Juvenile myoclonic epilepsy as a spectrum disorder: A focused review

Social cognition in Idiopathic generalised epilepsies

Social cognition is a set of mental skills necessary to create satisfactory interpersonal relationships and feel a sense of belonging to a social group. Its deficits significantly reduce the quality of life in people with epilepsy. Studies on social cognition and its impairments focus predominantly on people with focal epilepsies. Idiopathic generalised epilepsies are a group of diseases that share similar clinical, prognostic and electrographic characteristics. Despite their typically normal intelligence, people with Idiopathic generalised epilepsies can suffer from learning disabilities and executive dysfunctions. Current studies also suggest social cognition impairments, but their results are inconsistent. This review offers the latest knowledge of social cognition in adults with Idiopathic generalised epilepsies. In addition, we provide an overview of the most frequently used assessment methods. We explain possible reasons for different outcomes and discuss future research perspectives.

Sleep in juvenile myoclonic epilepsy: A systematic review

Sleep disturbances significantly impact the lives of individuals with Juvenile Myoclonic Epilepsy (JME). This study aimed to investigate sleep studies, disturbances, and the impact of anti-seizure drugs on sleep in JME patients. Relevant studies were retrieved from the National Library of Medicine (Pubmed) database and the Cochrane Library utilizing the search terms "Juvenile Myoclonic Epilepsy" and "sleep". A total of 160 papers' review, data extraction, and resolution of discrepancies were performed independently by two reviewers according to the PRISMA protocol and were registered in PROSPERO (CRD42023472439). A systematic review of 31 studies was conducted, encompassing various methodologies, including sleep questionnaires (Pittsburgh Sleep Quality Index (n = 13), Epworth Sleepiness Scale (n = 10)), polysomnography (n = 8), EEG (n = 9), actigraphy (n = 1), and transcranial magnetic stimulation (n = 1). Most studies were hospital-based (n = 31), cross-sectional (n = 11), and prospective (n = 25). Patients with JME exhibit a higher prevalence of sleep disturbances, worse quality of sleep (n = 4), daytime sleepiness (n = 2), sleep efficiency (n = 7), and increased sleep latency (n = 1) compared to controls. These disruptions are characterized by increased wakefulness (n = 3), frequent arousals (n = 3), decreased REM sleep (n = 2), and conflicting NREM sleep findings (n = 3). Additional sleep-related issues observed in JME patients include insomnia (n = 1) and increased prevalence of parasomnias such as nightmares and sleep talking. Periodic limb movement and obstructive sleep apnea are similar or less frequent (3/28). REM behavioral disorders and sleepwalking were not seen. Valproate showed conflicting effects on sleep (n = 7), while levetiracetam did not impact sleep (n = 1). These findings underlined the need for more sufficient evidence of sleep studies in JME. Future research should prioritize understanding the nature of sleep in JME and its impact on management.

Idiopathic generalized epilepsy in a family with SCN4A-related myotonia

OBJECTIVES

Myotonia is a clinical sign typical of a group of skeletal muscle channelopathies, the non-dystrophic myotonias. These disorders are electrophysiologically characterized by altered membrane excitability, due to specific genetic variants in known causative genes (CLCN1 and SCN4A). Juvenile Myoclonic Epilepsy (JME) is an epileptic syndrome identified as idiopathic generalized epilepsy, its genetics is complex and still unclarified. The co-occurrence of these two phenotypes is rare and the causes likely have a genetic background. In this study, we have genetically investigated an Italian family in which co-segregates myotonia, JME, or abnormal EEG without seizures was observed.

METHODS

All six individuals of the family, 4 affected and 2 unaffected, were clinically evaluated; EMG and EEG examinations were performed. For genetic testing, Exome Sequencing was performed for the six family members and Sanger sequencing was used to confirm the candidate variant.

RESULTS

Four family members, the mother and three siblings, were affected by myotonia. Moreover, EEG recordings revealed interictal generalized sharp-wave discharges in all affected individuals, and two siblings were affected by JME. All four affected members share the same identified variant, c.644 T > C, p.Ile215Thr, in SCN4A gene. Variants that could account for the epileptic phenotype alone, separately from the myotonic one, were not identified.

SIGNIFICANCE

These results provide supporting evidence that both myotonic and epileptic phenotypes could share a common genetic background, due to variants in SCN4A gene. SCN4A pathogenic variants, already known to be causative of myotonia, likely increase the susceptibility to epilepsy in our family.

PLAIN LANGUAGE SUMMARY

This study analyzed all members of an Italian family, in which the mother and three siblings had myotonia and epilepsy. Genetic analysis allowed to identify a variant in the SCN4A gene, which appears to be the cause of both clinical signs in this family.

Transcranial brain parenchyma sonography in patients with juvenile myoclonic epilepsy

INTRODUCTION

There are rising evidences that subcortical structures, including the basal ganglia, are affected in patients with epilepsy. These structures are thought to influence the modulation and phenotypic expression of epileptic seizures. Our study aimed to evaluate the presence of structural abnormalities in subcortical structures in patients with juvenile myoclonic epilepsy (JME).

METHODS

This cross-sectional study included 51 patients who were diagnosed with JME and who were monitored on an outpatient basis at the Clinic for Neurology and Psychiatry for Children and Youth in Belgrade from January 1985 to October 2017. All patients underwent transcranial parenchymal sonography (TCS) from October 2015 to October 2017. Relation of clinical parameters (seizure control andcognitive functioning,) with TCS results was assessed.

RESULTS

Hyperechogenicity of the substantia nigra (SN) was detected in 37.2% of JME subjects and it was significantly more common in patients with JME than in the control group. The marked echogenicity of the red nucleus (RN) was detected in 17.6% of cases, while 11.8% of subjects had hyperechogenic RN. The presence of hyperechogenic RN (both right and left) was significantly more frequent in the group of patients with JME compared to the control group. The third ventricle diameter was larger in patients with JME than in controls.

CONCLUSION

Structural changes of certain subcortical structures, primarily SN and RN, detected in JME patients indicate additional non-lesional abnormalities of the basal ganglia and midbrain structures in these patients.

Drug-resistant generalized epilepsies: Revisiting the frontiers of idiopathic generalized epilepsies

The 2017 International League Against Epilepsy (ILAE) classification suggested that the term "genetic generalized epilepsies" (GGEs) should be used for the broad group of epilepsies with so-called "generalized" seizure types and "generalized" spike-wave activity on EEG, based on a presumed genetic etiology. Within this framework, idiopathic generalized epilepsies (IGEs) are described as a subset of GGEs and include only four epileptic syndromes: childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy, and epilepsy with generalized tonic-clonic seizures alone. The recent 2022 ILAE definition of IGEs is based on the current state of knowledge and reflects a community consensus and is designed to evolve as knowledge advances. The term "frontiers of IGEs" refers to the actual limits of our understanding of these four syndromes. Indeed, among patients presenting with a syndrome compatible with the 2022 definition of IGEs, we still observe a significant proportion of patients presenting with specific clinical features, refractory seizures, or drug-resistant epilepsies. This leads to the discussion of the boundaries of IGEs and GGEs, or what is accepted within a clinical spectrum of a definite IGE. Here, we discuss several entities that have been described in the literature for many years and that may either constitute rare features of IGEs or a distinct differential diagnosis. Their recognition by clinicians may allow a more individualized approach and improve the management of patients presenting with such entities.

Increased Thalamic Connectivity in Juvenile Myoclonic Epilepsy Based on Electroencephalography Source-Level Analysis

Background: This study investigated alterations in the intrinsic thalamic network of patients with juvenile myoclonic epilepsy (JME) based on an electroencephalography (EEG) source-level analysis. Materials and Methods: We enrolled patients newly diagnosed with JME as well as healthy controls. The assessments were conducted in the resting state. We computed sources based on the scalp electrical potentials using a minimum-norm imaging method and a standardized, low-resolution, brain electromagnetic tomography approach. To create a functional connectivity matrix, we used the Talairach atlas to define thalamic nodes and applied the coherence method to measure brain synchronization as edges. We then calculated the intrinsic thalamic network using graph theory. We compared the intrinsic thalamic network of patients with JME with those of healthy controls. Results: This study included 67 patients with JME and 66 healthy controls. EEG source-level analysis revealed significant differences in the intrinsic thalamic networks between patients with JME and healthy controls. The measures of functional connectivity (radius, diameter, and characteristic path length) were significantly lower in patients with JME than in healthy controls (radius: 2.769 vs. 3.544, p = 0.015; diameter: 4.464 vs. 5.443, p = 0.024; and characteristic path length: 2.248 vs. 2.616, p = 0.046). Conclusions: We demonstrated alterations in the intrinsic thalamic network in patients with JME compared with those in healthy controls based on the EEG source-level analysis. These findings indicated increased thalamic connectivity in the JME group. These intrinsic thalamic network changes may be related to the pathophysiology of JME.

