Association of variants in the ABCB1, CYP2C19 and CYP2C9 genes for Juvenile Myoclonic Epilepsy

Juvenile myoclonic epilepsy (JME) is the most common of the generalized genetic epilepsies, with multiple causal and susceptibility genes; however, its etiopathogenesis is mainly unknown. The toxic effects caused by xenobiotics in cells occur during their metabolic transformation, mainly by enzymes belonging to cytochrome P450. The elimination of these compounds by transporters of the ABC type protects the central nervous system, but their accumulation causes neuronal damage, resulting in neurological diseases. The present study has sought the association between single nucleotide genetic variants of the CYP2C9, CYP2C19, and ABCB1 genes and the development of JME in patients compared to healthy controls. The CC1236 and GG2677 genotypes of ABCB1 in women; allele G 2677, genotypes GG 2677 and CC 3435 in men; the CYP2C19*2A allele, and the CYP2C19*3G/A genotype in both sexes were found to be risk factors for JME. Furthermore, carriers of the TTGGCC genotype combination of the ABCB1 gene (1236/2677/3435) have a 10.5 times higher risk of developing JME than non-carriers. Using the STRING database, we found an interaction between the proteins encoded by these genes and other possible proteins. These findings indicate that the CYP450 system and ABC transporters could interact with other genes in the JME.

Frequency and Focus of in Vitro Studies of Microglia-Expressed Cytokines in Response to Viral Infection: A Systematic Review

It is well known that as part of their response to infectious agents such as viruses, microglia transition from a quiescent state to an activated state that includes proinflammatory and anti-inflammatory phases; this behavior has been described through in vitro studies. However, recent in vivo studies on the function of microglia have questioned the two-phase paradigm; therefore, a change in the frequency of in vitro studies is expected. A systematic review was carried out to identify the microglial cytokine profile against viral infection that has been further evaluated through in vitro studies (pro-inflammatory or anti-inflammatory), along with analysis of its publication frequency over the years. For this review, 531 articles published in the English language were collected from PubMed, Web of Science, EBSCO and ResearchGate. Only 27 papers met the inclusion criteria for this systematic review. In total, 19 cytokines were evaluated in these studies, most of which are proinflammatory; the most common are IL-6, followed by TNF-α and IL-1β. It should be pointed out that half of the studies were published between 2015 and 2022 (raw data available in https://github.com/dadriba05/SystematicReview.git ). In this review, we identified that evaluation of pro-inflammatory cytokines released by microglia against viral infections has been performed more frequently than that of anti-inflammatory cytokines; additionally, a higher frequency of evaluation of the response of microglia cells to viral infection through in vitro studies from 2015 and beyond was noted.

Low quality of life, increased number of anti-seizure drugs, and the lack of caregiver support are associated with internalized stigma in adult Mexican patients with epilepsy

BACKGROUND

People with epilepsy (PWE) have been subject to stigma throughout history, a factor that could compromise their performance in daily life. In Mexico, little is known about the factors that may be affecting internalized stigma.

OBJECTIVE

To evaluate the internalized stigma in adult PWE, its relationship with the quality of life, cognitive and depressive symptomatology, and clinical-demographic characteristics.

MATERIAL AND METHODS

We conducted a cross-sectional study with a consecutive sampling approach in patients with epilepsy treated at the National Institute of Neurology and Neurosurgery Manuel Velasco Suárez (NINNMVS). Sociodemographic and clinical data, depressive symptomatology (Beck's depression inventory, DBI), cognition (MoCA test), quality of life (QOLIE-31 scale), and internalized stigma (King's internalized stigma scale, ISS) were evaluated. Correlations were made between the continuous variables and the ISS to select those with statistical significance and include them in a multiple linear regression model, along with the dummy variables, to explain internalized stigma.

RESULTS

Of 128 patients, 74 (58%) were women; 38% of the patients had more than 20 years of epilepsy evolution. In addition, 39% presented depressive symptoms, and around 60% manifested a possible cognitive impairment. The variables that showed statistical significance concerning the ISS were selected along with dummy variables for multiple linear regression analysis. The resultant model considers the QOLIE-31 total score (β = -0.489), the number of anti-seizure drugs (ASD, β = 0.253), and those patients without caregiver support (β = -0.166) with an adjusted R² value of 0.316.

CONCLUSIONS

A diminishing quality of life, an increased number of ASD, and patients without caregiver support influence a slight to moderate variation of internalized stigma in Mexican PWE. Therefore, it is necessary to continue studying other possible factors that influence internalized stigma to generate effective strategies to reduce its negative effects on PWE.

An international consortium in epilepsy surgery education: Clinical case-based discussions between Latin-American and Canadian Epilepsy Centers

An international consortium with a focus on Epilepsy Surgery Education was established with members from different centers in Latin America and Canada. All members of the consortium and attendees from different centers in Latin America and Canada have been meeting to discuss epilepsy surgery cases in a virtual manner. We surveyed all to assess the value of the meetings. The results and description of these meetings are being presented.

Relevance of NR1I2 variants on carbamazepine therapy in Mexican Mestizos with epilepsy at a tertiary-care hospital

Aim: We evaluated the potential influence of genetic (CYP3A5, EPHX1, NR1I2, HNF4A, ABCC2, RALBP1, SCN1A, SCN2A and GABRA1) and nongenetic factors on carbamazepine (CBZ) response, adverse drug reactions and CBZ plasma concentrations in 126 Mexican Mestizos (MM) with epilepsy. Subjects & methods: Patients were genotyped for 27 variants using TaqMan^® assays. Results: CBZ response was associated with NR1I2 variants and lamotrigine cotreatment. CBZ-induced adverse drug reactions were related to antiepileptic polytherapy and SCN1A rs2298771/rs3812718 haplotype. CBZ plasma concentrations were influenced by NR1I2-rs2276707 and -rs3814058, and by phenytoin cotreatment. CBZ daily dose was also influenced by NR1I2-rs3814055 and EPHX1-rs1051740. Conclusion: Interindividual variability in CBZ treatment was partly explained by NR1I2, EPHX1 and SCN1A variants, as well as antiepileptic cotreatment in MM with epilepsy.

