The EEG slow wave distribution should be interpreted according to different age groups. 1. It is normal for a child to have EEG slow wave distribution because the brain development of children is not complete and the EEG slow wave distribution is predominant, and after the age of 14 the EEG is close to the adult level. 2. The EEG slow waves are also predominant in the brain after extensive intracranial infections affecting the cortex. 3, if the EEG slow waves are issued for the elderly, the EEG examination is mainly based on the issuance of slow waves in the presence of cerebral decompensation and dementia. 4, some patients with epilepsy also show slow waves in the EEG when they have seizures.