Epilepsy is a brain disorder in which a person has repeated seizures over time. Seizures are episodes of uncontrolled and abnormal firing of brain cells that may cause changes in attention or behaviour.

Epilepsy may be due to a medical condition or injury that affects the brain. Or the cause may be unknown (idiopathic).

Common causes of epilepsy include:

• Stroke or transient ischemic attack ( TIA )
• Dementia, such as Alzheimer disease
• Traumatic brain injury
• Infections, including brain abscess, meningitis, encephalitis, and HIV/AIDS
• Brain problems that are present at birth (congenital brain defect)
• Brain injury that occurs during or near birth
• Metabolism disorders present at birth (such as phenylketonuria)
• Brain tumour
• Abnormal blood vessels in the brain
• Other illness that damages or destroys brain tissue

Epileptic seizures usually begin between ages 5 and 20. There is also a higher chance of seizures in adults older than 60. But epileptic seizures can happen at any age. There may be a family history of seizures or epilepsy.

Symptoms vary from person to person. Some people may have simple staring spells. Others have violent shaking and loss of alertness. The type of seizure depends on the part of the brain that is affected.

Most of the time, the seizure is similar to the one before it. Some people with epilepsy have a strange sensation before each seizure. Sensations may be tingling, smelling an odour that is not actually there, or emotional changes. This is called an aura.

Your doctor can tell you more about the specific type of seizure you may have:

• Absence (petit mal) seizure (staring spells)
• Generalized tonic-clonic (grand mal) seizure (involves the entire body, including aura, rigid muscles, and loss of alertness)
• Partial (focal) seizure (can involve any of the symptoms described above, depending on where in the brain the seizure starts)

The doctor will perform a physical exam. This will include a detailed look at the brain and nervous system.

An EEG (electroencephalogram) will be done to check the electrical activity in the brain. People with epilepsy often have abnormal electrical activity seen on this test. In some cases, the test shows the area in the brain where the seizures start. The brain may appear normal after a seizure or between seizures.

To diagnose epilepsy or plan for epilepsy surgery, you may need to:

• Wear an EEG recorder for days or weeks as you go about your everyday life.
• Stay in a special hospital where brain activity can be recorded while video cameras capture what happens to you during the seizure. This is called video EEG.

Tests that may be done include:

• Blood chemistry
• Blood sugar
• Complete blood count ( CBC )
• Kidney function tests
• Liver function tests
• Lumbar puncture (spinal tap)
• Tests for infectious diseases

Head CT or MRI scan is often done to find the cause and location of the problem in the brain.