Diagnosing seizures and epilepsy is like putting the pieces of a puzzle together. The “pieces” are information from many different people (including you, your doctor, and other members of your health care team) and test results.

How are seizures and epilepsy diagnosed?

First, your doctor will need to find out if you had a seizure. Next it’s important to find out what type of seizure or epilepsy syndrome best explains what happened. Doing this usually requires several steps:

The timing of each step may vary, since each person is different.

EEG tests and brain imaging tests give information about the electrical activity in your brain, what your brain looks like, and what might be causing your seizures. Sometimes, your doctor might order a test more than once to make sure it’s accurate.

The doctor will consider all this information, including how you’re feeling and how the seizures may be affecting your brain, in order to make a diagnosis. If your doctor gets new information later, she might change your initial (first) diagnosis.

It's important to keep in touch with your health care team. If you start to have new symptoms, or if your seizures are not responding to treatment, it might be time to take another look at your diagnosis.

Why see a doctor?

If you have had a seizure, it’s very important for you to see a doctor.

Even if you haven’t had a big, obvious seizure, you should see a doctor if you suspect (or if people tell you) that there are times when you aren’t aware of what you're doing.

The doctor will try to figure out whether you had a seizure — and what caused it. If your seizure was caused by another medical condition (like diabetes), you will usually need treatment for that condition. If your doctor thinks you have epilepsy, he will probably order some tests and prescribe medicine to keep you from having more seizures.

What kind of doctor is best?

If you think you may have had a seizure, go to your primary care doctor (like a pediatrician, internist, or family physician) first. Your primary care doctor may do some tests.

If your doctor thinks you’ve had a seizure, she will probably refer you to a neurologist ("ner-AH-luh-gist"). A neurologist is a doctor with special training in disorders of the brain, including epilepsy.

Some neurologists have special training in epilepsy and spend most of their time treating people with epilepsy. They are called epileptologists ("ep-i-lept-AH-luh-gists").

For routine treatment of epilepsy, you usually don’t need to see an epileptologist. You may need to see an epileptologist in certain cases, like for counseling about pregnancy and childbirth, or if you and your neurologist are having trouble controlling your seizures. 

Sometimes, a person will be taken by ambulance to the emergency room after their first seizure. In that case, an emergency room doctor will examine them, and maybe a neurologist too. They may be referred to a neurologist or epilepsy specialist for follow-up testing and treatment.

What will the doctor do?

When you visit your primary care doctor or neurologist, he’ll ask lots of questions about your health and what happened before, during, and after the seizure. This is called an interview, or “taking a history.”

It’s very helpful to bring along a family member or someone else who saw the seizure. That person can tell the doctor what happened, since you may have been unconscious. Even if you think you were aware the whole time, there may be important things about the seizure that you don’t remember.

After the interview, the doctor will examine you and will probably order some tests. He may have enough information from the first visit to start you on treatment, or he may suggest doing some other tests first.

Questions your doctor may ask:

  • Is there something that could have provoked the seizure or event, like sleep deprivation, alcohol or drug abuse, or anything else?
  • Where were you and what was going on when the seizure started?
  • Did it happen right after you stood up?
  • Was there a warning, like an unusual feeling before the seizure started?
  • Exactly what happened during the seizure?
  • How long did it last?
  • Were you tired or confused after the seizure?
  • Have you had more than one seizure? If so, were they all alike?
  • Have you seen a doctor before about this kind of event?
  • If so, what tests did that doctor do?
  • Have you taken medication for seizures before? What effect did it have?

What tests may be ordered?

A number of tests may be ordered which can help diagnose epilepsy and see if a cause can be found, including:

  • A brain wave test, also called an EEG (electroencephalogram). This test looks for changes in the brain's electrical patterns that are related to seizures.
  • Blood tests. These tests look for certain medical problems that can cause seizures.
  • Brain scans called a CT scan (or CAT scan), or an MRI scan (magnetic resonance imaging). These tests look for changes in the structure of the brain, like a tumor or bleeding.  Change in the way the brain developed that could lead to seizures can often be seen by a brain scan too.
  • In some cases, your doctor might recommend other tests, like a lumbar puncture (spinal tap to check fluid around the brain), an EKG (electrocardiogram, to check the heart), or a sleep test.

What if the test results are normal?

Often an EEG is normal in a person with epilepsy. This doesn’t mean a person does or does not have epilepsy. It just means that a seizure didn’t occur when the EEG test was done. Sometimes changes in brainwaves can be seen that show a person may be likely to have seizures though.

Most of the other tests are done to look for possible causes of the seizures. These tests are normal in many people with epilepsy and just means that we don’t yet know the cause.  In other people, one of the tests may find a cause that can be treated (like an infection) or a reason why the person is having seizures.

What if it’s not epilepsy?

After looking at your test results, your doctor may find that you don’t have epilepsy. You may have a medical or psychological condition that causes events that look like epilepsy seizures. In that case, your doctor will treat the condition you have instead of giving you seizure medicines.

What’s next?

If all your test results are normal, your doctor will have to figure out whether you still need treatment. Some people have only one seizure and don't have any more. But others may be at risk for more seizures and need to take medicine to stop these. Whether a person starts treatment right away or waits to see if more seizures occur will depend on the individual situation.


Authored By: 
Patty Obsorne Shafer RN, MN
Authored Date: 
Reviewed By: 
Joseph I. Sirven MD
Tuesday, October 28, 2014