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.

EFHC1 gene mutation profile of Turkish JME patients and its association with disease risk

OBJECTIVES

Juvenile myoclonic epilepsy (JME) is a common form of generalized epilepsy with an important genetic component. This cohort study aimed to examine the frequency of EFHC1 gene variants in Turkish JME patients and a healthy control group and evaluate the association between these mutations and disease risk.

METHODS

We screened 72 JME patients with a mean age of 31.8 ± 9.9 (20-65) years and 35 controls with a mean age of 29.1 ± 7.6 (17-50) years from southern Turkey using direct sequencing analyses.

RESULTS

EFCH1 single nucleotide variants were detected in 24 of 72 JME patients and 3 of 35 controls. The most common mutations were R182H in JME patients (p = 0.010) and 3'UTR in the control group (p < 0.001). The R182H mutation is a common variant in JME (95 % CI: 1.232-76.580, p = 0.031) and the 3'UTR mutation may be associated with lower risk of JME in the Turkish population (95 % CI: 13.89-166.67, p < 0.001).

SIGNIFICANCE

Our results indicate that EFHC1 gene variants carry a risk for JME and the 3'UTR variant may have a protective role against JME in the Turkish population. Screening for other genes is needed to further clarify the genetic inheritance of JME in Turkish patients.

Paroxysmal Slow-Wave Events Are Uncommon in Parkinson's Disease

Background: Parkinson’s disease (PD) is currently considered to be a multisystem neurodegenerative disease that involves cognitive alterations. EEG slowing has been associated with cognitive decline in various neurological diseases, such as PD, Alzheimer’s disease (AD), and epilepsy, indicating cortical involvement. A novel method revealed that this EEG slowing is composed of paroxysmal slow-wave events (PSWE) in AD and epilepsy, but in PD it has not been tested yet. Therefore, this study aimed to examine the presence of PSWE in PD as a biomarker for cortical involvement. Methods: 31 PD patients, 28 healthy controls, and 18 juvenile myoclonic epilepsy (JME) patients (served as positive control), underwent four minutes of resting-state EEG. Spectral analyses were performed to identify PSWEs in nine brain regions. Mixed-model analysis was used to compare between groups and brain regions. The correlation between PSWEs and PD duration was examined using Spearman’s test. Results: No significant differences in the number of PSWEs were observed between PD patients and controls (p > 0.478) in all brain regions. In contrast, JME patients showed a higher number of PSWEs than healthy controls in specific brain regions (p < 0.023). Specifically in the PD group, we found that a higher number of PSWEs correlated with longer disease duration. Conclusions: This study is the first to examine the temporal characteristics of EEG slowing in PD by measuring the occurrence of PSWEs. Our findings indicate that PD patients who are cognitively intact do not have electrographic manifestations of cortical involvement. However, the correlation between PSWEs and disease duration may support future studies of repeated EEG recordings along the disease course to detect early signs of cortical involvement in PD.

[Reflex triggers in juvenile myoclonic epilepsy]

INTRODUCTION

Juvenile myoclonic epilepsy (JME) is an epileptic syndrome with onset in childhood and adolescence with myoclonus, absences, and generalized tonic-clonic seizures. Reflex stimuli such as sensitivity to light or photosensitivity, eyelid opening and closing, and praxis induction produce epileptiform discharges and seizures. These reflex triggers are not all systematically studied.

OBJECTIVE

Examine reflex features in patients with JME.

METHODS

One hundred adolescents and adults with JME who received different anti-seizure treatments were evaluated consecutively. A standard electroencephalogram was performed with an intermittent light stimulation (SLI) protocol and another for the evaluation of praxias through neurocognitive activity (CNA). The statistical analysis was descriptive and of correlation with a p > 0.05.

RESULTS

Current age was 28±11 (14-67). The seizure began at 15 years ±3 (Range 8-25 years). They presented myoclonus and generalized tonic-clonic seizures in 58%. 50% received valproic acid and 31% continued with seizures. Epileptiform discharges at rest 20%; hyperventilation 30%; eyelid opening and closing 12%; photoparoxysmal response in SLI 40%; CNA 23%. Higher percentage of discharges and delay in performing CNA in those who presented seizures. Valproic acid compared to other drugs did not demonstrate superiority in seizure control.

CONCLUSIONS

These findings confirm the importance of studying reflex traits for diagnosis, follow-up, and therapeutic control.

Automated Detection of Juvenile Myoclonic Epilepsy using CNN based Transfer Learning in Diffusion MRI

Epilepsy is one of the largest neurological diseases in the world, and juvenile myoclonic epilepsy (JME) usually occurs in adolescents, giving patients tremendous burdens during growth, which really needs the early diagnosis. Advanced diffusion magnetic resonance imaging (MRI) could detect the subtle changes of the white matter, which could be a non-invasive early diagnosis biomarker for JME. Transfer learning can solve the problem of insufficient clinical samples, which could avoid overfitting and achieve a better detection effect. However, there is almost no research to detect JME combined with diffusion MRI and transfer learning. In this study, two advanced diffusion MRI methods, high angle resolved diffusion imaging (HARDI) and neurite orientation dispersion and density imaging (NODDI), were used to generate the connectivity matrix which can describe tiny changes in white matter. And three advanced convolutional neural networks (CNN) based transfer learning were applied to detect JME. A total of 30 participants (15 JME patients and 15 normal controls) were analyzed. Among the three CNN models, Inception_resnet_v2 based transfer learning is better at detecting JME than Inception_v3 and Inception_v4, indicating that the "short cut" connection can improve the ability to detect JME. Inception_resnet_v2 achieved to detect JME with the accuracy of 75.2% and the AUC of 0.839. The results support that diffusion MRI and CNN based transfer learning have the potential to improve the automated detection of JME.

Cognitive functioning in new-onset juvenile myoclonic epilepsy

PURPOSE

Juvenile myoclonic epilepsy (JME) is a common genetic generalized epilepsy syndrome. Adult patients with JME have shown a neuropsychological profile suggestive of subtle frontal dysfunction, but studies of cognitive functioning in the early phases of JME are rare. We analyzed the cognitive performance data of 18 patients who had undergone a neuropsychological assessment either at the time of JME diagnosis and before the initiation of an antiepileptic drug (AED) treatment (11 patients) or during the first 6 years after JME diagnosis (seven patients).

