Scientists have come up with an idea for a new type of brain scan to hone in on the region causing seizures in people with epilepsy.
These damaged areas, or lesions, are sometimes missed by traditional scans. The new method aims to locate these hard-to-find areas by using high resolution MRI to track amounts of a certain neurotransmitter in different parts of the brain, the researchers report in a pilot study.
About 65 million people worldwide have epilepsy. For one third of these people, medication does not control their seizures, and they can only find relief by undergoing surgery to remove the area with the lesion. But doctors can't always tell where in the brain the problem area is. Brain scans such as traditional MRI and EEG sometimes fail to pinpoint any seizure-causing region, even when combined.
"New neuroimaging techniques capable of detecting subtle lesions could potentially improve patient care and increase the chance of seizure freedom after surgery," wrote the researchers, a team at the University of Pennsylvania who published the findings in the October 14 issue of Science Translational Medicine.
The new technique, called GluCEST, picks up on patterns of glutamate, a neurotransmitter that relays messages through the brain. Normally, it quickly dissipates once its job is done. But previous research has found that glutamate builds up in people with epilepsy, causing overstimulation that leads to seizures.
The researchers tested it on four people with temporal lobe epilepsy, who weren't responding to drug treatment. In each of these people, the scans found more glutamate in the hippocampus on one side of the brain than the other. EEG tests showed that GluCEST picked the hippocampus located in the same hemisphere as the epileptic area.
The findings suggest the new method could develop into an effective technique for hard-to-spot lesions. However, the findings will have to be confirmed in more people.