Increased non-attendance at epilepsy clinic in patients with neuropsychiatric comorbidities: A prospective study

BACKGROUND

In patients with epilepsy, regular follow-up is vital for adequate seizure control, antiseizure drugs' (ASDs) side effects, psychiatric comorbidities, and planning for epilepsy surgery. Non-attendance creates barriers to adequate patient care, inefficient allocation of resources, loss of income, and unnecessary emergency department visits due to lack of seizure control. This study aimed to determine the causes and sociodemographic characteristics of the non-attendant population at the Epilepsy Clinic.

METHODS

A prospective and observational study was carried out on patients treated at the Epilepsy Clinic of the National Institute of Neurology and Neurosurgery (NINN) in Mexico from August 2015 to June 2016. A phone interview was made with all those patients who did not attend the epilepsy consultation. This call incorporated ad hoc questions to meet the objectives of this study.

RESULTS

During the study period, 1299 patients had an appointment at the epilepsy clinic, where 233 (17.9%) patients missed their consultation, 123 (52.8%) were male, mean age was 35.9 ± 14.42 years. The most frequent cause of non-attendance was forgetfulness of the appointment in 62 patients (26.6%). Two patients died; no patient was reported to have experienced SUDEP. Non-attendant patients showed statistically significant overall prevalence of psychiatric comorbidities (41.6%), particularly depression, anxiety, and interictal psychosis.

CONCLUSION

Information on non-attendance at various specialist consultations is scarce, and to our knowledge, this is the first study to address non-attendance in patients with epilepsy in Latin America. Improving hospital protocols to reduce non-attendance can increase patient adherence to follow-up, ultimately improving the quality of care in the epilepsy clinic.

Continuous Visual Focal Status Epilepticus as the Primary Presentation of NMDA-R and GAD65-R Autoimmune Epilepsy

Epilepsia partialis continua (EPC) has changed in its clinical and pathophysiological definition throughout time. Several etiologies have been described in addition to classic causes of EPC. The following case depicts a young woman who had a peculiar onset of epilepsy with a continuous visual aura becoming a form of chronic recurrent and non-progressive EPC. The patient was initially misdiagnosed as a non-neurological entity (assumed psychiatric in origin), but finally, an immune-mediated epilepsy was diagnosed, and EEG showed focal status epilepticus during evolution. Once the diagnosis was achieved and immune treatment was established, the patient is seizure free. Early identification of an immune basis in patients with epilepsy is important because immunotherapy can reverse the epileptogenic process and reduce the risk of chronic epilepsy. To date, this is the only case reported with EPC manifesting as a continuous visual aura associated with antiglutamic acid decarboxylase 65 (anti-GAD65) and anti-N-methyl-d-aspartate (anti-NMDA) antibodies.

Influence of genetic variants and antiepileptic drug co-treatment on lamotrigine plasma concentration in Mexican Mestizo patients with epilepsy

Genetic and nongenetic factors may contribute to lamotrigine (LTG) plasma concentration variability among patients. We simultaneously investigated the association of UGT1A1, UGT1A4, UGT2B7, ABCB1, ABCG2, and SLC22A1 variants, as well as antiepileptic drug co-treatment, on LTG plasma concentration in 97 Mexican Mestizo (MM) patients with epilepsy. UGT1A4*1b was associated with lower LTG dose-corrected concentrations. Patients with the UGT2B7-161T allele were treated with 21.22% higher LTG daily dose than those with CC genotype. Two novel UGT1A4 variants (c.526A>T; p.Thr185= and c.496T>C; p.Ser166Leu) were identified in one patient. Patients treated with LTG + valproic acid (VPA) showed higher LTG plasma concentration than patients did on LTG monotherapy or LTG + inducer. Despite the numerous drug-metabolizing enzymes and transporter genetic variants analyzed, our results revealed that co-treatment with VPA was the most significant factor influencing LTG plasma concentration, followed by UGT1A4*1b, and that patients carrying UGT2B7 c.-161T required higher LTG daily doses. These data provide valuable information for the clinical use of LTG in MM patients with epilepsy.

[E-health tools to overcome the gap in epilepsy care before, during and after COVID-19 pandemics]

INTRODUCTION

Epilepsy is a common chronic neurological disorder that affects around 50 million worldwide and there is an abundance of literature on the health care gap for this sector of the population. This gap will increase with the current pandemic due to COVID-19.

AIM

To evaluate the current availability of digital health tools for the care of people with epilepsy according to the world medical literature and their use during said pandemic.

DEVELOPMENT

We reviewed the publications in scientific journals in the last decade that had as their main topic the use of digital health tools or telemedicine focused on the care of patients with epilepsy, including 4 months after the national quarantines due to the appearance of the virus SARS-CoV-2. Seventeen publications were found on the use of telemedicine focused on epilepsy. The most widely used tools internationally are online platforms, followed by mobile applications, videoconferences, epileptic seizure capture systems, checklists, algorithms for understanding medical data, phone calls, tele-encephalography and text messages. None was published during the COVID-19 current pandemic.

CONCLUSIONS

Although there is little literature on the use of digital health tools focused on epilepsy, there are several that can be used to fight the attention gap, especially in this global pandemic by COVID-19 that forces quarantines of people and communities for long periods. It is necessary to remove barriers and facilitate patient access to these new information technologies.