METHODS

The cognitive performance of the18 patients with JME (mean age: 18.1, range: 15-33 years) and 18 healthy controls (mean age: 18.7, range: 15-25 years) was compared in a retrospective study. The assessed cognitive domains were visuomotor speed, attention, executive function, and verbal memory.

RESULTS

The patients with JME and the healthy controls did not differ in any of the assessed cognitive domains. The clinical variables did not correlate to cognitive performance. Furthermore, cognitive performance did not differ between the patients evaluated at the time of diagnosis and before the initiation of AEDs and the patients evaluated during the first 6 years after diagnosis and with an AED treatment.

CONCLUSIONS

The cognitive performance of patients with new-onset JME was similar to healthy controls. We could not detect the frontal dysfunction that has been suggested to be associated with JME. Patients were in adolescence or early adulthood with a short duration of epilepsy, which may have contributed to the discovery of no cognitive impairments.

A Sleepy Patient With Frequent Falls

Chada A, Dholakia S, Rye D. A sleepy patient with frequent falls. J Clin Sleep Med . 2019;15(11):1691–1693.

Developmental MRI markers cosegregate juvenile patients with myoclonic epilepsy and their healthy siblings

OBJECTIVE

MRI studies of genetic generalized epilepsies have mainly described group-level changes between patients and healthy controls. To determine the endophenotypic potential of structural MRI in juvenile myoclonic epilepsy (JME), we examined MRI-based cortical morphologic markers in patients and their healthy siblings.

METHODS

In this prospective, cross-sectional study, we obtained 3T MRI in patients with JME, siblings, and controls. We mapped sulco-gyral complexity and surface area, morphologic markers of brain development, and cortical thickness. Furthermore, we calculated mean geodesic distance, a surrogate marker of cortico-cortical connectivity.

RESULTS

Compared to controls, patients and siblings showed increased folding complexity and surface area in prefrontal and cingulate cortices. In these regions, they also displayed abnormally increased geodesic distance, suggesting network isolation and decreased efficiency, with strongest effects for limbic, fronto-parietal, and dorsal-attention networks. In areas of findings overlap, we observed strong patient-sibling correlations. Conversely, neocortical thinning was present in patients only and related to disease duration. Patients showed subtle impairment in mental flexibility, a frontal lobe function test, as well as deficits in naming and design learning. Siblings' performance fell between patients and controls.

CONCLUSION

MRI markers of brain development and connectivity are likely heritable and may thus serve as endophenotypes. The topography of morphologic anomalies and their abnormal structural network integration likely explains cognitive impairments in patients with JME and their siblings. By contrast, cortical atrophy likely represents a marker of disease.

Novel SCN2A mutation in a family associated with juvenile-onset myoclonus: Case report

RATIONALE

The phenotypic spectrum caused by SCN2A mutations includes benign neonatal/infantile seizures, Ohtahara syndrome, infantile spasms, West syndrome, and other unclassified epileptic phenotypes. Mutations in SCN2A have been implicated in neonatal seizure cases. Here, we described a Chinese family with 2 members having juvenile-onset myoclonus and identified a novel SCN2A point mutation within this family.

PATIENT CONCERNS

The 21-year-old male proband suffered from frequent myoclonus at 11 years old with subsequent progressive ataxia. His elder maternal half-sister also experienced myoclonus. Genomic DNA of the patients was extracted from the peripheral blood cells of the proband, elder maternal half-sister, parents, and uncle of the proband. Targeted next-generation sequencing was used to screen gene mutations in the proband. The potential functional effects of mutations within SCN2A were predicted In silico analyses.

DIAGNOSES

Genetic testing revealed a novel SCN2A variant, c.T4820C, which contains a highly conserved amino acid substitution within segment S5 (p.V1607A). This mutation was predicted to produce a dysfunctional Nav1.2 protein by Mutation Taster and Protein Variation Effect Analyzer (PROVEAN). Genotype-phenotype correlation showed an incomplete penetrance of p.V1607A.

INTERVENTIONS

The proband was treated by multiple antiepileptic drugs. These included carbamazepine, oxcarbazepine, valproate, and topiramate.

OUTCOMES

The duration of follow up was 2 years, and the proband developed drug-resistant epilepsy.

LESSONS

The case gives us the lesson that SCN2A mutation can contribute to juvenile-onset myoclonus. Our findings extend the spectrums of SCN2A mutations and the clinical features of patients with SCN2A mutations.

Juvenile myoclonic epilepsy as a spectrum disorder: A focused review

In consequence of newer research juvenile myoclonic epilepsy (JME) is no longer seen as a homogeneous disease. The causes of the existing variance are only partially known yet. We discuss to what extent the phenotypical spectrum of this polygenetically determined disorder expresses genetically defined endophenotypes, or is due to mere quantitative differences in the expression of the core phenotype. Of the three common seizure types of JME, myoclonic, generalized tonic-clonic and absences, absences also occur independently and are strong candidates for an endophenotype. Focal features may in some patients be seen in clinical seizures or the EEG but rarely in both. They have no morphological correlates. In a system epilepsy, local manifestations are possible, and some are due to reflex mechanisms. Of the four reflex epileptic traits common in JME, photosensitivity and praxis induction appear related to basic mechanisms of the core syndrome, whereas language-induced orofacial reflex myocloni and eye closure sensitivity are also seen in other clinical contexts and therefore seem to represent endophenotypes. Cognitive abnormalities indicating slight frontal lobe dysfunction seem to be ubiquitous in JME and are also seen in unaffected siblings of patients. Cluster B personality disorder is found in 1/3 of patients, representing a more severe expression of the underlying pathology. Treatment response and prognosis seem to be affected by an interplay of the described factors producing the severest end of the JME spectrum. The spectrum appears to be due to an interaction of stronger or weaker expression of the core phenotype with various endophenotypes.

Source localization of epileptiform discharges in juvenile myoclonic epilepsy (JME) using magnetoencephalography (MEG)

OBJECTIVE

The purpose of this study is to localize the sources of epileptiform discharges (EDs), in juvenile myoclonic epilepsy (JME) using Magnetoencephalography (MEG), at three different time instances and analyze the propagation of EDs, from onset to offset, for inferring the cortical and subcortical region of involvement.

