Which EEG pattern is typically observed during a generalized seizure?

In the context of generalized seizures, spike-and-wave complexes are the characteristic EEG pattern observed. These complexes are indicative of the synchronous and excessive neuronal discharge that occurs during these types of seizures, particularly in absence seizures, but can also be seen in other generalized forms of epilepsy.

Spike-and-wave complexes consist of a distinctive pattern where a spike followed by a slow wave occurs repetitively, often at a frequency of 2.5 to 3 Hz. This pattern reflects the underlying pathophysiology of generalized epilepsy, where there is a widespread involvement of both hemispheres of the brain leading to the alteration in consciousness and motor function typical of generalized seizures.

Other EEG patterns, such as alpha waves, beta waves, and slow waves, do not specifically correlate with generalized seizures. Alpha waves are typically seen in relaxed or resting states when the eyes are closed, whereas beta waves are associated with alertness and active concentration. Slow waves might occur in different contexts like deep sleep or certain types of focal seizures but they are not defining features of generalized seizures. Thus, spike-and-wave complexes are the hallmark EEG finding in these situations.