What is the critical difference between a classic migraine headache and a common migraine headache?

The distinction between a classic migraine and a common migraine primarily lies in the presence or absence of an aura. A classic migraine headache is characterized by the occurrence of an aura, which can involve visual disturbances, sensory changes, or even speech difficulties that precede the headache phase. This aura can serve as a warning sign for those who experience migraines.

In contrast, common migraines do not have this aura component and instead may simply present as a headache without any preceding visual or sensory changes. The definition of these two types of migraines helps in understanding their pathophysiology and guides treatment options as well as patient education regarding their symptoms and triggers.

The other choices related to EEG abnormalities are less relevant as EEG findings do not significantly differentiate between classic and common migraines, nor do they play a primary role in the diagnosis or management of these headaches.