At the University of Chicago Medicine Epilepsy Center, we know how important a correct diagnosis is to a successful treatment plan. To help us make an accurate diagnosis, physicians use data from EEG, CT and MRI tests to create functional 3D models of a patient's epileptic focus within the brain without using an invasive procedure. These models enable us to pinpoint the source of seizures. Finding the seizure source is the first step toward successful treatment.
Diagnosing epilepsy isn’t always straightforward. Tonic-clonic seizures, which involve full-body convulsions, are easily noticed and can be frightening to someone who has never witnessed one. However, partial seizures with subtle symptoms, such as fainting spells, staring or brief confusion, often are missed by family members and even the patients themselves.
Obtaining Your Medical History
It’s very important for your doctors to learn as much about your seizure(s) as possible. And since you won’t likely remember the seizure well, we may need to get a description of the seizure from someone who was there when it happened.
Performing a Physical Exam
A physical exam cannot diagnose or uncover epilepsy. But results of a physical exam can help us determine things, such as how well your reflexes work, which may help us find out if part of your brain isn’t working properly.
Measuring Your Brain Waves & Activity
The EEG, also known as an electroencephalogram, charts and records the electrical activity in the brain. Certain abnormal patterns, such as spiking and sharp wave activities on an EEG, can help support or confirm a clinical diagnosis. There are several different types of EEG studies. A routine outpatient EEG study typically lasts for approximately one hour. An ambulatory outpatient EEG study typically lasts 24 to 48 hours. A long-term video-EEG study lasts five to seven days, which we typically perform in the hospital.
At UChicago Medicine, we offer various structural and functional neuroimaging studies to help diagnose epilepsy and localize the seizure focus. These tests include high-resolution brain magnetic imaging (MRI), functional MRI (fMRI) and positron emission tomography (PET).
Magnetoencephalography (MEG) Test
MEG is a new technique for mapping brain activity by recording magnetic fields produced by electrical currents that occur naturally in the brain using very sensitive magnetometers. Since magnetic fields are less distorted than electrical fields by the skull and scalp, MEG has a better spatial resolution than EEG in detecting and localizing seizure activity in some patients with epilepsy.
Many people with epilepsy may also have co-existent medical conditions, including depression, anxiety and cognitive impairments (i.e. poor memory and concentration). We often partner with a neuropsychologist to assess cognitive functions, mood and personality.
Epilepsy patients who are candidates for surgery may undergo a Wada test. A neuroradiologist performs the procedure in the presence of a neuropsychologist and a neurologist. The Wada test helps determine which side of the brain controls language and memory capacity of each side of the brain. This information is important for planning epilepsy surgery and minimizing the risks of language and memory deficits. With the development of more sophisticated functional MRI techniques, the Wada test can now often be avoided.