Prevalence of juvenile myoclonic epilepsy in people <30 years of age-A population-based study in Norway

Altered dynamic functional connectivity of motor cerebellum with sensorimotor network and default mode network in juvenile myoclonic epilepsy

Objective

To investigate whether changes occur in the dynamic functional connectivity (dFC) of motor cerebellum with cerebral cortex in juvenile myoclonic epilepsy (JME).

Methods

We adopted resting-state electroencephalography-functional magnetic resonance imaging (EEG-fMRI) and a sliding-window approach to explore the dFC of motor cerebellum with cortex in 36 JME patients compared with 30 and age-matched health controls (HCs). The motor cerebellum was divided into five lobules (I-V, VI, VIIb, VIIIa, and VIIIb). Additionally, correlation analyses were conducted between the variability of dFC and clinical variables in the Juvenile Myoclonic Epilepsy (JME) group, such as disease duration, age at disease onset, and frequency score of myoclonic seizures.

Results

Compared to HCs, the JME group presented increased dFC between the motor cerebellum with SMN and DMN. Specifically, connectivity between lobule VIIb and left precentral gyrus and right inferior parietal lobule (IPL); between lobule VIIIa and right inferior frontal gyrus (IFG) and left IPL; and between lobule VIIIb and left middle frontal gyrus (MFG), bilateral superior parietal gyrus (SPG), and left precuneus. In addition, within the JME group, the strength of dFC between lobule VIIIb and left precuneus was negatively (r = -0.424, p = 0.025, Bonferroni correction) related with the frequency score of myoclonic seizures.

Conclusion

In patients with JME, there is a functional dysregulation between the motor cerebellum with DMN and SMN, and the variability of dynamic functional connectivity may be closely associated with the occurrence of motor symptoms in JME.

Deep brain stimulation of the subthalamic nucleus for a patient with drug resistant juvenile myoclonic epilepsy: 1 year follow-up

BACKGROUND

Drug-resistant juvenile myoclonic epilepsy (DR-JME) remains a significant challenge in neurology. Traditional management strategies often fail to achieve satisfactory control, necessitating innovative treatments.

OBJECTIVE

This case report aims to evaluate the efficacy and safety of deep brain stimulation (DBS) targeting the subthalamic nucleus (STN-DBS) in a patient with DR-JME.

METHODS

We describe the treatment of a patient with DR-JME using STN-DBS. The patient underwent implantation and received high-frequency stimulation (HFS) at the STN.

RESULTS

One year post-implantation, the patient demonstrated a substantial reduction in motor seizure frequency by 87.5%, with improvements in quality of life and seizure severity by 52.0% and 46.7%, respectively. No adverse events were reported during the follow-up period.

CONCLUSIONS

This case represents the first report of favorable outcomes with STN-DBS in a patient with DR-JME, suggesting that long-term HFS of the STN may be a promising treatment option for patients suffering from this condition.

Drug-resistant juvenile myoclonic epilepsy: A literature review

The ILAE's Task Force on Nosology and Definitions revised in 2022 its definition of juvenile myoclonic epilepsy (JME), the most common idiopathic generalized epilepsy disorder, but this definition may well change again in the future. Although good drug response could almost be a diagnostic criterion for JME, drug resistance (DR) is observed in up to a third of patients. It is important to distinguish this from pseudoresistance, which is often linked to psychosocial problems or psychiatric comorbidities. After summarizing these aspects and the various definitions applied to JME, the present review lists the risk factors for DR-JME that have been identified in numerous studies and meta-analyses. The factors most often cited are absence seizures, young age at onset, and catamenial seizures. By contrast, photosensitivity seems to favor good treatment response, at least in female patients. Current hypotheses on DR mechanisms in JME are based on studies of either simple (e.g., cortical excitability) or more complex (e.g., anatomical and functional connectivity) neurophysiological markers, bearing in mind that JME is regarded as a neural network disease. This research has revealed correlations between the intensity of some markers and DR, and above all shed light on the role of these markers in associated neurocognitive and neuropsychiatric disorders in both patients and their siblings. Studies of neurotransmission have mainly pointed to impaired GABAergic inhibition. Genetic studies have generally been inconclusive. Increasing restrictions have been placed on the use of valproate, the standard antiseizure medication for this syndrome, owing to its teratogenic and developmental risks. Levetiracetam and lamotrigine are prescribed as alternatives, as is vagal nerve stimulation, and there are several other promising antiseizure drugs and neuromodulation methods. The development of better alternative treatments is continuing to take place alongside advances in our knowledge of JME, as we still have much to learn and understand.

