Article published by Futurity
A measure of brain activity known as causal flow can help locate the source of epilepsy seizures before they occur, according to a new study.
The finding could reduce the need for invasive procedures in treating drug-resistant forms of the disorder.
“Seizures are often described as electrical storms in the brain,” says coauthor Mukesh Dhamala, an associate professor in Georgia State University’s Neuroscience Institute and physics and astronomy department. “And that can take over normal functioning. Patients can lose consciousness and control of their behaviors for seconds to minutes.”
While some cases of epilepsy can be treated with medication, about 30% are considered drug-resistant. These cases require surgical intervention on the brain area where the seizure starts, known as the seizure focus.
Neurosurgeons look for areas of abnormal activity using intracranial electroencephalogram (iEEG), a procedure in which electrodes are surgically implanted into the brain for the duration of the test. “That’s where we come in—to help neurosurgeons by analyzing recorded data,” Dhamala says.
Rather than looking at the output from each individual electrode, Dhamala and his team have started to combine data from each point to get a broader picture of the brain’s activity. Like using seismographs to determine the location and strength of an earthquake, these data points can be used to determine causal flow, a measurement that quantifies the activity of this broader network.
Previously, Dhamala and his colleagues used high-frequency activity known to be present during seizures to show that causal flow can locate foci. In its recent study, the team was able to do the same using low-frequency activity, which occurs before a seizure starts. Their findings suggest that using low frequencies to determine causal flow could help locate a seizure long before one occurs.
“The method can potentially open up a whole new possibility of localizing seizures with a… non-invasive approach,” Dhamala says. “That’s the idea.”