Dravet syndrome is a rare and catastrophic type of epilepsy in infants. Acute encephalopathy has been sporadically reported in patients with Dravet syndrome; however, the risk factors for this serious complication have not been identified. We report two patients with a clinical diagnosis of Dravet syndrome who experienced acute encephalopathy initiated by refractory status epilepticus. SCN1A mutational analysis revealed a previously reported nonsense mutation in one patient and a novel missense mutation in the other. Analysis of our cases and previously published cases revealed that patients with Dravet syndrome who have a more severe phenotype have an increased likelihood of developing acute encephalopathy compared with patients with less severe phenotypes.
Epilepsies, Myoclonic

No abstract available.
Epilepsies, Myoclonic* ; Neuroblastoma*

Child, Preschool ; Epilepsies, Myoclonic ; Humans ; Male

Unverricht-Lundborg disease(Baltic myoclonus) is one of the major causes of progressive myoclonus epilepsy. It is characterized by stimulus sensitive myoclonic seizure, generaized tonic-clonic seizure, generally synchronous polyspike and wave discharges on EEG and absence of severe or early dementia. It has usually been described in the countries around the Baltic area. But recently, it is regarded as the most common form of progressive myoclonus epilepsy in the other countries as well. We report, with the review of the literature, two patients who showed the typical features of this disorder.
Dementia ; Electroencephalography ; Humans ; Myoclonic Epilepsies, Progressive ; Seizures ; Unverricht-Lundborg Syndrome*

Humans ; Epilepsies, Myoclonic/diagnosis* ; NAV1.1 Voltage-Gated Sodium Channel

Mitochondnal encephalomyopathies are multisysternic diseases affecting predominantly the CNS and skeletal muscLes by mitochondrial dysfunction. Mitochondrial diseases include three distinct syndromes: mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS): myoclonus epilepsy associated with ragged-red fibers (MERRF):and chronic progressive external ophthalmoplegia(CPEO). A characteristic abnormality called "ragged-red fibers" is usually seen on histochemical evaluation of muscle biopsy specimens in these diseases. The characteristic clinical presentations of MELAS are short stature, recurrent stroke like episodes, migraine-like headache, sensorineural hearmg loss, glucose intolerance and neuropathy. We now report a case of MELAS syndrome confirmed by demonstrating "ragged-red fibers" and abnormal mitochondria in muscle biopsy.
Biopsy ; Epilepsies, Myoclonic ; Glucose Intolerance ; Headache ; MELAS Syndrome* ; Mitochondria ; Mitochondrial Diseases ; Muscle, Skeletal ; Stroke

Severe myoclonic epilepsy of infancy(SMEI) is a condition beginning with recurrent, prolonged febrile convulsion in normal children, followed within months to 4 years by generalized tonic clonic seizures, partial seizures, atypical absences, myoclonic seizures and status epilepticus. The seizures are generally difficult to control. Carbamazepine which is appropriate for partial seizures, is not effective and may aggravate generalized seizures, but sodium valproate has been reported to be helpful. The evolution is always bad with persistent seizures and mental retardation. We experienced a severe myoclonic epilepsy of infancy in a 16-month-old male patient who had episodes of prolonged febrile convulsions followed by mixed type of seizures. We report a case of SMEI with a brief review of literatures.
Carbamazepine ; Child ; Epilepsies, Myoclonic* ; Humans ; Infant ; Intellectual Disability ; Male ; Seizures ; Seizures, Febrile ; Status Epilepticus ; Valproic Acid

Lafora's disease is one of the major causes of progressive myoclonic epilepsy. The main clinical manifestrations are epilepsy, both generalized and focal, severe and progressive myoclonus, progressive dementia and cerebellar sign, then leading to death within 2-10 years. The definite diagnosis depends on the detection of the characteristic PAS positive inclusions, which are present in various tissues including the brain, liver, muscle and skin. We presented two brothers who showed typical clinical features of this disorder, confirmed by skin and muscle biopsy.
Biopsy ; Brain ; Dementia ; Diagnosis ; Epilepsy ; Humans ; Liver ; Myoclonic Epilepsies, Progressive ; Myoclonus ; Siblings ; Skin

PURPOSE: The aim of this study is to examine the SCN1A variants in Korean patients with Dravet syndrome. METHODS: We conducted a retrospective study of clinically confirmed thirty-nine patients with Dravet syndrome who visit our hospital from January 2007 to May 2015. We analyzed the SCN1A variants by direct sequencing. We analyzed and classified SCN1A variants according to ACMG/AMP (American College of Medical Genetics and Genomics and the Association for Molecular Pathology) guideline. RESULTS: A total thirty-nine patients (female 22, male 17) were included. Among them, twenty patients (51.2%) with Dravet syndrome had pathogenic or likely pathogenic SCN1A mutations including fifteen truncating mutations (12 nonsense and 3 splice region mutations), 5 missense mutations. The remained variants in nineteen patients with Dravet syndrome classified into ten variants of unknown significances, and 9 benign variants. In our study, truncation mutations are located whole span of SCN1A protein, while half of missense mutations are located at higher density on pore loop (S5-S6) regions. CONCLUSION: Unlike previous known study, lower positive rate of SCN1A mutation of Dravet syndrome was revealed in our study. The importance of parental test (trio test) and other additional tests have been emphasized.
Epilepsies, Myoclonic* ; Genetics, Medical ; Genomics ; Humans ; Male ; Mutation, Missense ; Parents ; Retrospective Studies

PURPOSE: The aim of this study is to examine the SCN1A variants in Korean patients with Dravet syndrome. METHODS: We conducted a retrospective study of clinically confirmed thirty-nine patients with Dravet syndrome who visit our hospital from January 2007 to May 2015. We analyzed the SCN1A variants by direct sequencing. We analyzed and classified SCN1A variants according to ACMG/AMP (American College of Medical Genetics and Genomics and the Association for Molecular Pathology) guideline. RESULTS: A total thirty-nine patients (female 22, male 17) were included. Among them, twenty patients (51.2%) with Dravet syndrome had pathogenic or likely pathogenic SCN1A mutations including fifteen truncating mutations (12 nonsense and 3 splice region mutations), 5 missense mutations. The remained variants in nineteen patients with Dravet syndrome classified into ten variants of unknown significances, and 9 benign variants. In our study, truncation mutations are located whole span of SCN1A protein, while half of missense mutations are located at higher density on pore loop (S5-S6) regions. CONCLUSION: Unlike previous known study, lower positive rate of SCN1A mutation of Dravet syndrome was revealed in our study. The importance of parental test (trio test) and other additional tests have been emphasized.
Epilepsies, Myoclonic* ; Genetics, Medical ; Genomics ; Humans ; Male ; Mutation, Missense ; Parents ; Retrospective Studies