EpiGrid: Soft and flexible high density electrode grids for epilepsy surgery

Epilepsy is a highly prevalent brain disorder affecting 1% of the population. Brain surgery can cure epilepsy if we can delineate the diseased tissue intra-operatively. Unfortunately this delineation is currently not performed precisely and leads to poor success rates (50-70%).

High frequency oscillations (HFOs) have been identified as a biomarker of epileptogenic tissues, which can be electrically recorded with intraoperative electrocorticography.

These HFOs are specific of diseased epileptogenic brain tissues and remnance after an initial resection predicts continuation of seizures after surgery and thus may indicate incomplete removal.

The problem is that currently available electrode grids do not provide an adequate recording resolution (too low electrode density).

Moreover these electrodes are made of stiff materials, which yields low signal-to-noise level when recording from the cortical surface and which does not offer the possibility to record from within resection cavities, as the rigid electrodes cannot conform to the curvature of the cavity. We need high density flexible electrode grids that can adhere to the cortical surface and cavities.

Neurosoft Bioelectronics produces flexible and high density electrode grids based on unique stretchable soft electrodes.

Our goal is to use this grant to translate our clinical needs into an optimal design of soft electrode grids adapted for epilepsy surgery, with the help of an industrial designer.

We will first test these newly designed soft electrodes in vitro for clinical handability and improved signal quality, and eventually test them during epilepsy surgery in 12 patients. The recorded signals and clinical outcomes will be compared to those from standard rigid electrode grids.

Improved delineation of the epileptogenic tissue will lead to a higher succes rate, make epilepsy surgery a first choice treatment, and over all change this otherwise life-long disease into a curable disorder for many people.