Detection of interictal epileptiform discharges using multiple bilateral insertions of a newly developed
Kota Araki1,2, Yosuke Masuda1, Ayataka Fujimoto3
1Department of Neurosurgery, Institute of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
Objective:
To assess the feasibility, technical performance, and safety of a novel endovascular electroencephalogram (eEEG) electrode, EP-01, designed for minimally invasive seizure localization in patients with drug-resistant epilepsy.
Methods:
This single-center, prospective, exploratory trial enrolled five patients with drug-resistant epilepsy undergoing the Wada test. The EP-01 electrode, featuring a platinum monopolar tip, was inserted into the venous sinuses using a microcatheter, and simultaneous recording of eEEG and scalp electroencephalography (EEG) signals was conducted. The primary outcome was the feasibility of eEEG signal acquisition, whereas the secondary outcomes included a signal sensitivity comparison between scalp and eEEG recordings, technical success assessment, and safety evaluation.
Results:
Successful eEEG recording was achieved in all five patients (mean age 34.2 years, 2 women) experiencing focal impaired awareness seizures. The EP-01 electrode successfully captured EEG signals, detecting 158 interictal epileptiform discharges (IEDs). eEEG demonstrated significantly higher amplitudes (median: 130.4 μV) compared with scalp EEG (median: 0 μV), with 57.0% of IEDs undetectable by scalp EEG (p < 0.001). EEG changes during eye opening/closing were consistently recorded by eEEG. The technical success rate was 100%, with an average of 4.5 eEEG electrodes placed per patient. The median displacement of electrode tips during neck rotation was 3.45 mm; hemorrhagic or thrombotic complications were absent; and all devices were safely removed.
Significance:
In this short-term study, the EP-01 eEEG device demonstrated high feasibility and safety for minimally invasive EEG acquisition in patients with epilepsy. To the best of our knowledge, this study provides the first evidence of IED detection in multiple patients using an eEEG system tailored for epilepsy monitoring, underscoring EP-01's potential for localizing seizure foci. Moreover, the capability to place multiple electrodes improves its utility in comprehensive epileptogenic mapping. Given the limited recording duration, long-term studies are necessary to validate EP-01's clinical efficacy and safety.
Plain Language Summary:
This study tested EP-01, a new device that records brain activity from inside the blood vessels, unlike traditional scalp EEG. In five people with epilepsy, the device safely captured stronger seizure-related signals than the traditional EEG. Moreover, the device could be placed and removed without complications. This less invasive method may help doctors more accurately find where seizures begin in the brain.