METHODS

Twenty patients (age 23.5±6.3years old) with JME were recruited in this prospective study. MEG source analysis was performed on the independently collected EDs of each patient. The distributed source model was employed for source localization using low resolution electromagnetic brain tomography (LORETA). In each EDs, the onset (leading edge of the spike from baseline), peak and offset (trailing edge of the spike), with time window of 8ms, were subjected for source localization in order to study the propagation of the EDs. The obtained source location coordinates, from each individual MRI, were transformed in Talairach space and the distribution of region of source involvement was analysed.

RESULTS

The frequency pattern of lobar distribution at onset, peak and offset respectively suggest that discharges most commonly localized at onset from sublobar region, at peak from frontal lobe and at offset from the sublobar region. It was observed that the maximum involvement of sources from the sublobar, limbic and frontal lobes at different time instances. It indicates that the restricted cortical-subcortical involvement during the generation and propagation of EDs in JME.

SIGNIFICANCE

This MEG study supported the cortical-subcortical region of involvement and provided further insights in our understanding the network involvement in generation and propagation of EDs in JME.

Third International Congress on Epilepsy, Brain, and Mind: Part 2

Epilepsy is both a disease of the brain and the mind. Here, we present the second of two papers with extended summaries of selected presentations of the Third International Congress on Epilepsy, Brain and Mind (April 3-5, 2014; Brno, Czech Republic). Humanistic, biologic, and therapeutic aspects of epilepsy, particularly those related to the mind, were discussed. The extended summaries provide current overviews of epilepsy, cognitive impairment, and treatment, including brain functional connectivity and functional organization; juvenile myoclonic epilepsy; cognitive problems in newly diagnosed epilepsy; SUDEP including studies on prevention and involvement of the serotoninergic system; aggression and antiepileptic drugs; body, mind, and brain, including pain, orientation, the "self-location", Gourmand syndrome, and obesity; euphoria, obsessions, and compulsions; and circumstantiality and psychiatric comorbidities.

[CHARACTERISTICS AND DIFFERENTIAL DIAGNOSTICS OF SLEEP RELATED PATHOLOGICAL MOVEMENTS. UPDATE 2013]

Wide variety of the movements (from the physiologic body position changes to different pathologic events) can be seen during the sleep period. The most important types of these movements are the sleep related events (from the parasomnias to the restless leg related movements), the movement disorders and the epilepsy related events. To differentiate between these events is required special skill, which is based on appropriate characterisation of the events (for example timing, repetition, pattern), the polysomnographic and video-EEG examination and validated questionnaires (FLEP scale). The appropriate differential diagnostics and therapy must be based on the knowledge of the relationship of the sleep architecture and movement events. This review would like to provide guideline for the understanding and recognizing the nature of the sleep related movements.

Novel carboxypeptidase A6 (CPA6) mutations identified in patients with juvenile myoclonic and generalized epilepsy

Carboxypeptidase A6 (CPA6) is a peptidase that removes C-terminal hydrophobic amino acids from peptides and proteins. The CPA6 gene is expressed in the brains of humans and animals, with high levels of expression during development. It is translated with a prodomain (as proCPA6), which is removed before secretion. The active form of CPA6 binds tightly to the extracellular matrix (ECM) where it is thought to function in the processing of peptides and proteins. Mutations in the CPA6 gene have been identified in patients with temporal lobe epilepsy and febrile seizures. In the present study, we screened for CPA6 mutations in patients with juvenile myoclonic epilepsy and identified two novel missense mutations: Arg36His and Asn271Ser. Patients harboring these mutations also presented with generalized epilepsy. Neither of the novel mutations was found in a control population. Asn271 is highly conserved in CPA6 and other related metallocarboxypeptidases. Arg36 is present in the prodomain and is not highly conserved. To assess structural consequences of the amino acid substitutions, both mutants were modeled within the predicted structure of the enzyme. To examine the effects of these mutations on enzyme expression and activity, we expressed the mutated enzymes in human embryonic kidney 293T cells. These analyses revealed that Asn271Ser abolished enzymatic activity, while Arg36His led to a ~50% reduction in CPA6 levels in the ECM. Pulse-chase using radio-labeled amino acids was performed to follow secretion. Newly-synthesized CPA6 appeared in the ECM with peak levels between 2-8 hours. There was no major difference in time course between wild-type and mutant forms, although the amount of radiolabeled CPA6 in the ECM was lower for the mutants. Our experiments demonstrate that these mutations in CPA6 are deleterious and provide further evidence for the involvement of CPA6 mutations in the predisposition for several types of epilepsy.

Cognitive functioning in idiopathic generalised epilepsies: a systematic review and meta-analysis

Cognitive function in idiopathic generalised epilepsies (IGE) is of increasing research attention. Current research seeks to understand phenotypic traits associated with this most common group of inherited epilepsies and evaluate educational and occupational trajectories. A specific deficit in executive function in a subgroup of IGE, juvenile myoclonic epilepsy (JME) has been a particular focus of recent research. This systematic review provides a quantitative synthesis of cognitive function outcomes in 26 peer-reviewed, case-control studies published since 1989. Univariate random-effects meta-analyses were conducted on seven cognitive factor-domains and separately on executive function. Patients with IGE demonstrated significantly lower scores on tests across all cognitive factor-domains except visual-spatial abilities. Effect sizes ranged from 0.42 to 0.88 pooled standard deviation units. The average reduction of scores on tests of executive function in IGE compared to controls was 0.72 standard deviation units. Contrary to current thinking, there was no specific deficit in executive function in JME samples, nor in other IGE syndromes. Of more concern, people with IGE are at risk of pervasive cognitive impairment.

Neurological problems in the adolescent population

Adolescent patients pose a unique challenge to child neurologists. Although there are a number of neurological disorders that present in childhood and persist through adolescence, there are some disorders like juvenile myoclonic epilepsy (JME) that occur more commonly in this age group. We discuss common neurological disorders encountered by adolescent medicine physicians that have been affected by recent advances in the field of adolescent neurology. We also address the challenges of transitioning care to an adult neurologist.

