Which EEG finding might indicate ongoing seizure activity?

Interictal spikes are abnormal waveforms that can be indicative of a predisposition to seizures and are often observed in individuals with epilepsy. These spikes represent synchronous discharges from a group of neurons and typically occur in a context where there may be underlying seizure activity or susceptibility.

While these spikes might be present during non-seizure periods (interictal), their frequent or sustained appearance during EEG recordings can suggest that the brain is in a state where seizure activity is actively occurring or is likely to occur shortly. This is particularly relevant in the evaluation of epilepsy, as their identification is crucial for the diagnosis and management of seizure disorders.

In contrast, continuous normal activity would suggest a lack of seizure activity and would not indicate an ongoing problem. Monophasic delta waves may appear in various conditions, including certain types of encephalopathy, but do not specifically indicate ongoing seizure activity. Focal sharp waves are also abnormal but represent a different manifestation; they might suggest an area of irritability but not necessarily confirm the presence of ongoing seizures. Thus, interictal spikes stand out as the most relevant finding when evaluating for ongoing seizure activity.