OBJECTIVETo summarize the electroclinical characteristics of myoclonic atonic epilepsy (MAE) in children.

METHODThe clinical data, video electroencephalogram (EEG) and simultaneous electromyography (EMG) of MAE patients were analyzed. The treatment and its effects were followed up.

RESULTIn 47 MAE patients, 25 had a history of febrile seizures (FS), 20 had a family history of FS or epilepsy. All patients had a normal development before the illness. The age of afebrile seizure onset was between 1.4 years to 5.8 years. The first seizure was generalized tonic-clonic seizure (GTCS) in 41 patients (87.2%). All patients had multiple seizure types, including 47 GTCS (97.9%), 34 myoclonic atonic seizures (72.3%), 47 myoclonic seizures (100%), 32 atonic seizures (68.1%), 36 atypical absences (76.6%) and 3 tonic seizures (6.4%). EEG backgrounds were slow or parietal θ rhythm, interictal EEG showed 1-4 Hz (predominant 2-3 Hz) generalized spike and wave or poly spike and wave discharges in all cases. Seizures were controlled by antiepileptic drugs (AEDs) in 41 patients (87.2%). Valproate was used in 37. Lamotrigine was used in 26. Mild mental retardation was observed in 10 children after the onset of the illness.

CONCLUSIONThe clinical features of MAE included the following: the development was normal before the onset of the illness; the onset of seizure type was often GTCS. All patients had multiple generalized seizure types. Myoclonic atonic seizure was its characteristic seizure type. EEG showed generalized discharges. Early diagnosis and rational choice of AEDs are important for getting a better prognosis.