focal seizure
A seizure that begins in a specific area of the brain and may remain localized or spread to other regions.
Full Definition
Focal seizures, previously known as partial seizures, originate in a specific region of the brain rather than affecting the entire brain simultaneously. They are classified as either focal aware seizures (where consciousness is preserved) or focal impaired awareness seizures (where consciousness is altered). Symptoms depend on the brain region involved and may include motor symptoms (jerking, stiffening), sensory symptoms (tingling, visual changes), autonomic symptoms (nausea, sweating), or psychic symptoms (déjà vu, fear). Focal seizures may remain localized or evolve into bilateral tonic-clonic seizures. Understanding the focal origin is crucial for surgical planning in medically refractory cases.
Usage
Usage note: The 2017 ILAE classification replaced 'partial seizure' with 'focal seizure' - use current terminology in modern documentation.
In Context
- "The patient's focal seizures originated in the right temporal lobe and presented with auditory hallucinations." — Clinical assessment
- "Focal seizures with preserved awareness allowed the child to describe the unusual sensations during the episode." — Patient history