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.
Epilepsy monitoring is generally reserved for patients who may qualify
for epilepsy surgery or for those whose diagnosis of seizures is unclear
or debilitating. These patients are expected to stay in the hospital until
enough events are captured to assure their physician that the correct
diagnosis and treatment plan are in place. In most cases, patients remain
in the epilepsy monitoring unit for three to five days.
MRI
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
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.
PET
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.
MEG
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
SPECT measures blood flow and brain metabolism by monitoring photons emitted
by iodine-labeled tracers carried in the blood to the brain.
CT
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.