Epileptic Encephalopathy With Continuous Spike And Wave During Sleep

Etiologies: structural brain abnormalities (account for one third of cases, developmental or acquired), some chromosomal abnormalities or gene mutations (such as GRIN2A、CNKSR2、MECP2) or metabolic etiologies (e.g. mitochondrial disorders) [1-3].

Age of onset: onset of seizures generally from age 2 to 12 years (peak 4 to 5 years).

Seizure characteristics: EEG with continuous spike-and-wave during sleep developing 1-2 years after seizure onset. There can be a variety of seizure types (including focal seizures, atypical absence, atonic seizures, generalized tonic clonic seizures, but generally no tonic seizures), often accompanied by neuropsychological dysfunction [4].

EEG: Background: it can be normal or manifested as focal or diffuse slowing; Interictal: discharge increased significantly during sleep, the spike and wave index (SWI) can reach 85% to 100% during non rapid eye movement sleep (NREM); Ictal: depending on different seizure types [4-5].

Brain MRI: More than 1/3 have abnormalities, which can be brain structural abnormalities (developmental or acquired).

Developmental progress: A progressive decline in cognitive, behavioral and psychiatric functioning (the late residual deficits is closely related to the control of seizure and electrical continuous state and the age of onset).

Reference

1. Lemke, J.R., et al., Mutations in GRIN2A cause idiopathic focal epilepsy with rolandic spikes.Nat Genet, 2013. 45(9): p. 1067-72.
2. Bonardi, C.M., et al., Expanding the clinical and EEG spectrum of CNKSR2-related encephalopathy with status epilepticus during slow sleep (ESES). Clin Neurophysiol, 2020. 131(5): p. 1030-1039.
3. Bhat, S., et al., Continuous spike and wave in slow-wave sleep in a patient with Rett syndrome and in a patient with Lhermitte-Duclos syndrome and neurofibromatosis 1. J Child Neurol, 2014. 29(12): p. NP176-80.
4. Panayiotopoulos.  癫痫综合征及临床治疗.  北京 : 人民卫生出版社, 2012.
5. 刘晓燕.  临床脑电图学. 第2版.  北京 : 人民卫生出版社, 2017.