Sarcopenia and anti-seizure medication response in juvenile myoclonic epilepsy

INTRODUCTION

This study aimed to investigate the presence of sarcopenia in patients with juvenile myoclonic epilepsy (JME) and the association between sarcopenia and response to anti-seizure medication (ASM) in patients with JME.

METHODS

We enrolled 42 patients with JME and 42 healthy controls who underwent brain magnetic resonance imaging with three-dimensional T1-weighted imaging. We measured the temporal muscle thickness (TMT), a radiographic marker for sarcopenia, using T1-weighted imaging. We compared the TMT between patients with JME and healthy controls and analyzed it according to the ASM response in patients with JME. We also performed a receiver operating characteristic (ROC) curve analysis to evaluate how well the TMT differentiated the groups.

RESULTS

The TMT in patients with JME did not differ from that in healthy controls (9.630 vs. 9.956 mm, p = .306); however, ASM poor responders had a lower TMT than ASM good responders (9.109 vs. 10.104 mm, p = .023). ROC curve analysis revealed that the TMT exhibited a poor performance in differentiating patients with JME from healthy controls, with an area under the ROC curve of .570 (p = .270), but good performance in differentiating between ASM good and poor responders, with an area under the ROC curve of .700 (p = .015).

CONCLUSION

The TMT did not differ between patients with JME and healthy controls; however, it was reduced in ASM poor responders compared to ASM good responders, suggesting a link between ASM response and sarcopenia in patients with JME. TMT can be used to investigate sarcopenia in various neurological disorders.

Resting-state electroencephalography microstates as a marker of photosensitivity in juvenile myoclonic epilepsy

Juvenile myoclonic epilepsy is an idiopathic generalized epilepsy syndrome associated with photosensitivity in approximately 30-40% of cases. Microstates consist of a brief period of time during which the topography of the whole resting-state electroencephalography signal is characterized by a specific configuration. Previous neurophysiological and neuroimaging studies have suggested that Microstate B may represent activity within the visual network. In this case-control study, we aimed to investigate whether anatomical and functional alterations in the visual network observed in individuals with photosensitivity could lead to changes in Microstate B dynamics in photosensitive patients with juvenile myoclonic epilepsy. Resting-state electroencephalography microstate analysis was performed on 28 patients with juvenile myoclonic epilepsy. Of these, 15 patients exhibited photosensitivity, while the remaining 13 served as non-photosensitive controls. The two groups were carefully matched in terms of age, sex, seizure control and anti-seizure medications. Multivariate analysis of variance and repeated-measures analysis of variance were performed to assess significant differences in microstate metrics and syntax between the photosensitive and the non-photosensitive group. Post hoc false discovery rate adjusted unpaired t-tests were used to determine differences in specific microstate classes between the two groups. The four classical microstates (Classes A, B, C and D) accounted for 72.8% of the total electroencephalography signal variance in the photosensitive group and 75.64% in the non-photosensitive group. Multivariate analysis of variance revealed a statistically significant class-group interaction on microstate temporal metrics (P = 0.021). False discovery rate adjusted univariate analyses of variance indicated a significant class-group interaction for both mean occurrence (P = 0.002) and coverage (P = 0.03), but not for mean duration (P = 0.14). Post hoc false discovery rate adjusted unpaired t-tests showed significantly higher coverage (P = 0.02) and occurrence (P = 0.04) of Microstate B in photosensitive patients compared with non-photosensitive participants, along with an increased probability of transitioning from Microstates C (P = 0.04) and D (P = 0.02) to Microstate B. No significant differences were found concerning the other microstate classes between the two groups. Our study provides novel insights on resting-state electroencephalography microstate dynamics underlying photosensitivity in patients with juvenile myoclonic epilepsy. The increased representation of Microstate B in these patients might reflect the resting-state overactivation of the visual system underlying photosensitivity. Further research is warranted to investigate microstate dynamics in other photosensitive epilepsy syndromes.

