Tests and diagnosis

By Mayo Clinic Staff

Medical history

Your doctor will need a detailed description of the seizures, preferably from a witness, because most people who have temporal lobe seizures don't remember the episodes.

Neurological exam

If you or your child has had a seizure, your doctor likely will perform a neurological exam that tests:

  • Reflexes
  • Muscle tone
  • Muscle strength
  • Sensory function
  • Gait
  • Posture
  • Coordination
  • Balance

He or she may also ask questions to assess your thinking, judgment and memory.

Blood tests and scans

Blood tests may be ordered to check for problems that could be causing or triggering the seizures.

Your doctor may also suggest scans or tests designed to detect abnormalities within the brain.

  • Electroencephalogram (EEG). An EEG displays the electrical activity of your brain as recorded by electrodes attached to your scalp. People with epilepsy often have changes in their brain wave patterns, even when not having a seizure. The EEG sometimes can help indicate the type of seizures you're having.

    In some cases, your doctor may recommend video-EEG monitoring in the hospital. This allows your doctor to compare — second by second — the behaviors observed during a seizure with your EEG pattern. This can help your doctor pinpoint the type of seizure disorder you have, which helps to identify appropriate treatments, and can help ensure that the seizure diagnosis is correct.

  • Magnetic resonance imaging (MRI). An MRI machine produces detailed images of your brain. Although many people with seizures and epilepsy have normal MRIs, certain MRI abnormalities may provide a clue to the cause of the seizures.

    During the test, you will lie on a padded table that slides into the MRI machine. Your head will be immobilized in a brace, to improve precision. The test is painless, but some people experience claustrophobia inside the MRI machine's close quarters. If you think you may have this reaction, tell your doctor before the study.

  • Single-photon emission computerized tomography (SPECT). Sometimes used when the area of seizure onset is unclear, SPECT imaging requires two scans — one during a seizure and one during a nonseizure period, each performed on separate days. Radioactive material is injected for both scans.

    The scans are then compared to find the area of the brain with the greatest activity during the seizure. The resulting image is then superimposed onto the MRI. This is used with EEG information to help guide the surgeons.

June 25, 2014