Seizures and electrophysiological features in familial cortical myoclonic tremor with epilepsy 1

OBJECTIVES

To investigate and characterize epileptic seizures and electrophysiological features of familial cortical myoclonic tremor with epilepsy (FCMTE) type 1 patients in a large Chinese cohort.

METHODS

We systematically evaluated 125 FCMTEtype 1 patients carrying the pentanucleotide (TTTCA) repeat expansion in the SAMD12 gene in China.

RESULTS

Among the 28 probands, epileptic seizures (96.4%, 27/28) were the most common reason for an initial clinic visit. Ninety-seven (77.6%, 97/125) patients had experienced seizures. The seizures onset age was 36.5 ± 9.0 years, which was 6.9 years later than cortical tremors. The seizures were largely rare (<1/year, 58.8%) and occasional (1-6/year, 37.1%). Prolonged prodromes were reported in 57.7% (56/97). Thirty-one patients (24.8%, 31/125) reported photosensitivity history, and 79.5% (31/39) had a photoparoxysmal response. Interictal epileptiform discharges (IEDs) were recorded in 69.1% (56/81) of patients. Thirty-three patients showed generalized IEDs and 72.7% (24/33) were occipitally dominant, while 23 patients presented with focal IEDs with 65.2% (15/23) taking place over the occipital lobe. Overnight EEG of FCMTE patients displayed paradoxical sleep-wake fluctuation, with a higher average IED index of 0.82 ± 0.88/min during wakefulness and a lower IED index of 0.04 ± 0.06/min during non-rapid eye movement sleep stages I-II.

INTERPRETATION

FCMTE type 1 has a benign course of epilepsy and distinct clinical and electrophysiological features. In addition to a positive family history and cortical myoclonus tremor, the seizure prodromes, specific seizure triggers, photosensitivity, distribution of IEDs, and unique fluctuations during sleep-wake cycle are cues for proper genetic testing and an early diagnosis of FCMTE.

Diffusion tensor imaging in photosensitive and nonphotosensitive juvenile myoclonic epilepsy

INTRODUCTION/BACKGROUND

Juvenile myoclonic epilepsy (JME) syndrome is known to cause alterations in brain structure and white matter integrity. The study aimed to determine structural white matter changes in patients with JME and to reveal the differences between the photosensitive (PS) and nonphotosensitive (NPS) subgroups by diffusion tensor imaging (DTI) using the tract-based spatial statistics (TBSS) method.

METHODS

This study included data from 16 PS, 15 NPS patients with JME, and 41 healthy participants. The mean fractional anisotropy (FA) values of these groups were calculated, and comparisons were made via the TBSS method over FA values in the whole-brain and 81 regions of interest (ROI) obtained from the John Hopkins University White Matter Atlas.

RESULTS

In the whole-brain TBSS analysis, no significant differences in FA values were observed in pairwise comparisons of JME patient group and subgroups with healthy controls (HCs) and in comparison between JME subgroups. In ROI-based TBSS analysis, an increase in FA values of right anterior corona radiata and left corticospinal pathways was found in JME patient group compared with HC group. When comparing JME-PS patients with HCs, an FA increase was observed in the bilateral anterior corona radiata region, whereas when comparing JME-NPS patients with HCs, an FA increase was observed in bilateral corticospinal pathway. Moreover, in subgroup comparison, an increase in FA values was noted in corpus callosum genu region in JME-PS compared with JME-NPS.

CONCLUSIONS

Our results support the disruption in thalamofrontal white matter integrity in JME, and subgroups and highlight the importance of using different analysis methods to show the underlying microstructural changes.

The Muddle of Myoclonus: Many Guises, 2 Disciplines, Consensus Needed

Myoclonus is often approached in different ways by epileptologists and movement disorder specialists, leading to confusion in the literature. Multiplicity and inconsistency over the past 2 centuries resulted in a lack of precision and ambiguity of the terminology. We show that this is a current problem in which one phenomenon has been described with many terms and vice versa. Of more importance, we discuss the conceptualization of myoclonus from perspectives of both fields and focus on the borderland that exists, especially in the spectrum of cortical and epileptic myoclonus. By giving 2 examples, we illustrate the conundrum: the spectrum of progressive myoclonus epilepsies and progressive myoclonic ataxias and "cortical tremor" observed in familial cortical myoclonic tremor with epilepsy or familial adult myoclonic epilepsy. We attempt to facilitate to bridge these subspecialties and form the base for a uniform understanding to take this issue forward toward future classifications, discussions, and scientific research.

Electroclinical Features and Long-Term Photosensitivity Outcome in Patients With Photoparoxysmal Response With Epilepsy

BACKGROUND

To investigate electroclinical phenotypes and long-term photosensitivity outcome in a large pediatric cohort of patients with epilepsy with photosensitivity.

METHODS

Patients with epilepsy with photosensitivity with four or more years of follow-up were included. Sustained terminal remission (STR) of photosensitivity (≥3.5 years) and seizure control were investigated, as well as the prognostic factors of photosensitivity. Furthermore, a cluster analysis was used to study the different subgroups of photoparoxysmal responses (PPR).

RESULTS

We included 190 individuals with a median age at diagnosis of photosensitivity of 93.1 months (interquartile range [IQR] 62.8 to 120 months) and a median follow-up duration of 68.5 months (IQR 51.8 to 84 months). STR of photosensitivity was achieved in 97 (51.1%) patients, and the mean time from age at diagnosis of photosensitivity onset to STR was 16.5 months. Age at the last follow-up (9 to 18 years [P = 0.001]), a history of photoconvulsive response (PCR) (P = 0.009), and posterior epileptiform discharges (EDs) of PPRs (P = 0.05) were significantly associated with a lower chance of entering STR according to a Cox proportional hazards model. The subgroup of generalized epilepsy syndrome exhibited 46.2% of eye closure sensitivity and 47.7% of PCR. The rates of focal epilepsy syndrome (cluster 1), generalized epilepsy syndrome (cluster 2), and unclassified epilepsy (cluster 3) were similar and not statistically different in photosensitive outcome (P = 0.527).

CONCLUSIONS

Age nine to 18 years, a history of PCR, and posterior EDs of PPRs were the adverse factors affecting photosensitivity, suggesting the effect of age-related brain changes in STR. There was no difference in the prognosis of photosensitivity in different epileptic syndromes.

Facial Emotion Recognition in Patients with Juvenile Myoclonic Epilepsy

Previous studies have found facial emotion recognition (FER) impairments in individuals with epilepsy. While such deficits have been extensively explored in individuals with focal temporal lobe epilepsy, studies on individuals with generalized epilepsies are rare. However, studying FER specifically in individuals with juvenile myoclonic epilepsy (JME) is particularly interesting since they frequently suffer from social and neuropsychological difficulties in addition to epilepsy-specific symptoms. Furthermore, recent brain imaging studies have shown subtle microstructural alterations in individuals with JME. FER is considered a fundamental social skill that relies on a distributed neural network, which could be disturbed by network dysfunction in individuals with JME. This cross-sectional study aimed to examine FER and social adjustment in individuals with JME. It included 27 patients with JME and 27 healthy controls. All subjects underwent an Ekman-60 Faces Task to examine FER and neuropsychological tests to assess social adjustment as well as executive functions, intelligence, depression, and personality traits. Individuals with JME performed worse in global FER and fear and surprise recognition than healthy controls. However, probably due to the small sample size, no significant difference was found between the two groups. A potential FER impairment needs to be confirmed in further studies with larger sample size. If so, patients with JME could benefit from addressing possible deficits in FER and social difficulties when treated. By developing therapeutic strategies to improve FER, patients could be specifically supported with the aim of improving social outcomes and quality of life.

Association of symptoms of psychiatric disease and electroencephalographic patterns in idiopathic generalized epilepsy

OBJECTIVE

Idiopathic generalized epilepsies (IGE) are genetic epilepsies with alterations of thalamo-frontocortical circuits that play a major role in seizure generation and propagation. Psychiatric diseases and drug resistance are strongly associated, but it remains unknown if they are symptoms of the same pathophysiological process. Hypothesizing that the same network alterations are associated with the frequency of epileptic discharges (ED) and psychiatric symptoms, we here tested the association of self-reported psychiatric symptoms and IGE severity estimated by electroencephalographic (EEG) biomarkers.

METHODS

Idiopathic generalized epilepsies patients were asked to fill out four validated psychiatric screening tools assessing symptoms of personality disorders (Standard Assessment of Personality- Abbreviated Scale), depression (Major Depression Inventory), impulsiveness (Barratt Impulsiveness Scale), and anxiety (brief Epilepsy Anxiety Survey Instrument). Blinded to results and clinical data on the patients, we analyzed the patients' EEGs, assessed, and quantified ED. The number and duration of ED divided by the duration of the EEG served as a proxy for the severity of IGE that was correlated with the results of the psychiatric screening.

