Myoclonic Epilepsy Research Articles

Power Spectral Density and Default Mode Network Connectivity in Generalized Epilepsy Syndromes: What to Expect from Drug-Resistant Patients

Background: Recent studies have described unique aspects of default mode network connectivity in patients with idiopathic generalized epilepsy (IGE). A complete background in this field could be gained by combining this research with spectral analysis. Objectives: An important objective of this study was to compare linear connectivity and power spectral densities across different activity bands of patients with juvenile absence epilepsy (JAE), juvenile myoclonic epilepsy (JME), generalized tonic–clonic seizures alone (EGTCSA), and drug-resistant IGE (DR-IGE) with healthy, age-matched controls. Methods: This was an observational case–control study. We performed EEG spectral analysis in MATLAB and connectivity analysis with LORETA for 39 patients with IGE and 12 drug-resistant IGE (DR-IGE) and healthy, age-matched subjects. We defined regions of interest (ROIs) from the default mode network (DMN) and performed connectivity statistics using time-varying spectra for paired samples. Using the same EEG data, we compared mean power spectral density (PSD) with epilepsy subgroups and controls across different activity bands. Results: We obtained a modified value for the mean power spectral density in the beta band for the JME group as follows. The connectivity analysis showed that, in general, there was increased linear connectivity in the DMN for the JAE, JME, and EGCTSA groups compared to the healthy controls. Reduced linear connectivity between regions of the DMN was found for DR-IGE. Conclusions: Spectral analysis of electroencephalography (EEG) for generalized epilepsy syndromes seems to be less informative than connectivity analysis for DMN. DMN connectivity analysis, especially for DR-IGE, opens up the possibility of finding biomarkers related to drug response in IGE.

Whole exome sequencing revealed ultra-rare genetic variations in juvenile myoclonic epilepsy.

Juvenile Myoclonic Epilepsy (JME) is the most common adolescent and adult-onset genetic generalized epilepsy. In this study, we aimed to identify all rare variants present in exons and exon-intron junctions in patients who met the criteria of JME, determine potentially pathogenic variants, and find the assumed genotype/phenotype correlation between the identified variants and the JME clinical features. Whole Exome Sequencing (WES) was performed for ten JME patients from different families. Validation, co-segregation and mode of inheritance were determined using Sanger DNA sequencing. Predictable damaging variants were found in six families with positive co-segregation. Eight variants in eight genes (SCN1B, KCNQ2, CACNA1I, GABRA3, BSN, RYR3, SEZ6, and RYR2) and one novel variant in (TNR) gene were found to be associated with JME. All these genes play key roles in the interactions between neurons, neurotransmitter release, and maintenance of the balance between neuronal excitation and inhibition. Since the identified genes are involved in the molecular mechanisms underlying seizures, such variants can potentially be epileptogenic. In conclusion, the identified variants that co-segregate with JME symptoms and likely contribute in creating the adequate genetic background for the JME phenotype.

Genetic heterogeneity in familial forms of genetic generalized epilepsy: from mono- to oligogenism

Genetic generalized epilepsy (GGE) including childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy (JME), and GGE with tonic–clonic seizures (TCS) (GGE-TCS), is genetically influenced with a two- to four- fold increased risk in the first-degree relatives of patients. Since large families with GGE are very rare, international studies have focused on sporadic GGE patients using whole exome sequencing, suggesting that GGE are highly genetically heterogeneous and rather involve rare or ultra-rare variants. Moreover, a polygenic mode of inheritance is suspected in most cases. We performed SNP microarrays and whole exome sequencing in 20 families from Sudan, focusing on those with at least four affected members. Standard genetic filters and Endeavour algorithm for functional prioritization of genes selected likely susceptibility variants in FAT1, DCHS1 or ASTN2 genes. FAT1 and DCHS1 are adhesion transmembrane proteins interacting during brain development, while ASTN2 is involved in dendrite development. Our approach on familial forms of GGE is complementary to large-scale collaborative consortia studies of sporadic cases. Our study reinforces the hypothesis that GGE is genetically heterogeneous, even in a relatively limited geographic area, and mainly oligogenic, as supported by the low familial penetrance of GGE and by the Bayesian algorithm that we developed in a large pedigree with JME. Since populations with founder effect and endogamy are appropriate to study autosomal recessive pathologies, they would be also adapted to decipher genetic components of complex diseases, using the reported bayesian model.Graphical

Identification of biallelic intronic EPM2A mutations in a Lafora disease kindred.

