What is typically seen in the interictal EEG of children with a history of untreated febrile seizures?

In the case of children with a history of untreated febrile seizures, the interictal EEG typically appears normal. This observation is significant because febrile seizures, although they can be concerning, do not usually lead to long-lasting changes in the brain's electrical activity when observed in the interictal period. These children often exhibit a normal EEG between seizures, which differentiates them from those with other types of epilepsy or neurological disorders that would show consistent abnormalities on the EEG even when the patient is not having a seizure.

This normalcy reflects the transient nature of febrile seizures and suggests that, while the child has experienced seizures in the context of fever, there is generally no underlying structural or chronic electrophysiological disturbance in the brain. Thus, an interictal EEG showing normal results is expected for this population of children.