Focal Seizure
1 medicine
A focal seizure starts in one localised area of the brain and can cause abnormal movements, sensations or altered awareness. Long-term control usually involves an anticonvulsant such as phenytoin.
Key facts
- A focal seizure starts in a specific, localised region of the brain rather than spreading across both hemispheres at once.
- Focal seizures are grouped by whether awareness is preserved: a focal aware seizure keeps the person conscious, while a focal impaired-awareness seizure reduces consciousness.
- Long-term control usually involves an anticonvulsant such as phenytoin, part of the neurology toolkit, which stabilises electrically excitable membranes in the brain.
- Seek urgent medical attention if a seizure lasts longer than five minutes, seizures cluster without recovery, or a first-ever seizure occurs.
How a focal seizure presents
Because the affected brain region varies from person to person, the experience can look very different: one person may notice rhythmic twitching in one hand while remaining fully conscious, while another may stare blankly and be unaware of what is happening around them for a minute or two.
Focal seizures are grouped by whether awareness is preserved. In a focal aware seizure the person stays conscious and may feel a strange smell, taste, rising sensation in the stomach, or jerking in one limb. In a focal impaired-awareness seizure, consciousness is reduced and the person may pick at clothing, make chewing movements, or wander without purpose. Either type can occasionally spread to involve both sides of the brain, becoming a generalised tonic-clonic seizure.
How focal seizures are treated
Long-term control usually involves an anticonvulsant medicine. Phenytoin is one of the older agents in the neurology toolkit; it stabilises electrically excitable membranes in the brain and slows the abnormal firing that drives a focal seizure. Blood levels need periodic monitoring because the therapeutic range is narrow.
When to see a doctor
Seek urgent medical attention if a seizure lasts longer than five minutes, if seizures cluster without recovery between them, or if a first-ever seizure occurs.
This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.