Focal clinical and electroencephalographic features in patients with juvenile myoclonic epilepsy

OBJECTIVE

To identify prevalence and factors associated with occurrence of focal clinical and electroencephalogram (EEG) abnormalities in patients with juvenile myoclonic epilepsy (JME).

MATERIALS AND METHODS

Clinical asymmetries in the seizures and focal EEG abnormalities were analyzed in 266 patients with JME.

RESULTS

All the patients had myoclonic jerks (MJ) and generalized tonic-clonic seizures (GTCS); 56 (21%) had absence seizures. Asymmetry in clinical seizures was reported in 45 (16.9%) and focal EEG abnormalities were noted in 92 (45.5%) patients. Amplitude asymmetry or focal onset of generalized discharges was noted in 41 (44.6%) and independent focal EEG abnormalities in 30 (32.6%) patients. A statistically significant association was seen with the presence of GTCS and MJ (P = 0.007), a family history of epilepsy (P = 0.001) and drug resistance (P = 0.04) and the occurrence of focal EEG abnormalities.

CONCLUSION

Patients with JME showed focal clinical and EEG features. These features should not be misinterpreted as indicative of partial epilepsy.

[Intellectual, psychomotor and speech development of children born to mothers with epilepsy]

Intellectual, psychomotor and speech development of 50 children born to mothers with epilepsy were studied. The sample has been stratified into 2 subgroups: children aged from 6 months to 4 years and children aged from 4 to 16 years. This group included 4 (8%) children with children absence epilepsy, juvenile myoclonic and unclassified epilepsy; one patient had a diagnosis of epileptic encephalopathy without epileptic seizures. Video-EEG monitoring revealed the epileptiform activity on EEG in 9 (18%) children from subgroup 2, four of them suffered from epilepsy. The subclinical epileptiform activity on EEG was observed in 5 (10%) children. The Wechsler test showed that general IQ scores were low (<95%) in 4 (20%) children of this subgroup. No significant difference was found in the performance on the Bayley-III scales between children from subgroup 1 and children born to healthy mothers (controls) though the scores on the fine motor scale and speech development scale were lower in 3 (10%) and 5 (16%) children of the index group, respectively.

[Photosensitivity and generalized idiopathic epilepsies of children]

The aim of this study is to evaluate the frequency of photosensitivity at patients of paediatric age diagnosed with different types of generalized idiophatic epilepsies.

MATERIAL AND METHOD

We used a group of 68 children aged 3-18 years diagnosed: 39 patients with childhood absence epilepsy (CAE), 11 with juvenile absence epilepsy (JAE), 10 with epilepsy with grand mal on awakening (EGMA), 8 with juvenile myoclonic epilepsy (JME). EEG was recording without and with stimulation (hyperventilation, intermittent photic stimulation -IPS) after sleep deprivation. For all children with CAE absences and anormal EEG was provoked by hyperventilation and in 12 cases seizures was provoked by IPS.

RESULTS

At 4 patients with JAE, EEG show photosensitivity. 5 children with JME have photosensitivity and for one child opening eyes provoked polyspike-wave discharges without clinical correspondent. The EEG of patients with EGMA showed photosensitivity at 6 children. The photosensitivity is frequently associated with generalized idiophatic epilepsies (32.35%) and it is most often seen at girls (54.54%) of puberty age.

[Case of juvenile myoclonic epilepsy misdiagnosed as simple partial seizure for more than 60 years]

A 77-years-old woman was admitted to our hospital due to uncontrolled myoclonus and generalized seizure. Since the age of 17, she has been suffering from myoclonic jerks and partial convulsions in her right arm. Administration of several unknown anticonvulsants had not alleviated her condition. She was able to spend her life without a handicap, except for the symptoms described above. She has been experiencing psychological stress since the age of 50, which has resulted in worsening of her symptoms, and she was prescribed phenytoin, carbamazepine, and phenobarbital, which were also ineffective. When a generalized convulsive attack occurs, she shows rapid muscle twitches in her right arm and her consciousness is clear. She also has cerebellar ataxia in her extremities. Brain magnetic resonance imaging (MRI) showed obvious cerebellar atrophy, and an electroencephalogram revealed a diffuse spike and wave complexes. A surface electromyogram (EMG) confirmed myoclonus in both arms. We diagnosed her as having juvenile myoclonus epilepsy and initiated sodium valproate monotherapy, which relieved the symptoms. The observed cerebellar ataxia might be due to long-term administration of phenytoin. When a neurologist encounters an intractable seizure without loss of consciousness, surface EMG is useful for diagnosing this treatable disease.

[Clinical and genetic diagnosis of Dravet syndrome: report of 20 cases]

OBJECTIVE AND BACKGROUND

Severe myoclonic epilepsy in infancy (SMEI; Dravet's syndrome) is a malignant epilepsy syndrome characterized by prolonged febrile hemiconvulsions or generalized seizures starting in the first year of life. Later on myoclonic, atypical absence, and complex partial seizures appear. When one of these seizure forms is lacking the syndrome of borderline SMEI (SMEB) is defined. Psychomotor delay resulting in mental retardation is observed during the second year of life. In most patients a de novo sodium channel alpha-1 subunit (SCN1A) mutation can be identified. By reviewing the clinical, laboratory, and neuroimaging data of our SMEI patients diagnosed between 2000 and 2008, we would like to share our experiences in this rare but challenging syndrome. Our results will facilitate the earlier and better diagnosis of Hungarian children with SMEI.

PATIENTS AND METHODS

Clinical, EEG, MRI and DNA mutation data of 20 SMEI patients treated in the Bethesda Children's Hospital (Budapest) were reviewed.

RESULTS

The first seizure appeared at age 6.3+/-3.0 months. At least one of the first two seizures were complex febrile seizures in 19/20 and unilateral seizures in 12/20 children. All children except for one showed hemiconvulsions at least once; all children had seizures lasting longer than 15 minutes. Eight of twenty patients had SMEB. DNA diagnostics identified an SCN1A mutation in 17 patients (6 missense, 4 nonsense, 4 frameshift, 2 splice site, 1 deletion) while 3 children had no mutation.