Lafora disease (LD) is a severe autosomal recessive disease, which usually presents as seizure and myoclonus, followed by behavioral changes, dysarthria, intellectual decline, and finally progressed to dementia and a vegetative state. The main cause of LD is the loss-of-function mutations in EPM2A and NHLRC1 that encode laforin and malin, respectively. Targeted genetic testing is the gold standard to confirm the diagnosis of LD. To describe the pathogenic role of biallelic EPM2A intronic mutations carried by patients in a family diagnosed as LD. Here, we present clinical findings in a patient presenting with epileptic seizures and Lafora bodies in muscle biopsy. Long-read DNA and RNA sequencing were performed to identify the causative mutation. Western blot and qPCR confirmed the pathogenic role of biallelic EPM2A intronic mutations. Genetic testing identified two intronic mutations in EPM2A which caused aberrant mRNA splicing. c.301+1 G > A in EPM2A caused aberrant splicing at donor site and resulted in intron retention in transcript NM_005670.4, while c.476+14860 C > A caused aberrant splicing in transcript NM_001368129.2 and NM_001368132.1. Our findings expand the spectrum of variants in LD disease, additionally providing evidence linking non-coding regulatory regions mutations to LD disease.

LNC-ing Genetics in Mitochondrial Disease.

Primary mitochondrial disease (MD) is a group of rare genetic diseases reported to have a prevalence of 1:5000 and is currently without a cure. This group of diseases includes mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS), maternally inherited diabetes and deafness (MIDD), Leber's hereditary optic neuropathy (LHON), Leigh syndrome (LS), Kearns-Sayre syndrome (KSS), and myoclonic epilepsy and ragged-red fiber disease (MERRF). Additionally, secondary mitochondrial dysfunction has been implicated in the most common current causes of mortality and morbidity, including cardiovascular disease (CVD) and cancer. Identifying key genetic contributors to both MD and secondary mitochondrial dysfunction may guide clinicians to assess the most effective treatment course and prognosis, as well as informing family members of any hereditary risk of disease transmission. Identifying underlying genetic causes of primary and secondary MD involves either genome sequencing (GS) or small targeted panel analysis of known disease-causing nuclear- or mitochondrial genes coding for mitochondria-related proteins. Due to advances in GS, the importance of long non-coding RNA (lncRNA) as functional contributors to the pathophysiology of MD is being unveiled. A limited number of studies have thus far reported the importance of lncRNAs in relation to MD causation and progression, and we are entering a new area of attention for clinical geneticists in specific rare malignancies. This commentary provides an overview of what is known about the role of lncRNAs as genetic and molecular contributors to disease pathophysiology and highlights an unmet need for a deeper understanding of mitochondrial dysfunction in serious human disease burdens.

Clinical efficacy of low-dose Perampanel correlates with neurophysiological changes in familial adult myoclonus epilepsy 2.

Familial adult myoclonus epilepsy (FAME) management relies on antiseizure medications (ASMs), which inadequately address myoclonus and cortical tremor. This study evaluates Perampanel (PER), an AMPA-receptor antagonist, for treating FAME symptoms. Fifteen FAME2 patients participated in an observational prospective study. They received up to 6 mg daily of PER and underwent Unified-Myoclonus-Rating-Scale (UMRS) before and after treatment. Neurophysiological evaluations, including somatosensory evoked potentials (SEPs) and transcranial magnetic stimulation (TMS), assessed PER's impact on cortical glutamatergic excitatory and GABAergic inhibitory circuits. PER treatment significantly reduced UMRS total scores (p = 0.001) and action-myoclonus subscores (p = 0.002), irrespective of disease duration, age at onset, or testing time (p >0.05). Patients with more severe baseline myoclonus demonstrated significant improvements. Neurophysiological assessments revealed a PER-induced decrease in sensorimotor hyperexcitability, characterized by diminished N33 amplitudes, attenuated glutamatergic facilitation, and enhanced GABAergic inhibition in the motor cortex. In conclusion, low-dose PER is well tolerated and effective in alleviating myoclonus in FAME2 patients, supported by its modulatory effects on glutamatergic and GABAergic neuronal circuits. Plain Language Summary: This study investigated the effects of low-dose perampanel in individuals with Familial Adult Myoclonus Epilepsy2 (FAME2), a hereditary condition characterized by epilepsy and tremors. Perampanel, an antiepileptic drug, blocks AMPA receptors in the brain, reducing excessive neural activity that causes seizures and abnormal movements. The results showed significant symptom improvement, which correlated with changes in brain activity as measured by neurophysiological tests. This study suggests that perampanel helps regulate abnormal brain signals and may help managing FAME2 symptoms.

