Focal seizure

What it is

A focal seizure (also called a partial seizure) is a seizure that arises from one specific area of the brain, causing localized symptoms that reflect the function of that area. It may occur with or without loss of awareness, and its features can help indicate where a glioma is located.

Understanding Focal seizure

Because a focal seizure begins in one part of the brain, its symptoms depend on where that part is and what it controls. For example, a focal seizure in the motor area may cause twitching or jerking of one limb or one side of the face; one in a sensory area may cause unusual sensations; one in the temporal lobe may cause strange smells, déjà vu, or altered awareness. A focal seizure may stay localized (focal aware, with the person conscious) or spread and impair awareness (focal impaired awareness), and it can sometimes evolve into a generalized convulsion. The specific pattern of a focal seizure provides clues to the tumor's location, which doctors consider alongside imaging. Recognizing focal seizures is important, as subtle ones can be mistaken for other conditions. Understanding focal seizures clarifies localized seizures whose features reflect a glioma's location.

Why it matters

Understanding focal seizures helps patients and families recognize seizures arising from one brain area — whose symptoms reflect that area's function and can help localize a glioma — including subtle forms that might otherwise be missed.