Diagnostic methods of assessment of the child with status epilepticus (SE) are outlined following an evidence-based review of literature by the Quality Standards Subcommittee of the AAN and Practice Committee of the CNS. SE is a seizure of at least 30 min duration or 2 or more sequential seizures without full recovery of consciousness between seizures lasting 30 min. SE is classified by seizure type (focal, generalized or indeterminate) and etiology: 1) acute symptomatic, during an acute illness (26%); 2) remote symptomatic, a prior CNS insult with chronic encephalopathy or malformation and no acute illness (33%); 3) progressive encephalopathy (3%); 4) febrile illness, with no direct CNS infection (22%); and 5) cryptogenic, with no definable cause (15%). The etiologic incidence figures were obtained from 20 class III studies of 2,093 children. Laboratory studies were abnormal in 2.5%, CNS infection in 12.8%, AED levels were low in 32%. An inborn error of metabolism was diagnosed in 4.2%. EEGs showed epileptiform abnormalities in 43%; 8% were generalized, 16% focal, and 19% both. MRIs were abnormal and indicative of the etiology of SE in 8%. Investigation of the cause of SE includes: 1) blood culture and lumbar puncture if there is clinical suspicion of a systemic or CNS infection; 2) AED blood levels: 3) toxicology and metabolic studies when clinically indicated or if etiology is unknown; 4) EEG to check for focal or generalized discharges, or if pseudostatus is suspected, or in diagnosis of nonconvulsive SE; and 5) MRI after SE is treated and stabilized, and if clinically indicated or if etiology is unknown. 
COMMENT. The authors recommend further prospective studies to determine what factors may precipitate SE in children; the role for routine or selective laboratory investigations; indications and treatment significance of EEG; role of routine or selective MRI; and the frequency, etiology, and prognosis of nonconvulsive SE after control of convulsive SE.
Cognition and electrical SE during sleep (ESES). The duration of ESES and the localization of interictal foci play a major role in the degree and type of cognitive dysfunction following continuous spike-wave activity. ESES interferes with slow-wave activity at the site of the epileptic focus, impairing learning and other cognitive functions.