Objective: To elucidate the characteristics of the myoclonic seizures alone, or predominant myoclonus combined with generalized tonic-clonic seizures (GTCS) and/or absences, in early childhood, and discuss its classification.
Methods: Forty-two children were retrospectively recruited between January 2006 and June 2015.
Results: The mean age of seizure onset was 40.5months. They were divided into 4 groups: myoclonic seizures alone; predominant myoclonus combined with GTCS; predominant myoclonus combined with absences; predominant myoclonus combined with both GTCS and absences. Interictal EEG showed generalized spike- or polyspike-wave discharges at 2-4Hz. Seizures were controlled in 22 patients at a mean age of 60.5months. The psychomotor development was normal (30/37) or mildly delayed (7/37).
Conclusions: We reported a cohort of patients with early childhood myoclonic epilepsy (ECME), with the following characteristics: Seizures started below 5years old in otherwise normal children; Seizure types included myoclonic seizures alone or combined with GTCS and/or absences; Febrile or afebrile GTCS might appear firstly; Interictal EEG showed generalized spike- or polyspike-wave; Seizures usually were in remission before adolescence with normal development or mild cognitive or behavioral deficits in most.
Significance: ECME might be an independent epileptic syndrome not established by International League Against Epilepsy (ILAE) previously.
Keywords: Absence seizures; Early childhood; Epileptic syndrome; Generalized tonic-clonic seizures; Myoclonic seizures.
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