Drug-resistant idiopathic generalized epilepsy: A meta-analysis of prevalence and risk factors

BACKGROUND

Idiopathic generalized epilepsy (IGE) is a common epilepsy syndrome with early age onset and generally good seizure outcomes. This study aims to determine the incidence and predictive risk factors for drug-resistant IGE.

METHODS

We systematically searched three databases (PubMed, Embase, and Cochrane Library) in November 2022 and included 12 eligible studies which reported long-term outcomes (mean = 14.05) after antiseizure medications (ASMs) from 2001 to 2020. We defined drug resistance as the persistence of any seizure despite ASMs treatment (whether as monotherapies or in combination) given the criteria of drug resistance varied in original studies. A random-effects model was used to evaluate the prevalence of refractory IGE. Studies reporting potential poor prognostic factors were included for subsequent subgroup meta-analysis.

RESULTS

The pooled prevalence of drug resistance in IGE cohorts was 27% (95% CI: 0.19-0.36). Subgroup analysis of the risk factors revealed that the psychiatric comorbidities (odds ratio (OR): 4.87, 95% confidence interval (CI): 2.97-7.98), combined three seizure types (absences, myoclonic jerks, and generalized tonic-clonic seizures) (OR: 5.37, 95% CI: 3.16-9.13), the presence of absence seizure (OR: 4.38, 95% CI: 2.64-7.28), generalized polyspike trains (GPT) (OR: 4.83, 95% CI: 2.42-9.64), sex/catamenial epilepsy (OR: 3.25, 95% CI: 1.97-5.37), and status epilepticus (OR: 5.94, 95% CI: 2.23-15.85) increased the risk of poor prognosis. Other factors, including age onset, family history, and side effects of ASMs, were insignificantly associated with a higher incidence of refractory IGE.

CONCLUSION

Drug resistance is a severe complication of IGE. Further standardized research about clinical and electroencephalography factors is warranted.

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.

Thalamocortical circuits in generalized epilepsy: Pathophysiologic mechanisms and therapeutic targets

Generalized epilepsy affects 24 million people globally; at least 25% of cases remain medically refractory. The thalamus, with widespread connections throughout the brain, plays a critical role in generalized epilepsy. The intrinsic properties of thalamic neurons and the synaptic connections between populations of neurons in the nucleus reticularis thalami and thalamocortical relay nuclei help generate different firing patterns that influence brain states. In particular, transitions from tonic firing to highly synchronized burst firing mode in thalamic neurons can cause seizures that rapidly generalize and cause altered awareness and unconsciousness. Here, we review the most recent advances in our understanding of how thalamic activity is regulated and discuss the gaps in our understanding of the mechanisms of generalized epilepsy syndromes. Elucidating the role of the thalamus in generalized epilepsy syndromes may lead to new opportunities to better treat pharmaco-resistant generalized epilepsy by thalamic modulation and dietary therapy.

