Diagnostic Testing for Epilepsy

Armed with the most sophisticated diagnostic technology and imaging techniques, Hoag's epilepsy specialists can accurately identify a patient's specific type of seizure and the region of the brain where the seizures originate. This includes an EEG to look at the electrical conduction in the brain and an MRI. It may also include monitoring with 24-hour surveillance of seizure activity by video cameras, high resolution MRI, MR spectroscopy, functional MR (fMR), and positron emission tomography (PET).

Epilepsy Monitoring Unit

For some patients, it may be necessary to directly observe seizures in order to provide an accurate diagnosis or to determine the region of the brain where seizures originate. Hoag Neurosciences Institute’s Epilepsy Monitoring Unit provides a safe, comfortable setting, equipped with the latest brain monitoring technology and staffed with highly trained physicians, nurses and technicians to evaluate and manage seizures.

During the hospital stay, the patient is under constant visual observation while electrical activity of the brain, other physiological changes and video monitoring of the body's movements during seizures are recorded. Once the cause of a patient's epilepsy is determined, treatment can be tailored to manage and control seizures.



An MR or MRI scan is an imaging technique that produces cross-sectional images, like slices, of your head or body that are more detailed than those produced by conventional X-ray exams. Instead of radiation, MRI uses a strong magnetic field to acquire the images.


fMRI has a unique potential in that it can be used to provide quantification of blood flow in addition to the more common structural information. This idea is termed functional MRI (fMRI) and is based on exploiting dynamic changes in magnetic susceptibility of nuclei commonly found in the brain . It has many advantages including: minimal invasiveness, no radioactivity, widespread availability, and a virtually unlimited number of available study repetitions.


Unlike the indirect biological mechanisms studied with fMRI, PET is a direct measure of metabolic activity in the body. As described in Noninvasive Instrumentation and Measurement in Medical Diagnosis, a PET image is basically a density map of radioactivity in a slice of tissue or organ viewed in two dimensions.


The magnetoencephalogram (MEG) is caused by the minute magnetic fields produced when ionic currents flow inside the brain as the result of neural activity. Magnetic sensors that are placed around the head pick up these fields.


SPECT measures blood flow and brain metabolism by monitoring photons emitted by iodine-labeled tracers carried in the blood to the brain.


A CT or CAT scan is an imaging technique that produces cross-sectional images, like slices, of your head or body that are more detailed than those images produced by conventional X-ray exams.