RESULTS

Paired data from 64 patients were available for analysis. The duration of EDs per minute EEG was inversely associated with the time since the last seizure. The number of patients with generalized polyspike trains (n = 2), generalized paroxysmal fast activity (n = 3), and prolonged epileptiform discharges (n = 10) were too low for statistically meaningful analyses. Self-reported symptoms of depression, personality disorder, and impulsivity were not associated with EDs. In contrast, the duration of EDs per minute EEG was associated with self-reported symptoms of anxiety in univariate analyses, not significant, however, following adjustment for time since the last seizure in regression models.

SIGNIFICANCE

Self-reported symptoms of psychiatric diseases were not strongly associated with EDs as the best available quantifiable biomarker of IGE severity. As expected, the duration of EDs per minute and anxiety was inversely associated with time since the last seizure. Our data argue against a direct link between the frequency of EDs - as an objective proxy of IGE severity - and psychiatric symptoms.

Variation in prognosis and treatment outcome in juvenile myoclonic epilepsy: a Biology of Juvenile Myoclonic Epilepsy Consortium proposal for a practical definition and stratified medicine classifications

Reliable definitions, classifications and prognostic models are the cornerstones of stratified medicine, but none of the current classifications systems in epilepsy address prognostic or outcome issues. Although heterogeneity is widely acknowledged within epilepsy syndromes, the significance of variation in electroclinical features, comorbidities and treatment response, as they relate to diagnostic and prognostic purposes, has not been explored. In this paper, we aim to provide an evidence-based definition of juvenile myoclonic epilepsy showing that with a predefined and limited set of mandatory features, variation in juvenile myoclonic epilepsy phenotype can be exploited for prognostic purposes. Our study is based on clinical data collected by the Biology of Juvenile Myoclonic Epilepsy Consortium augmented by literature data. We review prognosis research on mortality and seizure remission, predictors of antiseizure medication resistance and selected adverse drug events to valproate, levetiracetam and lamotrigine. Based on our analysis, a simplified set of diagnostic criteria for juvenile myoclonic epilepsy includes the following: (i) myoclonic jerks as mandatory seizure type; (ii) a circadian timing for myoclonia not mandatory for the diagnosis of juvenile myoclonic epilepsy; (iii) age of onset ranging from 6 to 40 years; (iv) generalized EEG abnormalities; and (v) intelligence conforming to population distribution. We find sufficient evidence to propose a predictive model of antiseizure medication resistance that emphasises (i) absence seizures as the strongest stratifying factor with regard to antiseizure medication resistance or seizure freedom for both sexes and (ii) sex as a major stratifying factor, revealing elevated odds of antiseizure medication resistance that correlates to self-report of catamenial and stress-related factors including sleep deprivation. In women, there are reduced odds of antiseizure medication resistance associated with EEG-measured or self-reported photosensitivity. In conclusion, by applying a simplified set of criteria to define phenotypic variations of juvenile myoclonic epilepsy, our paper proposes an evidence-based definition and prognostic stratification of juvenile myoclonic epilepsy. Further studies in existing data sets of individual patient data would be helpful to replicate our findings, and prospective studies in inception cohorts will contribute to validate them in real-world practice for juvenile myoclonic epilepsy management.

Onchocerciasis-associated epilepsy in Maridi, South Sudan: Modelling and exploring the impact of control measures against river blindness

BACKGROUND

Onchocerciasis, also known as "river blindness", is caused by the bite of infected female blackflies (genus Simuliidae) that transmit the parasite Onchocerca volvulus. A high onchocerciasis microfarial load increases the risk to develop epilepsy in children between the ages of 3 and 18 years. In resource-limited settings in Africa where onchocerciasis has been poorly controlled, high numbers of onchocerciasis-associated epilepsy (OAE) are reported. We use mathematical modeling to predict the impact of onchocerciasis control strategies on the incidence and prevalence of OAE.

METHODOLOGY

We developed an OAE model within the well-established mathematical modelling framework ONCHOSIM. Using Latin-Hypercube Sampling (LHS), and grid search technique, we quantified transmission and disease parameters using OAE data from Maridi County, an onchocerciasis endemic area, in southern Republic of South Sudan. Using ONCHOSIM, we predicted the impact of ivermectin mass drug administration (MDA) and vector control on the epidemiology of OAE in Maridi.

PRINCIPAL FINDINGS

The model estimated an OAE prevalence of 4.1% in Maridi County, close to the 3.7% OAE prevalence reported in field studies. The OAE incidence is expected to rapidly decrease by >50% within the first five years of implementing annual MDA with good coverage (≥70%). With vector control at a high efficacy level (around 80% reduction of blackfly biting rates) as the sole strategy, the reduction is slower, requiring about 10 years to halve the OAE incidence. Increasing the efficacy levels of vector control, and implementing vector control simultaneously with MDA, yielded better results in preventing new cases of OAE.

CONCLUSIONS/SIGNIFICANCES

Our modeling study demonstrates that intensifying onchocerciasis eradication efforts could substantially reduce OAE incidence and prevalence in endemic foci. Our model may be useful for optimizing OAE control strategies.

Prevalence, nature, and severity of the psychiatric comorbidities and their impact on quality of life in adolescents with Juvenile myoclonic epilepsy

INTRODUCTION

Adults with Juvenile myoclonic epilepsy (JME) are at increased risk for psychiatric comorbidities, personality traits, and abnormality in executive function. But studies on adolescents and their impact on quality of life are scarce in the literature.

MATERIALS AND METHODS

This cross-sectional study was performed between August 2019 and October 2022 to compare the prevalence of psychiatric comorbidities in adolescents with JME and age and gender-matched healthy controls. After completing DSM-5 Structured Clinical Interview (SCID-5) initially in all patients, we measured the severity of individual psychiatric problems like anxiety, depression, and somatic symptoms by using an appropriate psychometric scale. We also measured both groups' intelligence quotient (IQ), executive function, and quality of life.

RESULTS

One hundred patients with JME (14.3 ± 2.5 years, 48 boys) and 100 controls were enrolled. Psychiatric disorders were observed in 46% of JME and 6% of controls (p < 0.01). Psychiatric comorbidities noted in the patients with JME were: somatic symptom and related disorders(n = 14), anxiety (n = 13), adjustment disorders (n = 12), depression (n = 11), oppositional defiant disorder (n = 6), conduct disorder (n = 5), anorexia nervosa (n = 3), narcissistic (n = 3), histrionic (n = 1), substance-related disorder (n = 1), borderline (n = 2) and antisocial personality disorder (n = 2). The prevalence of depressive disorders, anxiety disorders, adjustment disorders, somatic symptoms, related disorders, and any personality disorder was significantly more in the JME group (p < 0.01 for all). Female gender, higher Epilepsy Stigma Scale score, and lower Epilepsy Outcome Expectancy Scale were significantly associated with depressive disorders (p = 0.04, 0.03, 0.03 respectively). Similarly, for anxiety, only female gender and lower Epilepsy Outcome Expectancy Scale were significant associated factors (p = 0.03, 0.02 respectively).

CONCLUSIONS

Psychiatric disorders like anxiety, depression, and personality disorders are more frequent in adolescents with JME than in controls.

Peri-ictal headache: An underestimated prognostic finding associated with idiopathic epilepsies

OBJECTIVE

There are a handful of studies investigating peri-ictal headache (PIH) and its clinical associations in patients with idiopathic/genetic epilepsies (I/GE). This multi-center study aimed to investigate PIH, which is an ignored comorbid condition in patients with I/GE, by headache experts and epileptologists working together.

METHODS

The data were collected from a cross-sectional large study, using two structured questionnaires for headache and epilepsy features, fulfilled by neurologists. Headaches were classified according to the International Classification of Headache Disorders, third edition, whereas seizure and syndrome types were diagnosed according to International League Against Epilepsy criteria. The patients with a headache starting 24 hours before the onset of the seizure (preictal) or within 3 hours after the seizure (postictal) were defined as patients with PIH. We compared demographic and clinical differences between two groups of patients with and without PIH statistically and used ROC curves to determine a threshold of the total number of seizure triggers associated with the occurrence of PIH.

RESULTS

Among 809 (531 females, 65.6%) consecutive patients with I/GE, 105 (13%) patients reported PIH (22 preictal, 82 postictal headaches, and one with both types). Peri-ictal headache was more frequently reported by females and those having a family history of migraine or epilepsy, and it was significantly associated with lower rates of seizure freedom for more than five years, drug resistance, and use of polytherapy, remarkably. Moreover, ROC curves showed that having more than 3 seizure triggers was associated with the presence of PIH.

CONCLUSION

Our findings revealed that PIH may be linked to poor outcomes in I/GEs and seems to be related to a lower ictal threshold precipitated by multiple triggers. Future prospective studies will illuminate the unknown underlying mechanisms and appropriate management strategies for PIH to improve the prognosis.

