What distinguishes generalized seizures from focal seizures?

• A. Generalized seizures involve both hemispheres.
• B. Focal seizures involve both hemispheres.
• C. Generalized seizures originate in the brainstem.
• D. Focal seizures are always without loss of consciousness.

Answer: (A)

Generalized seizures are defined by activity that starts in and rapidly involves both hemispheres, creating a diffuse, bilateral storm of electrical activity. This is why they often present with generalized symptoms and altered or lost consciousness. Focal seizures, on the other hand, begin in a single region of cortex in one hemisphere; the initial symptoms reflect that localized origin and may stay focal, or later spread to involve both sides (secondary generalization).

So the key distinction is where the discharge begins: generalized seizures involve both hemispheres from the outset, whereas focal seizures originate in a single hemisphere. Other statements don’t fit because focal seizures can have preserved or impaired consciousness depending on the region involved, and generalized seizures don’t have to originate in the brainstem.