Results of an international Delphi consensus in epilepsy with myoclonic atonic seizures/ Doose syndrome

Improving care for rare genetic neurodevelopmental disorders: A systematic review and critical appraisal of clinical practice guidelines using AGREE II

PURPOSE

Rare genetic neurodevelopmental disorders associated with intellectual disability require lifelong multidisciplinary care. Clinical practice guidelines may support healthcare professionals in their daily practice, but guideline development for rare conditions can be challenging. In this systematic review, the characteristics and methodological quality of internationally published recommendations for this population are described to provide an overview of current guidelines and inform future efforts of European Reference Network ITHACA (Intellectual disability, TeleHealth, Autism, and Congenital Anomalies).

METHODS

MEDLINE, Embase, and Orphanet were systematically searched to identify guidelines for conditions classified as "rare genetic intellectual disability" (ORPHA:183757). Methodological quality was assessed using the Appraisal of Guidelines, Research, and Evaluation II tool.

RESULTS

Seventy internationally published guidelines, addressing the diagnosis and/or management of 28 conditions, were included. The methodological rigor of development was highly variable with limited reporting of literature searches and consensus methods. Stakeholder involvement and editorial independence varied as well. Implementation was rarely addressed.

CONCLUSION

Comprehensive, high-quality guidelines are lacking for many rare genetic neurodevelopmental disorders. Use and transparent reporting of sound development methodologies, active involvement of affected individuals and families, robust conflict of interest procedures, and attention to implementation are vital for enhancing the impact of clinical practice recommendations.

Efficacy of felbamate in a cohort of patients with epilepsy with myoclonic atonic seizures (EMAtS)

Epilepsy with myoclonic atonic seizures (EMAtS) is a rare childhood onset developmental and epileptic encephalopathy which is frequently refractory to medical therapy. The optimal antiseizure medication remains unknown. This study reports the efficacy of felbamate in children with EMAtS. Six large pediatric epilepsy centers performed a retrospective chart review on patients diagnosed with EMAtS at their institutions and collected data on felbamate usage and efficacy. Responders were classified as patients who had a 50% or greater reduction in seizures with a given therapy. Out of 259 patients, 37 (14%) were treated with felbamate. The efficacy of felbamate was 62%, which was greater than that of either levetiracetam or valproic acid (15%, p < 0.001% and 32%, p = 0.001 respectively) and similar to that of the ketogenic diet (69%, p = 0.8). Felbamate appears to be an effective treatment for EMAtS and should be strongly considered in the treatment course of this disease.

Cannabidiol in children with treatment-resistant epilepsy with myoclonic-atonic seizures

PURPOSE

This multicenter study aimed to evaluate the efficacy and tolerability of add-on cannabidiol (CBD) in treatment-resistant patients with epilepsy with myoclonic-atonic seizures (EMAtS) (n = 22) and Sturge Weber syndrome (SWS) with myoclonic-atonic seizures (n = 4).

METHODS

Patients who met the diagnostic criteria of treatment-resistant EMAtS or SWS with myoclonic-atonic seizures were included. Cannabidiol was added in doses ranging from 8 to 40 mg/kg/day. Efficacy was assessed by comparing seizure frequency before and after initiating CBD therapy. Neurologic examinations, brain magnetic resonance imaging, repeated prolonged electroencephalography (EEG) and/or video-EEG recordings, and neurometabolic studies were performed in all patients, and genetic investigations in 15.

RESULTS

After a mean follow-up of 19 months, 15/26 patients (57.7%) who received add-on CBD had a >50% seizure decrease; three (11.5%) became seizure-free. The remaining 11 patients (42.3%) had a 25-50% seizure reduction. Drop attacks, including myoclonic-atonic seizures and generalized tonic-clonic seizures, as well as atypical absences and nonconvulsive status epilepticus responded well to CBD. In SWS patients, focal motor seizures without consciousness impairment and focal non-motor seizures with consciousness impairment were recognized in two each; in three a 30% reduction of focal seizures was observed. Side effects were mild and did not lead to CBD discontinuation.

CONCLUSION

This study evaluating the use of add-on CBD in children with EMAtS or SWS with myoclonic-atonic seizures found that 15/26 (57.7%) had a >50% seizure reduction with good tolerability; three (11.5%) became seizure-free.