Resolution of ictal bradycardia and asystole following temporal lobectomy: A case report, and review of available cases using pacemakers

Ictal bradycardia (IB) and ictal asystole (IA) are uncommonly recognized phenomena that increase morbidity in patients with epilepsy by causing syncope and seizure-related falls. These arrhythmias are also suspected to be involved in the pathophysiology of sudden unexpected death in epilepsy (SUDEP). We report a case of a 57-year-old male with left temporal lobe epilepsy who experienced both IB and IA. This patient was initially managed with pacemaker implantation, prior to undergoing left temporal lobectomy. Following surgery, the patient had no ongoing IB or IA on his pacemaker recordings, and his seizure control was greatly improved. His pacemaker was removed approximately one year post-operatively and he continued treatment with anti-seizure drugs (ASDs). A literature review of cases of IB and IA that were managed with pacemakers was performed. Pacemaker implantation appears to be quite effective for reducing seizure-related syncope and falls in the setting of IB/IA. Epilepsy surgery also seems to be an effective treatment option for IB/IA, as many patients are able to have their pacemakers removed post-operatively. Further investigations into the pathophysiology of IB and IA and long-term outcomes using different treatment modalities are clearly needed to help formulate treatment guidelines and, potentially, to reduce the occurrence of SUDEP in these patients.

•

Pacemaker implantation reduce seizure related syncope and falls in the setting of ictal bradycardia and ictal asystole.

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Ictal bradycardia and ictal asystole may contribute to the pathophysiology of sudden unexpected death in epilepsy.

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Epilepsy surgery seems to be an effective treatment option for ictal bradycardia and ictal asystole related with seizures.

Variant Intestinal-Cell Kinase in Juvenile Myoclonic Epilepsy

BACKGROUND

In juvenile myoclonic epilepsy, data are limited on the genetic basis of networks promoting convulsions with diffuse polyspikes on electroencephalography (EEG) and the subtle microscopic brain dysplasia called microdysgenesis.

METHODS

Using Sanger sequencing, we sequenced the exomes of six members of a large family affected with juvenile myoclonic epilepsy and confirmed cosegregation in all 37 family members. We screened an additional 310 patients with this disorder for variants on DNA melting-curve analysis and targeted real-time DNA sequencing of the gene encoding intestinal-cell kinase ( ICK). We calculated Bayesian logarithm of the odds (LOD) scores for cosegregating variants, odds ratios in case-control associations, and allele frequencies in the Genome Aggregation Database. We performed functional tests of the effects of variants on mitosis, apoptosis, and radial neuroblast migration in vitro and conducted video-EEG studies in mice lacking a copy of Ick.

RESULTS

A variant, K305T (c.914A→C), cosegregated with epilepsy or polyspikes on EEG in 12 members of the family affected with juvenile myoclonic epilepsy. We identified 21 pathogenic ICK variants in 22 of 310 additional patients (7%). Four strongly linked variants (K220E, K305T, A615T, and R632X) impaired mitosis, cell-cycle exit, and radial neuroblast migration while promoting apoptosis. Tonic-clonic convulsions and polyspikes on EEG resembling seizures in human juvenile myoclonic epilepsy occurred more often in knockout heterozygous mice than in wild-type mice (P=0.02) during light sleep with isoflurane anesthesia.

CONCLUSIONS

Our data provide evidence that heterozygous variants in ICK caused juvenile myoclonic epilepsy in 7% of the patients included in our analysis. Variant ICK affects cell processes that help explain microdysgenesis and polyspike networks observed on EEG in juvenile myoclonic epilepsy. (Funded by the National Institutes of Health and others.).

A comparison of waiting times for assessment and epilepsy surgery between a Canadian and a Mexican referral center

Objective

To provide a comprehensive transnational overview of wait times for epilepsy surgery in Canada and Mexico.

Methods

We reviewed all cases referred for epilepsy surgery between 2007 and 2015 at the Saskatchewan Epilepsy Program Royal University Hospital (SEP) (n = 70; Saskatoon, Canada) and the National Institute of Neurology and Neurosurgery (NINN) (n = 76; Mexico City, Mexico) and compared wait times, calculated as the time from diagnosis of epilepsy on assessment at an epilepsy center to epilepsy surgery.

Results

Mean wait times were similar across centers. Mean patient age was 37.4 ± 9 years (NINN) and 36.7 ± 13.2 years (SEP). The mean time from epilepsy diagnosis to referral was 18.9 (NINN) and 16.9 years (SEP), p = 0.30; first consult with the epileptologist, 19.7 (NINN) and 17.4 years (p = 0.23); neuropsychology consult, 21.4 (NINN) and 17.9 years (SEP); video electroencephalogram (video-EEG) telemetry, 21.1 (NINN) and 18.6 months (SEP); initial neurosurgical consult, 21.9 (NINN) and 19.1 years (SEP) (p = 0.35); and epilepsy surgery, 19.7 (NINN) and 19.6 years (SEP) (p = 0.29).

Significance

This is the first study to compare wait times between Canada and Mexico. Despite disparity in their health delivery systems and financial resources, surgical wait times appeared to be protracted in both nations, confirming that delayed treatment is a universal problem that requires collaborative scrutiny.

Quantitative and qualitative analysis of semantic verbal fluency in patients with temporal lobe epilepsy

INTRODUCTION

Patients with temporal lobe epilepsy (TLE) perform poorly on semantic verbal fluency (SVF) tasks. Completing these tasks successfully involves multiple cognitive processes simultaneously. Therefore, quantitative analysis of SVF (number of correct words in one minute), conducted in most studies, has been found to be insufficient to identify cognitive dysfunction underlying SVF difficulties in TLE.

