Automated detection of focal epileptic seizures in a sentinel area of the human brain
Patients with focal epilepsy that does not respond to medications badly need alternative treatments.
In a first-in-humans pilot study, researchers at the University of Alabama at Birmingham have identified a sentinel area of the brain that may give an early warning before clinical seizure manifestations appear. They have also validated an algorithm that can automatically detect that early warning.
These two findings offer the possibility of squelching a focal epilepsy seizure — before the patient feels any symptoms — through neurostimulation of the sentinel area of the brain. This is somewhat akin to the way an implantable defibrillator in the heart can staunch heart arrhythmias before they injure the heart.
In the pilot study, three epilepsy patients undergoing brain surgery to map the source of their focal epilepsy seizures also gave consent to add an investigational aspect to their planned surgeries. As neurosurgeons inserted long, thin, needle-like electrodes into the brain to map the location of the electrical storm that initiates an epileptic seizure, they also carefully positioned the electrodes to add one more task — simultaneously record the electrical activity at the anterior nucleus of the thalamus.
The thalamus is a structure sitting deep in the brain that is well connected with other parts of the brain. The thalamus controls sleep and wakefulness, so it often is called the “pacemaker” of the brain. Importantly, preclinical studies have shown that focal sources of seizures in the cortex can recruit other parts of the brain to help generate a seizure. One of these recruited areas is the anterior thalamic nucleus.
“This exciting finding opens up an avenue to develop brain stimulation therapy that can alter activities in the cortex by stimulating the thalamus in response to a seizure,” Pati said. “Neurostimulation of the thalamus, instead of the cortex, would avoid interference with cognition, in particular, memory.”