Clinical Characteristics and Prognosis of Juvenile Myoclonic Epilepsy: Single-Center Retrospective Study

Juvenile myoclonic epilepsy (JME) is one of the most common idiopathic (genetic) generalized epilepsy syndromes. It occurs in healthy adolescents and is characterized by the triad of myoclonic jerks, generalized tonic-clonic seizures (GTCs), and absence seizures. The study's primary aim was to determine the demographic and clinical characteristics, family history of seizure, electroencephalogram findings, treatments, and short-term prognosis of patients diagnosed with JME. Patients diagnosed with JME at the Pediatric Neurology Department of Sağlık Bilimleri University Adana Numune Training and Research Hospitals were enrolled. Thirteen (30%) of 44 patients were male, whereas 31 (70%) were female, with a mean age at diagnosis of 14 ± 1.3 years. In total, 21 patients (48%) had a family history of epilepsy, and 14 patients (32%) had JME in their families. Those having a family history of JME seizures were identified at a younger age. Thirty (68%) patients presented with GTCs, while 14 (32%) presented with myoclonic seizures at the time of diagnosis. In the history, 98% of patients had myoclonus and one patient had an absence seizure. Patients with the first seizure type GTCs were diagnosed later, while patients with myoclonus were diagnosed earlier (p < 0,05). The most precipitating factors for seizures were sleep deprivation and stress. Thirty-eight (86%) of the EEGs recorded during the initial admission was abnormal. Valproic acid was administered to 32 patients (73%), while levetiracetam was administered to 12 patients (27%) as the initial treatment. Forty-one (93%) of the patients exhibited a complete response to the initial medication therapy, while forty (91%) of the patients received monotherapy, and only four (9%) received polytherapy. JME may be well-controlled epilepsy with early diagnosis and appropriate treatment. A family history of JME is also common among patients with JME. Patients with the myoclonus as a first seizure type are diagnosed earlier than GTCs because of family awareness. A family history of JME may facilitate the diagnosis of new cases in the family.

Differential diagnosis of familial adult myoclonic epilepsy

OBJECTIVE

Familial adult myoclonic epilepsy (FAME) is an under-recognized disorder characterized by cortical myoclonus, generalized tonic-clonic seizures, and additional clinical symptoms, which vary depending on the FAME subtype. FAME is caused by pentanucleotide repeat expansions of intronic TTTCA/TTTTA in different genes. FAME should be distinguished from a range of differential diagnoses.

METHODS

The differential diagnoses and frequent presentations leading to misdiagnosis of FAME were investigated from the available literature and reported based on an expert opinion survey.

RESULTS

The phenotypic features of FAME, including generalized tonic-clonic and myoclonic seizures, are also seen in other epilepsy syndromes, such as juvenile myoclonic epilepsy, with a resultant risk of misdiagnosis and lack of identification of the underlying cause. Cortical myoclonus may mimic essential tremor or drug-induced tremor. In younger individuals, the differential diagnosis includes progressive myoclonus epilepsies (PMEs), such as Unverricht-Lundborg disease, whereas, in adulthood, late-onset variants of PMEs, such as sialidoses, myoclonus epilepsy, and ataxia due to potassium channel pathogenic variants should be considered. PMEs may also be suggested by cognitive impairment, cerebellar signs, or psychiatric disorders. Electroencephalography (EEG) may show similarities to other idiopathic generalized epilepsies or PMEs, with generalized spike-wave activity. Signs of cortical hyperexcitability may be seen, such as an increased amplitude of somatosensory evoked potentials or enhanced cortical reflex to sensory stimuli, together with the neurophysiological pattern of the movement disorder.

SIGNIFICANCE

Recognition of FAME will inform prognostic and genetic counseling and diagnosis of the insidious progression, which may occur in older individuals who show mild cognitive deterioration. Distinguishing FAME from other disorders in individuals or families with this constellation of symptoms is essential to allow the identification of underlying etiology.

Neurophysiology of Juvenile and Progressive Myoclonic Epilepsy

SUMMARY

Myoclonus can be epileptic or nonepileptic. Epileptic myoclonus has been defined in clinical, neurophysiological, and neuroanatomical terms. Juvenile myoclonic epilepsy (JME) is typically considered to be an adolescent-onset idiopathic generalized epilepsy with a combination of myoclonic, generalized tonic-clonic, and absence seizures and normal cognitive status that responds well to anti-seizure medications but requires lifelong treatment. EEG shows generalized epileptiform discharges and photosensitivity. Recent observations indicate that the clinical picture of JME is heterogeneous and a number of neuropsychological and imaging studies have shown structural and functional abnormalities in the frontal lobes and thalamus. Advances in neurophysiology and imaging suggest that JME may not be a truly generalized epilepsy, in that restricted cortical and subcortical networks appear to be involved rather than the entire brain. Some patients with JME may be refractory to anti-seizure medications and attempts have been made to identify neurophysiological biomarkers predicting resistance. Progressive myoclonic epilepsy is a syndrome with multiple specific causes. It is distinct from JME because of the occurrence of progressive neurologic dysfunction in addition to myoclonus and generalized tonic-clonic seizures but may sometimes be difficult to distinguish from JME or misdiagnosed as drug-resistant JME. This article provides an overview of progressive myoclonic epilepsy and focuses on the clinical and neurophysiological findings in the two most commonly recognized forms of progressive myoclonic epilepsy-Unverricht-Lundborg disease (EPM1) and Lafora disease (EPM2). A variety of neurophysiological tests can be used to distinguish between JME and progressive myoclonic epilepsy and between EPM1 and EPM2.

Drug resistance in idiopathic generalized epilepsies: Evidence and concepts

Although approximately 10%-15% of patients with idiopathic generalized epilepsy (IGE)/genetic generalized epilepsy remain drug-resistant, there is no consensus or established concept regarding the underlying mechanisms and prevalence. This review summarizes the recent data and the current hypotheses on mechanisms that may contribute to drug-resistant IGE. A literature search was conducted in PubMed and Embase for studies on mechanisms of drug resistance published since 1980. The literature shows neither consensus on the definition nor a widely accepted model to explain drug resistance in IGE or one of its subsyndromes. Large-scale genetic studies have failed to identify distinct genetic causes or affected genes involved in pharmacokinetics. We found clinical and experimental evidence in support of four hypotheses: (1) "network hypothesis"-the degree of drug resistance in IGE reflects the severity of cortical network alterations, (2) "minor focal lesion in a predisposed brain hypothesis"-minor cortical lesions are important for drug resistance, (3) "interneuron hypothesis"-impaired functioning of γ-aminobutyric acidergic interneurons contributes to drug resistance, and (4) "changes in drug kinetics"-genetically impaired kinetics of antiseizure medication (ASM) reduce the effectiveness of available ASMs. In summary, the exact definition and cause of drug resistance in IGE is unknown. However, published evidence suggests four different mechanisms that may warrant further investigation.

The spectrum of epilepsy with eyelid myoclonia: delineation of disease subtypes from a large multicenter study

OBJECTIVE

Epilepsy with eyelid myoclonia (EEM) has been associated with marked clinical heterogeneity. Early epilepsy onset has been recently linked to lower chances of achieving sustained remission and to a less favorable neuropsychiatric outcome. However, much work is still needed to better delineate this epilepsy syndrome.

METHODS

In this multicenter retrospective cohort study, we included 267 EEM patients from 9 countries. Data about electroclinical and demographic features, intellectual functioning, migraine with or without aura, family history of epilepsy and epilepsy syndromes in relatives were collected in each patient. The impact of age at epilepsy onset (AEO) on EEM clinical features was investigated, along with the distinctive clinical characteristics of patients showing sporadic myoclonia over body regions other than eyelids (body-MYO).

RESULTS

Kernel density estimation revealed a trimodal distribution of AEO and Fisher-Jenks optimization disclosed three EEM subgroups: early-onset (EO-EEM), intermediate-onset (IO-EEM) and late-onset subgroup (LO-EEM). EO-EEM was associated with the highest rate of intellectual disability, antiseizure medication refractoriness and psychiatric comorbidities and with the lowest rate of family history of epilepsy. LO-EEM was associated with the highest proportion of body-MYO and generalized tonic-clonic seizures (GTCS), whereas IO-EEM had the lowest observed rate of additional findings. A family history of EEM was significantly more frequent in IO-EEM and LO-EEM compared with EO-EEM. In the subset of patients with body-MYO (58/267), we observed a significantly higher rate of migraine and GTCS but no relevant differences in other electroclinical features and seizure outcome.

SIGNIFICANCE

Based on AEO, we identified consistent EEM subtypes characterized by distinct electroclinical and familial features. Our observations shed new light on the spectrum of clinical features of this generalized epilepsy syndrome and may help clinicians towards a more accurate classification and prognostic profiling of EEM patients.

Elevated photic response is followed by a rapid decay and depressed state in ictogenic networks

OBJECTIVE

The switch between nonseizure and seizure states involves profound alterations in network excitability and synchrony. In this study, we aimed to identify and compare features of neural excitability and dynamics across multiple zebrafish seizure and epilepsy models.

METHODS

Inspired by video-electroencephalographic recordings in patients, we developed a framework to study spontaneous and photically evoked neural and locomotor activity in zebrafish larvae, by combining high-throughput behavioral tracking and whole-brain in vivo two-photon calcium imaging.