OBJECTIVES

To determine whether a sample of patients with TLE had SVF difficulties compared with a control group (CG), and to identify the cognitive components associated with SVF difficulties using quantitative and qualitative analysis.

METHODS

SVF was evaluated in 25 patients with TLE and 24 healthy controls; the semantic verbal fluency test included 5 semantic categories: animals, fruits, occupations, countries, and verbs. All 5 categories were analysed quantitatively (number of correct words per minute and interval of execution: 0-15, 16-30, 31-45, and 46-60seconds); the categories animals and fruits were also analysed qualitatively (clusters, cluster size, switches, perseverations, and intrusions).

RESULTS

Patients generated fewer words for all categories and intervals and fewer clusters and switches for animals and fruits than the CG (P<.01). Differences between groups were not significant in terms of cluster size and number of intrusions and perseverations (P>.05).

CONCLUSIONS

Our results suggest an association between SVF difficulties in TLE and difficulty activating semantic networks, impaired strategic search, and poor cognitive flexibility. Attention, inhibition, and working memory are preserved in these patients.

High-dose versus low-dose valproate for the treatment of juvenile myoclonic epilepsy: Going from low to high

Juvenile myoclonic epilepsy (JME) is a genetic generalized epilepsy accounting for 3-12% of adult cases of epilepsy. Valproate has proven to be the first-choice drug in JME for controlling the most common seizure types: myoclonic, absence, and generalized tonic-clonic (GTC). In this retrospective study, we analyzed seizure outcome in patients with JME using valproate monotherapy for a minimum period of one year. Low valproate dose was considered to be 1000mg/day or lower, while serum levels were considered to be low if they were at or below 50mcg/dl. One hundred three patients met the inclusion criteria. Fifty-six patients (54.4%) were female. The current average age was 28.4±7.4years, while the age of epilepsy onset was 13.6±2.9years. Most patients corresponded to the subsyndrome of classic JME. Forty-six (44.7%) patients were free from all seizure types, and 76 (73.7%) patients were free from GTC seizures. No significant difference was found in seizure freedom among patients using a low dose of valproate versus a high dose (p=0.535) or among patients with low blood levels versus high blood levels (p=0.69). In patients with JME, it seems appropriate to use low doses of valproate (500mg to 1000mg) for initial treatment and then to determine if freedom from seizures was attained.

Chromosome loci vary by juvenile myoclonic epilepsy subsyndromes: linkage and haplotype analysis applied to epilepsy and EEG 3.5-6.0 Hz polyspike waves

Juvenile myoclonic epilepsy (JME), the most common genetic epilepsy, remains enigmatic because it is considered one disease instead of several diseases. We ascertained three large multigenerational/multiplex JME pedigrees from Honduras with differing JME subsyndromes, including Childhood Absence Epilepsy evolving to JME (CAE/JME; pedigree 1), JME with adolescent onset pyknoleptic absence (JME/pA; pedigree 2), and classic JME (cJME; pedigree 3). All phenotypes were validated, including symptomatic persons with various epilepsies, asymptomatic persons with EEG 3.5-6.0 Hz polyspike waves, and asymptomatic persons with normal EEGs. Two-point parametric linkage analyses were performed with 5185 single-nucleotide polymorphisms on individual pedigrees and pooled pedigrees using four diagnostic models based on epilepsy/EEG diagnoses. Haplotype analyses of the entire genome were also performed for each individual. In pedigree 1, haplotyping identified a 34 cM region in 2q21.2-q31.1 cosegregating with all affected members, an area close to 2q14.3 identified by linkage (Z max = 1.77; pedigree 1). In pedigree 2, linkage and haplotyping identified a 44 cM cosegregating region in 13q13.3-q31.2 (Z max = 3.50 at 13q31.1; pooled pedigrees). In pedigree 3, haplotyping identified a 6 cM cosegregating region in 17q12. Possible cosegregation was also identified in 13q14.2 and 1q32 in pedigree 3, although this could not be definitively confirmed due to the presence of uninformative markers in key individuals. Differing chromosome regions identified in specific JME subsyndromes may contain separate JME disease-causing genes, favoring the concept of JME as several distinct diseases. Whole-exome sequencing will likely identify a CAE/JME gene in 2q21.2-2q31.1, a JME/pA gene in 13q13.3-q31.2, and a cJME gene in 17q12.

Treatment of depression in patients with temporal lobe epilepsy: A pilot study of cognitive behavioral therapy vs. selective serotonin reuptake inhibitors

There is a high prevalence of depression in patients with epilepsy, which negatively impacts their quality of life (QOL) and seizure control. Currently, the first-line of treatment for depression in patients with epilepsy is based on selective serotonin reuptake inhibitors (SSRIs). The main objective of this pilot study was to compare cognitive behavioral therapy (CBT) versus SSRIs for the treatment of major depressive disorder (MDD) in patients with temporal lobe epilepsy (TLE). Seven patients who received group CBT were compared with eight patients treated with SSRIs. All were diagnosed with MDD and TLE. Patients were assessed at baseline before treatment and at six and 12weeks during treatment with the Quality of Life in Epilepsy Scale of 31 items (QOLIE 31), the Beck Depression Inventory (BDI), and the Hospital Anxiety and Depression Scale (HADS). Seizure records were also taken on a monthly basis. After 12weeks of treatment, both groups showed improved QOL and reduced severity of depression symptoms. There were no statistically significant group differences in the final scores for the BDI (p=0.40) and QOLIE 31 (p=0.72), although the effect size on QOL was higher for the group receiving CBT. In conclusion, the present study suggests that both CBT and SSRIs may improve MDD and QOL in patients with TLE. We found no significant outcome differences between both treatment modalities. These findings support further study using a double-blind controlled design to demonstrate the efficacy of CBT and SSRIs in the treatment of MDD and QOL in patients with TLE.