Juvenile Myoclonic Epilepsy: Seizure and Social Outcomes in Taiwan

Patients with juvenile myoclonic epilepsy (JME) may not achieve seizure freedom despite optimal treatment with antiseizure medications (ASMs). The aim of this study was to investigate the clinical and social features of patients with JME, and to determine the factors associated with outcomes. We retrospectively identified 49 patients with JME (25 females, mean age 27.6 ± 8.9 years) who were assessed at the Epilepsy Centre of Linkou Chang Gung Memorial Hospital in Taiwan. The patients were divided into two groups, those who were seizure-free and those with ongoing seizures according to their seizure outcome at the last follow-up for one year. Clinical features and social status were compared between these two groups. Twenty-four (49%) of the JME patients were seizure-free for at least one year, while 51% continued to experience seizures despite being treated with multiple ASMs. The presence of epileptiform discharges in the last electroencephalogram and seizures during sleep were significantly associated with worse seizure outcomes (p < 0.05). The patients who were seizure-free had a higher employment rate compared to those who continued to experience seizures (75% vs. 32%, p = 0.004). Despite receiving ASM treatment, a considerable proportion of the patients with JME continued to have seizures. Moreover, poor seizure control was associated with a lower employment rate, which may lead to negative socioeconomic consequences related to JME.

ILAE definition of the Idiopathic Generalized Epilepsy Syndromes: Position statement by the ILAE Task Force on Nosology and Definitions

In 2017, the International League Against Epilepsy (ILAE) Classification of Epilepsies described the "genetic generalized epilepsies" (GGEs), which contained the "idiopathic generalized epilepsies" (IGEs). The goal of this paper is to delineate the four syndromes comprising the IGEs, namely childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy, and epilepsy with generalized tonic-clonic seizures alone. We provide updated diagnostic criteria for these IGE syndromes determined by the expert consensus opinion of the ILAE's Task Force on Nosology and Definitions (2017-2021) and international external experts outside our Task Force. We incorporate current knowledge from recent advances in genetic, imaging, and electroencephalographic studies, together with current terminology and classification of seizures and epilepsies. Patients that do not fulfill criteria for one of these syndromes, but that have one, or a combination, of the following generalized seizure types: absence, myoclonic, tonic-clonic and myoclonic-tonic-clonic seizures, with 2.5-5.5 Hz generalized spike-wave should be classified as having GGE. Recognizing these four IGE syndromes as a special grouping among the GGEs is helpful, as they carry prognostic and therapeutic implications.

Seizure outcome trajectories in a well-defined cohort of newly diagnosed juvenile myoclonic epilepsy patients

OBJECTIVE

To investigate the temporal course of medication response and associated prognostic factors in a cohort of juvenile myoclonic epilepsy (JME) patients over a long-term follow-up.

MATERIALS AND METHODS

Data from 113 JME patients diagnosed according to recently proposed class II criteria were retrospectively reviewed. Early sustained remission was defined as 4-year seizure remission starting within 2 years from the first antiseizure medication (ASM) intake, as opposed to delayed sustained remission. Spontaneous relapse rate (ie, not related to ASM withdrawal) was also investigated, along with factors associated with seizure relapse.

RESULTS

Four-year seizure remission was obtained by 76/113 (67.3%) subjects. Early sustained remission was achieved by 45/76 (59.2%) patients. Absence seizures were significantly associated with no-remission at multivariable multinomial logistic regression analysis. Catamenial seizures and earlier age at epilepsy onset significantly predicted delayed sustained remission. Spontaneous seizure relapse after 4-year remission occurred in 15.7% of patients with early sustained remission and in 35.5% of those with delayed sustained remission (p = 0.045). The most common concomitant factors for a spontaneous relapse were irregular lifestyle habits and pregnancy-related switch from valproate to another ASM. Patients with a history of catamenial seizures were more likely to experience a spontaneous generalized tonic-clonic seizure relapse after 4-year remission at univariable analysis.

SIGNIFICANCE

Our data support the prognostic relevance of early medication response in JME patients. Furthermore, the prognostic significance of catamenial seizures and the impact of valproate switch on seizure relapse after a prolonged remission account for the challenging therapeutic management of women with childbearing potential.