A case of a 6-year-old girl with a rare compound heterozygous mutation of KCTD7 presenting with progressive myoclonic epilepsy

BackgroundProgressive myoclonic epilepsy is a clinically and genetically heterogeneous group of diseases characterized by myoclonic seizures, drug-resistant epilepsy and neurodevelopmental regression. The disease is attributed to mutations in KCTD7 (a member of the potassium channel tetramerization domain).Case presentationWe report the case of a 6-year-old girl with compound heterozygous mutation in KCTD7. Whole-exome sequencing was carried out to detect the mutations followed by Sanger sequencing of the patient in addition to the unaffected parents which confirmed the diagnosis. The first mutation [c. 202A > G (p.Thr68Ala)] was inherited from mother and the second one [c. 458G > A (p.Arg153His)] was inherited from father.ConclusionsTo our knowledge, this is the first report of compound heterozygousKCTD7-related progressive myoclonic epilepsy in Iran with c.202A > G in particular as a novel mutation. Our findings widen the scope of our knowledge of the underlying genetic etiology of the aforementioned disease which can further help us in the genetic diagnosis of these patients.

Progressive Myoclonus Epilepsy and Beyond: A Systematic Review of SEMA6B-related Disorders.

Progressive myoclonus epilepsy (PME) is a rare, clinically and genetically heterogeneous epilepsy syndrome, and pathogenic variants in the semaphorin 6B (SEMA6B) gene have recently been reported to be among the causes of PME. Cases with pathogenic variants in the SEMA6B gene are extremely rare, only a limited number of cases have been reported in the literature. In this systematic review, we aimed to present a summary of a PME case in which a heterozygous nonsense variant of c.2086C > T p.(Gln696*) in the SEMA6B gene was detected in the etiology and other cases with SEMA6B pathogenic variant in the literature. Except for our case, 35 cases from 12 studies were included. The main clinical findings in these patients were cognitive problems, seizures, gait and speech disturbances, and cognitive and/or motor regression, and they had a wide spectrum of severity. Response to antiseizure medications was also highly variable, almost half of the patients had pharmacoresistant seizures. Patients were divided into four different phenotypic groups according to their clinical presentations: PME (18/36), developmental and epileptic encephalopathy (13/36), neurodevelopmental disorder (4/36), and epilepsy (1/36), respectively. In conclusion, although SEMA6B has been associated with PME, it may actually cause a much broader phenotypic spectrum. Due to their extreme rarity, our knowledge of SEMA6B-related disorders is limited. As with all other rare diseases, each new SEMA6B-related disorder case could contribute to a better understanding of the disease. A better understanding of the disease may allow the development of specific treatment options in the future.