Genetic mechanisms in generalized epilepsies

The genetic generalized epilepsies (GGEs) have been proved to generate from genetic impact by twin studies and family studies. The genetic mechanisms of generalized epilepsies are always updating over time. Although the genetics of GGE is complex, there are always new susceptibility genes coming up as well as copy number variations which can lead to important breakthroughs in exploring the problem. At the same time, the development of ClinGen fades out some of the candidate genes. This means we have to figure out what accounts for a reliable gene for GGE, in another word, which gene has sufficient evidence for GGE. This will improve our understanding of the genetic mechanisms of GGE. In this review, important up-to-date genetic mechanisms of GGE were discussed.

Case report: Alexander's disease with "head drop" as the main symptom and literature review

Alexander's disease (AxD) is a rare autosomal dominant hereditary disorder that is caused by the mutations in the GFAP gene, which encodes the glial fibrillary acidic protein (GFAP). This neurogenerative disease has many clinical manifestations, and the onset of disease spans a wide range of ages, from newborns to children, adults, and even the elderly. An overaccumulation of the expression of GFAP has a close causal relationship with the pathogenesis of Alexander's disease. Usually, the disease has severe morbidity and high mortality, and can be divided into three distinct subgroups that are based on the age of clinical presentation: infantile (0-2 years), juvenile (2-13 years), and adult (>13 years). Children often present with epilepsy, macrocephaly, and psychomotor retardation, while adolescents and adults mainly present with muscle weakness, spasticity, and bulbar symptoms. Atonic seizures are a type of epilepsy that often appears in the Lennox-Gastaut syndrome and myoclonic-astatic epilepsy in early childhood; however, the prognosis is often poor. Atonic episodes are characterized by a sudden or frequent reduction in muscle tone that can be local (such as head, neck, or limb) or generalized. Here, we report a 4-year-old girl whose main symptoms were intermittent head drop movements, which could break the frontal frame and even bleed in severe conditions. A video-encephalography (VEEG) showed that the nodding movements were atonic seizures. A head magnetic resonance imaging (MRI) revealed abnormal signals in the bilateral paraventricular and bilateral subfrontal cortex. The gene detection analyses indicated that the GFAP gene exon 1 c.262 C>T was caused by a heterozygous mutation, as both her parents were of the wild-type. The girl had no other abnormal manifestations except atonic seizures. She could communicate normally and go to kindergarten. After an oral administration of sodium valproate, there were no atonic attacks. Although epilepsy is a common symptom of Alexander's disease, atonic seizures have not been reported to date. Therefore, we report a case of Alexander's disease with atonic seizures as the main symptom and provide a review of the literature.

Use of sulthiame as add-on therapy in children with myoclonic atonic epilepsy: A study of 35 patients

PURPOSE

The aim of this retrospective study was to evaluate efficacy and tolerability of sulthiame (STM) as add-on treatment in 35 patients with myoclonic atonic epilepsy (MAE) resistant to other antiseizure medications (ASMs) and/or non-pharmacological treatment.

METHODS

Patients were selected according to the diagnostic definition of MAE and were resistant to at least four previous to ASM, alone or in combination. Neurologic examinations, brain magnetic resonance imaging, and repeated prolonged electroencephalography (EEG) or video-EEG studies as well as neurometabolic studies were performed in all cases. Genetic studies were performed in 15 patients. Data on school achievements and/or neuropsychological evaluations were obtained over a mean follow-up of 30 months. Sulthiame was added in doses ranging from 10 to 30 mg/kg/day. Efficacy was assessed by comparing seizure frequency before and after initiating STM therapy.

RESULTS

Twenty-one of 35 patients (60%) who received STM as add-on therapy had a greater than 50% seizure decrease after a mean follow-up of 30 months. Complete seizure freedom was achieved in two patients (5.8%). The remaining 14 patients (40%) had a 25-50% seizure reduction. Adverse effects, consisting of hyperpnea and dyspnea, decreased appetite, nausea, drowsiness, headache, and irritability, were observed in 11 (31.4%). The adverse effects were mild and transient in all cases. Discontinuation of STM was not necessary.

CONCLUSION

Add-on STM led to a more than 50% seizure reduction in 21 of 35 patients with MAE with only mild or moderate adverse effects.

