How Doctors Diagnose Epilepsy

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Doctor talking with patient

A seizure can be a dramatic and scary event. But just because you or a loved one had a seizure doesn’t mean an epilepsy diagnosis.

Seizures can be an isolated event caused by fever, low blood sugar, drug or alcohol withdrawal, or an injury or accident. Medical conditions other than epilepsy can also cause seizures. 

Your First Step

Start with your primary care doctor—your pediatrician, internist, or family practitioner. Your doctor will evaluate your overall health and consider possible causes of your symptoms.  

If your doctor suspects epilepsy or some other neurological condition, he or she will refer you to a neurologist. Neurologists who specialize in epilepsy are epileptologists.

There are many types of seizures and different forms of epilepsy. Your neurologist will use several methods to evaluate your seizures and diagnose epilepsy. As part of the diagnostic process, your doctor will identify the part of the brain involved and the type of seizures you have. 

Your doctor will ask you questions about what the seizure looked like and what happened just before it began. It is important to provide as much detailed information as you can about your seizure. For example, some people have mild staring episodes and others have intense convulsions. Ask a loved one to record your symptoms during a seizure. The information you or witnesses of the seizure can give the doctor is critical to an accurate diagnosis of epilepsy. 

Tests for Epilepsy

In addition to learning about your symptoms, the details of your seizures, and your medical history, your doctor will conduct a series of tests.

  • Neurological exam. Your doctor will do a complete neurological, behavioral and developmental exam to understand the possible cause of seizures and if the seizures are affecting brain function. These tests include a combination of physical, verbal and written pieces.

  • EEG. An EEG (electroencephalography) records electrical activity in the brain. An EEG may show abnormal electrical activity in people with epilepsy. However, an EEG may look normal after a seizure and between seizures. It’s possible you may need to wear an EEG device for several days or longer in order to catch abnormal activity. Your doctor may also ask you to stay in the hospital for evaluation and to record brain activity.

  • Brain scans. CT (computed tomography) or MRI (magnetic resonance imaging) may be used to look for growths, scars, or other conditions in the brain that may be causing your seizures. PET (positron emission tomography) scans may be used to identify areas of the brain that are producing the seizures. 

Many other conditions can cause seizures, but it does not mean you have epilepsy. Your doctor may order a series of blood tests and other tests to check for the following:

  • Abnormal glucose (sugar) and sodium levels
  • Brain infection
  • Drug abuse and withdrawal
  • Liver and kidney function
  • Medication side effect or overdose
  • Poisoning such as carbon monoxide
  • Stroke

Making the Diagnosis

Doctors can usually diagnose epilepsy after at least two seizure episodes and when there is no other known cause, such as low blood sugar or abnormal kidney or liver function. In some cases, your doctor will be able to further identify the cause of epilepsy, such as an infection in the brain or a genetic condition. Unfortunately, in the majority of cases, doctors cannot find a cause. This is also known as idiopathic epilepsy.

Learn More 

Diagnosing epilepsy is challenging and requires a series of physical exams and many tests. It’s difficult to be patient when you are coping with the uncertainty of seizures. Stay in touch with your doctors and let them know how and what you are feeling. There are numerous support groups for epilepsy, including the Epilepsy Foundation.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2020 Aug 3
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.

  1. Diagnosing Epilepsy. The Epilepsy Foundation.

  2. What Type of Doctor Should I See? The Epilepsy Foundation.

  3. What Is a Neurologist? University of Rochester Medical Center.

  4. Epilepsy: Frequently Asked Questions. CDC.

  5. Seizures and Epilepsy: Hope Through Research.