CONCLUSION

Early diagnosis of SMEI is important for the avoiding unnecessary examinations and false therapies as well as for genetic counselling. Typical symptoms of SMEI are early and prolonged febrile hemiconvulsions with neurological symptoms, mental retardation and secondary seizure types later on. The presence of an SCN1A mutation supports the diagnosis. We propose the availability of molecular diagnostics and stiripentol therapy for SMEI children in Hungary

Usefulness of a morning routine EEG recording in patients with juvenile myoclonic epilepsy

OBJECTIVE

To evaluate if a standard awake EEG recording in the morning is superior to afternoon awake EEG session in detecting generalized epileptiform discharges (GEDs) in patients with juvenile myoclonic epilepsy (JME).

METHODS

The study group included 29 consecutive patients (23 women; mean age 22.3+/-6.3 years; age at onset of JME 15.4+/-3.4 years) with JME. Out of 29 patients 5 were untreated, 9 patients were treated with valproate, 8 with lamotrigine, 6 with levetiracetam and 1 patient with valproate plus phenobarbital. Two routine consecutive interictal EEG recordings were performed at 9a.m. and at 3p.m., respectively, while the subject was awake, on the same day after a a regular nocturnal sleep at own home.

RESULTS

The morning EEG recording showed GEDs (i.e., generalized polispike and waves, photoparoxysmal response, or both). in 20/29 patients. In 15 of these 20 patients, the afternoon recording was normal and this difference was statistically significant (p < or = 0.001). Moreover, there was a striking reduction of GEDs in three of the remaining five patients. Nine/29 patients had both morning and afternoon EEG recording normal.

CONCLUSIONS

The results of this study have illustrated a significant greater rate of detection of generalized epileptiform abnormalities by performing standard awake EEG in the morning in comparison with an afternoon session.

[Benign myoclonic epilepsy -a curious case report]

INTRODUCTION

Benign myoclonic epilepsy in infants is a rare condition that belongs to the group of epilepsies and generalised epileptic syndromes. Doubts have recently arisen as to whether it is really benign, with some reports of cases of compromised psychomotor development when therapy is started late. The differential diagnosis can be associated with epileptic and non-epileptic diseases, and it is important to preclude it from the former due to their severity. Lombroso and Fejerman's benign myocloni are the non-epileptic diseases that create most problems as far as the differential diagnosis is concerned. Congenital defects of the cranial vault are quite rare and are sometimes associated with other malformations. Exceptionally they appear in isolation, and familial cases have been reported.

CASE REPORT

Here we describe the case of a female infant, who had been subject to a follow-up in the Children's Neurology department from the age of 7 months and who had been diagnosed as suffering from unspecific bone erosion of the cranial vault and benign myoclonic epilepsy in infants. Psychomotor development has taken place within the range of parameters that can be considered to be normal and the patient is currently 25 months old.

CONCLUSIONS

From the clinical point of view, in this case we can rule out the most severe epileptic situations. This is a clinical case that is atypical, not only because of the coexistence of two rare diagnoses, but also due to the clinical features and electroencephalographic manifestations. Both situations are very uncommon and there is no apparent relationship between them.

Proton magnetic resonance spectroscopy study of bilateral thalamus in juvenile myoclonic epilepsy

PURPOSE

To investigate neuronal dysfunction in the thalami of juvenile myoclonic epilepsy (JME) by using proton magnetic resonance spectroscopy (MRS).

METHODS

We performed single-voxel proton MRS over the right and the left thalami of 15 consecutive patients (10 women, 5 men) with JME (mean age 20.3 years) and 16 healthy volunteers (10 women, 6 men) (mean age 24.5 years). All patients had seizure onset in late childhood-teenage, normal neurologic examination, typical electroencephalogram (EEG) of JME and normal magnetic resonance imaging (MRI). We determined N-acetylaspartate (NAA) values and NAA over creatine-phosphocreatine (Cr) values. Mann-Whitney U-test was used to evaluate group differences.

RESULTS

Group analysis showed that echo time (TE) 270 integral value of NAA over left thalamus were significantly decreased in JME patients as compared with controls (34.6033+/-15.8386; 48.0362+/-22.2407, respectively, P=0.019). Also group analysis showed that thalami NAA/Cr ratios were significantly decreased in JME patients (right side, 2.21+/-1.07; left side 2.00+/-0.72) as compared with controls (right side, 3.45+/-1.50; left side, 3.08+/-1.60; P=0.011 and P=0.030, respectively).

CONCLUSION

In the previous studies, NAA values in patients with JME found that they were not statistically lower in thalami than control group. But, in our study, NAA value was found low as well. It has been known that NAA is a neuronal marker and hence it is a valuable metabolite in the neuron physiopathology. As a result, in the patients with JME we tried to support the theory that the underlying mechanism of the generalized seizures was the abnormal thalamocortical circuity, determining the thalamic neuronal dysfunction in MRS statistically.

Circadian Rhythm and Personality Profile in Juvenile Myoclonic Epilepsy

Juvenile Myoclonic Epilepsy (JME) is a prototype of idiopathic generalized epilepsy and is characterized by a strong genetic predisposition. According to clinical observations by Janz and Christian (1), the syndrome is associated with a characteristic sleep/wake rhythm and a typical personality profile. These features have subsequently been interpreted as a mild frontal lobe behavior syndrome. Recent neuropsychological and imaging studies confirmed mesiofrontal and prefrontal dysfunction in JME. We studied 20 patients with JME and a matched comparison group with temporal lobe epilepsy (TLE) using standardized questionnaires with respect to the sleep-wake rhythm and with respect to personality profiles. We confirmed the characteristic circadian rhythm in JME with the tendency to go to bed later at night, to get up later in the morning, and to feel fit at a later time during the day compared to patients with TLE. With the exception of some subanalyses we did not find evidence for a specific personality profile in JME.

Idiopathic Generalized Epilepsies of Adolescence

The prevalence of idiopathic generalized epilepsies (IGEs) has been assessed as being 15-20% of all epilepsies. The seizure types in IGEs are typical absences, myoclonic jerks, and generalized tonic-clonic seizures (TCS), alone or in varying combinations and with variable severity. The seizures tend to be more frequent on awakening and with sleep deprivation. This group of clinical conditions includes among others, age-related epilepsy syndromes of adolescence such as juvenile absence epilepsy (JAE), juvenile myoclonic epilepsy (JME), and IGE with generalized TCS or epilepsy with grand mal on awakening (EGMA). The classification of IGEs follows two schools of thought; one maintains that IGEs are a group of different and separate syndromes while the other suggests that IGEs are one biological continuum. Patients with IGEs may have mild impairment of cognitive functions, especially verbal memory and other frontal lobe functions, despite a normal IQ, and some seem to have characteristic personality traits, although further studies are needed to support this theory. They appear to lack a degree of self-control, to neglect their physical needs, and are poorly compliant with therapy. Some patients become obstinate and are impressionable. The cognitive and behavioral aspects of these patients suggest an involvement of frontal lobes.

