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Medicine Sep 2022Myoclonic epilepsy in infancy (MEI) is a rare syndrome characterized by generalized myoclonic seizures (MS) that occur within the first 3 years of life. In the present...
Myoclonic epilepsy in infancy (MEI) is a rare syndrome characterized by generalized myoclonic seizures (MS) that occur within the first 3 years of life. In the present study, the form of onset, and clinical and electroencephalogram (EEG) features were analyzed. A retrospective chart review was conducted for 16 MEI patients between March 2009 and July 2022 in Peking Union Medical College. The clinical and video EEG (VEEG) characteristics, treatment strategy, and follow-up information were analyzed. Four cases presented with afebrile generalized tonic-clonic seizures (GTCS) at the onset of MEI (GTCS at onset or atypical MEI), while 12 cases presented with MS at onset (MS at onset or typical MEI). The 24-hour VEEG revealed a generalized discharge of polyspike (or spike)-and-wave complexes that lasted for 1-3 seconds in the ictal phase. All patients were treated with valproic acid monotherapy, and none of the patients experienced seizure recurrence. Furthermore, all patients had normal psychomotor development at the end of the follow up period. Typical MEI (MS at onset) and atypical MEI (GTCS at onset) were described in the present study. These 2 groups differed in form of onset, but there were no significant differences in clinical or EEG features.
Topics: Electroencephalography; Epilepsies, Myoclonic; Humans; Retrospective Studies; Seizures; Valproic Acid
PubMed: 36197249
DOI: 10.1097/MD.0000000000030512 -
Pediatric Neurology Jul 2009Myoclonic epilepsy associated with ragged-red fibers is one of the mitochondrial encephalomyopathies. Pathogenic mitochondrial DNA mutations have been identified in the...
Myoclonic epilepsy associated with ragged-red fibers is one of the mitochondrial encephalomyopathies. Pathogenic mitochondrial DNA mutations have been identified in the mitochondrial transfer RNA (tRNA)(Lys) at positions 8344 and 8356. Characteristics of myoclonic epilepsy associated with ragged-red fibers include myoclonic epilepsy, generalized epilepsy, hearing loss, exercise intolerance, lactic acidosis, and ragged-red fibers. The elevated lactate level is one of the most important symptoms needed to make a diagnosis of mitochondrial encephalomyopathy. In the present case, however, myoclonic epilepsy was associated with ragged-red fibers but without increased lactate levels. Therefore, myoclonic epilepsy associated with ragged-red fibers should be suspected in a patient who has myoclonic epilepsy that is difficult to control with antiepileptic medications and who has other symptoms of mitochondrial disease, such as mental retardation, even if the patient's lactate level is normal.
Topics: Adolescent; Anticonvulsants; DNA Mutational Analysis; DNA, Mitochondrial; Diagnosis, Differential; Epilepsies, Myoclonic; Humans; Lactic Acid; Male; Mitochondrial Encephalomyopathies; Muscle, Skeletal; Mutation; Pedigree; RNA, Transfer, Lys
PubMed: 19520275
DOI: 10.1016/j.pediatrneurol.2009.02.002 -
Acta Neurologica Belgica Jun 2022
Topics: Ataxia; Epilepsies, Myoclonic; Humans; Mutation; Myoclonic Epilepsies, Progressive; Myoclonus; Potassium Channels
PubMed: 33725338
DOI: 10.1007/s13760-021-01645-x -
Epilepsy Research Aug 2015To describe clinical and EEG phenotypes of a family with an unusual familial epilepsy syndrome characterized by myoclonus and dystonia.
PURPOSE
To describe clinical and EEG phenotypes of a family with an unusual familial epilepsy syndrome characterized by myoclonus and dystonia.
METHODS
Family members underwent electroclinical phenotyping including review of EEGs and MRI. DNA from family members was genotyped using Illumina OmniExpress genotyping arrays. Parametric and nonparametric linkage analyses were performed using MERLIN.
