Dr. Jaideep Kapur: Hi! I'm Jaideep Kapur for the International League Against Epilepsy. I would like to talk to you about how epilepsy is diagnosed.
Seizures are sudden, unexpected change in brain function that lasts several seconds to minutes. They happen repeatedly in a similar fashion and have a clear beginning and an end. Because it is quite rare for someone to have a seizure in front of the doctor, a detailed description of events provided by a witness is crucial for the diagnosis. The most common test used to help diagnose epilepsy is the Electroencephalogram or EEG, also called a brain-wave test. Wires will be placed on the head and the technician will record the electrical activity of the brain, usually for 20 to 40 minutes. In patients with epilepsy there are changes on EEG called Spikes or Spike Wave Discharges. Seizures are sometimes recorded on EEG; however, not everyone with epilepsy will have EEG changes. So the doctor will still need to rely on the description of the episodes. Because seizures and epilepsy can result from a change in brain structure, a brain scan usually an MRI is obtained. Rarely a doctor may find abnormalities such as a tumor that requires immediate attention. The scans are normal in many patients with epilepsy. The doctor will combine the test data with the description of events, past medical history, family history and neurological examination to judge whether epilepsy is likely, and whether treatment to control seizures should be started.