Multiple sensor integration for seizure onset detection in human patients comparing conventional disc versus novel tripolar concentric ring electrodes

As epilepsy affects approximately one percent of the world population, electrical stimulation of the brain has recently shown potential for additive seizure control therapy. Closed-loop systems that apply electrical stimulation when seizure onset is automatically detected require high accuracy of automatic seizure detection based on electrographic brain activity. To improve this accuracy we propose to use noninvasive tripolar concentric ring electrodes that have been shown to have significantly better signal-to-noise ratio, spatial selectivity, and mutual information compared to conventional disc electrodes. The proposed detection methodology is based on integration of multiple sensors using exponentially embedded family (EEF). In this preliminary study it is validated on over 26.3 hours of data collected using both tripolar concentric ring and conventional disc electrodes concurrently each from 7 human patients with epilepsy including five seizures. For a cross-validation based group model EEF correctly detected 100% and 80% of seizures respectively with <0.76 and <1.56 false positive detections per hour respectively for the two electrode modalities. These results clearly suggest the potential of seizure onset detection based on data from tripolar concentric ring electrodes.

GABAergic alterations in neocortex of patients with pharmacoresistant temporal lobe epilepsy can explain the comorbidity of anxiety and depression: the potential impact of clinical factors

Temporal lobe epilepsy (TLE) is a chronic neurodegenerative disease with a high prevalence of psychiatric disorders. Temporal neocortex contributes to either seizure propagation or generation in TLE, a situation that has been associated with alterations of the γ-amino-butyric acid (GABA) system. On the other hand, an impaired neurotransmission mediated by GABA in temporal neocortex has also been involved with the pathophysiology of psychiatric disorders. In spite of these situations, the role of the necortical GABA system in the comorbidity of TLE and mood disorders has not been investigated. The present study was designed to identify alterations in the GABA system such as binding to GABA_A and GABA_B receptors and benzodiazepine site, the tissue content of GABA and the expression of the mRNA encoding the α1–6, β1–3, and γ GABA_A subunits, in the temporal neocortex of surgically treated patients with TLE with and without anxiety, and/or depression. Neocortex of patients with TLE and comorbid anxiety and/or depression showed increased expression of the mRNA encoding the γ2-subunit, reduced GABA_B-induced G-protein activation in spite of elevated GABA_B binding, and lower tissue content of GABA when compared to autopsy controls. Some of these changes significantly correlated with seizure frequency and duration of epilepsy. The results obtained suggest a dysfunction of the GABAergic neurotransmission in temporal neocortex of patients with TLE and comorbid anxiety and/or depression that could be also influenced by clinical factors such as seizure frequency and duration of illness.

GABAergic alterations in neocortex of patients with pharmacoresistant temporal lobe epilepsy can explain the comorbidity of anxiety and depression: the potential impact of clinical factors

Temporal lobe epilepsy (TLE) is a chronic neurodegenerative disease with a high prevalence of psychiatric disorders. Temporal neocortex contributes to either seizure propagation or generation in TLE, a situation that has been associated with alterations of the γ-amino-butyric acid (GABA) system. On the other hand, an impaired neurotransmission mediated by GABA in temporal neocortex has also been involved with the pathophysiology of psychiatric disorders. In spite of these situations, the role of the necortical GABA system in the comorbidity of TLE and mood disorders has not been investigated. The present study was designed to identify alterations in the GABA system such as binding to GABAA and GABAB receptors and benzodiazepine site, the tissue content of GABA and the expression of the mRNA encoding the α1-6, β1-3, and γ GABAA subunits, in the temporal neocortex of surgically treated patients with TLE with and without anxiety, and/or depression. Neocortex of patients with TLE and comorbid anxiety and/or depression showed increased expression of the mRNA encoding the γ2-subunit, reduced GABAB-induced G-protein activation in spite of elevated GABAB binding, and lower tissue content of GABA when compared to autopsy controls. Some of these changes significantly correlated with seizure frequency and duration of epilepsy. The results obtained suggest a dysfunction of the GABAergic neurotransmission in temporal neocortex of patients with TLE and comorbid anxiety and/or depression that could be also influenced by clinical factors such as seizure frequency and duration of illness.

Visual hallucinations of autobiographic memory and asomatognosia: a case of epilepsy due to brain cysticercosis

The current study describes the case of a woman with symptomatic epilepsy due to brain cysticercosis acquired during childhood. During her adolescence, she developed seizures characterized by metamorphopsia, hallucinations of autobiographic memory and, finally, asomatognosia. Magnetic brain imaging showed a calcified lesion in the right occipitotemporal cortex, and positron emission tomography imaging confirmed the presence of interictal hypometabolism in two regions: the right parietal cortex and the right lateral and posterior temporal cortex. We discuss the link between these brain areas and the symptoms described under the concepts of epileptogenic lesion, epileptogenic zone, functional deficit zone, and symptomatogenic zone.

