Diagnosis

An EEG is a painless and important diagnostic test for epilepsy. Electrodes are attached to the scalp. These measure brainwave activity and can reveal patterns characteristic of different types of seizures and seizure syndromes. If the first EEG is normal, the test may be repeated after the patient has been intentionally exposed to seizure triggers such as sleep deprivation, flashing lights or hyperventilation.

Initial Exam and Testing

Before diagnosing you with epilepsy, your doctor will need to perform a thorough examination. This may include some or all of the following:

• a series of questions to see what your medical history is
• a general medical exam
• a neurological exam
• an EEG, which is a recording of the brain's electrical activity
• an MRI, which is a scan of the brain's structure
• blood tests to look for other medical conditions that may be causing your seizures

Extended EEG Monitoring

It is not uncommon for someone with epilepsy to have a normal EEG between seizures. If epilepsy is suspected but the EEG is normal, your doctor may suggest a longer period of EEG monitoring. Your doctor may choose ambulatory or inpatient video EEG monitoring.

Ambulatory EEG monitoring usually lasts 24 to 72 hours. The patient wears a portable EEG recorder and continues to take medication as usual during this period.

Inpatient video EEG monitoring is longer and more extensive, lasting from a few days to over a week. The patient is gradually withdrawn from medication, seizures are monitored by constant EEG recording, and a video camera correlates the patient's behavior with what occurs during the seizures or seizure-like episodes.