RESULTS
The disorder followed autosomal dominant (AD) inheritance and affected seven individuals over two generations. Seizures began at a mean of 14.5 years. Six individuals had spontaneous myoclonic seizures, of which five also had photic-induced myoclonus and four had photic-induced occipital seizures. Six individuals had convulsive seizures; generalized in two and focal in four. Photosensitivity was prominent with generalized spike wave and polyspike wave in four individuals of which two also had occipital spikes. MRI scans were normal in the four individuals tested. Extensive metabolic investigation was normal. Juvenile myoclonic epilepsy (JME) occurred in two; and JME overlapping with idiopathic photosensitive epilepsy (IPOE) in four individuals. All three affected males had a more severe disorder than the four affected females. Two males had a progressive neurological disorder with progressive myoclonus epilepsy and deterioration in their early 30s. They developed episodes of paroxysmal cervical dystonia with cognitive decline during periods of poor seizure control. One plateaued after years of poor seizure control but remained intractable with periods of deterioration. The other deteriorated with episodes of status dystonicus and status epilepticus, ataxia and a progressive ophthalmoplegia before succumbing at 38 years. Parametric linkage analysis identified three peaks achieving a maximum LOD score of 1.21. Nonparametric analysis identified eight peaks achieving LOD scores above 0.80. These were not statistically significant.
CONCLUSIONS
This is a novel autosomal dominant familial epilepsy syndrome. "Myoclonic occipital photosensitive epilepsy with dystonia" (MOPED) involves a spectrum of phenotypes from JME, sometimes with an IPOE overlap, to progressive myoclonus epilepsy with paroxysmal dystonia.
Topics: Adult; Anticonvulsants; Child; Cognition Disorders; DNA; Dystonic Disorders; Epilepsies, Myoclonic; Family; Female; Genetic Linkage; Humans; Inbreeding; Magnetic Resonance Imaging; Male; Middle Aged; Myoclonic Epilepsy, Juvenile; Pedigree; Phenotype; Photosensitivity Disorders; Seizures; Syndrome; Young Adult
PubMed: 26088892
DOI: 10.1016/j.eplepsyres.2015.04.014 -
Neurology Jul 2007
Topics: Anticonvulsants; Channelopathies; Epilepsies, Myoclonic; Humans; Infant; Mutation
PubMed: 17636058
DOI: 10.1212/01.wnl.0000271091.01436.35 -
Neuropediatrics Nov 1987A patient with intention and action myoclonus, epilepsy, ataxia, and mental deterioration in association with ragged-red fibers in striated muscle is described. This... (Review)
Review
A patient with intention and action myoclonus, epilepsy, ataxia, and mental deterioration in association with ragged-red fibers in striated muscle is described. This patient demonstrated a unique form of erratic myoclonus with continuous EEG spike activity during eye closure. Both the myoclonus and the EEG spiking disappeared on opening the eyes. A defect in the activity of complex I in the respiratory chain was demonstrated.
Topics: Adolescent; Ataxia; Electroencephalography; Epilepsies, Myoclonic; Female; Humans; Intellectual Disability; Mitochondria, Muscle; Muscular Diseases; Sarcolemma; Syndrome
PubMed: 3122068
DOI: 10.1055/s-2008-1052480 -
American Journal of Medical Genetics.... Aug 2013Interstitial deletions of the long arm of the chromosome 17 are relatively rare. Up to 17 cases involving the q22-q23.3 band have been reported so far. A common...
Interstitial deletions of the long arm of the chromosome 17 are relatively rare. Up to 17 cases involving the q22-q23.3 band have been reported so far. A common phenotype has not yet been delineated and epilepsy has been reported in only 2 out of 17 cases. We describe a clinical phenotype of epilepsy characterized by myoclonic atonic and absence seizures in a 6-year-old boy carrying a de novo 17q22q23 deletion detected by oligonucleotide array comparative genomic hybridization (aCGH).
Topics: Child; Chromosome Deletion; Chromosomes, Human, Pair 17; Comparative Genomic Hybridization; Epilepsies, Myoclonic; Humans; In Situ Hybridization, Fluorescence; Magnetic Resonance Imaging; Male; Phenotype
PubMed: 23794376
DOI: 10.1002/ajmg.a.36010 -
Developmental Medicine and Child... Apr 2011Severe myoclonic epilepsy of infancy (SMEI) is a complex form of epilepsy that was first described in France in 1978. Because the myoclonic component of this epilepsy is... (Review)
Review
Severe myoclonic epilepsy of infancy (SMEI) is a complex form of epilepsy that was first described in France in 1978. Because the myoclonic component of this epilepsy is not always present and because some variability has been observed in the symptomatology, the name was changed to Dravet syndrome in 1989. The genetic aetiology of this epilepsy was discovered in 2001, and since then numerous studies have contributed to a better knowledge of the disease. Around 70% of affected patients are carriers of a mutation on the alpha subunit of the SCN1A gene. An accurate analysis of the clinical features leads to the distinction between typical and atypical forms, both with the same unfavourable prognosis and the same genetic background. However, many studies are being conducted in order to establish correlations between phenotypes and genotypes, and to understand the factors underlying the cognitive impairment of the affected patients.
