<p>It is important to detect non-convulsive seizures in the treatment of critically ill children in ICU. Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is characterized by a febrile status epilepticus as the initial neurological symptom, followed by secondary seizures and subcortical white matter edema at day 4 to 6. As MRI shows no acute abnormality at the onset, EEG is useful to distinguish AESD from febrile status epilepticus in early stage. Recently therapeutic hypothermia is applied as a treatment of AESD, and continuous EEG monitoring during the therapy is also important. Amplitudeintegrated EEG (aEEG) and dense spectral array (DSA) are useful for the identification of non-convulsive seizures in long-term EEG monitoring in ICU.</p>