RESULTS

Our setup allowed us to dissect behavioral and physiological features that are divergent or convergent across multiple models. We observed that spontaneous locomotor and neural activity exhibit great diversity across models. Nonetheless, during photic stimulation, hyperexcitability and rapid response dynamics were well conserved across multiple models, highlighting the reliability of photically evoked activity for high-throughput assays. Intriguingly, in several models, we observed that the initial elevated photic response is often followed by rapid decay of neural activity and a prominent depressed state. Elevated photic response and following depressed state in seizure-prone networks are significantly reduced by the antiseizure medication valproic acid. Finally, rapid decay and depression of neural activity following photic stimulation temporally overlap with slow recruitment of astroglial calcium signals that are enhanced in seizure-prone networks.

SIGNIFICANCE

We argue that fast decay of neural activity and depressed states following photic response are likely due to homeostatic mechanisms triggered by excessive neural activity. An improved understanding of the interplay between elevated and depressed excitability states might suggest tailored epilepsy therapies.

Headache in idiopathic/genetic epilepsies: Cluster analysis in a large cohort

OBJECTIVES

The link between headache and epilepsy is more prominent in patients with idiopathic/genetic epilepsy (I/GE). We aimed to investigate the prevalence of headache and to cluster patients with regard to their headache and epilepsy features.

METHODS

Patients aged 6-40 years, with a definite diagnosis of I/GE, were consecutively enrolled. The patients were interviewed using standardized epilepsy and headache questionnaires and their headache characteristics were investigated by experts in headache. Demographic and clinical variables were analyzed and patients were clustered according to their epilepsy and headache characteristics using an unsupervized K-means algorithm.

RESULTS

Among 809 patients, 508 (62.8%) reported having any type of headache; 87.4% had interictal headache and 41.2% had migraine. Cluster analysis revealed two distinct groups for both adults and children/adolescents. In adults, having a family history of headache, ≥5 headache attacks, duration of headache ≥24 months, headaches lasting ≥ 1 hour, and visual analog scale scores >5 were grouped in one cluster, and juvenile myoclonic epilepsy (JME), myoclonic, and generalized tonic-clonic seizures (GTCS) were clustered in this group (cluster 1). Self-limited epilepsy with centro-temporal spikes and epilepsy with GTCS alone were clustered in cluster 2 with the opposite characteristics. For children/adolescents, the same features as in adult cluster 1 were clustered in a separate group, except for the presence of JME syndrome and GTCS alone as a seizure type. Focal seizures were clustered in another group with the opposite characteristics. In the entire group, the model revealed an additional cluster, including patients with the syndrome of GTCS-alone (50.51%), with ≥ 5 attacks, headache lasting >4 hours, and throbbing headache; 65.66% of patients had a family history of headache in this third cluster (n=99).

SIGNIFICANCE

Patients with I/GE can be clustered into distinct groups according to headache features along with seizures. Our findings may help in management and planning for future studies.

Genetic generalized epilepsies in adults - challenging assumptions and dogmas

Genetic generalized epilepsy (GGE) syndromes start during childhood or adolescence, and four commonly persist into adulthood, making up 15-20% of all cases of epilepsy in adults. These four GGE syndromes are childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy and epilepsy with generalized tonic-clonic seizures alone. However, in ~20% of patients with GGE, characteristics of more than one syndrome are present. Novel insights into the genetic aetiology, comorbidities and prognosis of the GGE syndromes have emerged and challenge traditional concepts about these conditions. Evidence has shown that the mode of inheritance in GGE is mostly polygenic. Neuropsychological and imaging studies indicate similar abnormalities in unaffected relatives of patients with GGE, supporting the concept that underlying alterations in bilateral frontothalamocortical networks are genetically determined. Contrary to popular belief, first-line anti-seizure medication often fails to provide seizure freedom in combination with good tolerability. Nevertheless, long-term follow-up studies have shown that with advancing age, many patients can discontinue their anti-seizure medication without seizure relapses. Several outcome predictors have been identified, but prognosis across the syndromes is more homogeneous than previously assumed. Overall, overlap in pathophysiology, seizure types, treatment responses and outcomes support the idea that GGEs are not separate nosological entities but represent a neurobiological continuum.

Glymphatic system dysfunction in patients with juvenile myoclonic epilepsy

OBJECTIVE

The glymphatic system is a glial cell-dependent waste clearance pathway in the brain that is essential for the maintenance of brain homeostasis. In this study, we evaluated glymphatic system function in patients with juvenile myoclonic epilepsy (JME) compared with healthy controls.

METHODS

Patients with JME and healthy controls were retrospectively enrolled in this study. All the participants underwent brain diffusion tensor imaging (DTI). The "DTI-analysis along the perivascular space (ALPS)"-index was calculated to evaluate the glymphatic system function of the participants. The ALPS-indices of the patients with JME were compared with those of the healthy controls. In addition, the correlations between ALPS-index and the clinical characteristics of the patients with JME were analyzed to validate changes in glymphatic system function.

RESULTS

A total of 39 patients with JME and 38 healthy controls were enrolled in this study. The mean ALPS- index of the patients with JME was significantly lower than that of the healthy controls (1.541 vs. 1.653, p = 0.041). ALPS-index was negatively correlated with age in patients with JME (r = -0.375, p = 0.018). However, ALPS-index was not correlated with age at onset, duration of epilepsy, or anti-seizure medication load in patients with JME.

CONCLUSION

This study is the first in which the ALPS method was used to demonstrate that patients with JME have significant glymphatic system dysfunction. The results also show that glymphatic system index is negatively correlated with age in patients with JME, a finding which demonstrates that the glymphatic system function of patients with JME gradually declines with age. The ALPS-index might be a potential biomarker for monitoring glymphatic system function in patients with epilepsy.

Psychotic Disorders in Epilepsy: Do They Differ from Primary Psychosis?

Any attempt to compare the definitions of symptoms listed for "primary psychoses" with those adopted in studies of psychoses in patients with epilepsy (PWE) will encounter problems of heterogeneity within both conditions. In this manuscript, five psychotic illnesses listed in Diagnostic and Statistical Manual of Mental Disorders-5th Edition (DSM-5), that is, brief psychotic illness, schizophreniform disorder, schizophrenia, delusional disorder, and schizoaffective disorder are compared with postictal (or periictal) and interictal psychotic disorders in PWE. After examining definitions of primary psychoses, definitions of psychoses adopted in the papers dealing with postictal and interictal psychoses are summarized. Further, diagnostic criteria of five types of psychotic disorders in PWE proposed in 2007 by Krishnamoorthy et al. are also discussed, which include postictal psychosis, comorbid schizophrenia, iatrogenic psychosis caused by antiepileptic drugs (AEDs) (AED-induced psychotic disorder: AIPD), and forced normalization. Evidently, a comparison between postictal psychosis and schizophrenia is pointless. Likewise, schizophrenia may not be an appropriate counterpart of forced normalization and AIPD, given their acute or subacute course.Based on these preliminary examinations, three questions are selected to compare primary psychoses and psychoses in PWE: Is postictal psychosis different from a brief psychotic disorder? Does epilepsy facilitate or prevent the development of psychosis or vice versa? Is interictal psychosis of epilepsy different from process schizophrenia? In conclusion, antagonism between psychosis and epileptic seizures in a later stage of active epilepsy seems not to be realized without reorganization of the nervous system promoted during an earlier stage. Both genetic predisposition and the summated effects of epileptic activity must be taken into consideration as part of a trial to explain interictal psychosis. Interictal psychosis is an aggregate of miscellaneous disorders, that is, co-morbid schizophrenia, AED-induced psychotic disorders, forced normalization, and "epileptic" interictal psychosis. Data are lacking to conclude whether differences exist between process schizophrenia and "epileptic" interictal psychosis in terms of negative symptoms, specific personal traits, and the "bizarre-ness" of delusory-hallucinatory contents. These discussions may shed light on the essence of process schizophrenia, thus allowing it stand out and receive increased focus.

Alterations of the intrinsic amygdala-hippocampal network in juvenile myoclonic epilepsy

INTRODUCTION

Several lines of evidence suggest that the amygdala-hippocampus is involved in the epileptogenic network of juvenile myoclonic epilepsy (JME). The aim of this study was to investigate the alterations in the individual nuclei of the amygdala and hippocampal subfields, and the intrinsic amygdala-hippocampal network of patients with JME compared to healthy controls.

METHODS

This retrospective study conducted at a single tertiary hospital involved 35 patients with newly diagnosed JME, and 34 healthy subjects. We calculated the individual structural volumes of 18 nuclei in the amygdala, and 38 hippocampal subfields using three-dimensional volumetric T1-weighted imaging and FreeSurfer program. We also performed an analysis of the intrinsic amygdala-hippocampal global and local network based on these volumes using a graph theory and Brain Analysis using Graph Theory (BRAPH) program. We investigated the differences in these volumes and network measures between patients with JME and healthy controls.

