Diagnosis of Seizure

By  , Expert Content
Aug 31, 2012

Subscribe for daily wellness inspiration

Like onlymyhealth on Facebook!

Seizure is diagnosed clinically based on history, but when one visit the doctor, he/she will recommend tests to diagnose the cause of seizures. Seizure may be caused by many different medical conditions, such as epilepsy, high fever, low blood sugar, damage to the brain from stroke, brain surgery or head injury.

Medical history: Your doctor will take a detailed medical history and ask questions, such as:

  • what was the seizure like(description of the seizure)? As the person may not remember it, a family or friend present during the seizure may be asked to describe the seizure.
  • Did you have any different feeling or odd sensation before the seizure started?
  • Do you have a family history of seizures (if you have a family history of seizures, it may be due to some type of epilepsy)?


Tests are done to confirm the cause of seizures. Some of the tests that may be done include:

  • Electroencephalography
  • Brain imaging (CT, MRI, PET)
  • Blood tests


Electroencephalography (EEG) is done to diagnose epilepsy as the possible cause of seizures. This is often the first and most frequently done test in a person suffering from seizure. In this test, electrodes are attached to the scalp to detect the brain's electrical messaging system. The electrical activity of the brain is recorded and printed as they travel through the brain. In people with epilepsy, the brain wave patterns are different as compared with those in a healthy brain even when the former is not having a seizure. EEG can diagnose the type of epilepsy as the patterns of some types of epilepsy are very characteristic. In some cases, EEG is the most accurate method of testing, especially when it is performed within 24 hours after a seizure. The EEG test can be done in a doctor’s office and takes about an hour. If the report of this type of EEG is non-conclusive, a 24-hour recording of the brain activity may be done. In this test, you will be made to wear a portable monitor for 24 hours as you carry on with your normal activities and the electrical signals of the brain will be recorded.

Brain Imaging

Computerised tomography (CT or CAT scan) and Magnetic Resonance Imaging (MRI) are the most commonly done imaging tests in a person with seizure for the first time (both adults and children).

These are painless and non-invasive tests that take a series of detailed pictures of the brain. They show a detailed structure of the brain and can help to identify any abnormality, such as tumours, cysts and other structural abnormalities that may be the cause of seizures. In some cases, there may be no abnormality in the structure of the brain, but they may continue to have seizures.  Positron Emission Tomography (PET) and functional MRI (fMRI) are useful in such cases. It helps to monitor the brain's activity and detect abnormalities in its function. They can identify damaged areas in the brain that may be the focal point for the start of a seizure. In most cases, these tests may be done if surgery is considered difficult to control seizures.

Blood tests

Sample of blood may be taken to test for signs of infections, electrolyte imbalance, lead poisoning, blood sugar which can be associated with seizures.



Write Comment Read ReviewDisclaimer
Is it Helpful Article?YES1 Vote 10726 Views 0 Comment