Analysis of Clinical Characteristics, Background, and Paroxysmal Activity in EEG of Patients with Juvenile Myoclonic Epilepsy

Juvenile myoclonic epilepsy (JME) appears in adolescence with myoclonic, absence, and generalized tonic clonic (GTC) seizures with paroxysmal activity of polyspike and slow wave (PSW), or spike and wave (SW) complexes in EEG. Our aim was to analyze the clinical characteristics, background EEG activity, and paroxysmal events in 41 patients with JME. Background EEG activity was analyzed with visual, quantitative (QEEG), and neurometric parameters. Our JME patients started with absence seizures at 11.4 ± 1.5 years old, myoclonic seizures at 13.6 ± 2.5 years, and GTC seizures at 15.1 ± 0.8 years. The seizures presented in awakening at 7:39 h with sleep deprivation, alcoholic beverage intake, and stress as the most frequent precipitant factors. Paroxysmal activity was of PSW and fast SW complexes with 40.5 ± 62.6 events/hour and a duration of 1.7 s. Right asymmetric paroxysmal activity was present in 68.3% of patients. Background EEG activity was abnormal in 31.7% of patients with visual analysis. With QEEG beta AP (absolute power) increase and AP delta decrease were the most frequent abnormalities found. Spectral analysis showed that 48.7% of patients had normal results, and 26.83% and 24.4% had higher and lower frequencies than 10.156 Hz, respectively. We concluded that, with visual analysis, background EEG activity was abnormal in a few patients and the abnormalities increased when QEEG was used.

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.

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.

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.

Trait impulsivity correlates with active myoclonic seizures in genetic generalized epilepsy

BACKGROUND

Juvenile myoclonic epilepsy (JME) is a common subtype of genetic generalized epilepsy (GGE) arising in adolescence and is often associated with executive function (EF) deficits. Some EF components like response inhibition have been extensively evaluated in JME, but few studies have focused upon trait impulsivity or compared between GGE subtypes. The aim of the present study was to compare the association of trait impulsivity in JME with other GGE subtypes.

METHODS

Patients with GGE aged between 14 and 40 years (n = 137) were divided into those with JME (n = 92) and those with other GGEs (n = 45: 8 childhood absence epilepsy (CAE), 22 juvenile absence epilepsy (JAE), and 15 epilepsy with generalized tonic-clonic seizures only (EGTCS)). The study participants were recruited through medical records of the general population of Buskerud County and the neighboring municipalities, covering 477,000 people or 9.1% of Norway's total population. All participants underwent a clinical interview including the Barratt Impulsiveness Scale (BIS), an established measure of trait impulsivity. We controlled for other potential predictors of BIS score using analysis of covariance (ANCOVA).

RESULTS

There were no differences between JME and other types of GGE for BIS scores, but the presence of myoclonic seizures within the last year, irrespective of GGE subtype, was independently associated with significantly increased behavioral impulsivity.

CONCLUSIONS

This study demonstrates that trait impulsivity in GGE is most strongly related to the recent occurrence of myoclonic seizures rather than GGE subtype.

Developmental decrease in parvalbumin-positive neurons precedes increase in flurothyl-induced seizure susceptibility in the Brd2+/- mouse model of juvenile myoclonic epilepsy

OBJECTIVE

BRD2 is a human gene repeatedly linked to and associated with juvenile myoclonic epilepsy (JME). Here, we define the developmental stage when increased seizure susceptibility first manifests in heterozygous Brd2+/- mice, an animal model of JME. We wanted to determine (1) whether seizure susceptibility correlates with the proven decrease of γ-aminobutyric acidergic (GABAergic) neuron numbers and (2) whether the seizure phenotype can be affected by sex hormones.

METHODS

Heterozygous (Brd2+/-) and wild-type (wt) mice of both sexes were tested for flurothyl-induced seizure susceptibility at postnatal day 15 (P15; wt, n = 13; Brd2+/-, n = 20), at P30 (wt, n = 20; Brd2+/-, n = 20), and in adulthood (5-6 months of age; wt, n = 10; Brd2+/-, n = 12). We measured latency to clonic and tonic-clonic seizure onset (flurothyl threshold). We also compared relative density of parvalbumin-positive (PVA+) and GAD67+ GABA neurons in the striatum and primary motor (M1) neocortex of P15 (n = 6-13 mice per subgroup) and P30 (n = 7-10 mice per subgroup) mice. Additional neonatal Brd2+/- mice were injected with testosterone propionate (females) or formestane (males) and challenged with flurothyl at P30.