RESULTS

There were no significant volume differences in the nuclei of the amygdala and hippocampal subfields between patients with JME and healthy controls. However, we found significant differences in the global network between patients with JME and healthy controls. The mean clustering coefficient was significantly decreased in patients with JME compared to healthy controls (0.473 vs. 0.653, p = .047). In addition, specific regions in the hippocampal subfields showed significant differences in the local network between the two groups. The betweenness centrality of the right CA1-head, right hippocampus-amygdala-transition area, left hippocampal fissure, left fimbria, and left CA3-head, was increased in patients with JME compared to healthy controls.

CONCLUSION

The intrinsic amygdala-hippocampal global and local networks differed in patients with JME compared to healthy controls, which may be related to the pathogenesis of JME, and memory dysfunction in patients with JME.

Predictors of successful valproate withdrawal in women with epilepsy

OBJECTIVE

Valproate (VPA) use was restricted due to its teratogenic risks in women with epilepsy (WWE). We aimed to assess the outcome and predictors of treatment decisions of withdrawal/switch or continuation of VPA in WWE.

METHODS

We included 214 consecutive WWE with a follow-up time of 9.57 ± 7.04 years, who have used (n = 142) or are still using VPA (n = 72) during their reproductive ages. The demographic, clinical, and electroencephalography (EEG) properties of WWE who could withdraw (successful withdrawal; n = 142) and could not withdraw VPA (unsuccessful withdrawal; n = 36) were compared statistically.

RESULTS

The main reasons for still using VPA were high risk of seizure recurrence (63.9%), cognitive impairment (27.8%), and no pregnancy prospect (8.3%). In the successful withdrawal group, 67 (47.1%) patients maintained remission after VPA withdrawal and 26 of them (38.8%) had relapse during the follow-up. The rate of side effects related to the new drugs (levetiracetam and lamotrigine) was 52/142 (36.6%). The unsuccessful withdrawal rate was 13.9% in focal epilepsy whereas it was 86.1% in generalized epilepsy (p = 0.002). Co-occurrence of three types of seizures and anti-seizure medication (ASM)-resistance was related to unsuccessful withdrawal in genetic generalized epilepsy (GGE) (p = 0.02 for both).

CONCLUSIONS

Although women with focal epilepsies are more ASM-resistant and more likely to have continuing seizures, they do not usually deteriorate after VPA discontinuation, therefore posing them to teratogenic risk is often unnecessary. In GGE, certain predictors such as previous ASM-resistance and the presence of three seizure types must be taken into account, before a withdrawal attempt of VPA treatment.

Diagnostic and therapeutic approach to drug-resistant juvenile myoclonic epilepsy

INTRODUCTION

Juvenile myoclonic epilepsy (JME), also known as Janz syndrome, is a common form of generalized epilepsy of presumed genetic origin representing up to 10% of all epilepsy cases. Despite adequate anti-seizure medication (ASM) treatment, seizures persist in one-third of JME patients.

AREAS COVERED

A literature search was conducted using Pubmed search on the topics of drug-resistant JME.

EXPERT OPINION

About 30% of JME patients are drug-resistant. Valproate (VPA) is considered the first-choice drug. In women of childbearing potential, levetiracetam (LEV) should represent the first-choice treatment. Alternative monotherapy or add-on therapy should be considered in subjects with resistant seizures after the exclusion of pseudo-drug resistance. The choice of the add-on ASM depends on the predominant seizure type. In subjects with persistent bilateral tonic-clonic seizures, LEV or lamotrigine should be firstly considered. In patients with difficult-to-treat myoclonic seizures, clonazepam or LEV are recommended. In case of persistent absences, ethosuximide should be considered. With appropriate selection and safeguards in place, VPA should remain available as an option in women of childbearing potential whose seizures are resistant to other treatments.

Eye closure sensitivity and genetic generalized epilepsies: A prospective study of 123 cases

PURPOSE

To investigate the possible relationship between eye closure sensitivity (ECS) and genetic generalized epilepsy (GGE) in terms of epilepsy syndromes, photosensitivity (PS), and prognosis.

METHOD

One hundred and twenty-three patients diagnosed with GGE were classified according to epilepsy syndromes. Among them, ECS and PS were detected in repeated video-EEGs. In patients with ECS, the impact of sleep deprived EEG on awakening on ECS was evaluated. To explore the ECS as a possible accurate predictor designating the prognosis in GGEs, we defined the ECS rate in poor prognosis group (n = 21) and in patients without antiseizure drug (ASD) treatment and seizure-free for at least for 2-5 years (n = 20).

RESULTS

ECS was found in almost all types of GGE but at different rates. ECS was detected in all groups with highest rate in eyelid myoclonia with or without absences (EMA). Sleep deprived EEG on awakening was performed in 44 of 59 patients with ECS and enhanced ECS prominently. In all groups except EMA, PS rate was lower compared with ECS. Both ECS and PS were observed in 15 patients with poor prognosis (71 %) and one patient with good prognosis (5%).

CONCLUSIONS

ECS can occur in all types of the GGEs. We claim that ECS can be asserted as a syndrome-specific feature for EMA among GGEs. Sleep deprived EEG on awakening can enhance ECS prominently in all types of GGE. ECS and PS might overlap but their impact on prognosis is different. In the poor prognosis group, the number of patients having ECS together with PS was high compared to the group without ASD and excellent prognosis. Therefore, we suggest that this combination predicts worse outcome in GGEs.

Prolonged epileptic discharges predict seizure recurrence in JME: Insights from prolonged ambulatory EEG

Objective

Markers of seizure recurrence are needed to personalize antiseizure medication (ASM) therapy. In the clinical practice, EEG features are considered to be related to the risk of seizure recurrence for genetic generalized epilepsies (GGE). However, to our knowledge, there are no studies analyzing systematically specific EEG features as indices of ASM efficacy in GGE. In this study, we aimed at identifying EEG indicators of ASM responsiveness in Juvenile Myoclonic Epilepsy (JME), which, among GGE, is characterized by specific electroclinical features.

Methods

We compared the features of prolonged ambulatory EEG (paEEG, 22 h of recording) of JME patients experiencing seizure recurrence within a year (“cases”) after EEG recording, with those of patients with sustained seizure freedom for at least 1 year after EEG (“controls”). We included only EEG recordings of patients who had maintained the same ASM regimen (dosage and type) throughout the whole time period from the EEG recording up to the outcome events (which was seizure recurrence for the “cases”, or 1‐year seizure freedom for “controls”). As predictors, we evaluated the total number, frequency, mean and maximum duration of epileptiform discharges (EDs) and spike density (i.e. total EDs duration/artifact‐free EEG duration) recorded during the paEEG. The same indexes were assessed also in standard EEG (stEEG), including activation methods.

Results

Both the maximum length and the mean duration of EDs recorded during paEEG significantly differed between cases and controls; when combined in a binary logistic regression model, the maximum length of EDs emerged as the only valid predictor. A cut‐off of EDs duration of 2.68 seconds discriminated between cases and controls with a 100% specificity and a 93% sensitivity. The same indexes collected during stEEG lacked both specificity and sensitivity.

Significance

The occurrence of prolonged EDs in EEG recording might represent an indicator of antiepileptic drug failure in JME patients.

Juvenile Myoclonic Epilepsy: Myoclonic Status Epilepticus without Coma - Report of Three Cases

Status epilepticus (SE) is rare in juvenile myoclonic epilepsy (JME). This report presents three patients with myoclonic status epilepticus (MSE). MSE is defined as prolonged period of myoclonic jerks that are correlated with epileptiform discharges on electroencephalogram. The precipitating factors among the three patients were: introduction of carbamazepine in case1, missing the dose in case2, and introduction of oxcarbazepine in case3. Of the three patients, one patient was a misdiagnosed case of JME. In him the diagnosis of JME was established after 35 years when he developed MSE with the addition of oxcarbazepine to the antiseizure medication (ASM) which he was taking. Detailed review of the history revealed that he used to get occasional myoclonic jerks with deprived sleep and stress. This patient illustrates that the diagnosis of JME can be missed or delayed if history of myoclonic jerks is not elicited, particularly in patents with pubertal onset epilepsy. The other lesson is that possibility of JME should be considered in patients with drug resistant epilepsy (pseudo-drug resistance).

Functional connectivity disturbances of ascending reticular activating system and posterior thalamus in juvenile myoclonic epilepsy in relation with photosensitivity: A resting-state fMRI study

OBJECTIVE

Juvenile myoclonic epilepsy (JME) is typified by the occurrence of myoclonic seizures after awakening, though another common trait is myoclonic seizures triggered by photic stimulation. We aimed to investigate the functional connectivity (FC) of nuclei in the ascending reticular activating system (ARAS), thalamus and visual cortex in JME with and without photosensitivity.

