A Head Phantom Study of Frontal Lobe Epilepsy Localization With Multichannel Acoustoelectric Brain Imaging

Acoustoelectric brain imaging (ABI) is a new modality for mapping brain electrical activity. This study demonstrates the feasibility of multichannel ABI for frontal lobe epilepsy localization with millimeter spatial resolution. First, the feasibility of frontal signal detection of ABI is investigated with different electrode configurations in both simulation and head phantom experiments. Both single-channel and multichannel ABI are considered, and the simulated electroencephalography (EEG) is also conducted for comparison. Besides, with multichannel ABI, the performance of frontal lobe epilepsy location is investigated. With head phantom experiment, three kinds of frontal lobe seizures are discussed, including focal onset, focal to bilateral tonic-clonic, and bilateral onset. The average offsets of EEG map and single-channel ABI are 17 and 2.8 mm, respectively, and spatial resolutions are 15.6 and 5.8 mm, respectively. Consistent with simulation results, the spatial resolution of single-channel ABI is 2.3 mm and the SNR is 14.3 dB. Besides, compared to that of single-channel ABI, the correlation coefficient (CC) of multichannel ABI is improved by 10%. In the Y plane, the offset of multichannel ABI is 1.3 mm, which is improved by 58% compared with single-channel ABI. What is more, the frontal lobe epilepsy can be accurately located by multichannel ABI with the offset less than 2 mm, and the time-frequency features of frontal lobe seizure can be distinguished in hertz level. Both simulation and phantom experiments validate that multichannel ABI can identify and locate different seizure types in both time and spatial domain within millimeter level. It is potential to bring new opportunities for noninvasive and high spatiotemporal resolution epilepsy monitoring.

I. Introduction

Epilepsy is a clinical syndrome caused by highly abnormal discharge of brain neurons, which is characterized by transience, repeatability, and inflexibility. Complex distribution and diffusion range of abnormal discharge leads to different seizure patterns, which acts as sensory, motor, conscious, mental, behavioral disfunction, and other different functional disorders in clinical [1], [2]. Therefore, epilepsy is a great health hazard to human beings in both physical and mental aspects.