Overlap cases of eyelid myoclonia with absences and juvenile myoclonic epilepsy

Eyelid myoclonia with absences (EMA) and juvenile myoclonic epilepsy (JME) are two separate epileptic syndromes included in the new classification of epilepsies and epileptic syndromes by ILAE in 2001. Both are idiopathic generalized epilepsies with their clinical onset in the first two decades. EMA is characterized by eyelid myoclonia associated with absences and photosensitivity. Self-induced seizures are frequently seen in EMA. It can be associated with mildly mental retardation and resistance to treatment. JME includes three types of generalized seizures: typical absences, myoclonic jerks and generalized tonic-clonic seizures. The myoclonic jerks occur almost exclusively on awakening, involve preferently the upper extremities, may rarely affect the lower extremities or the entire body. More severe attacks may be accompanied by a fall. The myoclonic jerks occur rarely in EMA. They are usually mild and are freqently restricted to the upper extremities. Generalized tonic-clonic seizures, photosensitivity and generalized polyspike-wave discharges provoked by eye closure are features of both epileptic syndromes. In this study, we describe four female patients with eyelid myoclonia associated with absences, myoclonic jerks causing falling down and rare generalized tonic-clonic seizures. All patients had good school performance and total seizure control under sodium valproate treatment. Their EEGs show generalized polyspike-wave discharges with a frequency of 3.5-6Hz always appearing a few seconds after eye closure and photoparoxysmal response. These patients show the characterictics of both epileptic syndromes. It is clinically important to make a syndromic diagnosis for an optimum advise on treatment, lifestyle restrictions and prognosis. In this study, we have gathered evidence that EMA and JME are dynamic syndromes that tend to evolve into one another.

Perioral Reflex Myoclonias: A Controlled Study in Patients with JME and Focal Epilepsies

PURPOSE

Perioral reflex myoclonias (PORM) are obvious, frequent, but often unobserved focal seizures in different epileptic syndromes and the leading seizure type in reading epilepsy. PORMs remain often undiagnosed because the patients are not aware that these are epileptic seizures and fail to report them. Their semiology is not fundamentally different in various epileptic syndromes.

METHODS

We studied the frequency of PORM in patients with juvenile myoclonic epilepsy (JME) compared with patients with focal epilepsies. Twenty-five patients with JME were investigated with a standardized neuropsychological test program and compared with 25 matched patients with focal epilepsies. Statistical significance was calculated by using Fisher's exact test.

RESULTS

We found significant differences between the groups regarding both frequency of PORM and activation of epileptic discharges. These observations seem to indicate that PORM, like praxis-induced seizures, are typical traits in JME.

CONCLUSIONS

PORM are more frequent in JME compared with focal epilepsies. The distinction between focal and generalized epileptic ictogenesis may be less clear than is traditionally believed.

Benign Myoclonic Epilepsy in Infants: Electroclinical Features and Long-term Follow-up of 34 Patients

PURPOSE

Benign myoclonic epilepsy in infants (BMEI) is a rare epileptic syndrome characterized only by generalized myoclonic seizures (MSs) in normal children during the first 2 years. Our aim was to assess the electroclinical features and the follow-up of this syndrome.

METHODS

BMEI was confirmed by electroencephalogram (EEG) in four neuropediatric units in France between 1981 and 2002. Clinical and electroencephalographic findings at diagnosis and during the follow-up were collected. The Vineland scale or Wechsler scale or both were used to perform neuropsychological evaluations.

RESULTS

We report 34 patients with BMEI characterized by MSs occurring many times a day. The ictal EEG showed a generalized discharge of polyspikes, polyspikes-and-waves, or spikes-and-waves. The interictal EEG was usually normal. A family history of febrile seizures (FSs) or epilepsy was noted in six patients. A history of FSs was noted in 11 patients. Eleven patients had reflex MSs. Monotherapy with valproic acid was effective in 23 of 30 treated patients. The onset of epilepsy was known in all patients. Four patients had seizures after the initial symptoms. Juvenile myoclonic epilepsy developed in two patients, and cryptogenic partial epilepsy in another. Neuropsychological outcome was evaluated in 20 patients (10 with Wechsler scales and 17 with the Vineland scale). Cognitive functions were normal in 17 patients, whereas developmental delay was observed in three others.

CONCLUSIONS

BMEI is clinically characterized by myoclonic seizures involving the upper part of the body, occurring many times a day. The ictal EEG showed a generalized discharge of polyspikes, polyspikes-and-waves, or spikes-and-waves. The interictal EEG was usually normal. Reflex MSs were frequently observed, suggesting that two distinctive syndromes are not necessary. BMEI may be followed by juvenile myoclonic epilepsy. Despite a generally favorable neuropsychological outcome, mental retardation can be observed more frequently than in the general population.

Juvenile myoclonic epilepsy: non-classic electroencephalographical presentation in adult patients*

Although diagnosis of juvenile myoclonic epilepsy (JME), a common form of idiopathic generalized epilepsy, is based on clinical and electroencephalogram (EEG) criteria, at times clinical symptoms may be misleading, like the occurrence of asymmetric myoclonic jerks. Thus EEG assumes an important role in these cases, it can fail to show the classical polyspike and slow wave (PSW) discharges of JME, specially in a routine evaluation in older patients. We analyzed retrospectively EEG results of 35 patients with JME [Commission on Classification and Terminology of the International League Against Epilepsy (ILAE) Epilepsia 1989; 30: 389] aged 12-44 years. (mean 22.7 years) at first medical evaluation. EEG findings of 35 patients (19 females, 16 males) with JME consisted of normal tracings in 22.9 and 54.3% had at least one normal exam. EEG abnormalities present in 27 patients (77.1%) consisted of isolated generalized slowing in two and generalized discharges in 25: irregular spike and wave complexes (SWC) in 76%; PSW in 48%; SWC faster than 3 Hz in 20%; spikes, sharp waves, and irregular slow waves in 24%; asymmetric generalized epileptiform discharges in 40%; and associated focal paroxysms in 12%. Thus JME is classically associated to PSW on EEG, the most frequent abnormality was irregular SWC. Generalized paroxysms could occur in an asymmetric fashion and rarely associated to focal activity.

