The doctor’s main tool in diagnosing epilepsy is a careful medical history with as much information as possible about what the seizures look like and what happened just before they began. The doctor will also perform a thorough physical examination, especially of the nervous system.
An electroencephalograph (EEG) is a machine that records brain waves picked up by tiny wires taped to the head. Electrical signals from brain cells are recorded as wavy lines by the machine. Brain waves during or between seizures may show special patterns that can help the doctor decide whether or not someone has epilepsy, or is at risk for epileptic seizures. A normal baseline EEG does not rule out the possibility of an underlying epileptic disorder.
Imaging methods such as computerized tomography (CT) or magnetic resonance imaging (MRI) scans may be used to search for any growths, scars, or other physical conditions in the brain that may be causing the seizures.
There are numerous other tests that can be performed to analyze the area of the brain causing seizures, but most of these are only done when a patient is being evaluated for possible epilepsy surgery.
Which tests and how many are ordered vary, depending on how much each test reveals.