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Revue Neurologique Apr 2024The ILAE's Task Force on Nosology and Definitions revised in 2022 its definition of juvenile myoclonic epilepsy (JME), the most common idiopathic generalized epilepsy... (Review)
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.
Topics: Humans; Myoclonic Epilepsy, Juvenile; Anticonvulsants; Drug Resistant Epilepsy; Female; Risk Factors
PubMed: 38461125
DOI: 10.1016/j.neurol.2024.02.385 -
Acta Neurologica Belgica Apr 2024Familial Adult Myoclonus Epilepsy (FAME), with a prevalence of < 1/35 000, is known under different acronyms. The disease is transmitted in an autosomal dominant... (Review)
Review
Familial Adult Myoclonus Epilepsy (FAME), with a prevalence of < 1/35 000, is known under different acronyms. The disease is transmitted in an autosomal dominant manner and is characterized by the occurrence of cortical myoclonic tremor, overt myoclonus, and rare bilateral tonic-clonic seizures. FAME is considered neurodegenerative, although it is relatively slow in progression. Diagnosis is based on specific neurophysiological testing, namely jerk-locked back-averaging, somatosensory evoked potentials, long latency reflex, and motor evoked potentials, among others. Imaging data, including functional magnetic resonance imaging, indicate a cortical origin of the cortical myoclonic tremor and decreased cerebellar activation. Cerebellar changes in Purkinje cells have been noted, from few neuropathology reports, in patients from isolated pedigrees. The differential diagnosis includes essential tremor, some forms of genetic generalized epilepsy, and progressive myoclonus epilepsies. Treatment is mainly symptomatic.
Topics: Adult; Humans; Myoclonus; Tremor; Epilepsies, Myoclonic; Evoked Potentials, Somatosensory; Reflex; Electroencephalography
PubMed: 38114875
DOI: 10.1007/s13760-023-02432-6 -
Epilepsia Jun 2023Familial adult myoclonic epilepsy (FAME) is an under-recognized disorder characterized by cortical myoclonus, generalized tonic-clonic seizures, and additional clinical...
OBJECTIVE
Familial adult myoclonic epilepsy (FAME) is an under-recognized disorder characterized by cortical myoclonus, generalized tonic-clonic seizures, and additional clinical symptoms, which vary depending on the FAME subtype. FAME is caused by pentanucleotide repeat expansions of intronic TTTCA/TTTTA in different genes. FAME should be distinguished from a range of differential diagnoses.
METHODS
The differential diagnoses and frequent presentations leading to misdiagnosis of FAME were investigated from the available literature and reported based on an expert opinion survey.
RESULTS
The phenotypic features of FAME, including generalized tonic-clonic and myoclonic seizures, are also seen in other epilepsy syndromes, such as juvenile myoclonic epilepsy, with a resultant risk of misdiagnosis and lack of identification of the underlying cause. Cortical myoclonus may mimic essential tremor or drug-induced tremor. In younger individuals, the differential diagnosis includes progressive myoclonus epilepsies (PMEs), such as Unverricht-Lundborg disease, whereas, in adulthood, late-onset variants of PMEs, such as sialidoses, myoclonus epilepsy, and ataxia due to potassium channel pathogenic variants should be considered. PMEs may also be suggested by cognitive impairment, cerebellar signs, or psychiatric disorders. Electroencephalography (EEG) may show similarities to other idiopathic generalized epilepsies or PMEs, with generalized spike-wave activity. Signs of cortical hyperexcitability may be seen, such as an increased amplitude of somatosensory evoked potentials or enhanced cortical reflex to sensory stimuli, together with the neurophysiological pattern of the movement disorder.
SIGNIFICANCE
Recognition of FAME will inform prognostic and genetic counseling and diagnosis of the insidious progression, which may occur in older individuals who show mild cognitive deterioration. Distinguishing FAME from other disorders in individuals or families with this constellation of symptoms is essential to allow the identification of underlying etiology.