Refractory calculation-induced idiopathic generalized epilepsy: a case report and review of the literature

We report a case with calculation-induced idiopathic generalized epilepsy (IGE) that, unlike most patients with IGE, was refractory to medications. This patient had a family history of (1) a similar condition in a relative of hers who, however, did not have identical manifestations, and (2) a mother who had migraine. Our observations illustrate that the occurrence of IGE in families usually follows rather complex patterns of inheritance and that some of them can be refractory to therapy.

Idiopathic generalized epilepsies imitating focal epilepsies

Classification of epileptic seizures and epilepsy syndromes as either focal or generalized is a fundamental and early part in the diagnostic process and is generally fairly easily accomplished. However, in patients with idiopathic generalized epilepsies, seizure and EEG features may suggest, particularly to the unwary, the occurrence of focal rather than generalized seizures. Misinterpretation of typical absence seizures as focal seizures, especially as temporal lobe seizures and of myoclonic seizures as focal clonic seizures, is a relatively common error and focal features during generalized tonic-clonic seizures may also be quite common. Sequences of seizures in idiopathic generalized epilepsies (such as absences or jerks followed by generalized tonic-clonic seizures) may also cause confusion. Versive and circling seizures are seizure types whose ictal semiology is clearly focal; nevertheless such seizures are described in idiopathic generalized epilepsies accompanied by generalized EEG discharges. The occurrence of focal EEG abnormalities in certain idiopathic generalized epilepsy syndromes is common. This is best known in juvenile myoclonic epilepsy.

Juvenile myoclonic epilepsy--a generalized epilepsy syndrome?

Juvenile myoclonic epilepsy (JME) has been classified as a syndrome of idiopathic generalized epilepsy and is characterized by specific types of seizures, showing a lack of pathology using magnetic resonance imaging (MRI) and computed tomography scanning. However, JME is associated with a particular personality profile, and behavioral and neuropsychologic studies have suggested the possible involvement of frontal lobe dysfunction. The development of highly sensitive neuroimaging techniques has provided a means of elucidating the underlying mechanisms of JME. For example, positron emission tomography has demonstrated neurotransmitter changes in the cerebral cortex, quantitative MRI has revealed significant abnormalities of cortical gray matter in medial frontal areas, and 1H-magnetic resonance spectroscopy has shown evidence of thalamic dysfunction, which appears to be progressive. Such techniques provide evidence of multi-focal disease mechanisms, suggesting that JME is a frontal lobe variant of a multi-regional, thalamocortical 'network' epilepsy, rather than a generalized epilepsy syndrome.

Management Guidelines for Children with Idiopathic Generalized Epilepsy

Most idiopathic generalized epilepsy (IGE) begins in childhood. Clinicians face many important management decisions for these children; however the existing literature provides little scientific guidance.

TIME OF DIAGNOSIS

At the time of presentation, it is unclear how accurately IGE seizures and syndromes are diagnosed and how consistent are the EEG correlates. Investigations beyond EEG are of uncertain value but probably are not needed. Selection of an initial antiepileptic drug (AED) is not based on any adequately powered, blinded, randomized comparative trials; however, reasonable evidence supports the use of valproic acid (VPA), lamotrigine and ethosuccimide as initial treatment for childhood absence epilepsy (CAE). Many large case series suggest the value of VPA for juvenile myoclonic epilepsy (JME) but the relative value of other, newer AEDs has not been established.

FIRST YEARS OF TREATMENT

Once AED treatment is started, it is difficult to establish that absence seizures are completely controlled and the importance of interictal spike-wave discharge remains uncertain. The value of restrictions on the child's activities has not been well studied; however serious accidents appear to be a justifiable concern in children with uncontrolled absence. Assessing the risk from photosensitivity in JME is challenging.

LENGTH OF TREATMENT

The optimal length of treatment for IGE is unclear. There is a high rate of remission in CAE when AEDs are discontinued after 1-2 years of seizure freedom; however, long-term remission in CAE occurs in only 65%. It is usually assumed that treatment for JME is life long, although about 10% appear to have permanent remission in adolescence. Discontinuing AED treatment in JME requires a very individual risk assessment.

PREPARATION FOR ADULT LIFE

Long-term social outcome for children with CAE is often unsatisfactory even if the epilepsy remits. The reasons are unclear and successful interventions have not been described. Long-term social outcome for JME has not been adequately described.

CONCLUSIONS

Further research is needed to justify the direction of many of the necessary management decisions in the diagnosis and treatment of IGE syndromes.

Focal semiologic and electroencephalographic features in patients with juvenile myoclonic epilepsy

PURPOSE

A few reports have described focal electroencephalographic or clinical features or both of juvenile myoclonic epilepsy (JME), but without video-EEG documentation. We examined focal clinical and EEG features in patients with JME who underwent video-EEG monitoring.

METHODS

Twenty-six patients (nine males and 17 females) who had seizures recorded during video-EEG monitoring were included. Age at seizure onset was 0 to 22 years (mean, 12.3 years), and age at monitoring was 12 to 44 years (mean, 26.5 years). In one patient with left parietooccipital epilepsy, primary generalized tonic-clonic seizures developed after resection of the parietal tumor. Two patients had both temporal lobe epilepsy and JME. Videotaped seizures in each patient were analyzed. Interictal and ictal EEG also were analyzed for any focal features.

RESULTS

Focal semiologic features were observed in 12 (46%) of 26 patients. Six patients had focal myoclonic seizures, and two had Figure 4 sign: one with version to the left, and another had left version followed by Figure 4 sign, and left arm clonic seizure. Their ictal EEGs were generalized at onset but with a lateralized evolution over the right hemisphere. The patient who had both JME and left parietooccipital epilepsy, right arm clonic seizure, and Figure 4 sign was seen during a generalized EEG seizure. Interictally, one patient had temporal sharp waves, and another had run of spikes in the right frontal region.