METHODS

We examined 29 patients with JME (16 photosensitive (PS), 13 non- photosensitive-(NPS)) and 28 healthy controls (HCs) using resting-state functional magnetic resonance imaging (rs-fMRI). Seed-to-voxel FC analyses were performed using 25 seeds, including the thalamus, visual cortex, and ARAS nuclei.

RESULTS

Mesencephalic reticular formation seed revealed significant hyperconnectivity between the bilateral paracingulate gyrus and anterior cingulate cortex in JME group, and in both JME-PS and JME-NPS subgroups compared to HCs (p_FWE-corr < 0.001; p_FWE-_corr < 0.001; p_FWE-_corr = 0.002, respectively). Locus coeruleus seed displayed significant hyperconnectivity with the bilateral lingual gyri, intracalcarine cortices, occipital poles and left occipital fusiform gyrus in JME-PS group compared to HCs (p_FWE-corr <0.001). Additionally, locus coeruleus seed showed significant hyperconnectivity in JME-PS group compared to JME-NPS group with a cluster corresponding to the bilateral lingual gyri and right intracalcarine cortex (p_FWE-corr < 0.001). Lastly, the right posterior nuclei of thalamus revealed significant hyperconnectivity with the right superior lateral occipital cortex in JME-PS group compared to HCs (p_FWE-corr < 0.002).

CONCLUSIONS

In JME, altered functional connectivity of the arousal networks might contribute to the understanding of myoclonia after awakening, whereas increased connectivity of posterior thalamus might explain photosensitivity.

Response to levetiracetam or lamotrigine in subjects with Juvenile Myoclonic Epilepsy previously treated with valproic acid: A single center retrospective study

BACKGROUND

Valproic acid (VPA) is the most effective medication in juvenile myoclonic epilepsy (JME) but, due to its teratogenic potential, levetiracetam (LEV) and lamotrigine (LTG) are preferred in women of childbearing age. The aim of this study was to compare the effectiveness and tolerability of LEV and LTG monotherapy in patients with a previous good seizure control in VPA monotherapy, in which VPA was withdrawn because of teratogenic potential or adverse drug effects.

METHODS

We retrospectively analyzed 65 patients with JME which had been followedup at the Epilepsy Center of Pisa University Hospital, identifying 28 subjects who had been successfully treated with VPA monotherapy and who were shifted to another monotherapy. The second monotherapy was LEV for 14 subjects and LTG for the remaining 14 ones. Drug efficacy was measured in terms of seizure freedom for more than twelve months after reaching the minimum effective or the highest tolerated dose.

RESULTS

In terms of seizure control, our analysis showed a significantly better outcome for LEV compared to LTG (14.3% and 71.4% of seizure relapse, respectively, p = 0.006) monotherapy. Such a higher efficacy was confirmed in those subjects with seizure relapse on LTG, who achieved good seizure control after switching to LEV monotherapy (89% of cases). Concerning tolerability, none of the patients reported severe side effects.

CONCLUSION

Although obtained in a small case series, our analysis showed a significant better efficacy of LEV compared to LTG in monotherapy, in patients with JME with a good response to VPA, concerning both myoclonic and generalized tonic-clonic seizures.

Case Report: Four Cases of Panayiotopoulos Syndrome Evolving to Juvenile Myoclonic Epilepsy

Panayiotopoulos syndrome (PS) is a self-limited focal epilepsy appearing in childhood. Seizures in PS are self-limiting and do not usually continue into adulthood. Juvenile myoclonic epilepsy (JME) is the most common type of idiopathic generalized epilepsy, developing around puberty and continuing throughout adulthood. We describe four cases of PS in childhood in which JME developed in adolescence. Age at onset ranged from 4 to 8 years for PS, and 11 to 14 years for JME. JME developed after PS subsided, with the interval between last PS seizure and first JME seizure ranging from 1 to 10 years. No link between the two conditions has previously been described. Since PS is considered to show good prognosis and to be self-limiting, long-term observation has been considered unnecessary. No definitive factors were found to predict future evolution to JME in our series, so longer-term follow-up may be warranted for all PS patients.

Altered dynamic effective connectivity of the default mode network in newly diagnosed drug-naïve juvenile myoclonic epilepsy

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We introduced an analysis framework to investigate the dynamic effective connectivity (DEC).

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The alteration of DEC in DMN was analyzed for patients with drug-naïve juvenile myoclonic epilepsy (JME).

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We found two distinct DEC states corresponding to strong (state 1) and week inter-influence (state 2).

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Patients showed state-specific EC changes that were associated with the severity of JME.

Juvenile myoclonic epilepsy (JME) has been repeatedly revealed to be associated with brain dysconnectivity in the default mode network (DMN). However, the implicit assumption of stationary and nondirectional functional connectivity (FC) in most previous resting-state fMRI studies raises an open question of JME-related aberrations in dynamic causal properties of FC. Here, we introduces an empirical method incorporating sliding-window approach and a multivariate Granger causality analysis to investigate, for the first time, the reorganization of dynamic effective connectivity (DEC) in DMN for patients with JME. DEC was obtained from resting-state fMRI of 34 patients with newly diagnosed and drug-naïve JME and 34 matched controls. Through clustering analysis, we found two distinct states that characterize the DEC patterns (i.e., a less frequent, strongly connected state (State 1) and a more frequent, weakly connected state (State 2)). Patients showed altered ECs within DMN subnetworks in the State 2, whereas abnormal ECs between DMN subnetworks were found in the State 1. Furthermore, we observed that the causal influence flows of the medial prefrontal cortex and angular gyrus were altered in a manner of state specificity, and associated with disease severity of patients. Overall, our findings extend the dysconnectivity hypothesis in JME from static to dynamic causal FC and demonstrate that aberrant DEC may underlie abnormal brain function in JME at early phase of illness.

Sleep and Epilepsy Link by Plasticity

We aimed to explore the link between NREM sleep and epilepsy. Based on human and experimental data we propose that a sleep-related epileptic transformation of normal neurological networks underlies epileptogenesis. Major childhood epilepsies as medial temporal lobe epilepsy (MTLE), absence epilepsy (AE) and human perisylvian network (PN) epilepsies - made us good models to study. These conditions come from an epileptic transformation of the affected functional systems. This approach allows a system-based taxonomy instead of the outworn generalized-focal classification. MTLE links to the memory-system, where epileptic transformation results in a switch of normal sharp wave-ripples to epileptic spikes and pathological high frequency oscillations, compromising sleep-related memory consolidation. Absence epilepsy (AE) and juvenile myoclonic epilepsy (JME) belong to the corticothalamic system. The burst-firing mode of NREM sleep normally producing sleep-spindles turns to an epileptic working mode ejecting bilateral synchronous spike-waves. There seems to be a progressive transition from AE to JME. Shared absences and similar bilateral synchronous discharges show the belonging of the two conditions, while the continuous age windows - AE affecting schoolchildren, JME the adolescents - and the increased excitability in JME compared to AE supports the notion of progression. In perisylvian network epilepsies - idiopathic focal childhood epilepsies and electrical status epilepticus in sleep including Landau-Kleffner syndrome - centrotemporal spikes turn epileptic, with the potential to cause cognitive impairment. Postinjury epilepsies modeled by the isolated cortex model highlight the shared way of epileptogenesis suggesting the derailment of NREM sleep-related homeostatic plasticity as a common step. NREM sleep provides templates for plasticity derailing to epileptic variants under proper conditions. This sleep-origin explains epileptiform discharges' link and similarity with NREM sleep slow oscillations, spindles and ripples. Normal synaptic plasticity erroneously overgrowing homeostatic processes may derail toward an epileptic working-mode manifesting the involved system's features. The impact of NREM sleep is unclear in epileptogenesis occurring in adolescence and adulthood, when plasticity is lower. The epileptic process interferes with homeostatic synaptic plasticity and may cause cognitive impairment. Its type and degree depends on the affected network's function. We hypothesize a vicious circle between sleep end epilepsy. The epileptic derailment of normal plasticity interferes with sleep cognitive functions. Sleep and epilepsy interconnect by the pathology of plasticity.

Neurophysiological and Genetic Findings in Patients With Juvenile Myoclonic Epilepsy

Objective

Transcranial magnetic stimulation (TMS), a non-invasive procedure, stimulates the cortex evaluating the central motor pathways. The response is called motor evoked potential (MEP). Polyphasia results when the response crosses the baseline more than twice (zero crossing). Recent research shows MEP polyphasia in patients with generalized genetic epilepsy (GGE) and their first-degree relatives compared with controls. Juvenile Myoclonic Epilepsy (JME), a GGE type, is not well studied regarding polyphasia. In our study, we assessed polyphasia appearance probability with TMS in JME patients, their healthy first-degree relatives and controls. Two genetic approaches were applied to uncover genetic association with polyphasia.

Methods

20 JME patients, 23 first-degree relatives and 30 controls underwent TMS, obtaining 10–15 MEPs per participant. We evaluated MEP mean number of phases, proportion of MEP trials displaying polyphasia for each subject and variability between groups. Participants underwent whole exome sequencing (WES) via trio-based analysis and two-case scenario. Extensive bioinformatics analysis was applied.