International League Against Epilepsy classification and definition of epilepsy syndromes with onset in childhood: Position paper by the ILAE Task Force on Nosology and Definitions

The 2017 International League Against Epilepsy classification has defined a three-tier system with epilepsy syndrome identification at the third level. Although a syndrome cannot be determined in all children with epilepsy, identification of a specific syndrome provides guidance on management and prognosis. In this paper, we describe the childhood onset epilepsy syndromes, most of which have both mandatory seizure type(s) and interictal electroencephalographic (EEG) features. Based on the 2017 Classification of Seizures and Epilepsies, some syndrome names have been updated using terms directly describing the seizure semiology. Epilepsy syndromes beginning in childhood have been divided into three categories: (1) self-limited focal epilepsies, comprising four syndromes: self-limited epilepsy with centrotemporal spikes, self-limited epilepsy with autonomic seizures, childhood occipital visual epilepsy, and photosensitive occipital lobe epilepsy; (2) generalized epilepsies, comprising three syndromes: childhood absence epilepsy, epilepsy with myoclonic absence, and epilepsy with eyelid myoclonia; and (3) developmental and/or epileptic encephalopathies, comprising five syndromes: epilepsy with myoclonic-atonic seizures, Lennox-Gastaut syndrome, developmental and/or epileptic encephalopathy with spike-and-wave activation in sleep, hemiconvulsion-hemiplegia-epilepsy syndrome, and febrile infection-related epilepsy syndrome. We define each, highlighting the mandatory seizure(s), EEG features, phenotypic variations, and findings from key investigations.

Genetic Epilepsy Syndromes

PURPOSE OF REVIEW

This article reviews the clinical features, typical EEG findings, treatment, prognosis, and underlying molecular etiologies of the more common genetic epilepsy syndromes. Genetic generalized epilepsy, self-limited focal epilepsy of childhood, self-limited neonatal and infantile epilepsy, select developmental and epileptic encephalopathies, progressive myoclonus epilepsies, sleep-related hypermotor epilepsy, photosensitive occipital lobe epilepsy, and focal epilepsy with auditory features are discussed. Also reviewed are two familial epilepsy syndromes: genetic epilepsy with febrile seizures plus and familial focal epilepsy with variable foci.

RECENT FINDINGS

Recent years have seen considerable advances in our understanding of the genetic factors underlying genetic epilepsy syndromes. New therapies are emerging for some of these conditions; in some cases, these precision medicine approaches may dramatically improve the prognosis.

SUMMARY

Many recognizable genetic epilepsy syndromes exist, the identification of which is a crucial skill for neurologists, particularly those who work with children. Proper diagnosis of the electroclinical syndrome allows for appropriate treatment choices and counseling regarding prognosis and possible comorbidities.

Epilepsy with myoclonic-atonic seizures, also known as Doose syndrome: Modification of the diagnostic criteria

The aim of this review is to propose the updated diagnostic criteria of epilepsy with myoclonic-atonic seizures (EMAS), which is a recent subject of genetic studies. Although EMAS has been well known as Doose syndrome, it is often difficult to diagnose due to a lack of consensus regarding some of the inclusion criteria. Along with progress in molecular genetic study on the syndrome, it becomes important to recruit electroclinical homogeneous EMAS patients, hence the validity of the clinical criteria should be verified based on recent clinical researches. At present, the most updated ILAE diagnostic manual of EMAS includes: (1) normal development and cognition before the onset of epilepsy; (2) onset of epilepsy between 6 months and 6 years of age (peak: 2-4 years); (3) myoclonic-atonic seizures (MAS) are mandatory (4) presence of generalized spike-wave discharges at 2-3 Hz without persistent focal spike discharges; and (5) exclusion of other myoclonic epilepsy syndromes. In the criteria, we should emphasize that the age at onset of MAS is between 2-5 years in (2), presence of myoclonic-atonic, atonic or myoclonic-flexor seizures (MASs) causing drop attacks associated with generalized spike-wave discharges is mandatory in (3), and epileptic spasms causing drop attacks must be excluded in (5). In the modified criteria, I propose that EMAS is redesignated as genetic generalized epilepsy with MASs, consistent with the familial genetic study conducted by Doose and the recent identification of candidate genes. It should also be noted that EMASs evolves to transient or long-lasting epileptic encephalopathy.