Topics: Humans; Adult; Aged; Diagnosis, Differential; Myoclonus; Epilepsies, Myoclonic; Epilepsy, Generalized; Electroencephalography; Myoclonic Epilepsies, Progressive; Myoclonic Epilepsy, Juvenile; Seizures
PubMed: 36751956
DOI: 10.1111/epi.17536 -
Pharmaceutical Patent Analyst Sep 2021
Topics: Epilepsies, Myoclonic; Humans; Spasms, Infantile
PubMed: 34488475
DOI: 10.4155/ppa-2021-0020 -
Acta Neurologica Scandinavica Jan 2021Brivaracetam (BRV) is a new antiseizure medication (ASM) that is currently approved for adjunctive treatment in patients with focal onset seizures. Similarly to... (Review)
Review
Brivaracetam (BRV) is a new antiseizure medication (ASM) that is currently approved for adjunctive treatment in patients with focal onset seizures. Similarly to levetiracetam (LEV), BRV works by binding SV2A vesicles with a high affinity and a linear pharmacokinetic profile. Retrospective studies and randomized clinical trials have already proven the efficacy of BRV, even in patients who failed treatment with LEV. Most studies about the efficacy and tolerability conducted so far were performed in adult cohorts, whereas few studies have been performed in children; however, BRV was proven to be a useful ASM for pediatric focal epilepsies, with fewer studies and conflicting results among patients with generalized epilepsies and epileptic syndromes. Retention rates were high in the cohorts analyzed, and no serious treatment-emergent adverse events were reported in the majority of patients, with somnolence, drowsiness, irritability, aggression, and decreased appetite being the most frequently reported side effects. Although there are few original papers published on the subject so far, the analysis of the literature data demonstrated the efficacy and safety of BRV in pediatric patients, with more evidence for children aged 4-16 years with an onset of focal seizures. However, a positive response was also achieved in patients affected by encephalopathic epilepsies (eg, Jeavons' epilepsy, Dravet syndrome, Lennox-Gastaut syndrome, and juvenile myoclonic epilepsy), and ongoing studies are now testing BRV in order to widen its application to other forms of epilepsy and to test its effectiveness when used in monotherapy. This review aims to provide a comprehensive analysis of the literature surrounding the efficacy and tolerability of BRV for pediatric patients.
Topics: Adolescent; Anticonvulsants; Child; Child, Preschool; Epilepsies, Partial; Female; Humans; Male; Myoclonic Epilepsy, Juvenile; Pyrrolidinones; Randomized Controlled Trials as Topic; Retrospective Studies; Treatment Outcome
PubMed: 32966640
DOI: 10.1111/ane.13347 -
Cerebral Cortex (New York, N.Y. : 1991) Aug 2023Mutations of the voltage-gated sodium channel SCN1A gene (MIM#182389) are among the most clinically relevant epilepsy-related genetic mutations and present variable...
Mutations of the voltage-gated sodium channel SCN1A gene (MIM#182389) are among the most clinically relevant epilepsy-related genetic mutations and present variable phenotypes, from the milder genetic epilepsy with febrile seizures plus to Dravet syndrome, a severe developmental and epileptic encephalopathy. Qualitative neuroimaging studies have identified malformations of cortical development in some patients and mild atrophic changes, partially confirmed by quantitative studies. Precise correlations between MRI findings and clinical variables have not been addressed. We used morphometric methods and network-based models to detect abnormal brain structural patterns in 34 patients with SCN1A-related epilepsy, including 22 with Dravet syndrome. By measuring the morphometric characteristics of the cortical mantle and volume of subcortical structures, we found bilateral atrophic changes in the hippocampus, amygdala, and the temporo-limbic cortex (P-value < 0.05). By correlating atrophic patterns with brain connectivity profiles, we found the region of the hippocampal formation as the epicenter of the structural changes. We also observed that Dravet syndrome was associated with more severe atrophy patterns with respect to the genetic epilepsy with febrile seizures plus phenotype (r = -0.0613, P-value = 0.03), thus suggesting that both the underlying mutation and seizure severity contribute to determine atrophic changes.
Topics: Humans; NAV1.1 Voltage-Gated Sodium Channel; Seizures, Febrile; Epilepsies, Myoclonic; Epilepsy; Mutation; Phenotype
PubMed: 37344172
DOI: 10.1093/cercor/bhad224 -
Epilepsy & Behavior : E&B Jun 2023This multicenter study aimed to evaluate the efficacy and tolerability of add-on cannabidiol (CBD) in treatment-resistant patients with epilepsy with myoclonic-atonic...
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.
Topics: Humans; Child; Cannabidiol; Epilepsies, Myoclonic; Seizures; Epilepsy, Generalized; Brain; Electroencephalography
PubMed: 37182500
DOI: 10.1016/j.yebeh.2023.109245 -
The Neuroscientist : a Review Journal... Dec 2023Dravet syndrome is a severe developmental and epileptic encephalopathy mostly caused by heterozygous mutation of the gene encoding the voltage-gated sodium channel α... (Review)
Review
Dravet syndrome is a severe developmental and epileptic encephalopathy mostly caused by heterozygous mutation of the gene encoding the voltage-gated sodium channel α subunit Na1.1. Multiple seizure types, cognitive deterioration, behavioral disturbances, ataxia, and sudden unexpected death associated with epilepsy are a hallmark of the disease. Recently approved antiseizure medications such as fenfluramine and cannabidiol have been shown to reduce seizure burden. However, patients with Dravet syndrome are still medically refractory in the majority of cases, and there is a high demand for new therapies aiming to improve behavioral and cognitive outcome. Drug-repurposing approaches for -related Dravet syndrome are currently under investigation (i.e., lorcaserin, clemizole, and ataluren). New therapeutic concepts also arise from the field of precision medicine by upregulating functional or by activating Na1.1. These include antisense nucleotides directed against the nonproductive transcript of with the poison exon 20N and against an inhibitory noncoding antisense RNA of . Gene therapy approaches such as adeno-associated virus-based upregulation of using a transcriptional activator (ETX101) or CRISPR/dCas technologies show promising results in preclinical studies. Although these new treatment concepts still need further clinical research, they offer great potential for precise and disease modifying treatment of Dravet syndrome.