Clinical characteristics of children with MT-TK gene m.8344A>G variation

Objective: To summarize the clinical characteristics of children carrying the m.8344A>G variant of MT-TK gene. Methods: A case series study was conducted to retrospectively collect data of 22 children with mitochondrial disease caused by MT-TK gene m.8344A>G variation who were treated at the Department of Neurology of Beijing Children's Hospital of Capital Medical University from January 2012 to January 2024. Their clinical data, laboratory tests, muscle pathology, genetic testing, and the follow-up results were analyzed. Pearson correlation analysis was used for correlation analysis. Results: Among the 22 children, there were 13 boys and 9 girls. The age of onset was 5.00 (2.75, 9.00) years. Fifteen children had myoclonic epilepsy with ragged-red fibers (MERRF), 3 had Leigh syndrome (LS), and 4 had LS-MERRF overlap syndrome (LS-MERRF). Myoclonus presented and worsened progressively in all 15 MERRF children, with 10 as the initial symptom and 5 developing progressively during the disease course. Myoclonus was predominantly focal, worsening with fine motor tasks or stress. Electroencephalogram monitoring in the 15 MERRF children revealed myoclonic seizures in 10 children, with 6 classified as myoclonic epilepsy, and 4 as subcortical myoclonus. Two children had generalized myoclonic seizures, and 1 each had absence seizures and generalized seizures. Twelve children had cerebellar ataxia, 10 children exhibited exercise intolerance, and 8 children had muscle weakness. Magnetic resonance imaging (MRI) revealed periventricular white matter involvement in 1 child and bilateral hippocampal involvement in 1 child, likely due to frequent seizures. All 3 children with LS exhibited developmental regressions, accompanied with 2 symptoms include cerebellar ataxia, muscle weakness, and dysphagia. The clinical manifestations of 4 LS-MERRF overlap children presented with combined features of MERRF and LS. Cranial MRI in the 7 LS and LS-MERRF children showed brainstem involvement (all affecting the midbrain) in 6 children and basal ganglia involvement in 4 children. Among the 22 children, 12 had m.8344A>G variant levels >90%, 3 had >80%-90%, 4 had >70%-80%, and 3 had >60%-70%. Higher variant level correlated with the LS phenotype and earlier onset age (r=0.47, -0.50; P=0.018 and 0.029, respectively). Sanger sequencing in 19 mothers revealed m.8344A>G variations in 18, with 4 showing exercise intolerance. Follow-up of 13 children on antimyoclonic treatment showed>75% reduction in seizures with levetiracetam monotherapy in 2 children, with combination therapy required in others. Most achieved >50% seizures reduction within 2 years, but the effectiveness declined with disease progression. Conclusions: The m.8344A>G variant is rare, with MERRF being the most common phenotype, while LS and LS-MERRF are less common. Children with higher ratio of the m.8344A>G variant are more likely to present LS phenotype. Myoclonus, primarily focal, is a key feature, with levetiracetam as the first-line treatment and benzodiazepines recommended for refractory cases.

Latent cognitive phenotypes in juvenile myoclonic epilepsy: Clinical, sociodemographic, and neuroimaging associations.

Application of cluster analytic procedures has advanced understanding of the cognitive heterogeneity inherent in diverse epilepsy syndromes and the associated clinical and neuroimaging features. Application of this unsupervised machine learning approach to the neuropsychological performance of persons with juvenile myoclonic epilepsy (JME) has yet to be attempted, which is the intent of this investigation. A total of 77 JME participants, 19 unaffected siblings, and 44 unrelated controls, 12 to 25 years of age, were administered a comprehensive neuropsychological battery (intelligence, language, memory, executive function, and processing speed), which was subjected to factor analysis followed by K-means clustering of the resultant factor scores. Identified cognitive phenotypes were characterized and related to clinical, family, sociodemographic, and cortical and subcortical imaging features. Factor analysis revealed three underlying cognitive dimensions (general ability, speed/response inhibition, and learning/memory), with JME participants performing worse than unrelated controls across all factor scores, and unaffected siblings performing worse than unrelated controls on the general mental ability and learning/memory factors, with no JME vs sibling differences. K-means clustering of the factor scores revealed three latent groups including above average (31.4% of participants), average (52.1%), and abnormal performance (16.4%). Participant groups differed in their distributions across the latent groups (p < 0.001), with 23% JME, 22% siblings, and 2% unrelated controls in the abnormal performance group; and 18% JME, 21% siblings, and 59% unrelated controls in the above average group. Clinical epilepsy variables were unassociated with cluster membership, whereas family factors (lower parental education) and abnormally increased thickness and/or volume in the frontal, parietal, and temporal-occipital regions were associated with the abnormal cognition group. Distinct cognitive phenotypes characterize the spectrum of neuropsychological performance of patients with JME for which there is familial (sibling) aggregation. Phenotypic membership was associated with parental (education) and imaging characteristics (increased cortical thickness and volume) but not basic clinical seizure features.

