Pediatric Epilepsy Surgery (cont.)
What tests are used to determine if a child is a candidate for epilepsy surgery?
As previously mentioned, surgery is only preferred once it is clear that the
child is resistant to or does not respond well to antiepileptic medications.
Many tests are used to make this determination.
Electroencephalograms (EEG) are very important in
determining the type of epileptic seizures as well as the area of the brain that
is responsible for the seizure disorder. When the routine EEG (usually one hour
long) does not give enough information, then the child might need to be
hospitalized (usually in special EEG wards) for a prolonged EEG with video
monitoring. During the hospital admission (which may last several days) the
EEG is recorded continuously throughout the entire day. The goal is to record
epileptic events for further analysis. In some children it is necessary to stop the antiepileptic
medications while the child is in the hospital to facilitate the emergence of an
epileptic event.
Neuroimaging studies are very important to help determine the presence of
brain lesions. A CT scan and an MRI, in some cases, might be helpful to point to
the specific area of the brain that is abnormal. These tests are very effective
to identify developmental abnormalities, brain tumors, scars due to prior
bleeding events, or the presence of vascular malformations that might be
responsible for the epileptic seizures.
In some children, functional MRI (fMRI), positron emission tomography (PET), single photon emission computed tomography (SPECT), magnetoencephalography
(MEG), or ictal SPECT (an SPECT obtained at the time of the epileptic event)
might also be indicated in order to determine the area of the brain to be
excised.
In some cases the localization of the epileptogenic area
requires invasive monitoring. In these children, electrodes that record the
brain activity are placed either inside the brain (intracerebral electrodes) or
directly on top of the brain (subdural electrodes). This procedure may be done
at the time of the surgery or days before, in which case it requires a small
operation and
admission to the hospital for several days for continuous EEG recording.
Resective surgery (removing specific areas of brain
tissue) may result in functional deficits. The functional deficits relate to the
area of the brain involved in the surgery. For example, operations near the
motor area might result in motor paralysis; surgery in the posterior area of the
brain (the occipital lobe) might result in visual deficiencies. Of particular
importance is the surgery that is performed in or near the temporal lobe which,
among other functions, is responsible for language comprehension and memory. In such cases a
special test, called the WADA test, is performed to ensure that removal of the
local lesion does not result in severe memory or language functional deficits.
Once the evaluation is completed the team will decide if the patient is a
viable candidate for surgery and in that case, what type of surgery is
indicated.
It is worthwhile to mention that not all of the above-mentioned tests are
necessary in all patients.
Next: Who performs pediatric epilepsy surgery? »
- CT Scan (Computerized Axial Tomography) - CT Scan (Computerized Axial Tomography, CAT scan) is a procedure that assists in diagnosing tumors, fractures, bony structures, and infections in the organs and tissues of the body.
- Seizure (Epilepsy) - Learn about epilepsy, or seizure disorder. Causes include head injury, trauma, prenatal injury, poisoning, medications, stroke, heart attacks, alcoholism, infection, and more. Symptoms, diagnosis, and treatment information is included in the information.
- MRI (Magnetic Resonance Imaging Scan) - Medical information on magnetic resonance imaging (MRI) used in detecting structural abnormalities of the body. Learn uses, risks, and how to prepare for an MRI scan
Latest Medical News
Kids Health RSS