The amount of pressure in the brain can regulate focal seizures, the kind that originate at a single point, according to new research.
The finding may revolutionize the treatment of drug-resistant epilepsy.
“People thought that the spread of seizures mainly depends on where seizures originate in the brain, but the propagation of a seizure is actually regulated by the surrounding tissues, which includes that seizure onset zone,” says Bin He, head of the biomedical engineering department at Carnegie Mellon University.
“By using an array of electrophysiological recordings, we found that it’s not moving outward necessarily; it depends on how much ‘pull’ a patient receives from the surrounding tissue towards the seizure onset zone, and how much ‘push’ propagates from the seizure onset zone in the same patient. If that pull is weak, then it’s going to spread. If that pull is strong, then we can contain the seizure where it is and prevent it from spreading.”
Researchers tackled the problem by looking at various frequencies, including both slow and fast brain rhythms. They also performed new analysis of functional networks for a given rhythmic band, or the interactions between low and high brain rhythms. By using a new “cross-frequency directionality” technique to study 24 focal drug-resistant epilepsy patients, the team found that the propagation of seizures through the brain depend on a “push-pull” antagonism control mechanism. This “push-pull” mechanism can potentially reflect connections in the epileptic network, suppressing the seizure
“This finding will have important implications, and suggests that future treatment options should consider interventions not only upon seizure onset zones, but also the surrounding tissues,” He says. “Further delineation of critical network nodes may assist the development of treatments for epilepsy using neuromodulation.”
The research will appear in the journal Annals of Neurology.