- American Academy
of Neurology has provided guidelines for brain imaging for people with
epilepsy undergoing surgery.
- People with
medial temporal epilepsy should have their brain mapped to identify
language and memory centers.
- Wada test is
invasive while Functional Magnetic Resonance Imaging (fMRI) is non-invasive and can also be used for predicting the outcome.
American Academy of Neurology has published guidelines which state that brain
imaging of regions associated with language and memory can be performed before
surgery for epilepsy rather than the currently used invasive methods. The
guidelines were provided after evidence was found, which makes this the first
ever systematically reviewed guideline.
was a note of caution that was also included, stating that the evidences that
were available were not very conclusive as they involved small study samples
and were carried out at only one institution.
‘Functional Magnetic Resonance Imaging (fMRI) is used to identify language and memory centers and for predicting language outcome after surgery.’
for epilepsy is required only when medications cannot control seizures. The
region of the brain where the seizures begin to develop are removed or
intervention strategies are used to prevent or restrict the spread of seizure.
As a part of the brain could be removed during epilepsy surgery, the research
team of this current study caution that a brain map of the region for language
and memory is essential to prevent loss.
research team compared the imaging results of an fMRI and the commonly used
procedure intracarotid amobarbital procedure, which is also called the Wada
that is conducted during angiography.
medication is injected into main artery of the neck, which is the carotid
artery. An EEG recording at the same time confirms that the injected side
of the brain is inactive as a neurologist performs a neurological examination.
The neurologist engages the patient in a series of language and memory related
tests. They evaluate the memory by showing a series of items or pictures to the
patient and—within a few minutes, as soon as the effect of the medication
dissipates—testing the patient's ability to recall. The test is typically
administered by a neuropsychologist as a result of expertise in psychometric
testing. Since this test is invasive, there are certain risks that are
Functional MRI (fMRI)
imaging technique detects activity in the brain by measuring the flow of blood.
Since this procedure is not invasive, it is considered to be safe.
these techniques are carried out to ensure that regions of the brain that are
associated with language and memory are not affected during surgery for
Jerzy Szaflarski who is the lead author of the study said "Because fMRI
becoming more widely available, we wanted to see how it compares to the Wada
test. While the risks associated with the Wada test are rare, they can be
serious, including stroke and injury to the carotid artery."
guidelines found evidence that the use of fMRI was a better alternative to the
Wada test for evaluating the language and memory centers of the brain for
people who have medial temporal epilepsy. The evidence obtained was not
sufficient enough for recommendations for people ailing with temporal tumors or
with temporal neocortical epilepsy.
- The fMRI
technique can also be considered for predicting verbal memory outcome
after the surgery and the guidelines state that moderate level of evidence
was obtained to carry out this procedure. Patients who are to undergo left
medial temporal lobe surgery can use the fMRI to understand the position
of the language and memory centers as well as to determine the level of
language after the surgery.
memory outcomes can be predicted using fMRI for people undergoing temporal
lobe surgery. The guidelines obtained weak evidence for the same.
The research team concludes by stating
that larger studies are required to increase the evidence that is currently
available. Both Wada test and fMRI are procedures that have not yet been
standardized. They also state that
doctors should exert caution while using the techniques and should explain the
benefits of both the procedure to patients. These guidelines are supported by
the American Academy of Neurology.
neurological condition, that is characterized by many different disorders that
are caused due to the tendency to have seizures in the brain. This condition is
normally identified in an individual after the first episode of seizure. Though
not all seizures are due to epilepsy, and other conditions like fainting or low
blood sugar can be confused for epilepsy.
condition can develop at any stage in life and is found in all races. The most
commonly affected people are children and adults over 65 years of age. More
than half a million people have epilepsy, which makes it one in every 100.
Causes for Epilepsy
are different epilepsies with varying causes. It could be caused due to one or
more of the following:
- A genetic
condition that is passed on from the parents.
- A genetic
condition that is caused due to mutation but not inherited
- Structural change
in the brain due to brain injury, meningitis tumor or stroke.
- Causes of epilepsy - (https://www.epilepsysociety.org.uk/causes-epilepsy#.WHWoXFN97IU)