HLA-A*02:01:01/-B*35:01:01/-C*04:01:01 haplotype associated with lamotrigine-induced maculopapular exanthema in Mexican Mestizo patients

Aim: Several HLA alleles have been associated with antiepileptic drugs (AEDs)-induced cutaneous adverse drug reactions (cADRs) in different populations; however, this has not been investigated in Mexican Mestizos (MM). Thus, the purpose of this preliminary study was to determine the association of HLA class I alleles with AED-induced cADRs in MM patients. Materials & methods: This case–control association study included 21 MM patients with phenytoin (PHT)-, carbamazepine (CBZ)-, or lamotrigine (LTG)-induced maculopapular exanthema (MPE) or Stevens–Johnson syndrome (SJS); 31 MM patients tolerant to the same AEDs; and 225 unrelated, healthy MM volunteers. HLA class I genotyping was performed. Differences in HLA allele frequencies between AED-induced cADR patients and AED-tolerant patients were assessed. Frequencies of alleles possibly associated with AED-induced cADRs in MM patients were compared with those in MM population. Results: The frequency of HLA-C*08:01 allele in PHT-induced MPE was higher than that in the PHT-tolerant group (pc = 0.0179) or in the MM population (pc < 0.0001). For the first time, HLA-A*02:01:01/-B*35:01:01/-C*04:01:01 haplotype was associated with LTG-induced MPE (pc = 0.0048 for LTG-tolerant groups and pc < 0.0001 for MM population). Conclusion: Our data suggest the HLA-A*02:01:01/-B*35:01:01/-C*04:01:01 haplotype may be a biomarker for LTG-induced MPE and the HLA-C*08:01 allele for PHT-induced MPE. We also identified HLA-A*01:01:01 and -A*31:01:02 as candidates alleles associated with CBZ-induced MPE in MM patients. However, further investigations are necessary to confirm these findings.

Original submitted 28 March 2014; Revision submitted 15 September 2014

High-Frequency Oscillations Recorded on the Scalp of Patients With Epilepsy Using Tripolar Concentric Ring Electrodes

Epilepsy is the second most prevalent neurological disorder ([Formula: see text]% prevalence) affecting [Formula: see text] million people worldwide with up to 75% from developing countries. The conventional electroencephalogram is plagued with artifacts from movements, muscles, and other sources. Tripolar concentric ring electrodes automatically attenuate muscle artifacts and provide improved signal quality. We performed basic experiments in healthy humans to show that tripolar concentric ring electrodes can indeed record the physiological alpha waves while eyes are closed. We then conducted concurrent recordings with conventional disc electrodes and tripolar concentric ring electrodes from patients with epilepsy. We found that we could detect high frequency oscillations, a marker for early seizure development and epileptogenic zone, on the scalp surface that appeared to become more narrow-band just prior to seizures. High frequency oscillations preceding seizures were present in an average of 35.5% of tripolar concentric ring electrode data channels for all the patients with epilepsy whose seizures were recorded and absent in the corresponding conventional disc electrode data. An average of 78.2% of channels that contained high frequency oscillations were within the seizure onset or irritative zones determined independently by three epileptologists based on conventional disc electrode data and videos.

Lifetime prognosis of juvenile myoclonic epilepsy

Juvenile myoclonic epilepsy (JME) is among the most common types of genetic epilepsies, displaying a good prognosis when treated with appropriate drugs, but with a well-known tendency to relapse after withdrawal. The majority of patients with JME have continuing seizures after a follow-up of two decades. However, 17% are able to discontinue medication and remain seizure-free thereafter. Clinicians should remember that there is a small but still considerable subgroup of JME patients whose seizures are difficult to treat before informing patients with newly-diagnosed JME about their "benign" prognosis. This resistant course is not fully explained, though there are many suggested factors. The dominating myoclonic seizures disappear or diminish in severity in the fourth decade of life. Despite the favorable seizure outcome in most of the cases, 3/4 of patients with JME have at least one major unfavorable social outcome. The possible subsyndromes of JME, its genetic background, and its pathophysiological and neuroimaging correlates should be further investigated.

Consensus on diagnosis and management of JME: From founder's observations to current trends

An international workshop on juvenile myoclonic epilepsy (JME) was conducted in Avignon, France in May 2011. During that workshop, a group of 45 experts on JME, together with one of the founding fathers of the syndrome of JME ("Janz syndrome"), Prof. Dr. Dieter Janz from Berlin, reached a consensus on diagnostic criteria and management of JME. The international experts on JME proposed two sets of criteria, which will be helpful for both clinical and scientific purposes. Class I criteria encompass myoclonic jerks without loss of consciousness exclusively occurring on or after awakening and associated with typical generalized epileptiform EEG abnormalities, with an age of onset between 10 and 25. Class II criteria allow the inclusion of myoclonic jerks predominantly occurring after awakening, generalized epileptiform EEG abnormalities with or without concomitant myoclonic jerks, and a greater time window for age at onset (6-25years). For both sets of criteria, patients should have a clear history of myoclonic jerks predominantly occurring after awakening and an EEG with generalized epileptiform discharges supporting a diagnosis of idiopathic generalized epilepsy. Patients with JME require special management because their epilepsy starts in the vulnerable period of adolescence and, accordingly, they have lifestyle issues that typically increase the likelihood of seizures (sleep deprivation, exposure to stroboscopic flashes in discos, alcohol intake, etc.) with poor adherence to antiepileptic drugs (AEDs). Results of an inventory of the different clinical management strategies are given. This article is part of a supplemental special issue entitled Juvenile Myoclonic Epilepsy: What is it Really?

Severity of anxiety and depression are related to a higher perception of adverse effects of antiepileptic drugs

After reviewing the negative effects of antiepileptic drugs (AEDs) on general health and quality of life, the Commission on Outcome Measurement from the International League Against Epilepsy (ILAE) recommended incorporating reliable and valid tools in clinical essays in order to achieve a more accurate assessment of the subjective adverse effects rate and disease severity when using AEDs.

PURPOSE

The aim of this study was to correlate the severity of adverse effects of AEDs, with the presence of anxiety and depression in patients with epilepsy.

METHODS

The Spanish version of the Liverpool Adverse Events Profile (LAEP) and the hospital anxiety and depression scale (HADS) were applied on 130 consecutive outpatients with epilepsy from the epilepsy clinic at the Mexico's National Institute of Neurology and Neurosurgery. A correlation analysis was carried out to determine if the presence of depression and anxiety was related to the adverse effects of AEDs. The relation between LAEP scores with other epidemiological variables was also assessed.