Results

We identified increased polyphasia in patients (85%) and relatives (70%) compared to controls (47%) and significantly higher mean number of zero crossings (i.e., occurrence of phases) (patients 1.49, relatives 1.46, controls 1.22; p < 0.05). Trio-based analysis revealed a candidate polymorphism, p.Glu270del,in SYT14 (Synaptotagmin 14), in JME patients and their relatives presenting polyphasia. Sanger sequencing analysis in remaining participants showed no significant association. In two-case scenario, a machine learning approach was applied in variants identified from odds ratio analysis and risk prediction scores were obtained for polyphasia. The results revealed 61 variants of which none was associated with polyphasia. Risk prediction scores indeed showed lower probability for non-polyphasic subjects on having polyphasia and higher probability for polyphasic subjects on having polyphasia.

Conclusion

Polyphasia was present in JME patients and relatives in contrast to controls. Although no known clinical symptoms are linked to polyphasia this neurophysiological phenomenon is likely due to common cerebral electrophysiological abnormality. We did not discover direct association between genetic variants obtained and polyphasia. It is likely these genetic traits alone cannot provoke polyphasia, however, this predisposition combined with disturbed brain-electrical activity and tendency to generate seizures may increase the risk of developing polyphasia, mainly in patients and relatives.

Energy landscape of resting magnetoencephalography reveals fronto-parietal network impairments in epilepsy

Juvenile myoclonic epilepsy (JME) is a form of idiopathic generalized epilepsy. It is yet unclear to what extent JME leads to abnormal network activation patterns. Here, we characterized statistical regularities in magnetoencephalograph (MEG) resting-state networks and their differences between JME patients and controls by combining a pairwise maximum entropy model (pMEM) and novel energy landscape analyses for MEG. First, we fitted the pMEM to the MEG oscillatory power in the front-oparietal network (FPN) and other resting-state networks, which provided a good estimation of the occurrence probability of network states. Then, we used energy values derived from the pMEM to depict an energy landscape, with a higher energy state corresponding to a lower occurrence probability. JME patients showed fewer local energy minima than controls and had elevated energy values for the FPN within the theta, beta, and gamma bands. Furthermore, simulations of the fitted pMEM showed that the proportion of time the FPN was occupied within the basins of energy minima was shortened in JME patients. These network alterations were highlighted by significant classification of individual participants employing energy values as multivariate features. Our findings suggested that JME patients had altered multistability in selective functional networks and frequency bands in the fronto-parietal cortices.

Dysfunctional personality beliefs and executive performance in patients with juvenile myoclonic epilepsy

BACKGROUND

This article intends to verify the association of dysfunctional beliefs of personality disorders with the executive performance in people with juvenile myoclonic epilepsy (JME).

METHODS

Fifty-two patients (35 women, 67.3%) with JME aged 18-50 yrs. (32.3 ± 9.7) were evaluated between May 2017 and April 2018 and compared with controls. All subjects were submitted to the Personality Beliefs Questionnaire (PBQ) (Beck & Beck, 1991; Savoia et al., 2006), Dysexecutive Questionnaire (DQ; Wilson et al., 1996; Macuglia et al., 2016), estimated intelligence quotient (IQ) using Vocabulary and Block Design tests, attention and executive functions evaluation (Controlled Oral Word Association (COWA), Digit Span, Trail Making Tests (TMT) A and B, Stroop and Wisconsin Card Sorting Test (WCST)). The inclusion criteria were as follows: diagnosis of JME (ILAE, 1989); age ≥18 yrs., schooling ≥ 11 yrs. and IQ ≥70. The inclusion criteria for the control group were the same except diagnosis of epilepsy.

RESULTS

Compared with controls, patients presented higher scores in PBQ for personality disorders, namely Narcissistic (z = -0.79; p < 0.001), Borderline (z = -0.58; p = 0.002), Paranoid (z = -0.43; p = 0.017), and Histrionic (z = -0.39; p = 0.041). Executive functions were impaired when compared with controls in TMT A (z = -0.97; p = 0.038), TMT B (z = -0.65; p = 0.023), and COWA (z = -0.51; p = 0.001). Patients showed higher WCST scores for Errors (z = -1.62; p ≤ 0.001), Perseverative Errors (z = -0.77; p = 0.001), Non-Perseverative Errors (z = -1.01; p = 0.001), Conceptual Level Response (z = -1.56; p ≤ 0.001), Completed Categories (z = -2.12; p = 0.002), and Failure to Maintain Context (z = -0.49; p = 0.015). Personality Beliefs Questionnaire results showed correlation with lower values in TMT A, Antisocial (r = -0.298; p = 0.032), Narcissistic (r = -0.303; p = 0.029), Schizoid (r = - 0.410; p = 0.003), Histrionic (r = -0.341; p = 0.013), Passive-aggressive (r = -0.341; p = 0.015), and Obsessive-compulsive (r = -0.319; p = 0.021); TMT B results showed a trend for Obsessive-compulsive traits (r = -0.261; p = 0.052); COWA was correlated to Dependent (r = 0.319; p = 0.021); and Digit Span to Passive-aggressive (r = 0.287; p = 0.039). On WCST, Failure to Maintain Context was correlated to Avoidant (r = 0.335; p = 0.017). The DQ was not correlated with PBQ.

CONCLUSION

People with JME presented dysfunctional beliefs of personality disorder that were correlated with executive dysfunction. These findings reinforce the need for psychological rehabilitation in these patients.

Thalamic nuclei volumes and network in juvenile myoclonic epilepsy

OBJECTIVE

The aim of this study was to investigate the alterations of thalamic nuclei volumes and intrinsic thalamic networks in patients with juvenile myoclonic epilepsy (JME) compared to healthy controls.

METHODS

We enrolled 50 patients with JME and 42 healthy controls. We obtained structural volumes of the individual thalamic nuclei based on T1-weighted imaging and performed intrinsic thalamic network analysis using graph theoretical analysis. We analyzed the differences of thalamic nuclei volumes and intrinsic thalamic networks between the patients with JME and healthy controls.

RESULTS

In the patients with JME, there were significant alterations of thalamic nuclei volumes compared to healthy controls. Right laterodorsal and left suprageniculate nuclei volumes were significantly increased (0.0019% vs 0.0014%, P < .0001; 0.0011% vs 0.0008%, P = .0006, respectively), whereas left ventral posterolateral, left ventromedial, and left pulvinar inferior nuclei volumes (0.0572% vs 0.0664%, P = .0001; 0.0013% vs 0.0015%, P = .0002; 0.0120% vs 0.0140%, P < .0001, respectively) were decreased in the patients with JME. Furthermore, the intrinsic thalamic network of the patients with JME was significantly different from that of the healthy controls. The modularity in the patients with JME was significantly increased over that in healthy controls (0.0785 vs 0.0212, P = .039).

CONCLUSION

We found that there were significant alterations of thalamic nuclei volumes and intrinsic thalamic networks in patients with JME compared to healthy controls. These findings might contribute to the underlying pathogenesis of in JME.

Reflex epileptic features in patients with focal epilepsy of unknown cause

OBJECTIVES

There is a gap of knowledge regarding reflex seizures in patients with focal epilepsy of unknown cause (FEUC). We aimed to evaluate the prevalence, demographic and clinical characteristics of reflex seizures in patients with FEUC to provide an insight to the underlying ictogenic mechanisms and to draw attention to this important but under-investigated topic.

PATIENTS AND METHODS

After carefully questioning for reflex triggers, 186 patients diagnosed according to ILAE criteria and followed-up for a minimum of 5 years were included. The demographic and clinical properties as well as electrophysiological and neuroimaging data of these patients were reevaluated and compared to the patients without reflex seizures.

RESULTS

The reflex seizure rate was 6.5 % in patients with FEUC. Patients with reflex features had lower monotherapy rates (p = 0.005) and higher major depression rates (p = 0.001) than patients without reflex features. The distribution of the patients according to their reflex triggers were as follows: hot-water induced (n = 3, 25 %), photosensitive (n = 2, 16.7 %), eating- induced (n = 2, 16.7 %), musicogenic (n = 2, 16.7 %), startle induced (n = 2, 16.7 %) and both musicogenic and startle type (n = 1, 8.3 %) respectively. The drug resistance rate of patients with reflex seizures was 25 % (n = 3). One patient with drug resistant reflex seizures showed benefit from epilepsy surgery and became seizure-free during last 3 years of follow-up.

CONCLUSION

A careful and thoroughly history taking specifically questioning and focusing on seizure inducing factors in patients with FEUC is needed to confirm the presence of reflex seizures in patients with FEUC, who had higher rates of polytherapy and major depression. Elaborative evaluation of reflex features in FEUC might contribute to effective seizure control, ensure new therapeutic approaches, enlighten the obscurity and the resulting anxiety of having a diagnosis of FEUC in epilepsy patients.