Abstract: 　Objective　To investigate the electro-clinical characteristics of epileptic negative myoclonus (ENM) as the first or only seizure type in children. Methods　The EEG characteristics, clinical manifestations, treatment and outcome of 4 children with epilepsy featured by ENM as the first or only seizure type were retrospectively analyzed. Results　Among 4 cases, there were 3 males and 1 female, the average age of onset was 1.85±0.61 years (1 year 5 months to 2 years 9 months old). Mental development and neuroimaging findings were normal, and blood/urine tandem mass spectrum is negative. ENM was the first seizure type in all 4 cases, of which ENM were the only type of seizure in 3 cases, and 1 case had focal seizures after ENM. EEG findings showed the EEG background rhythm was normal, the onset period and interictal period were Rolandic region spikeslow waves, the discharge mode of onset period is consistent with the interictal period. Two cases were controlled with valproate within 3 months, and other 2 cases were treated with many methods but eventually the seizures were completely controlled, in which seizure was worsened by carbamazepine treatment in one case, but controlled after stopping carbama zepine and adding clonazepam treatment. Another case was found with EEG findings of electrical status epilepticus during sleep after treatment for 5 months, the symptom was controlled by methylprednisolone treatment. Follow-up of 3 cases (1 lost follow-up) showed discharges of different quantities still existed in Rolandic region in last VEEG, and 3 cases had learning difficulties, behavioral disorders or ADHD in varied degrees. Conclusion　Children with ENM as the first or the only seizure type had specific EEG patterns and similar clinical features.

Key words: epileptic negative myoclonus;　centrotemporai region spikes;　video-electroencephalogram