What EEG pattern is most characteristic of typical absence seizures in children?

• A. Focal sharp waves in temporal regions
• B. Slowing of background activity
• C. High-frequency beta activity
• D. Generalized 3 Hz spike-and-wave discharges

Answer: (D)

The key concept is the EEG hallmark of typical absence seizures in children: generalized 3 Hz spike-and-wave discharges. This pattern reflects synchronized thalamocortical bursts that briefly disrupt consciousness, producing the characteristic brief lapse in awareness. On EEG, you see bilateral, generalized spikes followed by slow waves at about three cycles per second, without a focal onset. Clinically, these seizures are brief and often accompanied by subtle symptoms like eyelid fluttering or gentle eye movements, and they can be provoked by hyperventilation during testing. This 3 Hz generalized spike-and-wave pattern is the defining feature that distinguishes typical absence seizures from other seizure types, such as focal epileptiform activity or diffuse slowing, which align with different conditions.