RESULTS

P15 Brd2+/- mice showed no difference in seizure susceptibility compared to P15 wt mice. However, even at this early age, Brd2+/- mice showed fewer PVA+ neurons in the striatum and M1 neocortex. Compared to wt, the striatum in Brd2+/- mice showed an increased proportion of immature PVA+ neurons, with smaller cell bodies and limited dendritic arborization. P30 Brd2+/- mice displayed increased susceptibility to flurothyl-induced clonic seizures compared to wt. Both genotype and sex strongly influenced the density of PVA+ neurons in the striatum. Susceptibility to clonic seizures remained increased in adult Brd2+/- mice, and additionally there was increased susceptibility to tonic-clonic seizures. In P30 females, neonatal testosterone reduced the number of flurothyl-induced clonic seizures.

SIGNIFICANCE

A decrease in striatal PVA+ GABAergic neurons developmentally precedes the onset of increased seizure susceptibility and likely contributes to the expression of the syndrome.

Genetic generalized and focal epilepsy prevalence in the North American SUDEP Registry

Objective

To assess relative rates and clinical features of patients with genetic generalized epilepsy (GGE), focal epilepsy (FE), and developmental encephalopathic epilepsy (DEE) in the North American SUDEP Registry (NASR).

Methods

We identified all adjudicated definite, definite plus, and probable sudden unexpected death in epilepsy (SUDEP) cases (n = 262) and determined epilepsy type (GGE, FE, or DEE) from medical record review including history, imaging and EEG results, genetics, and next-of-kin interviews.

Results

Of the 262 SUDEP cases, 41 occurred in GGE, 95 in FE, 24 in DEE, and 102 were unclassifiable. GGE cases comprised 26% of NASR cases with an epilepsy syndrome diagnosis. The relative frequency of FE:GGE was slightly lower (2.3:1) than in population cohorts (2.1–6:1). Compared to patients with FE, patients with GGE had similar (1) ages at death and epilepsy onset and rates of (2) terminal and historical antiseizure medication adherence; (3) abnormal cardiac pathology; (4) illicit drug/alcohol use histories; and (5) sleep state when SUDEP occurred.

Conclusions

GGE cases were relatively overrepresented in NASR. Because GGEs are less often treatment-resistant than FE or DEE, seizure type rather than frequency may be critical. Many people with GGE predominantly have generalized tonic-clonic seizures (GTCS) when they have uncontrolled or breakthrough seizures, whereas patients with FE more commonly experience milder seizures. Future mechanistic SUDEP studies should assess primary and focal-to-bilateral GTCS to identify potential differences in postictal autonomic and arousal disorders and to determine the differential role that lifestyle factors have on breakthrough seizures and seizure types in GGE vs FE to effectively target SUDEP mechanisms and prevention.

Treatment and challenges with antiepileptic drugs in patients with juvenile myoclonic epilepsy

BACKGROUND

Patients with juvenile myoclonic epilepsy (JME) may have uncontrolled seizures. The purpose of this study was to investigate the use and challenges with antiepileptic drugs (AEDs) and the patients' view of these challenges.

METHOD

A questionnaire about the use of AEDs, adherence to therapy, and quality of life was given to patients with JME recruited from Drammen Hospital. Data regarding AEDs were confirmed from medical records at Drammen Hospital, Norway (2007-2018). Additional clinical interviews were performed, and a mixed method approach was applied.

