NeuroOne’s Thin-Film Electrode Technology Offers Less Invasive Solution for Brain Surgery


For patients with epilepsy, the diagnosis and treatment process can be long, arduous, and filled with lengthy hospital stays. The medical device company NeuroOne Medical Technologies Corporation hopes to change that. Their new thin-film electrode technology, Evo Cortical, offers a potentially faster and less invasive diagnostic tool for identifying brain abnormalities in patients with epilepsy and brain tumors.

Epilepsy is a chronic neurological disorder characterized by recurrent seizures. Epileptic seizures result from sudden bursts of abnormal electrical signals in the brain and are associated with a range of symptoms including shaking, loss of consciousness and loss of awareness.

The first option for epilepsy treatment is typically pharmaceutical intervention. However, about one third of epilepsy patients don’t respond to epilepsy drugs. For these patients, the best option is usually a procedure known as surgical resection. Surgical resection involves removing a small portion of brain tissue in the area where seizures originate (known as the epileptogenic zone). The procedure is only an option if doctors can clearly identify the epileptogenic zone and if the brain tissue can be safely removed without affecting critical brain functions.

Epileptic seizures often originate in an area of the brain known as the temporal lobe. Because this brain region plays a critical role in language and memory, it is important for doctors to identify the precise location of seizure origin to minimize how much brain tissue is removed and preserve critical brain functions. However, identifying the area where seizures originate is not an easy task.

Identifying the epileptogenic zone is a lengthy and slow process. Typically, doctors use an electroencephalogram (EEG) to ‘map out’ areas of normal and abnormal brain activity. EEG recordings can be collected in several different ways, including with electrodes placed on the scalp, electrodes placed on the surface of the brain, or electrodes placed deep within brain folds.

To locate the epileptogenic zone with EEG, patients are required to stay in the hospital for weeks at a time, often with bulky cables connected to their head, waiting for seizures to occur. Then, if doctors can clearly identify the epileptogenic zone, patients must return home and schedule a separate surgery for the actual resection. In some cases, patients may need to repeat the whole process for further resection. Due to this lengthy, expensive, and often stressful process, many patients who are eligible for resection opt not to have the surgery.

Evo Cortical, the first FDA-cleared thin-film electrode technology, offers doctors and patients an alternative to traditional EEG recording methods. The technology is more brain-friendly and has improved electrical signal clarity for more precise epileptogenic zone localization.

Evo Cortical is thinner and lighter than traditional electrodes, meaning that it causes less disruption to brain tissue and avoids complications like hemorrhaging and inflammation.

“The brain doesn't like weight on it,” NeuroOne CEO Dave Rosa told BioSpace. “But if you can imagine putting something that's about seven, eight times the thickness that we have, what you get is compression on the brain, and that's what can cause hemorrhages and inflammation. The Mayo Clinic did an animal study comparing our device and a traditional silicone-based electrode. Our device created little to no inflammation while the other device had a significant amount of inflammation associated with it. So, our material is a bit friendlier than silicone and clearly much thinner and much lighter.”

In addition to its thin and light construction, its flexible design means that it can be inserted using a minimally invasive surgery. Unlike full craniotomies that involve the removal of a relatively large chunk of skull, Evo Cortical is flexible enough to be rolled up and inserted through a 3 cm hole in the skull, as demonstrated in cadaver testing. This smaller, more precise opening minimizes damage to the scalp, brain, blood vessels, and nerves.

Another benefit of Evo Cortical is its efficient and cost-effective manufacturing process. Many other electrodes are still made by hand. This manual process is both time consuming and expensive.

“You can imagine, if I'm building an electrode, I’ve got to place 64 dots on this electrode, and then solder the wires, and then put down a top piece of silicone, and then test all that. There's time involved in that, versus machines spitting out electrode after electrode. The process we use is much more efficient than doing the work manually. And clearly, it’s efficient not just in terms of how quickly we can produce these - it's much more cost-effective to have this process automated than to have it manual,” Rosa said.

While Evo Cortical is particularly promising for epilepsy patients, it also has other potential clinical applications.

“The other thing that doctors can use this device for is patients that have brain tumors,” Rosa said. “So, if a patient has a brain tumor, what they want to be able to do is outline the perimeter of the tumor, because they want to make sure that they get all of the tumor - nothing more, nothing less. They don't want to leave anything behind. Therefore, they want to be as precise as possible, so that they're not removing healthy tissue, but removing all of the tumor.”

The third application for Evo Cortical is basic research. Given its utility in mapping out areas of brain activity, the technology can be used by scientists to better understand brain activity patterns.

NeuroOne has partnered with Zimmer Biomet to distribute the device. The Evo electrode product line - which also includes a depth electrode (which is used deeper in the brain and has not yet been submitted to the FDA for clearance) - is expected to complement Zimmer Biomet’s ROSA One platform, a set of robotic devices designed to assist surgeons.

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