Topics: Humans; NAV1.1 Voltage-Gated Sodium Channel; Epilepsies, Myoclonic; Epilepsy; Seizures; Neurodevelopmental Disorders
PubMed: 35414300
DOI: 10.1177/10738584221088244 -
Epilepsia Jun 2023Familial adult myoclonus epilepsy (FAME) is characterized by cortical myoclonus and often epileptic seizures, but the pathophysiology of this condition remains... (Review)
Review
Familial adult myoclonus epilepsy (FAME) is characterized by cortical myoclonus and often epileptic seizures, but the pathophysiology of this condition remains uncertain. Here, we review the neuroimaging and neuropathological findings in FAME. Imaging findings, including functional magnetic resonance imaging, are in line with a cortical origin of involuntary tremulous movements (cortical myoclonic tremor) and indicate a complex pattern of cerebellar functional connectivity. Scarce neuropathological reports, mainly from a single family, provide evidence of morphological changes in the Purkinje cells. Cerebellar changes seem to be part of the syndrome, in at least some FAME pedigrees. Cortical hyperexcitability in FAME, resulting in the cardinal clinical symptoms, might be the result of decreased cortical inhibition via the cerebellothalamocortical loop. The pathological findings might share some similarities with other pentanucleotide repeat disorders. The relation with genetic findings in FAME needs to be elucidated.
Topics: Adult; Humans; Myoclonus; Epilepsies, Myoclonic; Epilepsy; Neuroimaging; Cerebellum
PubMed: 37096373
DOI: 10.1111/epi.17628 -
Epilepsy Research May 2022The aim was to describe age at diagnosis, cumulative incidence, SCN1A variants, mortality, seizure types and treatments in children with Dravet Syndrome (DS) in Sweden.
OBJECTIVE
The aim was to describe age at diagnosis, cumulative incidence, SCN1A variants, mortality, seizure types and treatments in children with Dravet Syndrome (DS) in Sweden.
METHODS
Children diagnosed with DS, born between January 1st 2000 and December 31st 2018 were included in a population-based study. Clinical data, frequency of seizure types and treatments were collected from caregivers and medical records in 42 children. Age at diagnosis, cumulative incidence and treatment were compared between children born in Sweden 2000-2009 and 2010-2018.
RESULTS
We identified 55 children with DS, 53 were born in Sweden. Three children had died of definite, probable, or possible sudden unexpected death in epilepsy, one of acute anoxic brain injury and three of pneumonia or pneumonitis. Median age at death was 4.7 (range 3.3-11) years. In 49/53 children with known SCN1A status, a pathogenic/likely pathogenic variant of SCN1A was detected. In two a SCN1A variant of unknown significance was found. For children born in Sweden 2010-2018, median age at DS diagnosis was lower (1.6 vs 4.5 years, p = 0.001) and cumulative incidence higher (1/33,000 vs 1/46,000 live-born children, p = 0.03), compared to children born in 2000-2009. The most common seizure types were focal to bilateral tonic clonic (n = 41/42) and myoclonic (n = 35/42). Tonic seizures were reported in 25/42 children. Sodium-channel inhibitors had been used in 9/24 children born in 2010-2018 and 17/18 children born in 2000-2009 (p = 0.001).
SIGNIFICANCE
A SCN1A variant that could explain the syndrome was found in over 90% of children. Tonic seizures seem to be more frequent than earlier described. Median age at diagnosis was lower, cumulative incidence higher and use of contra-indicated sodium-channel inhibitors less common for children born in 2010-2018 compared with children born in 2000-2009. This could indicate an increased awareness of DS.
Topics: Child; Child, Preschool; Death, Sudden; Epilepsies, Myoclonic; Epileptic Syndromes; Humans; Mutation; NAV1.1 Voltage-Gated Sodium Channel; Seizures; Sodium; Spasms, Infantile
PubMed: 35461153
DOI: 10.1016/j.eplepsyres.2022.106922