First-in-human Experience Using Novel Ultraflexible Low-impedance Electrode Arrays: an IDEAL Stage 1 Study

Epilepsy affects 100,000 people under 25. Many children with epilepsy also have a learning disability or developmental problems and 25-30% continue to have seizures despite best medical treatment.

Neuromodulation or brain stimulation is the delivery of electricity to the brain cells. It may alter the brain activity and overall brain connectivity and currently is rarely used as a treatment for epilepsy. However, it has the potential to reduce the number of seizures and improve other problems that children with epilepsy may have such as concentration, memory and learning. 'Precision neuromodulation', which involves individually tailored treatments requires us to identify where in the brain to stimulate and what the best settings are in each individual. A limitation of current neuromodulation treatment is limited understanding of the abnormal signatures of electrical activity in abnormal tissue.

The investigators have developed a novel electrode that can record signals from the brain at higher resolution than current electrodes. The 2 micrometer, ultraflexible, low-impedance electrode arrays are smaller, less damaging, and provide multiple contacts at multiple depths. The investigators propose a first-in-human study to investigate the feasibility and safety of using these electrodes in patients undergoing surgery for epilepsy - either focal cortical dysplasia (FCD) or long-term associated epilepsy tumours (LEAT).

The investigators will insert the electrode into brain tissue that is going to be removed as part of the planned surgery. The extent of tissue damage caused by insertion will be examined, and whether the electrode is able to capture signals at difference scales from the brain will be assessed; this includes signals from an area of tissue (termed local field potential) and signals from single nerve cells (termed single unit recordings). If safe, it will lay the foundation to use these electrodes in future precision neuromodulation platforms that can be applied to epilepsy and other neurological diseases.