Summary: New long-term brain monitoring technologies that continuously record neural activity beneath the scalp could transform how epilepsy is diagnosed, tracked and treated.
Source: Wyss Center for Bio and Neuroengineering
Today, physicians rely largely on patients’ own seizure diaries to estimate how many seizures a person with epilepsy experiences outside the clinic. Despite advances in wearable and medical devices, self-reporting remains the primary method for tracking seizures in daily life. The quality of treatment decisions—drug adjustments, lifestyle guidance and surgical considerations—depends heavily on the accuracy and detail of these subjective records. Compounding the problem, roughly half of epileptic seizures go unnoticed by the patient, which undermines reliable seizure counting and hinders optimal care.
A new generation of long-term brain monitoring systems is emerging to address these limitations. These minimally invasive subscalp electroencephalography (EEG) devices are designed to record brain electrical activity continuously for months or years, either in the clinic or at home. In a review published in the journal Epilepsia, an international team of clinicians, engineers and scientists outlines how subscalp EEG systems can provide objective, high-fidelity seizure logs and support improved management of epilepsy.
Maxime Baud, MD, PhD, epileptologist at Bern University Hospital and Wyss Center staff neurologist, explains the clinical need: “Current epilepsy care often depends on short-term EEGs captured during hospital visits. Seizures can be infrequent and occur in cycles, so continuous, accurate monitoring in the patient’s normal environment is essential to personalize treatment and measure response reliably. Subscalp systems like the Epios platform are promising tools for enabling that continuous monitoring.”
The review describes six subscalp and ultra–long–term monitoring technologies, each offering distinct capabilities such as precise seizure counting, seizure forecasting, real-time alerting and integration with neuromodulation. Because these devices are implanted beneath the skin but outside the brain tissue, they may avoid some risks associated with deeper intracranial implants while still providing high-quality EEG signals.
One system profiled is Minder, developed by Epi-Minder in Australia. Now in clinical trials, Minder uses a multichannel electrode array positioned across the skull to capture signals from both hemispheres. “By delivering continuous EEG over long periods, Minder aims to give people with epilepsy accurate, objective information about their brain activity and seizures so they can better manage daily life,” says Professor Mark Cook, MD, PhD, Chair of Medicine at the University of Melbourne and co-author of the review.
Another example is the Epios™ system from the Wyss Center, which supports configurable subscalp electrode layouts ranging from focal placements to broad head coverage with higher channel counts. Thin sensing electrodes connect to a miniature implant beneath the skin; neural data are transmitted wirelessly to an external behind-the-ear receiver. A wearable processor enriches the EEG with physiological measures such as heart rate, accelerometry and audio, and uploads annotated data to a secure cloud platform for visualization and analysis.
George Kouvas, MBA, Chief Technology Officer at the Wyss Center, emphasizes the role of advanced analytics: “Recording continuous EEG is only part of the solution. High-performance algorithms and software are necessary to turn vast data streams into clinically meaningful insights. We are also exploring applications of subscalp monitoring beyond epilepsy, including conditions such as tinnitus and stroke.”
Potential clinical uses for ultra–long–term subscalp monitoring extend beyond accurate seizure counting. These systems can identify biomarkers for disease progression, evaluate pharmaceutical efficacy in real-world settings, enable seizure forecasting and support closed-loop neuromodulation strategies that respond to detected brain activity. As device performance, data analytics and regulatory frameworks mature, subscalp EEG could become a standard component of personalized epilepsy care.
Technologies reviewed in the paper include:
24/7 EEG™ SubQ (UNEEG medical A/S, Lynge, Denmark)
EASEE – Epicranial Application of Stimulation Electrodes for Epilepsy (Precisis AG, Heidelberg, Germany)
Epios™ system (Wyss Center for Bio and Neuroengineering, Geneva, Switzerland)
Minder (Epi-Minder Pty Ltd, Melbourne, Australia)
Neuroview Technology (Englewood, USA)
UltimateEEG (BrainCare Oy Ltd., Tampere, Finland)
About this research article
Source:
Wyss Center for Bio and Neuroengineering
Contacts:
Jo Bowler – Wyss Center for Bio and Neuroengineering
Image Source:
Image credited to Wyss Center.
Original Research: Open access — “A new era in electroencephalographic monitoring? Subscalp devices for ultra–long‑term recordings” by Jonas Duun‑Henriksen et al., published in Epilepsia. The review evaluates current devices, clinical value, barriers to adoption and the future promise of continuous EEG for diagnosis, alarm systems, forecasting and treatment personalization.
Abstract
A new era in electroencephalographic monitoring? Subscalp devices for ultra–long‑term recordings
Subjective seizure counts are often inaccurate, creating challenges for diagnosis and treatment and limiting the quality of epilepsy care. Limitations of current hospital- and home-based monitoring have motivated development of minimally invasive, subscalp implantable EEG systems paired with cloud-based analytics. These ultra–long‑term monitoring approaches promise a step change in clinical epilepsy practice by providing objective, continuous electrophysiological data. Potential impacts include definitive diagnoses, reliable seizure logs, improved treatment optimization, presurgical localization and new alarm and forecasting tools. This paper summarizes independent solutions from leading researchers and organizations, discusses the immediate clinical value, and outlines drivers and obstacles to wider adoption of subscalp EEG monitoring.