What type of activity does an EEG sample show during an ictal event?

During an ictal event, the EEG (electroencephalogram) captures the specific electrical activity of the brain as a seizure occurs. This is referred to as ictal activity, which is characterized by abnormal, rhythmic brain waves that depict the heightened neurotransmission occurring during a seizure. Such patterns differ significantly from the typical brain activity seen when a person is awake or in between seizures, showcasing an immediate, often dramatic change in brain function.

The normal awake pattern represents the typical brain activity when a person is conscious and alert but does not align with the seizure activity present during an ictal event. Interictal spikes refer to the abnormal discharges that occur between seizures but are not representative of what is happening during the seizure itself. Background attenuation indicates a decrease in normal brain activity but does not specifically describe the activity occurring during a seizure.

Thus, identifying the type of activity as ictal activity is essential for understanding and diagnosing seizure disorders, as it directly correlates to the active state of the brain during a seizure.