/or COC, based on the common behavioural/neural plasticity and combined use of NC/COC, and reviews the interacting role of the ECB system. The epigenetic processes inseparable from the effects of NC and/or COC (i.e. DNA methylation, histone modifications and alterations in microRNAs) and the putative therapeutic involvement of the ECB system at the epigenetic level are also discussed.

Intracerebroventricular administration of cigarette smoke condensate induced generalized seizures reduced by muscarinic receptor antagonist in rats

Tobacco smoking is considered the greatest risk factor for early death caused by noncommunicable diseases. Currently, there are more than one billion tobacco smokers in the world predisposed to many diseases including heart attack, stroke, cancer, and premature birth or birth defects related to the consumption of cigarettes. However, studies on the association between tobacco smoking and seizures or epilepsy are insufficient and not well documented. In the present study, the authors examined the convulsive effects of the intracerebroventricular administration of cigarette smoke condensate (CSC, 2μl/Rat) in rats and compared it with the intensity of seizures in the kainic acid (KA)-induced seizure model of epilepsy. The role of the cholinergic system was also investigated by testing the effect of the muscarinic acetylcholine receptors (mAChRs) antagonist atropine (2ml/kg) on CSC-induced seizures. The results indicate that a central injection of CSC produces an epileptic behavior similar to that induced by KA, the similarities include the following parameters: time latency of seizures, latency and duration of tonic-clonic seizures, duration of seizures, survival, and tonic-clonic rate. However, a pretreatment with atropine reduced seizures and all their parameters.

Integrated network analysis reveals potentially novel molecular mechanisms and therapeutic targets of refractory epilepsies

Epilepsy is a complex neurological disorder and a significant health problem. The pathogenesis of epilepsy remains obscure in a significant number of patients and the current treatment options are not adequate in about a third of individuals which were known as refractory epilepsies (RE). Network medicine provides an effective approach for studying the molecular mechanisms underlying complex diseases. Here we integrated 1876 disease-gene associations of RE and located those genes to human protein-protein interaction (PPI) network to obtain 42 significant RE-associated disease modules. The functional analysis of these disease modules showed novel molecular pathological mechanisms of RE, such as the novel enriched pathways (e.g., "presynaptic nicotinic acetylcholine receptors", "signaling by insulin receptor"). Further analysis on the relationships between current drug targets and the RE-related disease genes showed the rational mechanisms of most antiepileptic drugs. In addition, we detected ten potential novel drug targets (e.g., KCNA1, KCNA4-6, KCNC3, KCND2, KCNMA1, CAMK2G, CACNB4 and GRM1) located in three RE related disease modules, which might provide novel insights into the new drug discovery for RE therapy.

Nicotine Elicits Convulsive Seizures by Activating Amygdalar Neurons

Nicotinic acetylcholine (nACh) receptors are implicated in the pathogenesis of epileptic disorders; however, the mechanisms of nACh receptors in seizure generation remain unknown. Here, we performed behavioral and immunohistochemical studies in mice and rats to clarify the mechanisms underlying nicotine-induced seizures. Treatment of animals with nicotine (1–4 mg/kg, i.p.) produced motor excitement in a dose-dependent manner and elicited convulsive seizures at 3 and 4 mg/kg. The nicotine-induced seizures were abolished by a subtype non-selective nACh antagonist, mecamylamine (MEC). An α7 nACh antagonist, methyllycaconitine, also significantly inhibited nicotine-induced seizures whereas an α4β2 nACh antagonist, dihydro-β-erythroidine, affected only weakly. Topographical analysis of Fos protein expression, a biological marker of neural excitation, revealed that a convulsive dose (4 mg/kg) of nicotine region-specifically activated neurons in the piriform cortex, amygdala, medial habenula, paratenial thalamus, anterior hypothalamus and solitary nucleus among 48 brain regions examined, and this was also suppressed by MEC. In addition, electric lesioning of the amygdala, but not the piriform cortex, medial habenula and thalamus, specifically inhibited nicotine-induced seizures. Furthermore, microinjection of nicotine (100 and 300 μg/side) into the amygdala elicited convulsive seizures in a dose-related manner. The present results suggest that nicotine elicits convulsive seizures by activating amygdalar neurons mainly via α7 nACh receptors.

Long-term potentiation in autonomic ganglia: Potential role in cardiovascular disorders

Ganglionic long-term potentiation (gLTP) is an activity-dependent, enduring enhancement of ganglionic transmission. This phenomenon may be induced in autonomic ganglia of an organism under certain conditions where repetitive impulses surge from the central nervous system (CNS) to the periphery. Chronic stress, repetitive epileptic seizure or chronic use of CNS stimulants could induce gLTP, which would result in a long lasting heightening of sympathetic tone to the cardiovascular system causing hypertension and disturbed cardiac rhythm that may lead to sudden cardiac death. These conditions are briefly reviewed in this article.

