Epilepsy can be difficult to diagnose, in part because doctors rarely witness seizures firsthand. The symptoms of epilepsy can also be challenging to distinguish from those of other conditions, including migraine, sleep disorders, heart problems, and more. It’s also possible to have one or more of these conditions in addition to epilepsy, further complicating diagnosis.

It’s important to note that not all seizures are caused by epilepsy. Epilepsy is a neurological disorder that involves recurrent seizures caused by abnormal electrical activity in the brain. Nonepileptic seizures don’t originate from abnormal electrical activity and may require different treatment than epileptic seizures.

Typically, a neurologist (a doctor who specializes in treating the nervous system and brain) diagnoses epilepsy. It may also be diagnosed by a pediatrician, emergency room physician, or general practitioner.

How Do Doctors Test for Epilepsy?

There is no single diagnostic test that can confirm you have epilepsy. Instead, a doctor will consider your medical history and may perform a variety of tests to reach a diagnosis, including electroencephalograms and imaging tests.

Medical History

The doctor will take a thorough history, asking detailed questions about what happens during your seizures, how long they last, and how often they occur. The physician may ask about a history of head injuries, infections, or other neurological symptoms. The doctor will likely ask about your family history of seizures. A clear picture may emerge from the medical history to help the doctor strengthen the suspicion of epilepsy or rule out other conditions.

Electroencephalography

An electroencephalogram (EEG) is used to visualize brainwaves to monitor seizure activity. For an EEG, the technologist administering the test will place electrodes on your scalp. The electrodes pick up the tiny electrical charges resulting from brain activity. Most EEGs record brain activity for 20 to 40 minutes. Receiving an EEG is painless and generally safe.

EEG results are not always clear, as about half of the EEG tests done on people who have seizures look normal. Even if you have frequent seizures, your EEG may be normal if you are not having a seizure during the test. You may be asked to stare at blinking lights or breathe deeply for several minutes to provoke seizure activity.

In addition to a standard EEG, your doctor may suggest an ambulatory or video EEG. Ambulatory EEGs record brainwaves for a longer period of time, usually 24 hours to three days, to increase the chances of recording seizure activity. Electrodes will be placed on your scalp, and you’ll have a small recorder to wear on your waist. Once the electrodes are in place, you can go home and go about your usual routine.

During video EEGs, video and audio of your movement, behavior, and sounds are recorded along with the brainwave patterns recorded in an EEG. Video EEGs allow the neurologist to see what’s happening in your brain during specific seizure behavior. Video EEGs can be done on an inpatient or outpatient basis.

When EEGs do capture seizure activity, they’re very valuable tools. Some brainwave patterns can help doctors know if someone has a certain type of epilepsy, type of seizure, or another brain problem. Sometimes, EEG results can even point to the place in the brain where the seizures start.

If your EEG looks normal, it doesn’t prove whether you have epilepsy or not. More tests will be needed.

Brain Imaging

Imaging tests are performed to evaluate brain function and structure. The most common neuroimaging procedures used to detect brain abnormalities associated with epilepsy are magnetic resonance imaging (MRI), functional MRI (fMRI), and CT scans. Single-photon emission computed tomography (SPECT) brain imaging and positron emission tomography (PET) scans can also be used.

Neuroimaging scans can detect potential causes of seizures, including tumors, scar tissue, abnormal blood vessel formations, or an excess of spinal fluid.

Other Tests

Your doctor may order blood tests to check for other causes of seizures (for example, disorders in your electrolytes or blood sugar) or genetic causes of epilepsy. Blood tests can also screen for infections that may be causing seizures.

The doctor may order a neuropsychiatric test to evaluate cognitive (related to thinking, memory, speech, and reasoning) abilities. A neurological exam may be performed by a doctor, a psychologist, or another specialist.

What Is the Prognosis for Epilepsy?

As many as 70 percent of people diagnosed with epilepsy who receive appropriate treatment could become seizure-free within a few years. Some people will never have another seizure, while others may have sporadic seizures or uncontrolled seizures despite being on anti-seizure medications (ASMs).

What Is Remission From Epilepsy?

The International League Against Epilepsy defines remission from epilepsy as 10 years without having a seizure, with at least five years not taking ASMs. Someone who has gone at least two years without seizures (the last year off ASMs) or five years without seizures (the last two years off ASMs) is considered to be in early remission. The chances for remission are higher for people who take their ASMs consistently, take only one ASM, and start treatment early.

Age at Diagnosis

The age at which a person receives an epilepsy diagnosis varies widely and is often correlated to the cause of epilepsy. Some forms of epilepsy, especially those that are caused by birth trauma or a genetic condition, are diagnosed in infancy or early childhood. Other types of epilepsy don’t develop until adolescence or adulthood.

Talk With Others Who Understand

MyEpilepsyTeam is the social network for people with epilepsy and their loved ones. On MyEpilepsyTeam, more than 124,000 members come together to ask questions, give advice, and share their stories with others who understand life with epilepsy.

Have you or your child been diagnosed with epilepsy? Which tests helped support your diagnosis? Share your experience in the comments below, or start a conversation by posting on your Activities page.