Electroclinical characteristics of epilepsy children with midline epileptiform discharges related epileptic negative myoclonus as the first symptom / 中华儿科杂志

ABSTRACT

Objective@#To investigate the electroclinical findings in epilepsy children with epileptic negative myoclonus (ENM) restricted to the lower limb as the first seizure type.@*Methods@#Each retrieved electroencephalogram record performed between March 2011 and March 2018 at the Department of Pediatrics of Peking University First Hospital was searched with "midline" . There were 302 records of 175 patients with "benign" or "functional" midline spikes. A retrospective review of each patient′s hospital record was performed. Thirteen patients had ENM restricted to the lower limb as the first seizure type. The clinical and electroencephalogram characteristics of them were analyzed.@*Results@#Thirteen patients manifested ENM restricted to the lower limb as the first seizure type, diagnosed as benign childhood focal epilepsy with vertex spikes (BEVS). Six patients had ENM as the first and only seizure type during the short-time follow-up. Among them, there were 1 male and 5 females. The age at seizure onset was (2.5±0.7) years. One of them had electrical status epilepticus during sleep (ESES) identified on electroencephalogram at theage of 4 years and 8 months. The last follow-up age was (3.8±1.5) years. The remaining 7 patients developed nocturnal focal motor seizures. Among them, there were 4 males and 3 females. The age at seizure onset was (3.5±0.7) years. Two of them were diagnosed as BEVS evolving into benign childhood epilepsy with centrotemporal spikes (BECTS) and 5 were diagnosed as BEVS concurring with BECTS. The age at focal seizures was (4.1±0.6) years. The interval ranged from 1 month to 1 years. Six of 7 patients had electrical ESES with the age of (5.2±1.0) years. All had developmental regression, further diagnosed as atypical benign partial epilepsy (ABPE). The median age at last follow-up was 5.9 years. Five of 13 patients had repeated electroencephalogram records at our apartment, showing that epileptiform discharges in midline regions were significantly reduced either in frequency or amplitude with the improvement of ENM restricted to the lower limb and that independent epileptiform discharges in Rolandic regions from midline regions were noticed with the onset of nocturnal focal seizures.@*Conclusions@#ENM restricted to the lower limb has a close association with vertex (midline) epileptiform discharges. ENM restricted to the lower limb as the first seizure type is a peculiar phenomenon of BEVS. Some patients could evolve into BECTS or overlap with BECTS, and further into ABPE. The age of seizure onset in BEVS with ENM restricted to the lower limb as the first symptom is a little earlier than in BECTS. Ignorance of the close association between midline spikes and ENM restricted to the lower limb may lead to misdiagnosis of these patients.