Researchers from King's College London, Mayo Clinic, and UNEEG medical have demonstrated that a subcutaneous electroencephalography (sqEEG) device can accurately track epileptic seizures in real-world settings, potentially revolutionizing treatment approaches for patients with treatment-resistant epilepsy.
The landmark study, published in Epilepsia and funded by the Epilepsy Foundation of America, recruited 10 adults with treatment-resistant epilepsy from King's College Hospital and St. George's University Hospital. Over 15 months, the AI-powered miniature implantable device collected almost 72,000 hours of real-world brainwave data, capturing 754 seizures.
Device Design and Implementation
The sqEEG system consists of a small electrode about the size of a UK pound coin with a 10cm wire attached. Under local anesthetic, the device is placed behind the ear beneath the scalp, with the wire directed to where seizures are expected to occur. The implant wirelessly communicates with an external recorder attached with an adhesive pad behind the ear and secured with a magnet or clip.
"sqEEG is an AI powered miniature implantable EEG for real life monitoring of people with epilepsy," according to the study description. Participants largely reported that the implant was acceptable and unobtrusive, with half recording for more than 20 hours a day.
Superior Detection Accuracy
The study revealed significant discrepancies between patient-reported seizures and objective electronic monitoring. When comparing electronic data to participants' diaries, patients had only correctly recorded 48% of their episodes. Conversely, more than a quarter (27%) of episodes recorded in their diaries were not associated with actual seizure activity.
"It is vital that people with treatment resistant epilepsy are able to access the best possible care. This is made significantly more challenging by the fact that clinicians must rely on patient reporting to establish when episodes have taken place," said Professor Mark Richardson, Paul Getty III Professor of Epilepsy at King's IoPPN and the study's senior author.
The sqEEG system also demonstrated superior accuracy in classifying seizure types. Epileptic seizures can be divided into three groups: nonconvulsive with preserved awareness, nonconvulsive with impaired awareness, and convulsive. The device more accurately tracked the type of seizure experienced compared to participants' diary entries.
Clinical Implications
The findings address a critical challenge in epilepsy management, particularly for the approximately one-third of patients with treatment-resistant epilepsy who continue experiencing seizures despite anti-seizure medication. Traditional seizure tracking relies on subjective patient diaries, which are unreliable due to impaired consciousness, memory loss during seizures, or misinterpretation of symptoms.
"The ability to monitor seizures in the real world, accurately collecting data on the type and timing that they occur will be an invaluable tool for clinicians moving forwards, and should hopefully have a big impact on how we approach the treatment of this life-threatening condition," said Dr. Pedro Viana, Senior Clinical Research Fellow and Neurologist at King's IoPPN and the study's lead author.
Technology Validation and Future Directions
Dr. Benjamin Brinkmann, Professor of Neurology at Mayo Clinic, emphasized the technology's potential: "Overall, these results demonstrate that Subscalp EEG devices are able to provide objective information about seizures and brain activity over long timeframes. This technology could provide physicians and patients with new insights about long-term patterns and help optimize their epilepsy treatment."
Jonas Duun-Henriksen, Senior Director AI & Science at UNEEG medical, described the study as "a significant milestone for UNEEG medical," noting that while they had received positive feedback from patients and physicians, "this is the first time a study based on more than a full year of continuous EEG recordings confirms those experiences."
The research team acknowledges that larger trials are needed to further validate the technology before it can be made widely available to patients in need. The work was supported by the Epilepsy Foundation's Epilepsy Innovation Institute My Seizure Gauge Project.