Therapeutic perspectives for lysosomal storage disorders caused by acid ceramidase deficiency

Farber disease and spinal muscular atrophy with progressive myoclonic epilepsy are two ultra-rare lysosomal storage disorders resulting from loss-of-function mutations in the ASAH1 gene encoding for acid ceramidase (ACDase). ACDase deficiency leads to the intracellular accumulation of ceramides with an inflammatory response in tissues. These two diseases manifest differently but are part of a clinical continuum with variable severity affecting the nervous system and/or peripheral tissues, including the neuromuscular system. To date, no specific or curative treatments are available for patients affected by acid ceramidase deficiency. Here, we summarize the clinical features, enzyme function, mouse models and therapeutic perspectives for these allelic diseases.

Causal relationships between epilepsy and the microstructure of the white matter: A Mendelian randomization study.

To examine the causal bidirectional relationships between epilepsy and microstructural changes in the white matter (WM). A genome-wide association study meta-analysis of the International League Against Epilepsy Consortium on Epilepsy and 360 WM imaging-derived phenotypes (IDPs) from the UK Biobank was used for the analysis. Genetic correlation analyses were conducted based on summary statistics of various "IDP-epilepsy" pairs for 2-sample Mendelian randomization (MR) analysis to explore the causal relationships. We used the inverse variance weighted (IVW) method as the primary MR analysis approach, and conducted sensitivity analyses for pleiotropy and heterogeneity. Forward MR analysis revealed that alterations in the 16 WM IDPs increased the risk of epilepsy (q value < 0.05). Changes in the 38 WM IDPs were associated with a decreased risk of epilepsy (q value < 0.05). In the reverse analysis, seizures from all epilepsy types changed 5 WM IDPs, whereas seizures from juvenile myoclonic epilepsy altered 11 WM IDPs (q value < 0.05). This study revealed causal associations between changes in the WM microstructure and epilepsy subtypes. These findings offer new directions for early prevention and treatment of epilepsy.

Sleep-related epilepsies in the course of development in childhood

AbstractEpilepsy, as one of the most prevalent neurological diseases in childhood, has a strong reciprocal relationship with sleep. Sleep-associated epilepsy syndromes in childhood are mostly genetic and can be divided into (a) the group of self-limited focal epilepsies of childhood including self-limited epilepsy with autonomic seizures (SeLEAS) and self-limited epilepsy with centrotemporal spikes (SeLECTS) and (b) (non-self-limited) sleep-related hypermotor epilepsy (SHE). Sleep-accentuated (developmental and) epileptic encephalopathies (DEE/EE-SWAS, Landau–Kleffner syndrome [LKS]) are either genetic (possible transition from SeLEAS or SeLECTS) or structural, and they are characterized by continuous bilateral focal or generalized epileptic activity throughout the night with a clinical manifestation of stagnation or regression, in particular of cognition (verbal agnosia in LKS). Epilepsy syndromes with increased seizure frequency after sleep deprivation or with seizures in the transition to awakening include juvenile generalized epilepsy syndromes such as epilepsy with generalized tonic-clonic seizures alone (GTCA) or juvenile myoclonic epilepsy (JME), but also SeLECTS. Sleep is a very active process: Regeneration, reorganization, and consolidation of memory facilitate development and cognitive functioning. Epilepsy can alter sleep architecture and vice versa, which can appear as a vicious circle in epilepsies that are sleep related. Macrostructural elements of sleep such as sleep efficiency, sleep onset latency, wakefulness after sleep onset, REM and non-REM sleep fraction, as well as microstructural sleep elements such as slow-wave activity, slope of slow waves, cyclic alternating pattern (CAP), and physiological sleep figures, are important biomarkers with which to understand clinical symptoms such as cognitive stagnation and regression, to monitor treatment, but also to determine prognostic factors and will be an important tool for future studies.

Adult-onset neuronal ceroid lipofuscinosis misdiagnosed as autoimmune encephalitis and normal-pressure hydrocephalus: A 10-year case report and case-based review.

