Abstracts

This is a Late Breaking abstract

Rationale: Seizure detection and alarming are essential for the diagnosis and treatment of epilepsy and the quality of life of patients with epilepsy. Management of epilepsy in the current clinical setting relies on patient or caregiver reports, but the low sensitivity of seizure diaries has been well established. Although identification of seizures with intracranial electroencephalography (EEG) has been demonstrated, invasiveness limits its use. There is a GTC (general tonic-clonic seizure) detector based on accelerometer and electrodermal activity; EEG-based focal seizure detectors are still in the development stage and is the multimodal wearable device. Multimodal wearable devices are needed to detect focal electrographic and electro-clinical focal seizures. The purpose of this study was (1) to show the applicability of wearable EEG, (2) to show the feasibility of multimodal wearable devices for seizure detection, and (3) to find limitations and suggestions for future development of wearable devices and systems which may lead to greater participation and data collection.

Methods: We developed a monitoring system using noninvasive multimodal wearable devices. The multimodal wearable device detects signals of up to four electrode EEG (2 behind the ears and 2 frontal electrodes), 3-axis accelerometry, and electrocardiogram (ECG). Patients were selected based on their clinical information that forehead and behind-the-ear EEG electrodes could detect their seizures. Patients used this device at home and made a report regarding when the seizure occurred and its semiology with the device (smartphone). Their data were transferred to the server for review by epileptologists. Wearable EEG recordings were compared to the patient’s most recent routine scalp EEG or long-term monitoring. Seizures were counted after reviewing entire signals with the help of patient’s or caregiver’s seizure diary.

Results: Fourteen patients (7 males and 7 females, aged 9-27) were included. During the 3723 hours of recording, we identified 1686 seizures. EEG recorded with a wearable device was similar to the patient’s previous scalp EEG concerning epileptiform discharges and ictal EEG. Nine patients used the device for longer than one month. Three patients showed mild irritation with the EEG patch, which was resolved with discontinuation. We could find this system helpful in detecting seizures in intractable focal epilepsy, tonic seizures in Lennox-Gastaut syndrome, and confirming seizure/non-seizure events in patients with suspicious events. The limitation was the limited duration of battery time (8~12 hours) and discomfort that led to discontinuation.

Conclusions: Patients used a multimodal wearable device using EEG, accelerometer (ACM), and ECG well. Electroclinical and electrographic seizures were well detected using the device. Adverse events were minimal. Ease of use and long battery life should be improved for better applicability.

Funding: SK Biopharmaceuticals, Co. Ltd.