Using a standalone ear-EEG device for focal-onset seizure detection

McGregor Joyner; Sheng-Hsiou Hsu; Stephanie Martin; Jennifer Dwyer; Denise Fay Chen; Reza Sameni; Samuel H Waters; Konstantin Borodin; Gari D Clifford; Allan I Levey; John Hixson; Daniel Winkel; Jonathan Berent

doi:10.1186/s42234-023-00135-0

Using a standalone ear-EEG device for focal-onset seizure detection

Bioelectron Med. 2024 Feb 7;10(1):4. doi: 10.1186/s42234-023-00135-0.

Authors

Affiliations

¹ NextSense Inc., Mountain View, CA, USA.
² Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA.
³ Department of Biomedical Informatics, Emory University School of Medicine, Atlanta, GA, USA.
⁴ Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA.
⁵ Department of Neurology, University of California San Francisco, San Francisco, CA, USA.
⁶ NextSense Inc., Mountain View, CA, USA. jb@nextsense.io.

^# Contributed equally.

Abstract

Background: Seizure detection is challenging outside the clinical environment due to the lack of comfortable, reliable, and practical long-term neurophysiological monitoring devices. We developed a novel, discreet, unobstructive in-ear sensing system that enables long-term electroencephalography (EEG) recording. This is the first study we are aware of that systematically compares the seizure detection utility of in-ear EEG with that of simultaneously recorded intracranial EEG. In addition, we present a similar comparison between simultaneously recorded in-ear EEG and scalp EEG.

Methods: In this foundational research, we conducted a clinical feasibility study and validated the ability of the ear-EEG system to capture focal-onset seizures against 1255 hrs of simultaneous ear-EEG data along with scalp or intracranial EEG in 20 patients with refractory focal epilepsy (11 with scalp EEG, 8 with intracranial EEG, and 1 with both).

Results: In a blinded, independent review of the ear-EEG signals, two epileptologists were able to detect 86.4% of the seizures that were subsequently identified using the clinical gold standard EEG modalities, with a false detection rate of 0.1 per day, well below what has been reported for ambulatory monitoring. The few seizures not detected on the ear-EEG signals emanated from deep within the mesial temporal lobe or extra-temporally and remained very focal, without significant propagation. Following multiple sessions of recording for a median continuous wear time of 13 hrs, patients reported a high degree of tolerance for the device, with only minor adverse events reported by the scalp EEG cohort.

Conclusions: These preliminary results demonstrate the potential of using ear-EEG to enable routine collection of complementary, prolonged, and remote neurophysiological evidence, which may permit real-time detection of paroxysmal events such as seizures and epileptiform discharges. This study suggests that the ear-EEG device may assist clinicians in making an epilepsy diagnosis, assessing treatment efficacy, and optimizing medication titration.

Keywords: Ear-EEG; Focal epilepsy; Long-term EEG; Seizure detection; Temporal lobe; Wearable technologies.