Neuronal ceroid lipofuscinoses (NCLs) are rare, fatal, inherited neurodegenerative disorders characterized by myoclonic epilepsy, cognitive decline, brain atrophy, and retinopathy. The pathogenesis and clinical manifestations of NCL are not well understood and frequently result in misdiagnosis and overtreatment. The aim of this case report and review is to improve our understanding of the clinical features and management of NCL. A 36-year-old woman initially presented with refractory epilepsy. Initially diagnosed with autoimmune encephalitis, the patient was later diagnosed with normal-pressure hydrocephalus. A definitive diagnosis of adult-onset neuronal ceroid lipofuscinosis (ANCL) was established after 10 years of observation, utilizing biopsy and genetic testing. High-dose intravenous immunoglobulin and methylprednisolone were administered, along with the insertion of a ventriculoperitoneal shunt. Despite various treatments, the patient's condition did not improve. ANCL typically presents with the clinical triad of refractory seizures, progressive cognitive decline, and movement disorders. Neuroimaging often reveals progressive brain atrophy on magnetic resonance imaging, while electroencephalograms frequently show epileptiform discharges. The prognosis is generally poor. Improved understanding of ANCL from both clinical and radiological perspectives, coupled with early consideration of differential diagnoses, could minimize unnecessary interventions and optimize patient care.

Emotional Blind Spots in Juvenile Myoclonic Epilepsy.

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Utility of Optical Genome Mapping in Repeat Disorders.

Genomic repeat sequences are patterns of nucleic acids that exist in multiple copies throughout the genome. More than 60 Mendelian disorders are caused by the expansion or contraction of these repeats. Various specific methods for determining tandem repeat variations have been developed. However, these methods are highly specific to the genomic region being studied and sometimes require specialized tools. In this study, we have investigated the use of Optical Genome Mapping (OGM) as a diagnostic tool for detecting repeat disorders. We evaluated 19 patients with a prediagnosis of repeat disorders and explained the molecular etiology of 9 of them with OGM (5 patients with Facioscapulohumeral Muscular Dystrophy (FSHD), 2 patients with Friedreich's Ataxia (FA), 1 patient with Fragile X Syndrome (FXS), and 1 patient with Progressive Myoclonic Epilepsy 1A (EPM1A)). We confirmed OGM results with more widely used fragment analysis techniques. This study highlights the utility of OGM as a diagnostic tool for repeat expansion and contraction diseases such as FA, FXS, EPM1A, and FSHD.

Quantitative MRI Measures and Cognitive Function in People With Drug-Resistant Juvenile Myoclonic Epilepsy.

Neuroimaging studies have so far identified structural changes in individuals with juvenile myoclonic epilepsy (JME) when compared with controls. However, the underlying mechanisms of drug-resistant JME remain unknown. In this study, we aimed at characterizing the structural underpinnings of drug-resistant JME using MRI-derived cortical morphologic markers. In this prospective cross-sectional 2-center study, T1-weighted MRI and neuropsychological measures of verbal memory and executive function were obtained in individuals with drug-resistant and drug-responsive JME recruited from epilepsy outpatient clinics and healthy controls. We performed vertexwise measurements of cortical thickness, surface area, and local gyrification index (LGI). Vertexwise group comparisons were corrected for multiple comparisons at a familywise error (FWE) of 0.05. The neuropsychological profile of disease subgroups was analyzed through principal component analysis. We studied 42 individuals with drug-resistant JME (mean age 29 ± 11 years, 50% female), 37 with drug-responsive JME (mean age 34 ± 10, years, 59% female), and 71 healthy controls (mean age 21 ± 9 years, 61% female). Surface area was increased in participants with drug-resistant JME in the left temporal lobe (Cohen d = 0.82 [-0.52 to -1.12], pFWE < 0.05) when compared with the drug-responsive group. Although no cortical thickness changes were observed between disease subgroups, drug-resistant and drug-sensitive participants showed discrete cortical thinning against controls (Cohen d = -0.42 [-0.83 to -0.01], pFWE < 0.05; Cohen d = -0.57 [-1.03 to -0.11], pFWE < 0.05, respectively). LGI was increased in the left temporal and occipital lobes in drug-resistant participants (Cohen d = 0.60 [0.34-0.86], pFWE < 0.05) when contrasting against drug-sensitive participants, but not controls. The composite executive function score was reduced in drug-resistant individuals compared with controls and drug-sensitive individuals (-1.74 [-2.58 to -0.90], p < 0.001 and -1.29 [-2.25 to -0.33], p < 0.01, respectively). Significant correlations were observed between executive function impairment and increased surface area in the precuneus and medial prefrontal regions (r = -0.79, pFWE < 0.05) in participants with drug-resistant JME. We identified a developmental phenotype in individuals with drug-resistant JME characterized by changes in cortical surface area and folding complexity, the extent of which correlates with executive dysfunction. No association was observed between cortical thickness and disease severity. Our findings support a neurodevelopmental basis for drug resistance and cognitive impairment in JME.