RESULTS

Our study found a positive correlation between the LAEP and the HADS scores (p < or = 0.01). The most common adverse effects were drowsiness (81.5% [n=106]), difficulty in concentrating (76% [n=99]), and nervousness and/or agitation (75% [n=97]). Female gender, a history of febrile seizures, persistent seizures and polytherapy were associated with a higher toxicity on LAEP. In our study, age at epilepsy onset, duration of epilepsy, type of epilepsy and patients' age were not related to higher LAEP scores.

CONCLUSION

Adverse effects to AEDs can be related with the presence of psychiatric disorders such as anxiety and depression in patients with epilepsy.

Novel Myoclonin1/EFHC1 mutations in Mexican patients with juvenile myoclonic epilepsy

PURPOSE

The purpose of this study was to identify the prevalence of mutations in the Myoclonin1/EFHC1 gene in Mexican patients with juvenile myoclonic epilepsy (JME).

METHOD

We studied forty-one patients at the National Institute of Neurology and Neurosurgery in Mexico City and 100 healthy controls. DNA was extracted from the peripheral venous blood of all participants. The exons of EFHC1 were then amplified and sequenced.

RESULTS

We found three new putative mutations, all of which were heterozygous missense mutations located in exon 3. The first identified mutation, 352C>T, produces a R118C change in the protein and cosegregated in the patient's affected father and brother. The second identified mutation, 544C>T, produces a R182L change in the protein and was found in the patient's asymptomatic father. The third identified mutation, 458>A, produces a R153Q change in the protein and was also found in the patient's father. These mutations were not found in controls.

CONCLUSIONS

The frequency of Myoclonin1/EFHC1 mutations in our sample is 7.3%. Thus, we conclude that mutations in the Myoclonin1/EFHC1 gene are an important cause of JME in Mexican patients.

[Refractory epilepsy: use of the new definition and related risk factors. A study in the Mexican population of a third-level centre]

INTRODUCTION

The International League against Epilepsy (ILAE) has recently proposed a consensus to define refractory epilepsy.

PATIENTS AND METHODS

A retrospective, analytical, descriptive study was conducted involving 206 patients who were attended at the epilepsy clinic of a third-level centre in Mexico. The ILAE's new definition of pharmacoresistance was used to classify the patients. The frequency and risk factors involved in the refractoriness were reported. The tendency to prescribe antiepileptic drugs (AED) in this population was analysed using secondary data.

RESULTS

Of the 206 patients analysed, 57 (28%) were free of seizures, 115 (56%) continued to have seizures, 17 (8%) were classified as undetermined and 17 (8%) were pseudo-refractory. The statistically significant factors associated to pharmaco-resistance that were found in our population were: focal versus generalised epilepsy (p = 0.02), catamenial epilepsy (p = 0.02), abnormal psychomotor development (p = 0.02), history of epilepsy in the family (p = 0.025), neurological examination with focal abnormality (p = 0.04), perinatal hypoxia (p = 0.06) and prior psychiatric illness (p = 0.03). The mostly frequently AED used in mono- and polytherapy were valproate and carbamazepine. Of all the patients who were free of seizures, 47% were treated using monotherapy.

CONCLUSIONS

The frequency of pharmacoresistance in the population analysed was estimated to be 56%. Identification of the factors associated with pharmacoresistance makes it possible to consider surgical treatment or to optimise the treatment with AED. There is a tendency to use the new AED, above all in combination therapy. Our findings are consistent with those described in the literature.

DNA variants in coding region of EFHC1: SNPs do not associate with juvenile myoclonic epilepsy

PURPOSE

Juvenile myoclonic epilepsy (JME) accounts for 3 to 12% of all epilepsies. In 2004, we identified a mutation-harboring Mendelian gene that encodes a protein with one EF-hand motif (EFHC1) in chromosome 6p12. We observed one doubly heterozygous and three heterozygous missense mutations in EFHC1 segregating as an autosomal dominant gene with 21 affected members of six Hispanic JME families from California and Mexico. In 2006, similar and three novel missense mutations were reported in sporadic and familial Caucasian JME from Italy and Austria. In this study, we asked if coding single nucleotide polymorphisms (SNPs) of EFHC1 also contribute as susceptibility alleles to JME with complex genetics.

METHODS

We screened using denaturing high-performance liquid chromatography (DHPLC) and then directly sequenced the 11 exons of EFHC1 in 130 unrelated JME probands, their 352 family members, and seven exons of EFHC1 in 400-614 ethnically matched controls. We carried out case-control association studies between 124 unrelated Hispanic JME probands and 552-614 ethnically matched controls using four SNPs, rs3804506, rs3804505, rs1266787, and rs17851770. We also performed family-based association on SNPs rs3804506 and rs3804505 in 84 complete JME families using the Family-Based Association Test (FBAT) program.

RESULTS

We found no statistically significant differences between JME probands and controls in case-control association and no genetic transmission disequilibria in family-based association for the tested SNPs. In addition, we identified four new DNA variants in the coding region of EFHC1.

CONCLUSION

The four coding SNPs, rs3804506, rs3804505, rs1266787, and rs17851770, of EFHC1 may not be susceptibility alleles for JME.

Novel mutations in Myoclonin1/EFHC1 in sporadic and familial juvenile myoclonic epilepsy

BACKGROUND

Juvenile myoclonic epilepsy (JME) accounts for 3 to 12% of all epilepsies. In 2004, the GENESS Consortium demonstrated four missense mutations in Myoclonin1/EFHC1 of chromosome 6p12.1 segregating in 20% of Hispanic families with JME.

