Subcutaneous EEG in Epilepsy

The problem of unrecognized seizures is common for certain types of epilepsy. Electroencephalography (EEG) is an excellent method for seizure identification and recognition, but until now, it has not been feasible to perform EEG recordings for more than a few days outside a hospital or laboratory. A novel device has been developed, which might remedy that. The device is a EEG-electrode for subcutaneous implantation connected to an external data storage device. The investigators in this study hypothesize that this device might be a useful tool for ultra-long-term epilepsy monitoring. The study aims to investigate that. While the device might be used to diagnose epilepsy, it is more likely to be a good seizure counting tool and that is what the study aims to determine. Subjects include patients with mesial temporal lobe epilepsy and high seizure frequency. These will have the device implanted. Study phase 1 is a proof of concept to determine whether the device is actually able to detect epileptic seizures. This will take place during admission and be performed as simultaneous recordings with ordinary scalp EEG and the investigational device. Study phase 2 is a home monitoring to prove that devices actually provides clinically useful information regarding seizures in an outpatient setting. The study requires 9 visits from each subject over the course of 4-6 months. The investigational device will be explanted after approximately 75 days of wear.