CONCLUSIONS

Fourteen (54%) of 26 patients with JME exhibited focal semiologic or electroencephalographic features or both. Video-EEG was essential in reaching a correct diagnosis and choosing an appropriate antiepileptic drug regimen.

Prognostic value of electrocorticography findings during callosotomy in children with Lennox–Gastaut syndrome

OBJECTIVE

To analyze findings and acute changes in electrocorticograms (ECoGs) obtained during corpus callosotomy in order to identify any relationships with the postoperative outcome of seizure activity.

METHODS

We retrospectively analyzed ECoGs obtained during anterior callosotomy (4-6 cm) in 48 patients with Lennox-Gastaut syndrome (32 boys and 16 girls, age 1-20 years, mean age 7.6 years) who underwent surgery between July 1993 and November 1996 to correlate recording findings with postoperative seizure activity. At the time of analysis, all patients had been followed postoperatively for more than 4 years.

RESULTS

Of 48 patients, 31 (64.6%) had significant improvement in seizure control after surgery. In pre-excisional ECoGs, 38 (79.2%) of 48 patients had bisynchronous epileptiform discharges. Patients (23 of 33 patients, 69.7%) with significant blockage of bisynchronous discharges recorded during callosotomy achieved the best postoperative seizure outcomes, but the difference did not reach statistical significance (P>0.05).

CONCLUSIONS

Based on our experience, changes in ECoG during callosotomy do not predict postoperative seizure outcome. Insignificant blockage of bisynchronous epileptiform discharges in ECoGs during callosotomy does not predict a worse prognosis than that associated with significant intraoperative blockage.

[EEG recording after sleep deprivation in a series of patients with juvenile myoclonic epilepsy]

Seizures in Juvenile Myoclonic Epilepsy (JME) are dependent on the sleep-wake cycle and precipitant factors, among which sleep deprivation (SD) is one of the most important. Still an under diagnosed syndrome, misinterpretation of the EEGs contributes to diagnostic delay. Despite this, a quantitative EEG investigation of SD effects has not been performed. We investigated the effect of SD on EEGs in 41 patients, aged 16-50 yr. (mean 25.4), who had not yet had syndromic diagnosis after a mean delay of 8.2 yr. Two EEG recordings separated by a 48-hour interval were taken at 7 a.m. preceded by a period of 6 hours of sleep (routine EEG) and after SD (sleep-deprived EEG). The same protocol was followed and included a rest wakefulness recording, photic stimulation, hyperventilation and a post-hyperventilation period. The EEGs were analyzed as to the effect of SD on the number, duration, morphology, localization and predominance of abnormalities in the different stages. A discharge index (DI) was calculated. Out of the 41 patients, 4 presented both normal EEG recordings. In 37 (90.2%) there were epileptiform discharges (ED). The number of patients with ED ascended from 26 (70.3%) in the routine EEG to 32 (86.5%) in the sleep-deprived exam. The presence of generalized spike-wave and multispike-wave increased from 20 (54.1%) and 13 (35.1%) in the first EEG to 29 (78.4%) and 19 (51.4%) in the second, respectively (p<0.05 and p<0.01). As to localization, the number of generalized, bilateral and synchronous ED increased from 21 (56.8%) to 30 (81.1%) (p<0.01). The DI also increased; while 8 patients (21.6%) presented greater rate in the routine EEG, 25 (67.6%) did so in the sleep-deprived EEG mainly during somnolence and sleep (p<0.01). Moreover, the paroxysms were also longer in the sleep-deprived EEG. Sleep-deprived EEG is a powerful tool in JME and can contribute significantly to the syndromic characterization of this syndrome.

[A course of idiopathic generalized epilepsy in adult and elderly patients]

Thirty-six patients with idiopathic generalized epilepsy (IGE) aged 35-67 years (mean age 44.4 +/- 10.6 years, 14 male, 22 female) have been studied. Ten of them were over 50 years, 8 had a diagnosis of juvenile absence epilepsy (JAE); 12--juvenile myoclonic epilepsy (JME) and 16--awakening epilepsy (AE), IGE with isolated generalized tonic-clonic seizures. The control group included 80 patients with IGE (22 male, 58 female aged 15-34 years, mean age 20.5 +/- 4.3 years), 29 of them being affected with JAE, 28--JME, 23--AE. Elderly patients with IGE experienced difficulties in the control over absences, myoclonic seizures and generalized seizures. In this group, the seizures-free cases were rare. The results suggest worse clinical prognosis of IGE for elderly patients as compared with young ones.

Efficacy and tolerability of zonisamide in juvenile myoclonic epilepsy

The recommended treatment for juvenile myoclonic epilepsy (JME) is valproate (VPA). Recently, topiramate and lamotrigine have also been shown to be effective. The objective of this study was to evaluate the efficacy and tolerability of zonisamide (ZNS) in the treatment of JME. We retrospectively analyzed the records of 15 patients (three M, 12 F, ages 11-20 years) diagnosed with JME at our institution during 2001-2003, and treated with ZNS. Generalized tonic-clonic (GTC), myoclonic and absence seizure response was assessed. The ZNS dose range was 200-500 mg/day (2.0-8.5 mg/kg/day). ZNS was started as the first drug, and as monotherapy, in 13 and was added to VPA in two patients. Follow-up range was 2-24 months (mean 12 months). Overall, 80% of patients on ZNS monotherapy showed good control (> or = 50% seizure reduction). Sixty-nine, 62 and 38% of patients were free of GTC, myoclonic, and absence seizures, respectively. Seizure control was achieved within four to eight weeks of attaining the maintenance dose. One patient on polytherapy had a 75% reduction in seizure frequency, whereas the other patient showed no response. There were no ZNS-VPA interactions. One patient stopped ZNS and was switched to VPA because of poor seizure control. Three patients (20%) experienced side effects (weight loss, headache, dizziness) during escalation, which resolved during maintenance. In this open-label, retrospective study, ZNS was shown to be an effective and well-tolerated drug in the treatment of patients with JME. The ease of titration, good safety profile, once-a-day dosing, lack of significant drug interaction, and short latency for onset of efficacy make ZNS an attractive therapeutic alternative for the treatment of JME.