Associations between neurolinguistic deficits and personality traits in people with epilepsy.

People with epilepsy (PWE) have been hypothesized to have higher prevalence of personality disorders and cognitive disorders. The objective of this study was to investigate the controversial notion of "epileptic personality," a series of supposedly specific personality traits of people with epilepsy (PWE). For this purpose, 29 individuals with Mesial Temporal lobe Epilepsy (MTLE) and 23 with Juvenile myoclonic epilepsy (JME) as confirmed by electroencephalography (EEG), MRI scans and clinical examination, underwent a thorough neuropsychological and personality assessment. The resulting neuropsychological profiles were statistically analyzed considering possible personality disorders, character traits, cognitive and linguistic deviations from 20 healthy controls (HC). Our findings suggest accumulative cognitive and linguistic deficits in individuals with epilepsy compared to controls. It is possible that these might be misinterpreted as personality disorders. Specifically, personality traits (p = 0.049) and verbal fluency (p = 0.013), were significantly different between PWEs and controls. Also, the type of epilepsy and lateralization seem to affect executive function (p = 0.049) and pragmatology scores (p < 0.001), exhibiting differences in subgroup analysis. Different theories are considered as plausible pathophysiological explanations for the aforementioned differences. This research might serve as a basis to further investigate the cognitive aspects of epilepsy and possible pharmacological interventions, which are currently lacking.

Neuromuscular junction dysfunction in Lafora disease.

Lafora disease (LD), a fatal neurodegenerative disorder, is caused by mutations in the EPM2A gene encoding laforin phosphatase or NHLRC1 gene encoding malin ubiquitin ligase. LD symptoms include epileptic seizures, ataxia, dementia and cognitive decline. Studies on LD have primarily concentrated on the pathophysiology in the brain. A few studies have reported motor symptoms, muscle weakness and muscle atrophy. Intriguingly, skeletal muscles are known to accumulate Lafora polyglucosan bodies. Using laforin-deficient mice, an established model for LD, we demonstrate that LD pathology correlated with structural and functional impairments in the neuromuscular junction (NMJ). Specifically, we found impairment in NMJ transmission, which coincided with altered expression of NMJ-associated genes and reduced motor endplate area, fragmented junctions and loss of fully innervated junctions at the NMJ. We also observed a reduction in alpha-motor neurons in the lumbar spinal cord, with significant presynaptic morphological alterations. Disorganised myofibrillar patterns, slight z-line streaming and muscle atrophy were also evident in LD animals. In summary, our study offers insight into the neuropathic and myopathic alterations leading to motor deficits in LD.

First person – Monica Shukla

ABSTRACT First Person is a series of interviews with the first authors of a selection of papers published in Disease Models &amp; Mechanisms, helping researchers promote themselves alongside their papers. Monica Shukla is first author on ‘ Neuromuscular junction dysfunction in Lafora disease’, published in DMM. Monica is a PhD scholar in the lab of Professor S. Ganesh at the Indian Institute of Technology, Kanpur, India, investigating the influence of aberrant glycogen accumulation in neurodegenerative disorders, emphasising its effects on both the brain and muscles, and exploring how mitigating glycogen levels could alleviate the associated disease phenotype.