Omics for prediction of environmental health effects: Blood leukocyte-based cross-omic profiling reliably predicts diseases associated with tobacco smoking

The utility of blood-based omic profiles for linking environmental exposures to their potential health effects was evaluated in 649 individuals, drawn from the general population, in relation to tobacco smoking, an exposure with well-characterised health effects. Using disease connectivity analysis, we found that the combination of smoking-modified, genome-wide gene (including miRNA) expression and DNA methylation profiles predicts with remarkable reliability most diseases and conditions independently known to be causally associated with smoking (indicative estimates of sensitivity and positive predictive value 94% and 84%, respectively). Bioinformatics analysis reveals the importance of a small number of smoking-modified, master-regulatory genes and suggest a central role for altered ubiquitination. The smoking-induced gene expression profiles overlap significantly with profiles present in blood cells of patients with lung cancer or coronary heart disease, diseases strongly associated with tobacco smoking. These results provide proof-of-principle support to the suggestion that omic profiling in peripheral blood has the potential of identifying early, disease-related perturbations caused by toxic exposures and may be a useful tool in hazard and risk assessment.

α5-nAChR modulates nicotine-induced cell migration and invasion in A549 lung cancer cells

Cigarette smoking is the most important risk factor in the development of human lung cancer. Nicotine, the major component in tobacco, not only contributes to carcinogenesis but also promotes tumor metastasis. By binding to nicotinic acetylcholine receptors (nAChRs), nicotine induces the proliferation and migration of non-small cell lung cancer. Recently studies have indicated that α5-nAChR is highly associated with lung cancer risk and nicotine dependence. Nevertheless, it is unclear whether nicotine promotes the migration and invasion through activation of α5-nAChR in lung cancer. In the present study, A549 cell was exposed to 1μN nicotine for 8, 24 or 48h. Wound-healing assay and transwell assay were used to evaluate the capability of A549 cell migration and cell invasion, respectively. Silencing of α5-nAChR was done by siRNA. Western blotting and PCR were used to detect α5-nAChR expression. Nicotine can induce activation of α5-nAChR in association with increased migration and invasion of human lung cancer A549 cell. Treatment of cells with α5-nAChR specific siRNA blocks nicotine-stimulated activation of α5-nAChR and suppresses A549 cell migration and invasion. Reduction of α5-nAChR resulted in upregulation of E-cadherin, consistent with E-cadherin being inhibitive of cancer cell invasion. These findings suggest that nicotine-induced migration and invasion may occur in a mechanism through activation of α5-nAChR, which can contribute to metastasis or development of human lung cancer.

Health behaviors among people with epilepsy--results from the 2010 National Health Interview Survey

OBJECTIVES

This study aimed to estimate and compare the prevalence of selected health behavior-alcohol use, cigarette smoking, physical activity, and sufficient sleep-between people with and without a history of epilepsy in a large, nationally representative sample in the United States.

METHODS

We used data from the 2010 cross-sectional National Health Interview Survey (NHIS) to compare the prevalence of each health behavior for people with and without epilepsy while adjusting for sex, age, race/ethnicity, and family income. We also further categorized those with epilepsy into active epilepsy and inactive epilepsy and calculated their corresponding prevalences.

RESULTS

The percentages of adults with a history of epilepsy (50.1%, 95% CI=45.1%-55.2%) and with active epilepsy (44.4%, 95% CI=37.6%-51.5%) who were current alcohol drinkers were significantly lower than that of those without epilepsy (65.1%, 95% CI=64.2%-66.0%). About 21.8% (95% CI=18.1%-25.9%) of adults with epilepsy and 19.3% (95% CI=18.7%-19.9%) of adults without epilepsy were current smokers. Adults with active epilepsy were significantly less likely than adults without epilepsy to report following recommended physical activity guidelines for Americans (35.2%, 95% CI=28.8%-42.1% vs. 46.3%, 95% CI=45.4%-47.2%) and to report walking for at least ten minutes during the seven days prior to being surveyed (39.6%, 95% CI=32.3%-47.4% vs. 50.8%, 95% CI=49.9%-51.7%). The percentage of individuals with active epilepsy (49.8%, 95% CI=42.0%-57.7%) who reported sleeping an average of 7 or 8h a day was significantly lower than that of those without epilepsy (61.9%, 95% CI=61.2%-62.7%).

CONCLUSIONS

Because adults with epilepsy are significantly less likely than adults without epilepsy to engage in recommended levels of physical activity and to get the encouraged amount of sleep for optimal health and well-being, promoting more safe physical activity and improved sleep quality is necessary among adults with epilepsy. Ending tobacco use and maintaining low levels of alcohol consumption would also better the health of adults with epilepsy.

Midwakh-induced seizures: case series from UAE

Drug-induced seizures are rare causes of hospital admissions (Coleman, 2004). Various classes of drugs are reported to induce seizures either directly, due to their epileptogenic potential or due to drug withdrawal effect, or indirectly, due to systemic and CNS-related side effects (Thundiyil et al., 2011). Midwakh is commonly used among young Emiratis. However, its CNS-related adverse effects are not well studied. We report seven consecutive patients with a history of seizures provoked by smoking midwakh and a negative workup for epilepsy. Six of these patients had no further seizures after they had agreed to discontinue smoking midwakh.