Interictal epileptiform activity as a marker for clinical outcome

Interictal epileptiform activity (IEA) is a term that describes the appearance of electrical discharges limited in duration which may be observed in EEGs (electroencephalograms) of patients suffering from epilepsy. These are spark-like phenomena produced by the brain, even when a patient is not suffering a seizure (interictal means occurring between seizures). Detecting IEA in EEGs is indicative of a susceptibility to epilepsy. The amount of IEA differs between patients and epilepsy syndromes. Although there was a relation between the (change in the) amount of IEA and seizures at group level, assessing the amount of IEA was not found to be a good method to evaluate individual patient treatments.
Furthermore, it was found that a larger amount of IEA was linked to impaired cognition in children regarding speed of information processing and reading, among other things. In the future, it may be useful to set up a trial in which children with large amounts of IEA are treated with medication in order to reduce their learning disabilities, even if they are not having seizures (anymore) or only suffer very few.