Topics: Brain; Child, Preschool; Diagnosis, Differential; Electroencephalography; Epilepsies, Myoclonic; Genetic Predisposition to Disease; Humans; Infant; NAV1.1 Voltage-Gated Sodium Channel; Nerve Tissue Proteins; Sodium Channels; Syndrome
PubMed: 21504424
DOI: 10.1111/j.1469-8749.2011.03964.x -
Epilepsy Research Jan 1998Based on small numbers of patients, it is possible to make the following suggestions rather than categorical statements. For myoclonic seizures and epilepsies which are... (Review)
Review
Based on small numbers of patients, it is possible to make the following suggestions rather than categorical statements. For myoclonic seizures and epilepsies which are not otherwise specified, valproate seems of proven efficacy. Ethosuximide may be a useful adjunct. The exact place of lamotrigine, which controls some myoclonia and makes them worse in other patients, requires further study. The findings are clearer when specific syndromes are considered. Valproate is the treatment of first choice for benign myoclonic epilepsy in infants, myoclonic astatic epilepsy, epilepsy with myoclonic absences, eyelid myoclonia with absences, juvenile myoclonic epilepsy and progressive myoclonus epilepsy. The addition of ethosuximide to valproate can be helpful to those with myoclonic absences, where this combination appears more beneficial than either valproate or ethosuximide alone and in eyelid myoclonia with absences. Lamotrigine can be effective therapy for juvenile myoclonic epilepsy and eyelid myoclonia with absences when used alone and, in conjunction with other antiepileptic drugs (AED) (usually valproate) for early myoclonic encephalopathy, myoclonic-astatic epilepsy and particularly, epilepsy with myoclonic absences. The myoclonia of infantile neuronal ceroid lipofuscinosis respond to lamotrigine. Severe myoclonic epilepsy of infants usually worsens with lamotrigine, but occasionally, children improve. Zonisamide added to clonazepam and valproate or a barbiturate, can reduce the cascade of myoclonia in progressive myoclonus epilepsies for at least 2 years, but relapse may occur thereafter.
Topics: Anticonvulsants; Child; Child, Preschool; Epilepsies, Myoclonic; Ethosuximide; Humans; Infant; Isoxazoles; Lamotrigine; Triazines; Valproic Acid; Zonisamide
PubMed: 9477147
DOI: 10.1016/s0920-1211(97)00080-6 -
Clinical Neurophysiology : Official... Feb 2014To investigate electroencephalographic (EEG) features of benign adult familial myoclonic epilepsy (BAFME).
OBJECTIVE
To investigate electroencephalographic (EEG) features of benign adult familial myoclonic epilepsy (BAFME).
METHODS
We reviewed interictal EEG features in patients with BAFME treated between April 2005 and November 2012 at a tertiary referral center. The diagnostic criteria for BAFME were the presence of infrequent generalized tonic-clonic seizures, myoclonus or myoclonic seizures, and autosomal dominant inheritance. Interictal EEG findings of epilepsy with generalized tonic-clonic seizure only (EGTCS) were reviewed for comparison. We randomly selected 10 generalized spike/polyspike and wave complexes (GSW) for each BAFME patient and measured the duration of them. Photic stimulation and hyperventilation were performed in all.
RESULTS
Nineteen (eight men, 11 women) patients with BAFME were included in this study. The mean frequency of GSW was 4.3±1.0Hz (mean±SD, n=14) in BAFME and 3.2±0.8Hz (n=10) in EGTCS. There was a statistically significant difference (p=0.008) between the two. Photoparoxysmal responses (PPR) were noted in 18 (95%) patients with BAFME but 1 (10%) with EGTCS.
CONCLUSION
Faster frequency of GSW, compared with that in EGTCS, accompanied by PPR may be characteristic EEG features of BAFME.
SIGNIFICANCE
These findings may lead the diagnosis of BAFME.
Topics: Adult; Aged; Aged, 80 and over; Cerebral Cortex; Electroencephalography; Epilepsies, Myoclonic; Female; Humans; Male; Middle Aged; Seizures
PubMed: 24011985
DOI: 10.1016/j.clinph.2013.08.002