OBJECTIVE

To examine what percentage of consecutive JME clinic cases have mutations in Myoclonin1/EFHC1.

METHODS

We screened 44 consecutive patients from Mexico and Honduras and 67 patients from Japan using heteroduplex analysis and direct sequencing.

RESULTS

We found five novel mutations in transcripts A and B of Myoclonin1/EFHC1. Two novel heterozygous missense mutations (c.755C>A and c.1523C>G) in transcript A occurred in both a singleton from Mexico and another singleton from Japan. A deletion/frameshift (C.789del.AV264fsx280) in transcript B was present in a mother and daughter from Mexico. A nonsense mutation (c.829C>T) in transcript B segregated in four clinically and seven epileptiform-EEG affected members of a large Honduran family. The same nonsense mutation (c.829C>T) occurred as a de novo mutation in a sporadic case. Finally, we found a three-base deletion (-364--362del.GAT) in the promoter region in a family from Japan.

CONCLUSION

Nine percent of consecutive juvenile myoclonic epilepsy cases from Mexico and Honduras clinics and 3% of clinic patients from Japan carry mutations in Myoclonin1/EFCH1. These results represent the highest number and percentage of mutations found for a juvenile myoclonic epilepsy causing gene of any population group.

Corpus callosotomy using conformal stereotactic radiosurgery

OBJECTS

To show the clinical results of a corpus callosotomy (CC) treatment using conformal stereotactic radiosurgery (SRS) on a patient with medically intractable multifocal epilepsy.

MATERIALS AND METHODS

A 17-year-old male patient underwent corpus callosotomy conformal SRS using a dedicated linear accelerator (linac) with dynamic arcs technique. The prescribed dose was 36.0 Gy at the periphery of the rostrum, genu, and a half of the body of the corpus callosum (CCA). At 8 months after conformal SRS, the patient developed a significant brain edema and moderate transitory motor deficit, which were controlled with steroids. After 32 months follow-up, there is an improvement of 84% on drop attacks and generalized tonic-clonic seizures.

CONCLUSIONS

Conformal SRS for corpus callosotomy with a single isocenter reproduce the results reported on literature using Gamma Knife-based SRS. The results show that this technique is safe and demonstrate its efficacy to control seizures.

Juvenile myoclonic epilepsy subsyndromes: family studies and long-term follow-up

The 2001 classification subcommittee of the International League Against Epilepsy (ILAE) proposed to 'group JME, juvenile absence epilepsy, and epilepsy with tonic clonic seizures only under the sole heading of idiopathic generalized epilepsies (IGE) with variable phenotype'. The implication is that juvenile myoclonic epilepsy (JME) does not exist as the sole phenotype of family members and that it should no longer be classified by itself or considered a distinct disease entity. Although recognized as a common form of epilepsy and presumed to be a lifelong trait, a long-term follow-up of JME has not been performed. To address these two issues, we studied 257 prospectively ascertained JME patients and encountered four groups: (i) classic JME (72%), (ii) CAE (childhood absence epilepsy) evolving to JME (18%), (iii) JME with adolescent absence (7%), and (iv) JME with astatic seizures (3%). We examined clinical and EEG phenotypes of family members and assessed clinical course over a mean of 11 +/- 6 years and as long as 52 years. Forty per cent of JME families had JME as their sole clinical phenotype. Amongst relatives of classic JME families, JME was most common (40%) followed by grand mal (GM) only (35%). In contrast, 66% of families with CAE evolving to JME expressed the various phenotypes of IGE in family members. Absence seizures were more common in family members of CAE evolving to JME than in those of classic JME families (P < 0.001). Female preponderance, maternal transmission and poor response to treatment further characterized CAE evolving to JME. Only 7% of those with CAE evolving to JME were seizure-free compared with 58% of those with classic JME (P < 0.001), 56% with JME plus adolescent pyknoleptic absence and 62% with JME plus astatic seizures. Long-term follow-up (1-40 years for classic JME; 5-52 years for CAE evolving to JME, 5-26 years for JME with adolescent absence and 3-18 years for JME with astatic seizures) indicates that all subsyndromes are chronic and perhaps lifelong. Seven chromosome loci, three epilepsy-causing mutations and two genes with single nucleotide polymorphisms (SNPs) associating with JME reported in literature provide further evidence for JME as a distinct group of diseases.

Seizures of idiopathic generalized epilepsies

Idiopathic generalized epilepsies (IGEs) comprise at least 40% of epilepsies in the United States, 20% in Mexico, and 8% in Central America. Here, we review seizure phenotypes across IGE syndromes, their response to treatment and advances in molecular genetics that influence nosology. Our review included the Medline database from 1945 to 2005 and our prospectively collected Genetic Epilepsy Studies (GENESS) Consortium database. Generalized seizures occur with different and similar semiologies, frequencies, and patterns, ages at onset, and outcomes in different IGEs, suggesting common neuroanatomical pathways for seizure phenotypes. However, the same seizure phenotypes respond differently to the same treatments in different IGEs, suggesting different molecular defects across syndromes. De novo mutations in SCN1A in sporadic Dravet syndrome and germline mutations in SCN1A, SCN1B, and SCN2A in generalized epilepsies with febrile seizures plus have unraveled the heterogenous myoclonic epilepsies of infancy and early childhood. Mutations in GABRA1, GABRG2, and GABRB3 are associated with absence seizures, while mutations in CLCN2 and myoclonin/EFHC1 substantiate juvenile myoclonic epilepsy as a clinical entity. Refined understanding of seizure phenotypes, their semiology, frequencies, and patterns together with the identification of molecular lesions in IGEs continue to accelerate the development of molecular epileptology.