RESULTS

Ninety patients with defined JME diagnosis, 54/36 women/men aged 14-39 (mean: 25) years, were included. Only 29 (33%) were seizure-free. Within the last year, 21% experienced generalized tonic-clonic seizures (GTCS), and 68% had myoclonic jerks. Seventy-six (84%) used AEDs, 78% in monotherapy. A total of 10 AEDs were used;: most commonly valproate (n = 33), lamotrigine (n = 27), and levetiracetam (n = 21). Two-thirds of valproate users were men while all other AEDs were used more in females than in men. Valproate and levetiracetam displayed better efficacy against GTCS than lamotrigine. One-third often/sometimes forgot their medication nonintentionally while 14% had intentional poor adherence. The majority reported good quality of life (76%). No significant correlations between the use of AEDs, use of valproate, poor adherence, quality of life score, and seizure freedom were demonstrated. Half of the patients had serum concentrations measured every year, and two-thirds thought this was important. Qualitative interviews elucidated treatment challenges in JME;, adverse effect burden, adherence, and activities of daily life.

CONCLUSION

Despite the use of AEDs in the majority of patients, only one-third were seizure-free. Other challenges included polypharmacy, the use of valproate in women, and variable adherence. This points to a need for closer follow-up in patients with JME.

Long-term follow-up with therapeutic drug monitoring of antiepileptic drugs in patients with juvenile myoclonic epilepsy

BACKGROUND AND PURPOSE

Patients with juvenile myoclonus epilepsy (JME) may experience uncontrolled seizures and challenges regarding adherence. Implementation of therapeutic drug monitoring (TDM) may contribute to individualization of the therapy with antiepileptic drugs (AEDs). The purpose of this study was to investigate how the treatment of patients with JME is monitored and to demonstrate pharmacokinetic variability within and between patients with a long-term TDM approach.

METHOD

Retrospective data from patients with JME from the TDM-database at Drammen Hospital and the National Center for Epilepsy in Norway (2007-2018) were included.

RESULTS

Data from 80 of 90 patients with JME using AEDs with TDM measurements was included (88%, 49/31 women/men aged 14-39). One third (27, 33%) was seizure free, 19 (24%) had generalized tonic-clonic seizures, and 53 (66%) myoclonic seizures during the last year. The most common AEDs measured included lamotrigine, valproate, and levetiracetam. Long-term TDM demonstrated variability over time expressed as intra-patient median values and inter-patient ranges of 19% (7-47) for valproate, 43% (10-83) for lamotrigine and 35% (6-111) for levetiracetam. Fifteen pecent (83/563) of serum concentrations were below the reference ranges and clould be due to variable adherence. Comedication with valproate for lamotrigine and pregnancy contributed to variability. The applicability is illustrated in a case of 10 years' follow-up in a young woman.

CONCLUSION

There was extensive pharmacokinetic variability of AEDs in and between patients with JME. A long-term TDM approach may contribute to closer monitoring of patients with JME and be used as a practical tool during clinical consultations.

Antiepileptic drug withdrawal in juvenile myoclonic epilepsy

OBJECTIVES

Withdrawal of antiepileptic drugs (AEDs) has been discouraged in juvenile myoclonic epilepsy (JME). However, impulsivity as a consequence of executive dysfunction in JME may influence treatment adherence. The aim of the present study was to assess how common withdrawal of AEDs is in a large and representative JME group.

MATERIALS AND METHODS

Patients with genetic generalized epilepsy (GGE) were identified through a retrospective search of medical records at Drammen Hospital, Norway, and invited to a clinical interview. Information related to AED withdrawal was analyzed in those classified as JME.

RESULTS

A total of 132 patients with GGE were interviewed (87 JME). Thirty-five patients with JME (40%) discontinued AEDs, of which 74% did so without consulting a doctor. The rate of self-withdrawal was significantly higher in JME than in other types of GGE. Having a parent with psychosocial difficulties was significantly over-represented in the JME self-withdrawal group. Twelve of those who discontinued AEDs (34%) were free from generalized tonic-clonic seizures (GTCS) and without antiepileptic drugs >1 year. All but one of them withdrew AEDs without consulting a doctor. Age at first motor seizure was significantly higher in those with a favorable outcome of AED withdrawal.

