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

The myoclonic epilepsies of infancy and early childhood pose the most difficult problems in the diagnosis and classification of epilepsies because they are often confused with the Lennox-Gastaut syndrome sharing a number of common features. However, their correct differentiation is easily justifiable because some of the myoclonic epilepsies of early childhood have better prognosis than the Lennox-Gastaut syndrome. We experienced and treated a 4-year-old boy who had normal intellectual function but frequent myoclonic and generalized clinic-tonic-clinic seizures, which were successfully controlled by anti-epileptic drugs. Hence we report a case with brief review of literatures.
Child, Preschool ; Classification ; Diagnosis ; Epilepsies, Myoclonic* ; Epilepsy ; Humans ; Male ; Prognosis ; Seizures

OBJECTIVEEpilepsy with myoclonic absences (EMA) is a type of childhood epilepsy characterized by a specific seizure type, i.e. myoclonic absences (MA). This study aimed to investigate the clinical and electrophysiological characteristics of EMA.

METHODVideo-EEG monitoring was carried out in 6 patients with EMA, and 2 of them were examined with simultaneous deltoid muscle surface electromyogram (EMG). The clinical and EEG characteristics, treatment and prognoses of EMA were analyzed.

RESULTOf the 6 patients, 3 were female, and 3 were male. The age of onset was from 2 years and 3 months to 11 years (average 5 years and 2 months). MA was the sole seizure type in 5 patients. One patient presented generalized tonic clonic seizures (GTCS) at the onset and then switched to MA. The manifestations of MA included an impairment of consciousness of variable intensity, rhythmic myoclonic jerks with evident tonic contraction mainly involving the upper extremities, a deviation of head and body to one side or asymmetrical jerks observed in some cases, a duration ranging from 2 to 30 s, an abrupt onset and termination, a high frequency of attacks, at least several times to over 30 times per day, and easily provoked by hyperventilation. The ictal EEG consisted of rhythmic 3 Hz spike and wave discharges that were bilateral, synchronous and symmetrical in all patients. The deltoid muscle EMG recording in 2 patients showed rhythmic myoclonus at the same frequency as the spike and waves. The interictal EEG showed generalized spike and wave discharges in all patients, and focal discharges in some patients. Valproate was the drug of choice, which was often combined with other antiepileptic drugs. The ages at follow up ranged from 6 years and 4 months to 19 years. Seizures were controlled from 8 months to 3 years in 4 cases. The treatment at the onset was late in one case and was irregular in another who had GTCS during the course of the disease. These two cases were followed up for 2 years and 6 months and 5 years, respectively. Seizures could not be controlled in the 2 patients with intellectual impairment.

CONCLUSIONEMA was a rare type of childhood epilepsy characterized by MA. Clinical observation and ictal video-EEG and EMG were essential to diagnose EMA. Valproate alone or combined with other antiepileptic drugs given early could have a favorable effect to EMA. Delayed therapy and the presence of GTCS might suggest poor prognosis.

Child ; Child, Preschool ; Electroencephalography ; Electromyography ; Epilepsies, Myoclonic ; diagnosis ; physiopathology ; Female ; Humans ; Male ; Prognosis ; Retrospective Studies

Adult ; Humans ; Male ; Myoclonic Epilepsies, Progressive ; diagnostic imaging ; genetics ; therapy ; Nerve Tissue Proteins ; genetics ; Pedigree

Adult ; Aged ; Chromosome Aberrations ; Epilepsies, Myoclonic ; diagnosis ; genetics ; Female ; Humans ; Male ; Middle Aged ; Pedigree

Adolescent ; Adult ; Child ; Epilepsies, Myoclonic ; genetics ; Female ; Humans ; Male ; Middle Aged ; Pedigree ; Young Adult