CONCLUSIONS

Self-withdrawal of AEDs is common in JME, especially in those with troublesome conditions at home. However, about 1/3 may remain free from GTCS without AEDs. The findings indicate a need for a stronger follow-up with appropriate information about the prognosis of the disorder.

Psychosocial complications in juvenile myoclonic epilepsy

Juvenile myoclonic epilepsy (JME) constitutes about 10% of all epilepsies. Because of executive dysfunction, people with JME may be prone to impulsivity and risk-taking behavior. Our aim was to investigate whether psychosocial issues associated with impulsivity are more prominent in people with JME than in those with other types of genetic generalized epilepsy (GGE). Patients with GGE were recruited retrospectively through the Drammen Hospital records in Buskerud County, Norway, 1999-2013. They were invited to a semi-structured interview, either at the hospital or at home. Ninety-two patients with JME and 45 with other types of GGE were interviewed. Variables were evaluated in terms of their association with JME versus other GGE diagnosis using a logistic regression model. Juvenile myoclonic epilepsy was associated with use of illicit recreational drugs and police charges, although with borderline significance (odds ratio [OR] 3.4, p = 0.087 and OR 4.2, p = 0.095); JME was also associated with being examined for attention-deficit hyperactivity disorder (ADHD) in females (OR 15.5, p = 0.015), a biological parent with challenges like addiction or violent behavior (OR 3.5, p = 0.032), and use of levetiracetam (OR 5.1, p = 0.014). After controlling for group differences, we found psychosocial complications to be associated with JME, potentially influencing the lives of the individuals and their families to a greater extent than the seizures per se. Thus, JME should be considered a disorder of the brain in a broader sense than a condition with seizures only.

Prolonged epileptiform EEG runs are associated with persistent seizures in juvenile myoclonic epilepsy

OBJECTIVE

In juvenile myoclonic epilepsy (JME), various EEG characteristics have been suggested as poor prognostic signs, but their significance is unclear. The aim of this study was to assess the influence of EEG variables on seizure and psychosocial outcome after a follow-up exceeding 20 years.

METHODS

396 EEG recordings were available for assessment in 40 patients (42 complete digital, 330 paper segments and 24 written reports only). Mean follow-up was 31 years (range 20-68). The number of EEGs per patient ranged from 2 to 23 (mean 9). Twenty-one patients were in remission for >5 years, whereas 19 had persistent seizures. Favorable psychosocial outcome was found in 14 of 37. EEGs were retrospectively categorized into four main groups; normal, slowing, epileptiform discharges or both slowing and epileptiform discharges, with further sub-classification. Hyperventilation and photoparoxysmal responses were also evaluated. Scoring of EEG findings was blinded to seizure and psychosocial outcome.

RESULTS

Significant associations were found between poor seizure control and prolonged ≥3s epileptiform runs, p=0.03 (8/19 vs 2/21), long ≥3s photoparoxysmal runs, p=0.04 (6/19 vs 1/21) and long ≥3s hyperventilation-induced epileptiform runs, p=0.02 (5/19 vs 0/21). The strongest association between persistent seizures and EEG was found when all epileptiform runs ≥3s were combined (p=0.007), with a positive predictive value equal to 79% and a negative predictive value equal to 69%. Fast (4-5c/s) spike-wave runs were also more frequent in patients with persistent seizures compared to the remission group, p=0.04 (9/19 vs 3/21). Other epileptiform elements occurred equally in the two prognostic groups. Psychosocial outcome was not influenced by EEG findings. Prolonged runs within 6 months from first recording did also predict clinical outcome, p=0.03; (8/19 vs 2/21), with a positive predictive value equal to 80% and a negative predictive value equal to 63%.

SIGNIFICANCE

Fast spike-wave runs and prolonged (≥3s) epileptiform runs, including photoparoxysmal and hyperventilation-induced runs were associated with persistent seizures in JME. Focal EEG abnormalities were not associated with clinical outcome. Conceivably, the duration of epileptiform bursts reflects the degree of deficient intracortical inhibition. Prolonged runs may represent an essential predictive feature for poor seizure control in JME.